JP5227563B2 - Method for manufacturing semiconductor device - Google Patents

Description

  The present invention relates to a method for manufacturing a semiconductor device. In particular, the present invention relates to a method for forming an opening in a thin film such as a conductive layer or an insulating layer.

  Conventionally, MOS transistors and thin film transistors (hereinafter also referred to as TFTs) and semiconductor devices having them are manufactured by forming a thin film such as an insulating layer and a conductive layer on a substrate and appropriately forming a desired pattern by lithography. Yes. Lithography technology is a technology that uses light to transfer a circuit pattern, etc., formed of a light-shielding material on a transparent flat plate called a photomask to a target object, such as a semiconductor integrated circuit. It is widely used in the manufacturing process.

  However, a manufacturing process using a lithography technique requires a multi-step process such as resist coating using a photosensitive resin called a photoresist, pattern exposure, development, etching using a resist as a mask, and resist stripping. Therefore, as the number of lithography processes increases, the cost increases and the throughput decreases.

For example, Patent Document 1 describes a method for manufacturing a semiconductor device that eliminates an etching process when forming an opening in an insulating film and simplifies the lithography process. Specifically, a resist film is formed in advance in a region where an opening is to be formed, an insulating film is formed in a region other than the resist film, and the resist film is removed to form an opening in the insulating film.
JP 2001-77194 A

  An object of the present invention is to provide a semiconductor device manufacturing technique that simplifies the lithography process or a semiconductor device manufacturing technique that reduces the number of lithography processes.

  The present invention uses an ablation by irradiation of a laser beam without using a photoresist, or an opening for electrically connecting conductive layers, or for electrically connecting a conductive layer and a semiconductor layer. An opening is formed. A process of forming a pattern using laser ablation as in the present invention is referred to herein as a laser ablation patterning process (LAPP). The present invention is characterized in that an opening pattern is formed using laser ablation.

  Note that in this specification, ablation (also referred to as laser ablation) refers to a phenomenon in which part or all of an irradiation region of an irradiated object is removed by irradiation with a laser beam. Here, the ablation is a sublimation in which a part or all of the irradiation region of the irradiated object changes from a solid state to a gas state by irradiation with a laser beam, and a part or all of the irradiation region passes from a solid state to a liquid state. Including both evaporation to gas state.

  The irradiated body is a stacked body in which a first material layer and a second material layer are sequentially stacked on a substrate. In addition, another material layer (for example, a conductive layer, an insulating layer, a semiconductor layer, or the like) may be formed below the first material layer.

  Irradiation is performed so that the first laser beam absorbed in the first material layer and the second laser beam absorbed in the second material layer are superimposed on the object to be irradiated, and the irradiation is performed so as to overlap A part or the whole is ablated to form an opening.

  In the present invention, an opening can be formed by using laser ablation without using a lithography process using a photoresist.

  The first laser beam has a wavelength that is absorbed by at least the first material layer. That is, the oscillation wavelength of the first laser beam is preferably within the absorption wavelength region of the first material layer. More preferably, the first laser beam has an oscillation wavelength of 400 nm or more.

  The second laser beam has a wavelength that is absorbed by at least the second material layer. That is, the oscillation wavelength of the second laser beam is preferably within the absorption wavelength region of the second material layer. More preferably, the second laser beam has an oscillation wavelength of 400 nm or less.

  The present invention forms a first material layer, forms a second material layer on the first material layer, and the first material layer and the second material layer absorb the first laser beam in the first material layer. And the second material in the region irradiated with the first laser beam and the second laser beam superimposed by irradiating with the second laser beam absorbed by the second material layer. The layer is removed to form an opening in the second material layer.

  According to another configuration of the present invention, a first material layer is formed, a second material layer is formed on the first material layer, and an oscillation wavelength of the first material layer is the first material layer and the second material layer. By irradiating the first laser beam in the absorption wavelength region and the second laser beam having an oscillation wavelength in the absorption wavelength region of the second material layer so as to overlap, the first laser beam and The second material layer in the region irradiated with the second laser beam is removed to form an opening in the second material layer.

  In another configuration of the present invention, a first material layer is formed, a second material layer is formed on the first material layer, and an oscillation wavelength is 400 nm or more in the first material layer and the second material layer. And the second laser beam having an oscillation wavelength of 400 nm or less so as to overlap with each other, the first laser beam and the second laser beam overlap each other in the region irradiated with the first laser beam and the second laser beam. The two material layers are removed to form openings in the second material layer.

  The first laser beam preferably has a longer wavelength than the second laser beam.

  In addition, the second harmonic emitted from the YAG laser can be used as the first laser beam, and the third harmonic emitted from the YAG laser can be used as the second laser beam.

  According to another configuration of the present invention, when the beam spot area of the first laser beam formed on the irradiated body is S1, and the beam spot area of the second laser beam is S2, the first laser beam and the first laser beam The second laser beam is preferably irradiated so as to satisfy S1 <S2.

  In another configuration of the present invention, when the beam diameter of the first laser beam is W1 and the beam diameter of the second laser beam is W2, the first laser beam and the second laser beam have W1 <W2. Irradiation is preferably performed so as to satisfy.

  Moreover, this invention provides the laser processing apparatus which can process an to-be-irradiated body directly.

  The laser processing apparatus of the present invention includes a first laser having an oscillation wavelength of 400 nm or more, a second laser having an oscillation wavelength of 400 nm or less, a laser beam emitted from the first laser, and a laser beam emitted from the second laser. And an optical system that controls the irradiated object to be superimposed and a stage that is movable while holding the irradiated object, and is emitted from the first laser to the irradiated object. A part of the irradiation object is removed by superimposing the laser beam and the laser beam emitted from the second laser.

  According to another aspect of the present invention, there is provided a laser processing apparatus having a first laser having an oscillation wavelength of 400 nm or more, a second laser having an oscillation wavelength of 400 nm or less, and a laser beam emitted from the first laser on an object to be irradiated. The first optical system that is controlled to be irradiated and the laser beam emitted from the second laser are controlled so as to be superimposed on the laser beam emitted from the first laser in the irradiated object. A laser beam emitted from the first laser and a laser beam emitted from the second laser, the second optical system; and a stage movable while holding the irradiated object. A part of the irradiated object is removed by irradiating with overlapping. At this time, the laser beam emitted from the first laser and the laser beam emitted from the second laser may be irradiated from opposite directions.

  The first laser is preferably a visible light laser. The second laser is preferably an ultraviolet laser.

  In addition, a laser processing apparatus having another configuration of the present invention includes a solid-state laser, a beam splitter that separates wavelengths of laser beams emitted from the solid-state laser, and a second harmonic laser of the solid-state laser separated by the beam splitter. An optical system for controlling the third harmonic laser beam of the solid-state laser separated by the beam and the beam splitter so as to be superimposed on the irradiated object, and a stage movable while holding the irradiated object; , And a part of the irradiated object is removed by superimposing the second harmonic laser beam of the solid-state laser and the third harmonic laser beam of the solid-state laser on the irradiated object. It is characterized by doing.

The solid-state laser is preferably a YAG laser, a Y ₂ O ₃ laser, a YVO ₄ laser, a YAlO ₃ laser, or a GdVO ₄ laser.

  Further, the optical system can be configured by combining a mirror or a condenser lens.

  By applying the present invention, an opening can be formed in a thin film such as an insulating layer without using a photoresist. Therefore, the present invention can simplify the process of forming the opening in the manufacturing process of the semiconductor device, so that the manufacturing cost can be reduced and the throughput can be improved.

  Embodiments of the present invention will be described below with reference to the drawings. However, the present invention is not limited to the following description, and it will be easily understood by those skilled in the art that modes and details can be variously changed without departing from the spirit and scope of the present invention. Therefore, the present invention should not be construed as being limited to the description of the embodiments below. Note that in the structures of the present invention described below, the same reference numerals may be used in common in different drawings.

(Embodiment 1)
The present invention is characterized in that an opening is formed in a desired region without using a lithography technique using a photoresist. In this embodiment mode, an opening for electrically connecting the conductive layers is formed in the irradiation object. Hereinafter, one mode of a method for forming an opening in an irradiation object by applying the present invention will be described with reference to FIGS.

  FIG. 1A shows an example of a structure of an irradiation object in which an opening is formed by applying the present invention. The irradiated body has a structure in which a conductive layer 12, a first material layer 14, and a second material layer 16 are sequentially stacked on a substrate 10. Irradiation is performed so that the first laser beam 18 and the second laser beam 20 are superimposed on the object to be irradiated from the second material layer 16 side. A region irradiated with the first laser beam 18 and the second laser beam 20 superimposed on the object to be irradiated is referred to as a superimposed irradiation region 22 (see FIG. 1A).

  As the substrate 10, a glass substrate, a quartz substrate, a sapphire substrate, a ceramic substrate, a semiconductor substrate, or the like is used. A base insulating layer may be formed over the substrate 10. In that case, the base insulating layer is formed using an insulating material such as silicon oxide (SiOx), silicon nitride (SiNx), silicon oxynitride (SiOxNy) (x> y), or silicon nitride oxide (SiNxOy) (x> y). Form.

  The conductive layer 12 is formed using a conductive material. For example, silver (Ag), gold (Au), nickel (Ni), platinum (Pt), palladium (Pd), iridium (Ir), rhodium (Rh), tantalum (Ta), tungsten (W), titanium (Ti) ), Molybdenum (Mo), aluminum (Al), copper (Cu), or the like, or an alloy material or a compound material containing the metal element as a main component can be used. As the compound material, a nitrogen compound, an oxygen compound, a carbon compound, a halogen compound, or the like can be used. Specific examples include aluminum nitride, tungsten nitride, and tantalum nitride. The conductive layer 12 can be formed using a single layer structure or a stacked layer structure using one or a plurality of these conductive materials by a sputtering method, a CVD method, or the like.

  The first material layer 14 is formed using a material capable of absorbing the irradiated first laser beam 18. For example, a metal element such as chromium (Cr), molybdenum (Mo), nickel (Ni), titanium (Ti), cobalt (Co), copper (Cu), aluminum (Al), or an alloy containing the element as a main component Materials or compound materials can be used. As the compound material, a nitrogen compound, an oxygen compound, a carbon compound, a halogen compound, or the like can be used. In addition, silicon, germanium, silicon germanium, molybdenum oxide, tin oxide, bismuth oxide, vanadium oxide, nickel oxide, zinc oxide, gallium arsenide, gallium nitride, indium oxide, indium phosphide, indium nitride, cadmium sulfide, cadmium telluride A semiconductor material such as strontium titanate can be used. Further, zinc sulfide, silicon nitride, mercury sulfide, aluminum chloride, or the like can be used. The first material layer 14 is formed in a single layer structure or a stacked structure by using one or more of these materials by an evaporation method, a sputtering method, a CVD method, or the like. Further, hydrogen or an inert gas (a rare gas such as helium (He), argon (Ar), krypton (Kr), neon (Ne), or xenon (Xe)) can be added to the first material layer 14. . By adding hydrogen or an inert gas to the first material layer 14, it is possible to easily cause gas emission or evaporation in the first material layer 14 when the laser beam is irradiated later. The first material layer 14 is preferably formed using a material having a boiling point or a sublimation temperature lower than the melting point of the conductive layer 12 provided in the lower layer. By forming the first material layer 14 using such a material, damage to the lower conductive layer 12 during laser ablation can be prevented.

  The second material layer 16 is formed using a material that can absorb the irradiated second laser beam 20. The second material layer 16 is formed using a material that can transmit the first laser beam 18. For example, inorganic insulating materials such as silicon oxide, silicon nitride, silicon oxynitride, and silicon nitride oxide, and organic insulating materials such as polyimide, acrylic, polyamide, polyimide amide, benzocyclobutene, and epoxy resin can be used. The second material layer 16 is formed with a single layer structure or a stacked structure by using one or more of these materials by a sputtering method, a CVD method, a coating method, or the like.

  The first laser beam 18 has a wavelength that is absorbed by the first material layer 14, and has energy sufficient to ablate a part or all of the region irradiated with the second laser beam 20. Features. The oscillation wavelength of the first laser beam 18 is preferably within the absorption wavelength region of the first material layer 14. More preferably, the oscillation wavelength of the first laser beam 18 is longer than visible light (including visible light here), specifically, 400 nm or more.

As described above, the wavelength of the first laser beam 18 is determined by the material constituting the first material layer 14. For example, excimer lasers such as KrF, ArF, XeCl, etc., gas lasers such as He, He—Cd, Ar, He—Ne, single crystal YAG, YVO ₄ , forsterite (Mg ₂ SiO ₄ ), YAlO ₃ , GdVO ₄ Alternatively, one or more of Nd, Yb, Cr, Ti, Ho, Er, Tm, and Ta are added as dopants to polycrystalline YAG, Y ₂ O ₃ , YVO ₄ , YAlO ₃ , and GdVO _4. Using a solid-state laser, a semiconductor laser such as GaN, GaAs, GaAlAs, or InGaAsP, a picosecond laser, a femtosecond laser, etc., and appropriately setting the oscillation wavelength of these lasers, the desired wavelength can be set. The first laser beam 18 can be obtained. Here, the picosecond laser is a laser that emits a laser beam having a pulse width on the order of picoseconds (10 ^{−12 to} 10 ⁻¹⁰ seconds). The femtosecond laser is a laser that emits a laser beam having a pulse width in the order of femtoseconds (10 ^{−15 to} 10 ⁻¹³ seconds). When the first laser beam 18 is a laser beam having a wavelength of 400 nm or more, a He—Cd laser (440 nm), a He—Ne laser (632.8 nm), or an Ar laser having a strong oscillation wavelength in a region of 400 nm or more. (488 nm, 514.5 nm), fundamental wave (1054 nm to 1064 nm) of a solid-state laser such as a YAG laser, Y ₂ O ₃ laser, YVO ₄ laser, YAlO ₃ laser, GdVO ₄ laser, and the second harmonic ( 527 nm to 532 nm), GaAlAs laser (780 nm) or the like is preferably used. Note that the first laser beam 18 may be either a continuous wave laser beam or a pulsed laser beam.

  The second laser beam 20 has a wavelength that is absorbed by the second material layer 16 and has energy that does not cause an irreversible change in the irradiated object. The oscillation wavelength of the second laser beam 20 is preferably within the absorption wavelength region of the second material layer 16. More preferably, the oscillation wavelength of the second laser beam 20 is about the wavelength of ultraviolet light shorter than visible light (here, not including visible light), specifically, 400 nm or less.

The wavelength of the second laser beam 20 is determined by the material constituting the second material layer 16. For example, excimer laser such as KrF, ArF, XeCl, XeF, gas laser such as He, He—Cd, Ar, He—Ne, single crystal YAG, YVO ₄ , YLF, forsterite (Mg ₂ SiO ₄ ), YAlO ₃ , GdVO ₄ or polycrystalline (ceramic) YAG, Y ₂ O ₃ , YVO ₄ , YAlO ₃ , GdVO ₄ , one of Nd, Yb, Cr, Ti, Ho, Er, Tm, Ta as a dopant, or By using a solid-state laser, a semiconductor laser such as GaN, GaAs, GaAlAs, InGaAsP, a picosecond laser, a femtosecond laser, or the like using a medium in which a plurality of types are added, by appropriately setting the oscillation wavelength of these lasers, A second laser beam 20 having a desired wavelength can be obtained. Note that a picosecond laser is a laser that emits a laser beam having a pulse width on the order of picoseconds (10 ⁻¹² seconds to 10 ⁻¹⁰ seconds). The femtosecond laser is a laser that emits a laser beam having a pulse width in the order of femtoseconds (10 ^{−15 to} 10 ⁻¹³ seconds). When the second laser beam 20 is a laser beam having a wavelength of 400 nm or less, it is preferable to use an ultraviolet laser having a strong oscillation wavelength in a region of 400 nm or less, such as a XeF excimer laser (351 nm), a XeCl excimer laser (308 nm). ), A KrF excimer laser (248 nm), an ArF excimer laser (193 nm), a third harmonic (355 nm) of a YAG laser, or the like is preferably used. Note that the second laser beam 20 may be either a continuous wave laser beam or a pulsed laser beam.

  The first laser beam 18 irradiated to the irradiation object is absorbed by the first material layer 14, and the second laser beam 20 is absorbed by the second material layer 16. The first laser beam 18 and the second laser beam 20 are irradiated so as to overlap each other. Note that the superimposed irradiation region 22 includes a region where the first laser beam 18 and the second laser beam 20 are superimposed and irradiated on the second material layer 16, and a first laser beam on the upper second material layer 16. 18 and the region of the first material layer 14 corresponding to the region irradiated with the second laser beam 20 superimposed (see FIG. 1A). The first material layer 14 is ablated in the superimposed irradiation region 22 and removed together with the superimposed irradiation region 22 of the upper second material layer 16. As a result, the opening 24 is formed. The conductive layer 12 is exposed at the bottom surface of the opening 24 (see FIG. 1B).

  The second material layer 16 is heated by irradiating the irradiated body with the second laser beam 20. Then, the first laser beam 18 is irradiated so as to overlap with the second laser beam 20, and a part of the irradiated body (superimposed irradiation region 22) is ablated to form an opening. At this time, since the second material layer 16 in the region irradiated with the second laser beam 20 is preheated, the bonding of the material constituting the heated region of the second material layer 16 (including chemical bonding). ) Has become weaker and more susceptible to ablation. Therefore, by irradiating the first laser beam 18 so as to overlap with the second laser beam 20, it is possible to easily ablate a part of the irradiated object.

  Further, since the bonding of the material constituting the second material layer 16 in the region irradiated with the second laser beam 20 can be weakened, the energy of the first laser beam 18 can be reduced. Therefore, it is possible to prevent damage due to the irradiation of the laser beam to the layer or substrate below the first material layer 14.

  The first laser beam 18 and the second laser beam 20 are irradiated by (1) a method in which the first laser beam 18 is irradiated while the second laser beam 20 is being irradiated, and (2) a second laser beam. Any of the methods of irradiating the first laser beam 18 simultaneously with the two laser beams 20 may be used.

Here, FIG. 3A shows a schematic view of FIG. 1A viewed from an oblique direction. In FIG. 3A, a first beam spot 19 by the first laser beam 18 and a second beam spot 21 by the second laser beam 20 are formed on the irradiated object. Here, the area S 1 of the first beam spot 19 is smaller than the area S 2 of the second beam spot 21. That is, the first laser beam 18 and the second laser beam 20 are appropriately adjusted and irradiated so that S1 <S2. The irradiated object is ablated in a region (superimposed irradiation region 22) irradiated with the first laser beam 18 and the second laser beam 20 superimposed. In FIG. 3A, when the beam diameter W1 of the first laser beam 18 is smaller than the beam diameter W2 of the second laser beam 20, S1 <S2 can be easily achieved. The beam diameter in this specification is defined by the width of the beam intensity at the 1 / e ² level of the peak value when the energy intensity distribution in the cross section perpendicular to the traveling direction (optical axis) of the laser beam is viewed. Shall be.

  Further, the first laser beam and the second laser beam may be irradiated so as to partially overlap with each other, and the present invention is not limited to FIG. For example, a laser beam may be irradiated as shown in FIGS.

  First, FIG. 2A will be described. The irradiated object is the same as the irradiated object shown in FIG. 1A, and has a structure in which a conductive layer 12, a first material layer 14, and a second material layer 16 are sequentially stacked over a substrate 10. Irradiation is performed so that the first laser beam 30 and the second laser beam 32 are superimposed on the object to be irradiated from the second material layer 16 side. A region irradiated with the first laser beam 30 and the second laser beam 32 superimposed on the irradiated body is referred to as a superimposed irradiation region 34.

  The first laser beam 30 satisfies the same conditions as the first laser beam 18 in FIG. In other words, it has a wavelength that is absorbed by the first material layer 14 and has an energy enough to ablate a part or the whole of the region irradiated with the second laser beam 32 in an overlapping manner. Further, the second laser beam 32 satisfies the same condition as the second laser beam 20 in FIG. 1A, has a wavelength absorbed by the second material layer 16, and is irreversible to the irradiated object. It is characterized by having energy that does not give a change. The first laser beam 30 irradiated to the irradiation object is absorbed by the first material layer 14, and the second laser beam 32 is absorbed by the second material layer 16.

  FIG. 3B corresponds to a schematic view of FIG. 2A viewed from an oblique direction. In FIG. 3B, a first beam spot 31 formed by the first laser beam 30 and a second beam spot 33 formed by the second laser beam 32 are formed on the irradiated object. Here, the area S1 of the first beam spot 31 and the area S2 of the second beam spot 33 are substantially the same. That is, the first laser beam 30 and the second laser beam 32 are appropriately adjusted and irradiated so that S1≈S2. The irradiated object is ablated in a region (superimposed irradiation region 34) irradiated with the first laser beam 30 and the second laser beam 32 superimposed. In FIG. 3B, when the beam diameter W1 of the first laser beam 30 and the beam diameter W2 of the second laser beam 32 are the same, S1≈S2 can be easily obtained.

  2B, the irradiated object is the same as the irradiated object shown in FIG. 1A, and the conductive layer 12, the first material layer 14, and the second material layer 16 are sequentially stacked over the substrate 10. Has a structure. Irradiation is performed so that the first laser beam 40 and the second laser beam 42 are superimposed on the object to be irradiated from the second material layer 16 side. A region irradiated with the first laser beam 40 and the second laser beam 42 superimposed on the irradiated body is referred to as a superimposed irradiation region 44.

  The first laser beam 40 satisfies the same conditions as the first laser beam 18 in FIG. In other words, it has a wavelength that is absorbed by the first material layer 14 and has an energy sufficient to ablate part or all of the region irradiated with the second laser beam 42 in an overlapping manner. The second laser beam 42 also satisfies the same conditions as the second laser beam 20 in FIG. 1A, has a wavelength absorbed by the second material layer 16, and is irreversible to the irradiated object. It is characterized by having energy that does not give a change. The first laser beam 40 irradiated to the irradiation object is absorbed by the first material layer 14, and the second laser beam 42 is absorbed by the second material layer 16.

  FIG. 3C corresponds to a schematic view of FIG. 2B viewed from an oblique direction. In FIG. 3C, a first beam spot 41 by the first laser beam 40 and a second beam spot 43 by the second laser beam 42 are formed on the irradiated object. Here, the area S 1 of the first beam spot 41 is larger than the area S 2 of the second beam spot 43. That is, the first laser beam 40 and the second laser beam 42 are appropriately adjusted and irradiated so that S1> S2. The irradiated object is ablated in a region (superimposed irradiation region 44) irradiated with the first laser beam 40 and the second laser beam 42 superimposed. In FIG. 3C, when the beam diameter W1 of the first laser beam 40 is larger than the beam diameter W2 of the second laser beam 42, S1> S2 can be easily achieved.

  Note that in FIGS. 3A to 3C, the beam spots formed on the irradiated object are highlighted, and actually, the beam spot is formed more minutely on the irradiated object.

  Note that in this embodiment mode, the first laser beam and the second laser beam are preferably irradiated so that S1 <S2. The irradiated object is ablated in the region irradiated with the first laser beam and the second laser beam superimposed. Further, the second material layer 16 in the region irradiated with the second laser beam is likely to be ablated in the irradiated body. By irradiating the first laser beam and the second laser beam so that S1 <S2, all S1 is ablated. On the other hand, when the first laser beam and the second laser beam are irradiated so as to satisfy S1> S2, a region where S2 is ablated but S1 is not ablated is generated. In consideration of damage to the layer and the substrate below the first material layer 14, the irradiation region of the first laser beam is preferably small. Therefore, the condition of S1 <S2 that can ablate the beam spot S1 by the first laser beam is preferable because the first laser beam and the second laser beam can be used effectively.

  Next, a conductive layer 26 is formed in the opening 24. The conductive layer 26 is electrically connected to the conductive layer 12 (see FIG. 1C). When the first material layer 14 is formed using a conductive material, the conductive layer 26 is also electrically connected to the first material layer 14. Through the above steps, an opening for electrically connecting the conductive layer and the conductive layer is formed in the object to be irradiated (in this embodiment, the second material layer 16 and the first material layer without using a lithography technique using a photoresist). 14).

  By applying the present invention, an opening can be formed in a desired region without using a lithography process using a photoresist. Therefore, the lithography process can be reduced and simplified, loss of materials such as a resist material and a developer can be prevented, and the number of necessary photomasks can be reduced. In addition, irradiation is performed so that two types of laser beams absorbed by different layers (layer to be ablated (first material layer) and layer stacked thereon (second material layer)) constituting the irradiated object are superimposed. By doing so, damage to other layers can be prevented and an opening can be easily formed. Therefore, in manufacturing a semiconductor device, manufacturing cost can be reduced and throughput can be improved. In addition, the reliability of the semiconductor device can be improved.

(Embodiment 2)
In this embodiment, a method for forming an opening for electrically connecting conductive layers or a conductive layer and a semiconductor layer in an irradiation object will be described. In the first embodiment, an example is shown in which an opening is formed so as to penetrate the first material layer and the second material layer stacked on the conductive layer, and the conductive layer is exposed at the bottom surface of the opening. In this embodiment mode, another example of forming an opening reaching the conductive layer is described. An example of forming an opening reaching the semiconductor layer is also shown.

  7A to 7C, an opening reaching the conductive layer or the first material layer is formed in the irradiated body in which the conductive layer, the first material layer, and the second material layer are sequentially stacked on the substrate. The configuration is shown. In addition, a structure in which a conductive layer is formed in the opening and the conductive layer is electrically connected to the conductive layer formed over the substrate is shown.

  7A to 7C, the opening formed in the irradiation object uses ablation by laser beam irradiation as described in Embodiment Mode 1. Specifically, with respect to the irradiated object, the first laser beam having a wavelength absorbed by the first material layer stacked on the conductive layer and the second material layer that is the outermost surface layer of the irradiated object are absorbed. A second laser beam having a certain wavelength is irradiated so as to overlap, and a part or all of the overlapped and irradiated region is ablated to form an opening. The first laser beam has an energy sufficient to ablate part or all of the region irradiated with the second laser beam. The second laser beam has an energy that does not give an irreversible change to the irradiated object. By appropriately selecting the energy of the first laser beam or the second laser beam, the material constituting the first material layer or the second material layer, and the like, the portion to be ablated and removed from the irradiated object can be selected. Is possible.

  As described above, the irradiated object in FIGS. 7A to 7C has a structure in which a conductive layer, a first material layer, and a second material layer are sequentially stacked over a substrate. As the substrate, a glass substrate, a quartz substrate, a sapphire substrate, a ceramic substrate, a semiconductor substrate, or the like may be used. The conductive layer stacked over the substrate may be formed using a conductive material. For example, the conductive layer is made of silver (Ag), gold (Au), nickel (Ni), platinum (Pt), palladium (Pd), iridium (Ir), rhodium (Rh), tantalum (Ta), tungsten (W). , Titanium (Ti), molybdenum (Mo), aluminum (Al), copper (Cu), or the like, or an alloy material or a compound material containing the metal element as a main component. Note that a base insulating layer functioning as a protective layer may be formed between the substrate and the conductive layer. The base insulating layer may be formed using an insulating material such as silicon oxide, silicon nitride, silicon oxynitride, or silicon nitride oxide. When the base insulating layer is formed, damage to the substrate due to laser beam irradiation can be prevented.

  The first material layer is formed using a material that can absorb the irradiated first laser beam. For example, conductive materials including chromium (Cr), molybdenum (Mo), nickel (Ni), titanium (Ti), cobalt (Co), copper (Cu), aluminum (Al), etc., silicon, germanium, silicon germanium, oxidation Semiconductor materials such as molybdenum, tin oxide, bismuth oxide, vanadium oxide, nickel oxide, zinc oxide, gallium arsenide, gallium nitride, indium oxide, indium phosphide, indium nitride, cadmium sulfide, cadmium telluride, and strontium titanate are used. be able to. Note that the first material layer is preferably formed using a material whose boiling point or sublimation point is lower than the melting point of the lower conductive layer. When a material having a boiling point or sublimation temperature lower than the melting point of the lower conductive layer is used as the first material layer, damage to the lower conductive layer during laser ablation can be prevented.

  The second material layer is formed using a material that can absorb the irradiated second laser beam. Further, a light-transmitting inorganic insulating material or organic insulating material that can transmit the first laser beam is used. Hereinafter, it demonstrates concretely using drawing.

  FIG. 7A illustrates an example in which only the second material layer is removed by laser ablation in the first material layer and the second material layer which are stacked over the conductive layer. The irradiation object illustrated in FIG. 7A has a structure in which a conductive layer 802, a first material layer 804, and a second material layer 806 are sequentially stacked over a substrate 800, and penetrates only the second material layer 806. Thus, an opening 810 is formed. On the bottom surface of the opening 810, the first material layer 804 is exposed. A conductive layer 808 is formed in the opening 810 and is in contact with the first material layer 804. Note that in the case of FIG. 7A, the first material layer 804 is formed using a conductive material. As described above, the conductive layer 808 and the first material layer 804 are electrically connected.

  FIG. 7B illustrates an example in which the upper layer portion of the second material layer and the first material layer is removed by laser ablation in the first material layer and the second material layer which are stacked over the conductive layer. The irradiation object illustrated in FIG. 7B has a structure in which a conductive layer 822, a first material layer 824, and a second material layer 826 are sequentially stacked over a substrate 820 so as to penetrate the second material layer 826. In addition, the first material layer 824 is formed with an opening 830 so that the upper layer portion is removed and the lower layer portion remains. The first material layer 824 is exposed at the bottom surface of the opening 830. In the first material layer 824, the thickness of the region where the opening 830 is formed is thinner than that of other regions. A conductive layer 828 is formed in the opening 830 and is in contact with the first material layer 824. Note that in the case of FIG. 7B as well, as in FIG. 7A, the first material layer 824 is formed using a conductive material. As described above, the conductive layer 828 and the first material layer 824 are electrically connected.

  FIG. 7C illustrates an example in which the side surface of the opening formed in the irradiation object has a tapered shape. The irradiation object illustrated in FIG. 7C has a structure in which a conductive layer 842, a first material layer 844, and a second material layer 846 are sequentially stacked over a substrate 840. An opening 850 is formed in the irradiated body. Here, an example in which the opening 850 is formed so as to penetrate the second material layer 846 and the first material layer 844 is shown. Note that the opening 850 may be formed so as to penetrate only the second material layer 846, or the upper layer portion of the first material layer 844 is removed so that the lower layer portion penetrates the second material layer 846. You may form so that it may remain | survive.

  In FIG. 7C, the opening 850 formed in the irradiation object is tapered, and the side surface of the opening 850 is tapered with respect to the bottom surface. A conductive layer 848 is formed in the opening 850 and is in contact with the conductive layer 842. Further, the first material layer 844 is also in contact with the side surface of the opening 850. Through the above steps, the conductive layer 842 and the conductive layer 848 are electrically connected. In the case where the first material layer 844 is formed using a conductive material, the conductive layer 848 and the first material layer 844 are also electrically connected.

  Next, an example in which an opening reaching the conductive layer or an opening reaching the semiconductor layer is formed in the irradiation object will be described. 8A to 8D illustrate a structure in which an opening reaching the first material layer is formed in an irradiated body in which a first material layer and a second material layer are sequentially stacked over a substrate. In addition, a structure in which a conductive layer is formed in the opening and the conductive layer and the first material layer are electrically connected is shown.

  8A to 8D, the opening formed in the irradiation object uses ablation by laser beam irradiation as described in Embodiment Mode 1. Specifically, the first laser beam having a wavelength that is absorbed by the first material layer with respect to the irradiated body, and the second laser beam having a wavelength that is absorbed by the second material layer that is the outermost surface layer of the irradiated body. Irradiation is performed so as to superimpose a laser beam, and a part or the whole of the superimposed and irradiated region is ablated to form an opening. The first laser beam has an energy sufficient to ablate part or all of the region irradiated with the second laser beam. The second laser beam has an energy that does not give an irreversible change to the irradiated object. By appropriately selecting the energy of the first laser beam or the second laser beam, the material constituting the first material layer or the second material layer, and the like, the portion to be ablated and removed from the irradiated object can be selected. Is possible.

  8A to 8D has a structure in which a first material layer and a second material layer are sequentially stacked over a substrate. As the substrate, the first material layer, and the second material layer, the same materials as those illustrated in FIGS. 7A to 7C can be used. As the substrate, a glass substrate, a quartz substrate, a sapphire substrate, a ceramic substrate, a semiconductor substrate, or the like may be used. The first material layer may be formed using a conductive material, a semiconductor material, or the like that can absorb the first laser beam. The first material layer is preferably formed using a material having a boiling point or a sublimation point lower than the melting point of the lower conductive layer. For example, the first material layer is formed of a conductive material including chromium (Cr), molybdenum (Mo), nickel (Ni), titanium (Ti), cobalt (Co), copper (Cu), aluminum (Al), silicon, Germanium, silicon germanium, molybdenum oxide, tin oxide, bismuth oxide, vanadium oxide, nickel oxide, zinc oxide, gallium arsenide, gallium nitride, indium oxide, indium phosphide, indium nitride, cadmium sulfide, cadmium telluride, strontium titanate A semiconductor material such as can be used. The second material layer is formed using an insulating material that can absorb the second laser beam and transmit the first laser beam. For example, the second material layer can use a light-transmitting inorganic insulating material such as silicon oxide or silicon nitride, or a light-transmitting organic insulating material such as acrylic or epoxy resin.

  8A to 8D, when a light-transmitting substrate is used as the substrate, the first material layer can be irradiated with the first laser beam from the substrate side. In this case, the second material layer may not be a material that transmits the first laser beam. Further, a base insulating layer may be formed between the substrate and the first material layer using an inorganic insulating material such as silicon oxide or silicon nitride. The base insulating layer functions as a protective layer and can prevent damage to the substrate due to laser ablation. This will be specifically described below.

  FIG. 8A shows an example in which only the second material layer is removed by laser ablation in the first material layer and the second material layer stacked on the substrate. The irradiation object illustrated in FIG. 8A has a structure in which a first material layer 862 and a second material layer 864 are sequentially stacked over a substrate 860, and the opening 868 passes through only the second material layer 864. Is formed. On the bottom surface of the opening 868, the first material layer 862 is exposed. A conductive layer 866 is formed in the opening 868 and is in contact with the first material layer 862. At this time, if the first material layer 862 is formed using a conductive material, the conductive layers are electrically connected to each other through the opening 868. When the first material layer 862 is formed using a semiconductor material, the conductive layer and the semiconductor layer are electrically connected through the opening 868.

  FIG. 8B shows an example in which the upper layer portions of the second material layer and the first material layer are removed by laser ablation in the first material layer and the second material layer stacked on the substrate. The irradiated object illustrated in FIG. 8B has a structure in which a first material layer 872 and a second material layer 874 are sequentially stacked over a substrate 870, and penetrates the second material layer 874, and An opening 878 is formed so that the upper layer portion of the one material layer 872 is removed and the lower layer portion remains. The first material layer 872 is exposed at the bottom surface of the opening 878. In the first material layer 872, the thickness of the region where the opening 878 is formed is smaller than that of other regions. In addition, a conductive layer 876 is formed in the opening 878 and is in contact with the first material layer 872 on the bottom and side surfaces of the opening 878. At this time, when the first material layer 872 is formed using a conductive material, the conductive layers are electrically connected to each other through the opening 878. When the first material layer 872 is formed using a semiconductor material, the conductive layer and the semiconductor layer are electrically connected through the opening 878.

  FIG. 8C illustrates an example in which the second material layer and the first material layer are removed by laser ablation in the first material layer and the second material layer which are stacked over the substrate. The irradiation object illustrated in FIG. 8C has a structure in which a first material layer 882 and a second material layer 884 are sequentially stacked over a substrate 880, and penetrates the second material layer 884 and the first material layer 882. Thus, an opening 888 is formed. The first material layer 882 is exposed at the side surface of the opening 888. A conductive layer 886 is formed in the opening 888 and is in contact with the first material layer 882 on the side surface of the opening 888. At this time, if the first material layer 882 is formed using a conductive material, the conductive layers are electrically connected to each other through the opening 888. When the first material layer 882 is formed using a semiconductor material, the conductive layer and the semiconductor layer are electrically connected through the opening 888.

  FIG. 8D illustrates an example in which the side surface of the opening formed in the irradiation object has a tapered shape. The irradiation object illustrated in FIG. 8D has a structure in which a first material layer 892 and a second material layer 894 are sequentially stacked over a substrate 890. An opening 898 is formed in the irradiated object. Here, an opening 898 is formed so as to penetrate the second material layer 894. Note that the opening 898 may be formed so as to penetrate the second material layer 894 and so that the upper layer portion of the first material layer 892 is removed and the lower layer portion remains, or the second material layer 894 and the second material layer 894 are formed. One material layer 892 may be formed so as to penetrate.

  In FIG. 8D, the opening 898 formed in the irradiation object is tapered, and the side surface of the opening 898 is tapered with respect to the bottom surface. A conductive layer 896 is formed in the opening 898 and is in contact with the first material layer 892. At this time, when the first material layer 892 is formed using a conductive material, the conductive layers are electrically connected to each other through the opening 898. When the first material layer 892 is formed using a semiconductor material, the conductive layer and the semiconductor layer are electrically connected to each other through the opening 898.

  By applying the present invention, an opening having a desired shape can be formed in a desired region without using a lithography process using a photoresist. In addition, by irradiating an object to be irradiated, which is a laminate, so as to superimpose two types of laser beams absorbed in different layers, processing of the object to be irradiated by laser ablation may damage other layers. And can be easily performed. Thus, in manufacturing a semiconductor device, manufacturing cost can be reduced and throughput can be improved. In addition, a highly reliable semiconductor device can be manufactured.

  Further, the present invention can be realized in various forms by appropriately selecting the structure of the irradiated object, the materials constituting the first material layer and the second material layer, the energy of the first laser beam and the second laser beam, and the like. Can be formed.

  This embodiment mode can be freely combined with Embodiment Mode 1.

(Embodiment 3)
In this embodiment, a configuration example of a laser processing apparatus according to the present invention will be described.

  FIG. 11 is a schematic diagram showing the configuration of the laser processing apparatus according to the present invention. The laser processing apparatus according to the present invention includes a first laser 3120 and a second laser 3130. A first laser beam 3122 is emitted from the first laser 3120. A second laser beam 3132 is emitted from the second laser 3130. Laser beams (first laser beam 3122 and second laser beam 3132) emitted from the respective lasers (first laser 3120 and second laser 3130) travel by an optical system in which a mirror and a condenser lens are combined. The direction, the deflection direction, and the like are controlled, and irradiation is performed by superimposing on the irradiated object. Specifically, the traveling direction, the deflection direction, and the like of the first laser beam 3122 emitted from the first laser 3120 and the second laser beam 3132 emitted from the second laser 3130 are controlled by the mirror 3142 and the mirror 3146. Then, the light is condensed by the condensing lens 3140 and irradiated on the irradiated object 3110. At this time, the first laser beam 3122 and the second laser beam 3132 are controlled so as to be superimposed on the irradiation object 3110 by a mirror or a condenser lens. The irradiated body 3110 is held by the stage 3100 and moved to a desired position.

  The irradiated body 3110 has a structure in which a conductive layer 3104, a first material layer 3106, and a second material layer 3108 are sequentially stacked over a substrate 3102. Note that the conductive layer 3104 is not necessarily provided, or an insulating layer or the like which is in contact with the substrate 3102 and functions as a protective layer may be provided. In this case, the insulating layer may be formed using silicon oxide, silicon nitride, silicon oxynitride, silicon nitride oxide, or the like.

  As the substrate 3102, the conductive layer 3104, the first material layer 3106, and the second material layer 3108, the same materials as those described in Embodiment Modes 1 and 2 can be used. For example, the substrate 3102 can be a glass substrate, a quartz substrate, a sapphire substrate, a ceramic substrate, a semiconductor substrate, or the like. The conductive layer 3104 includes silver (Ag), gold (Au), nickel (Ni), platinum (Pt), palladium (Pd), iridium (Ir), rhodium (Rh), tantalum (Ta), tungsten (W), It can be formed using a conductive material including titanium (Ti), molybdenum (Mo), aluminum (Al), copper (Cu), and the like. The first material layer 3106 can be formed using a material that can absorb the first laser beam 3122. The second material layer 3108 can be formed using a material that can absorb the second laser beam and transmit the first laser beam. Note that the first material layer 3106 is preferably formed using a material whose boiling point or sublimation point is lower than the melting point of the lower conductive layer 3104 (eg, chromium having a relatively low melting point). In this embodiment, a glass substrate is used as the substrate 3102. The conductive layer 3104 is formed using tungsten, the first material layer 3106 is formed using chromium, and the second material layer 3108 is formed using silicon oxide.

  The first laser beam 3122 has a wavelength that is absorbed by the first material layer 3106. In addition, the first laser beam 3122 has energy that can be ablated in a region irradiated with the second laser beam 3132 in an overlapping manner. Therefore, the first laser 3120 that emits the first laser beam 3122 preferably has an oscillation wavelength in the absorption wavelength region of the first material layer 3106. More preferably, the oscillation wavelength of the first laser 3120 is longer than visible light (including visible light), specifically 400 nm or more.

Examples of the first laser 3120 include excimer lasers such as KrF, ArF, and XeCl, gas lasers such as He, He—Cd, Ar, and He—Ne, single crystal YAG, YVO ₄ , forsterite (Mg ₂ SiO ₄ ), YAlO ₃ , GdVO ₄ or polycrystalline (ceramic) YAG, Y ₂ O ₃ , YVO ₄ , YAlO ₃ , GdVO ₄ , and Nd, Yb, Cr, Ti, Ho, Er, Tm, Ta as dopants Or, by using a solid-state laser, a semiconductor laser such as GaN, GaAs, GaAlAs, or InGaAsP, a picosecond laser, a femtosecond laser, etc., with a medium in which a plurality of types are added, and appropriately setting the oscillation wavelength of these lasers The first laser beam 3122 having a desired wavelength can be emitted. Preferably, a visible light laser having a strong oscillation wavelength in a region of 400 nm or more may be used. He—Cd laser (440 nm), He—Ne laser (632.8 nm), Ar laser (488 nm, 514.5 nm), YAG It is desirable to use a solid-state laser such as a laser, Y ₂ O ₃ laser, YVO ₄ laser, YAlO ₃ laser, or GdVO ₄ laser, GaAlAs laser (780 nm), or the like. Note that a picosecond laser is a laser that emits a laser beam having a pulse width on the order of picoseconds (10 ⁻¹² seconds to 10 ⁻¹⁰ seconds). The femtosecond laser is a laser that emits a laser beam having a pulse width in the order of femtoseconds (10 ^{−15 to} 10 ⁻¹³ seconds). As the first laser beam 3122, either a continuous wave laser beam or a pulsed laser beam may be used. In this embodiment, a YAG laser is used as the first laser 3120.

  The second laser beam 3132 has a wavelength that is absorbed by the second material layer 3108. Moreover, it has an energy of the grade which does not give an irreversible change to an irradiated body. Therefore, the second laser 3130 that emits the second laser beam 3132 preferably has an oscillation wavelength in the absorption wavelength region of the second material layer 3108. More preferably, the oscillation wavelength of the second laser 3130 is about the wavelength of ultraviolet light shorter than visible light (not including visible light), specifically, 400 nm or less.

  As the second laser 3130, the laser described as a specific example of the first laser 3120 is used, and the second laser beam 3132 having a desired wavelength can be emitted by appropriately setting the oscillation wavelength of the laser. Preferably, an ultraviolet laser having a strong oscillation wavelength in a region of 400 nm or less is used, such as an XeF excimer laser (351 nm), an XeCl excimer laser (308 nm), a KrF excimer laser (248 nm), an ArF excimer laser (193 nm), and a YAG laser. It is desirable to use the third harmonic (355 nm) or the like. In this embodiment, a KrF excimer laser is used as the second laser 3130.

  The first laser beam 3122 emitted from the first laser 3120 is reflected by the mirror 3142, condensed by the condenser lens 3140, irradiated to the irradiated object 3110, and absorbed by the first material layer 3106. Is done. The second laser beam 3132 emitted from the second laser 3130 is reflected by the mirror 3146, passes through the mirror 3142, is condensed by the condenser lens 3140, and is irradiated on the irradiated object 3110, and the second Absorbed by the material layer 3108. In the irradiation object 3110, the first laser beam 3122 and the second laser beam 3132 are irradiated so as to overlap each other. In the irradiation object 3110, part or all of the region irradiated with the first laser beam 3122 and the second laser beam 3132 superimposed is ablated to form an opening. At this time, the irradiated body 3110 is moved by the stage 3100, and a desired area is processed.

  The configuration of the laser processing apparatus according to the present invention may be as shown in the schematic diagram of FIG. The laser processing apparatus shown in FIG. 32 includes a first laser 3220 and a second laser 3230. A first laser beam 3222 is emitted from the first laser 3220. A second laser beam 3232 is emitted from the second laser 3230. Laser beams (first laser beam 3222 and second laser beam 3232) emitted from the respective lasers (first laser 3220 and second laser 3230) are optical systems (mirrors) combined with mirrors and condenser lenses. 3242 and a condensing lens 3244 and a second optical system in which a mirror 3246 and a condensing lens 3240 are combined), the traveling direction, the deflection direction, and the like are controlled and superimposed on the irradiated object. And irradiated. Specifically, the traveling direction, the deflection direction, and the like of the first laser beam 3222 emitted from the first laser 3220 and the second laser beam 3232 emitted from the second laser 3230 are controlled by a mirror 3242 and a mirror 3246. Then, the light is condensed by the condensing lens 3244 and the condensing lens 3240 and is irradiated to the irradiated object 3210. At this time, the first laser beam 3222 and the second laser beam 3232 are controlled so as to be superimposed on the irradiation object 3210 by a mirror or a condenser lens. The irradiated body 3210 is held by the stage 3200 and moved to a desired position.

  The irradiated body 3210 has a structure in which a first material layer 3204 and a second material layer 3206 are sequentially stacked over a substrate 3202. As the substrate 3202, a substrate that can transmit the first laser beam 3222 is used. For example, a light-transmitting substrate such as a glass substrate or a quartz substrate is used. Note that a light-transmitting insulating layer functioning as a protective layer may be provided in contact with the substrate 3202. For example, an inorganic insulating material such as silicon oxide or silicon nitride may be used.

  The first material layer 3204 may be the same as the first material layer 3106 illustrated in FIG. 11 and is formed using a material that can absorb the first laser beam 3222. The second material layer 3206 may be the same as the second material layer 3108 illustrated in FIG. 11, and is formed using a material that can absorb the second laser beam 3232. In FIG. 32, since the first laser beam 3222 is irradiated from the substrate 3202 side, a material that does not transmit the first laser beam 3222 can be used for the second material layer 3206.

  The first laser beam 3222 and the first laser 3220 that emits the first laser beam 3222 may be the same as the first laser beam 3122 and the first laser 3120 illustrated in FIG. To do. Similarly, the second laser beam 3232 and the second laser 3230 that emits the second laser beam 3232 to the second laser beam 3232 may be the same as the second laser beam 3132 and the second laser 3130 illustrated in FIG. .

  The first laser beam 3222 emitted from the first laser 3220 is reflected by the mirror 3242, condensed by the condenser lens 3244, and irradiated on the irradiated object 3210 from the substrate 3202 side, and the first material Absorbed by layer 3204. On the other hand, the second laser beam 3232 emitted from the second laser 3230 is reflected by the mirror 3246 and then collected by the condenser lens 3240 and irradiated on the irradiated object 3210 from the second material layer 3206 side. And absorbed by the second material layer 3206. In the irradiation object 3210, the first laser beam 3222 and the second laser beam 3232 are irradiated so as to overlap each other. In the irradiation object 3210, a part or the whole of the region irradiated with the first laser beam 3222 and the second laser beam 3232 is overlapped to form an opening. At this time, the irradiated object 3210 is held vertically on the stage 3200, moved to a desired position by the stage 3200, and a desired area is processed.

  11 and 32 are largely different depending on whether the first laser beam is irradiated from the substrate side or the second material layer side. That is, the configuration of the laser processing apparatus shown in FIG. 32 irradiates the first laser beam and the second laser beam from opposite directions. In the case of irradiating the first laser beam from the substrate side, the substrate needs to transmit the first laser beam. On the other hand, when the first laser beam is irradiated from the second material layer side, the second material layer needs to transmit the first laser beam.

  Further, the configuration of the laser processing apparatus according to the present invention may be as shown in the schematic diagram of FIG. The laser processing apparatus shown in FIG. 33 includes a solid-state laser 3430. A fundamental laser beam 3412 is emitted from the solid-state laser 3430. In the laser beam 3412, the second harmonic laser beam 3422 and the third harmonic laser beam 3432 are separated by the beam splitter 3460. Hereinafter, the fundamental laser beam 3412 is referred to as a fundamental laser beam 3412, the second harmonic laser beam 3422 is referred to as a first laser beam 3422, and the third harmonic laser beam 3432 is referred to as a second laser beam 3432. The laser beam (the first laser beam 3422 and the second laser beam 3432) separated by the beam splitter 3460 is controlled in its traveling direction and deflection direction by an optical system in which a mirror and a condensing lens are combined. Irradiated in superposition on the body. Specifically, the first laser beam 3422 and the second laser beam 3432 emitted from the solid-state laser 3430 and separated by the beam splitter 3460 are changed in traveling direction, deflection direction, and the like by a mirror 3452, a mirror 3456, and a mirror 3458. Controlled, condensed by the condenser lens 3440 and irradiated to the irradiated object 3410. At this time, the first laser beam 3422 and the second laser beam 3432 are controlled so as to be superimposed on the irradiation object 3410 by a mirror or a condenser lens. The irradiated body 3410 is held by the stage 3400 and moved to a desired position.

As the solid-state laser 3430, a solid-state laser such as a YAG laser, a Y ₂ O ₃ laser, a YVO ₄ laser, a YAlO ₃ laser, or a GdVO ₄ laser is used. The fundamental wave (1054 nm to 1062 nm) of these solid-state lasers can be divided into a second harmonic (527 nm to 532 nm) and a third harmonic (351 nm to 355 nm) by a beam splitter. In this embodiment, a YAG laser is used as the solid-state laser 3430.

  The irradiated body 3410 has a structure in which a first material layer 3406 and a second material layer 3408 are sequentially stacked over a substrate 3402. Note that a conductive layer or an insulating layer and a conductive layer may be provided between the substrate 3402 and the first material layer 3406 as illustrated in FIG. In FIG. 33, a glass substrate, a quartz substrate, a sapphire substrate, a ceramic substrate, a semiconductor substrate, or the like can be used as the substrate 3402. The first material layer 3406 is formed using a material that can absorb the first laser beam 3422. The second material layer 3408 is formed using a material that can absorb the second laser beam 3432.

  For example, when a YAG laser is used as the solid-state laser 3430, the first laser beam 3422 is the second harmonic (532 nm) of the YAG laser, and the second laser beam 3432 is the third harmonic (355 nm) of the YAG laser. It is. In this case, the first material layer 3406 is formed using molybdenum (Mo). The second material layer 3408 is formed using silicon nitride.

  A fundamental laser beam 3412 emitted from the solid-state laser 3430 is divided into a first laser beam 3422 and a second laser beam 3432 by a beam splitter 3460. The first laser beam 3422 is reflected by the mirror 3456, the mirror 3458, and the mirror 3452, condensed by the condenser lens 3440, irradiated to the irradiated object 3410, and absorbed by the first material layer 3406. . The second laser beam 3432 passes through the mirror 3452, is collected by the condenser lens 3440, is irradiated on the irradiation object 3410, and is absorbed by the second material layer 3408. In the irradiation object 3410, the first laser beam 3422 and the second laser beam 3432 are irradiated so as to overlap with each other. In the irradiation object 3410, a part or the whole of the region irradiated with the first laser beam 3422 and the second laser beam 3432 is overlapped to form an opening. At this time, the irradiation object 3410 is moved by the stage 3400, and a desired region is processed.

  As shown in FIG. 33, a laser beam having two types of wavelengths (second harmonic and third harmonic) can be obtained from one solid-state laser by incorporating a beam splitter into the laser processing apparatus. Therefore, since the number of lasers provided can be reduced, the cost of the apparatus can be reduced. It is also possible to reduce the size of the apparatus.

  The configuration of the laser processing apparatus according to the present embodiment shown in FIGS. 11, 32, and 33 is merely an example, and the number and positional relationship of mirrors and condenser lenses arranged in the optical path of the laser beam are not particularly limited. . In addition to the mirror and the condenser lens, a beam expander, a homogenizer, a polarizer, a slit, and the like can be used, and these may be used in combination.

  As described above, by using the laser processing apparatus as described in this embodiment mode, an opening can be formed in a desired region of an irradiation object without using a photoresist. Further, it is possible to form an opening by irradiating an irradiation object so that two kinds of laser beams are overlapped with each other, absorbing each laser beam in a different layer, and performing ablation. By using such a laser processing apparatus, the number of lithography processes can be reduced and simplified in the manufacturing process of the semiconductor device, and the manufacturing cost can be reduced and the throughput can be improved.

  Note that this embodiment can be freely combined with the first and second embodiments.

(Embodiment 4)
In this embodiment, a method for manufacturing a display device including a transistor and a display element, to which the present invention is applied, will be described. As the transistor, an example of manufacturing an inverted staggered transistor is described. An example of manufacturing a light-emitting element as a display element is described.

  As shown in FIG. 9A, a transistor 720 is formed over a substrate 7000 with a base insulating layer 7002 interposed therebetween. Hereinafter, a specific method for manufacturing the transistor 720 will be described with reference to FIGS.

  A base insulating layer 7002 is formed over the substrate 7000, and a conductive layer 703 is formed over the base insulating layer 7002 (see FIG. 4A). As the substrate 7000, a glass substrate containing barium borosilicate glass, aluminoborosilicate glass, or the like, a quartz substrate, a sapphire substrate, a ceramic substrate, or a plastic substrate having heat resistance that can withstand the processing temperature in this manufacturing process is used. Further, polishing may be performed by a CMP method or the like so that the surface of the substrate 7000 is planarized.

  The base insulating layer 7002 has a single-layer structure or a stacked structure using an insulating material such as silicon oxide, silicon nitride, silicon oxynitride, or silicon nitride oxide by various methods such as a CVD method, a sputtering method, and a spin coating method. Form. The base insulating layer 7002 is not necessarily formed, but has an effect of blocking contaminants from the substrate 7000. Further, there is an effect of preventing damage to the substrate when the laser beam is irradiated later.

  The conductive layer 703 may be formed using a conductive material. For example, silver (Ag), gold (Au), nickel (Ni), platinum (Pt), palladium (Pd), iridium (Ir), rhodium (Rh), A metal element such as tantalum (Ta), tungsten (W), titanium (Ti), molybdenum (Mo), aluminum (Al), copper (Cu), or an alloy material or a compound material containing the metal element as a main component. May be used. Alternatively, a semiconductor material typified by polycrystalline silicon doped with an impurity element such as phosphorus (P), or an AgPdCu alloy may be used. Alternatively, a single layer structure or a stacked structure may be used. For example, a two-layer structure of a tungsten nitride film and a molybdenum (Mo) film may be used, a tungsten film with a thickness of 50 nm, an alloy of aluminum and silicon with a thickness of 500 nm (Al A three-layer structure in which a -Si) film and a titanium nitride film with a thickness of 30 nm are sequentially stacked may be employed. In the case of a three-layer structure, tungsten nitride may be used instead of tungsten of the first conductive layer, or aluminum instead of the aluminum and silicon alloy (Al-Si) film of the second conductive layer. A titanium alloy film (Al—Ti) may be used, or a titanium film may be used in place of the titanium nitride film of the third conductive layer.

  The conductive layer 703 is formed by a sputtering method, a PVD method (Physical Vapor Deposition), a low pressure CVD method (LPCVD method), or a CVD method (Chemical Vapor Deposition) such as a plasma CVD method.

  A first material layer 7402 and a second material layer 7404 are sequentially stacked over the conductive layer 703. The first laser beam 7412 and the second laser beam 7414 are selectively irradiated from the second material layer 7404 side. At this time, irradiation is performed so that the first laser beam 7412 and the second laser beam 7414 overlap at least partially. A region irradiated with the first laser beam 7412 and the second laser beam 7414 superimposed is a superimposed irradiation region 7416 (see FIG. 4A).

  The first material layer 7402 is formed using a material that can absorb the first laser beam 7412. Note that the first material layer 7402 is preferably formed using a material whose boiling point or sublimation point is lower than the melting point of the conductive layer 703 provided in the lower layer. For example, a metal element such as chromium (Cr), molybdenum (Mo), nickel (Ni), titanium (Ti), cobalt (Co), copper (Cu), aluminum (Al), or an alloy containing the element as a main component Conductive materials such as materials or compound materials, silicon, germanium, silicon germanium, molybdenum oxide, tin oxide, bismuth oxide, vanadium oxide, nickel oxide, zinc oxide, gallium arsenide, gallium nitride, indium oxide, indium phosphide, indium nitride Semiconductor materials such as cadmium sulfide, cadmium telluride, and strontium titanate can be used. Further, zinc sulfide, silicon nitride, mercury sulfide, aluminum chloride, or the like can be used. The first material layer 7402 may be formed using a single layer structure or a stacked layer structure using one or more of these materials by an evaporation method, a sputtering method, a CVD method, or the like. A film, a zinc oxide film, or an aluminum nitride film can be used. Note that if the conductive layer 703 is formed using a material that is ablated by absorbing the first laser beam 7412, the first material layer 7402 is not necessarily provided.

  The second material layer 7404 is formed using a material that can absorb the second laser beam 7414. The second material layer 7404 is formed using a material that can transmit the first laser beam 7412. For example, inorganic insulating materials such as silicon oxide, silicon nitride, silicon oxynitride, and silicon nitride oxide, and organic insulating materials such as polyimide, acrylic, polyamide, polyimide amide, benzocyclobutene, and epoxy resin can be used. The second material layer 7404 may be formed using a single layer structure or a stacked layer structure using one or more of these materials by a sputtering method, a CVD method, a coating method, or the like. A silicon film or a polyimide film can be used.

  The first laser beam 7412 has a wavelength that can be absorbed by the first material layer 7402 and has an energy enough to ablate part or all of the overlapped irradiation region 7416 irradiated with the second laser beam 7414 so as to overlap therewith. Use what you have. The oscillation wavelength of the first laser beam 7412 is preferably in the absorption wavelength region of the first material layer 7402. More preferably, the oscillation wavelength of the first laser beam 7412 is longer than that of visible light, specifically 400 nm or more. Such a laser beam can be obtained by using various lasers such as a gas laser, a solid-state laser, a semiconductor laser, a picosecond laser, and a femtosecond laser and appropriately setting the oscillation wavelength of these lasers. Note that the first laser beam 7412 may be either a continuous wave laser beam or a pulsed laser beam.

  The second laser beam 7414 has a wavelength that is absorbed by the second material layer 7404 and does not give an irreversible change to the irradiated object (here, a stacked body from the substrate 7000 to the conductive layer 703). Use what has. The oscillation wavelength of the second laser beam 7414 is preferably in the absorption wavelength region of the second material layer 7404. More preferably, the oscillation wavelength of the second laser beam 7414 is about the wavelength of ultraviolet light shorter than visible light, specifically 400 nm or less. Such a laser beam can be obtained by using various lasers such as an excimer laser, a gas laser, a solid-state laser, and a semiconductor laser and appropriately setting the oscillation wavelength of these lasers. Note that the second laser beam 7414 may be either a continuous wave laser beam or a pulsed laser beam.

  The first laser beam 7412 is absorbed by the first material layer 7402 and the second laser beam 7414 is absorbed by the second material layer 7404. The first material layer 7402 and the second material layer 7404 are ablated in a region irradiated with the first laser beam 7412 and the second laser beam 7414 superimposed (superimposed irradiation region 7416). The conductive layer 703 is selectively etched using the remaining first material layer 7403 and second material layer 7405 as a mask to form a gate electrode layer 704 (see FIG. 4B).

  The gate electrode layer 704 can be formed by various printing methods (screen (stencil) printing, offset (lithographic printing) printing, a method of forming a desired pattern such as relief printing or gravure printing (intaglio printing)), nanoimprinting method, droplet discharge method, dispenser. It may be formed using a method, a selective coating method, or the like. When such a method is used, a conductive layer can be selectively formed at a desired place. Alternatively, the gate electrode layer 704 may be formed by forming a mask using a photoresist over the conductive layer 703 and selectively etching the conductive layer 703 using the mask.

  After the first material layer 7403 and the second material layer 7405 are removed by etching or laser ablation, a gate insulating layer 706 is formed over the gate electrode layer 704, and a semiconductor layer is formed over the gate insulating layer 706. (See FIG. 4C).

  The gate insulating layer 706 is formed using an insulating material such as silicon oxide, silicon nitride, silicon oxynitride, or silicon nitride oxide by a CVD method, a sputtering method, or the like. The gate insulating layer 706 may have a single-layer structure or a stacked structure. For example, the gate insulating layer 706 may have a single-layer structure of a silicon oxynitride layer or a stacked structure of two layers of a silicon nitride layer and a silicon oxide layer. Moreover, it is good also as a laminated structure of three or more layers using these. Preferably, silicon nitride having a dense film quality is used. Further, the gate insulating layer 706 is preferably formed using silicon nitride or NiB when the lower gate electrode layer 704 is formed using silver or copper by a droplet discharge method. A film formed using silicon nitride or NiB has an effect of preventing diffusion of impurities and flattening the surface. Note that a rare gas element such as argon may be included in the reaction gas during the formation of the gate insulating layer 706. By including the rare gas element in the reaction gas, a dense insulating layer with low leakage current can be obtained at a low film formation temperature.

  The semiconductor layer forms a stacked structure of a semiconductor layer 705 and a semiconductor layer 709 having one conductivity. The semiconductor layer is made of an amorphous semiconductor (hereinafter also referred to as “AS”) manufactured by vapor deposition or sputtering using a semiconductor material gas typified by silane or germane, or light or thermal energy of the amorphous semiconductor. It can be formed using a polycrystalline semiconductor that is crystallized using a crystalline semiconductor such as a semi-amorphous (also referred to as microcrystal or microcrystal; hereinafter referred to as “SAS”) semiconductor. The semiconductor layer can be formed by various means (such as sputtering, LPCVD, or plasma CVD).

SAS is a semiconductor having an intermediate structure between amorphous and crystalline structures (including single crystals and polycrystals) and having a third state that is stable in terms of free energy, and has short-range order and lattice distortion. It includes a crystalline region having. A crystal region of 0.5 nm to 20 nm can be observed in at least a part of the film, and when silicon is the main component, the Raman spectrum shifts to a lower wave number side than 520 cm ^−1. Yes. In X-ray diffraction, diffraction peaks of (111) and (220) that are derived from the silicon crystal lattice are observed. In order to terminate dangling bonds (dangling bonds), hydrogen or halogen is contained at least 1 atomic% or more. SAS is formed by glow discharge decomposition (plasma CVD) of a gas containing silicon. As a gas containing silicon, SiH ₄ , Si ₂ H ₆ , SiH ₂ Cl ₂ , SiHCl ₃ , SiCl ₄ , SiF _{4, and the} like can be used. Further, F ₂ and GeF ₄ may be mixed. The gas containing silicon may be diluted with H ₂ , or H ₂ and one or more kinds of rare gas elements selected from He, Ar, Kr, and Ne. The dilution rate ranges from 2 to 1000 times, the pressure ranges from approximately 0.1 Pa to 133 Pa, and the power supply frequency ranges from 1 MHz to 120 MHz, preferably from 13 MHz to 60 MHz. The substrate heating temperature is preferably 300 ° C. or lower, and can be formed even at a substrate heating temperature in the range of 100 ° C. to 200 ° C. Here, as an impurity element mainly taken in at the time of film formation, impurities derived from atmospheric components such as oxygen, nitrogen, and carbon are preferably 1 × 10 ²⁰ cm ⁻³ or less, and in particular, the oxygen concentration is 5 × 10 5. It is preferable to be ¹⁹ cm ⁻³ or less, preferably 1 × 10 ¹⁹ cm ⁻³ or less. Further, by adding a rare gas element such as helium, argon, krypton, or neon to further promote lattice distortion, stability is improved and a favorable SAS can be obtained. In addition, a SAS layer formed of a hydrogen-based gas may be stacked on a SAS layer formed of a fluorine-based gas as a semiconductor layer.

  A typical example of an amorphous semiconductor is hydrogenated amorphous silicon, and a typical example of a crystalline semiconductor is polysilicon. Polysilicon (polycrystalline silicon) is mainly made of so-called high-temperature polysilicon using polysilicon formed through a process temperature of 800 ° C. or more as a main material, or polysilicon formed at a process temperature of 600 ° C. or less. And so-called low-temperature polysilicon, and polysilicon crystallized by adding an element that promotes crystallization. Of course, as described above, a semi-amorphous semiconductor or a semiconductor including a crystal phase in a part of the semiconductor layer can also be used.

In the case where a crystalline semiconductor such as a polycrystalline semiconductor or a semi-amorphous semiconductor is used for the semiconductor layer, various methods (laser crystallization method, thermal crystallization method, or crystallization of nickel, etc. are promoted). For example, a thermal crystallization method using an element to be formed). In addition, a microcrystalline semiconductor that is a SAS can be crystallized by laser irradiation to improve crystallinity. For example, in the case where a semiconductor layer is manufactured using silicon and without introducing an element that promotes crystallization, the amorphous silicon layer is heated at 700 ° C. for 1 hour in a nitrogen atmosphere before being irradiated with a laser beam. Thus, it is preferable to release the hydrogen concentration of the amorphous silicon layer to 1 × 10 ²⁰ atoms / cm ³ or less. This is because the amorphous silicon layer is destroyed when the amorphous silicon layer containing a large amount of hydrogen is irradiated with a laser beam.

  The method for introducing the metal element into the amorphous semiconductor layer is not particularly limited as long as the metal element can be present on the surface of the amorphous semiconductor layer or inside the amorphous semiconductor layer. For example, a sputtering method, a CVD method, A plasma treatment method (including a plasma CVD method), an adsorption method, or a method of applying a metal salt solution can be used. Among these, the method using a solution is simple and useful in that the concentration of the metal element can be easily adjusted. At this time, in order to improve the wettability of the surface of the amorphous semiconductor layer and to spread the aqueous solution over the entire surface of the amorphous semiconductor layer, irradiation with UV light in an oxygen atmosphere, thermal oxidation method, hydroxy radical It is desirable to form an oxide film on the surface of the amorphous semiconductor layer by treatment with ozone-containing water or hydrogen peroxide water.

  For crystallization of the amorphous semiconductor layer, heat treatment and crystallization by laser beam irradiation may be combined, or heat treatment and laser beam irradiation may be performed several times independently.

  Alternatively, the crystalline semiconductor layer may be directly formed over the substrate by a plasma method. Alternatively, the crystalline semiconductor layer may be selectively formed over the substrate by a linear plasma method.

  The semiconductor layer can be formed using an organic semiconductor material. As the organic semiconductor material, a low molecular material, a polymer material, or the like is used, and a material such as a conductive polymer material can also be used. For example, a π-electron conjugated polymer material whose skeleton is composed of conjugated double bonds can be used. Specifically, polythiophene, polyfluorene, poly (3-alkylthiophene), polythiophene derivatives, pentacene, and the like can be used. Soluble materials can be used. In addition, as an organic semiconductor material, there is a material capable of forming a semiconductor layer by processing after forming a soluble precursor. Examples of such an organic semiconductor material include polythienylene vinylene, poly (2,5-thienylene vinylene), polyacetylene, a polyacetylene derivative, and polyarylene vinylene.

  When converting the precursor into an organic semiconductor, a reaction catalyst such as hydrogen chloride gas is added as well as heat treatment. Typical solvents for dissolving these soluble organic semiconductor materials include toluene, xylene, chlorobenzene, dichlorobenzene, anisole, chloroform, dichloromethane, γ-butyllactone, butyl cellosolve, cyclohexane, NMP (N-methyl-2) -Pyrrolidone), cyclohexanone, 2-butanone, dioxane, dimethylformamide (DMF), THF (tetrahydrofuran), or the like can be applied.

  In this embodiment, an amorphous semiconductor layer is formed as the semiconductor layer 705 and the semiconductor layer 709 having one conductivity. As the semiconductor layer 709 having one conductivity, an n-type semiconductor layer containing phosphorus (P) which is an impurity element imparting n-type conductivity is formed. The semiconductor layer 709 having one conductivity functions as a source region and a drain region, and improves ohmic contact between the semiconductor layer 705 and the conductive layer functioning as a source electrode or a drain electrode. Note that the semiconductor layer 709 having one conductivity may be formed as needed, and an n-type semiconductor layer containing an n-type impurity element (P, As) or a p-type impurity element (B A p-type semiconductor layer can be formed.

  A first material layer 7422 and a second material layer 7424 are sequentially stacked over the semiconductor layer 709 having one conductivity. The first laser beam 7432 and the second laser beam 7434 are selectively irradiated from the second material layer 7424 side. At this time, irradiation is performed so that the first laser beam 7432 and the second laser beam 7434 overlap at least partially. A region irradiated with the first laser beam 7432 and the second laser beam 7434 superimposed is a superimposed irradiation region 7436 (see FIG. 4C).

  The first material layer 7422 and the second material layer 7424 may be formed in the same manner as the first material layer 7402 and the second material layer 7404 described above. The first laser beam 7432 has a wavelength that is absorbed by the first material layer 7422 in the same manner as the first laser beam 7412 described above, and has an energy enough to ablate part or all of the overlapped irradiation region 7436. What has this may be used. Similarly to the second laser beam 7414 described above, the second laser beam 7434 has a wavelength that is absorbed by the second material layer 7424, and an irradiated object (here, the semiconductor layer 709 having one conductivity from the substrate 7000). What is necessary is just to use what has the energy which does not give an irreversible change to the laminated body.

  The first laser beam 7432 is absorbed by the first material layer 7422, and the second laser beam 7434 is absorbed by the second material layer 7424. The first material layer 7422 and the second material layer 7424 are ablated in a region irradiated with the first laser beam 7432 and the second laser beam 7434 superimposed (superimposed irradiation region 7436). The semiconductor layer 705 and the semiconductor layer 709 having one conductivity are selectively etched using the remaining first material layer 7423 and second material layer 7425 as a mask, so that the semiconductor layer 707 and the semiconductor layer 711 having one conductivity are formed. (See FIG. 4D).

  After the first material layer 7423 and the second material layer 7425 are removed by etching or laser ablation, a conductive layer 713 is formed over the semiconductor layer 711 having one conductivity (see FIG. 5A).

  The conductive layer 713 may be formed using a conductive material. For example, silver (Ag), gold (Au), nickel (Ni), platinum (Pt), palladium (Pd), iridium (Ir), rhodium (Rh) , Tantalum (Ta), tungsten (W), chromium (Cr), molybdenum (Mo), titanium (Ti), cobalt (Co), copper (Cu), aluminum (Al), or other metal elements, or such elements A conductive material such as an alloy material or a compound as a component may be used. The conductive layer 713 may have a single-layer structure or a stacked structure.

  The conductive layer 713 may be formed by a sputtering method, a PVD method (Physical Vapor Deposition), a low pressure CVD method (LPCVD method), or a CVD method (Chemical Vapor Deposition) such as a plasma CVD method.

  A first material layer 7442 and a second material layer 7444 are sequentially stacked over the conductive layer 713. The first laser beam 7452 and the second laser beam 7454 are selectively irradiated from the second material layer 7444 side. At this time, the first laser beam 7452 and the second laser beam 7454 are irradiated so as to overlap at least partially. A region irradiated with the first laser beam 7452 and the second laser beam 7454 overlapped with each other is referred to as a superimposed irradiation region 7456 (see FIG. 5A).

  The first material layer 7442 and the second material layer 7444 may be formed in a manner similar to that of the first material layer 7402 and the second material layer 7404 described above. Further, the first laser beam 7452 has a wavelength that is absorbed by the first material layer 7442 in the same manner as the first laser beam 7412 described above, and has an energy enough to ablate part or all of the overlapping irradiation region 7456. What has this may be used. Similarly to the second laser beam 7414 described above, the second laser beam 7454 has a wavelength that is absorbed by the second material layer 7444, and an irradiated object (here, a stacked body from the substrate 7000 to the conductive layer 713). What has an energy which does not give an irreversible change to is used. Note that the first material layer 7442 is not necessarily provided as long as the conductive layer 713 is formed using a material that is ablated by absorbing the first laser beam 7452.

  The first laser beam 7452 is absorbed by the first material layer 7442 and the second laser beam 7454 is absorbed by the second material layer 7444. The first material layer 7442 and the second material layer 7444 are ablated in a region (superimposed irradiation region 7456) where the first laser beam 7452 and the second laser beam 7454 are superimposed and irradiated. The conductive layer 713 is selectively etched using the remaining first material layer 7443a, the first material layer 7443b, the second material layer 7445a, and the second material layer 7445b as masks, so that the conductive layer 713 functions as a source electrode layer or a drain electrode layer. A layer 712a and a conductive layer 712b are formed (see FIG. 5B).

  The conductive layers 712a and 712b can be formed by various printing methods (screen (stencil) printing, offset (planographic printing) printing, a method of forming a desired pattern such as relief printing or gravure printing (intaglio printing)), nanoimprinting method, droplet discharge method, You may form using the dispenser method, the selective application method, etc. When such a method is used, a conductive layer can be selectively formed at a desired place. Alternatively, the conductive layers 712a and 712b may be formed by forming a mask using a photoresist over the conductive layer 713 and selectively etching the conductive layer 713 using the mask.

  The first material layers 7443a and 7443b and the second material layers 7445a and 7445b are removed by etching or laser ablation (see FIG. 6A). Then, using the conductive layers 712a and 712b as masks, the semiconductor layer 711 having one conductivity is selectively etched to expose the semiconductor layer 707. The semiconductor layers are separated into a semiconductor layer 710a having one conductivity, a semiconductor layer 710b having one conductivity, and a semiconductor layer 708 (see FIG. 6B). Note that after the semiconductor layer 711 having one conductivity is selectively etched, an exposed portion of the lower semiconductor layer 708 may be recessed as compared with other portions.

  The semiconductor layer 708 and the semiconductor layers 710a and 710b having one conductivity are selected using a mask formed with a photoresist over a semiconductor layer formed by a sputtering method, an LPCVD method, a plasma CVD method, or the like. Alternatively, it may be formed by etching.

  Further, the semiconductor layer 708 and the semiconductor layers 710a and 710b having one conductivity are formed in various patterns such as various printing methods (screen (stencil printing), offset (lithographic printing), relief printing, gravure (intaglio printing), and the like. Method), nanoimprint method, droplet discharge method, dispenser method, selective coating method and the like. When such a method is used, a semiconductor layer can be selectively formed at a desired place.

  Through the above process, the transistor 720 which is an inverted staggered transistor (also referred to as a bottom-gate transistor) can be manufactured.

  Next, an insulating layer 7010 is formed so as to cover the transistor 720 (see FIG. 9A).

  The insulating layer 7010 was selected from materials including silicon oxide, silicon nitride, silicon oxynitride, aluminum oxide, aluminum nitride, aluminum oxynitride, diamond-like carbon (DLC), nitrogen-containing carbon, polysilazane, and other inorganic insulating materials. A single layer structure or a stacked structure is formed using a material or the like. Alternatively, a material containing siloxane may be used. An organic insulating material may be used, and polyimide, acrylic, polyamide, polyimide amide, resist, or benzocyclobutene can be used. Moreover, it can also form using an oxazole resin, for example, photocurable polybenzoxazole etc. can be used.

  The insulating layer 7010 can be formed by a sputtering method, a PVD method (Physical Vapor Deposition), a low pressure CVD method (LPCVD method), a CVD method such as a plasma CVD method (Chemical Vapor Deposition), a spin coating method, or the like.

  Next, laser beam irradiation is performed (see FIG. 9B), and an opening 7038 reaching the conductive layer 712b is formed in the insulating layer 7010 (see FIG. 9C).

  In FIG. 9C, the opening 7038 formed in the insulating layer 7010 is formed using ablation by laser beam irradiation as described in Embodiment Modes 1 to 3.

  Specifically, as shown in FIG. 9B, a first laser beam 7032 having a wavelength absorbed by the conductive layer 712b from the insulating layer 7010 side and a second laser having a wavelength absorbed by the insulating layer 7010 Irradiation is performed so that the beam 7034 is overlapped, and a part or all of the overlapped and irradiated region is ablated to form an opening 7038. The first laser beam 7032 has energy sufficient to ablate part or all of the region irradiated with the second laser beam 7034 so as to overlap therewith. The second laser beam 7034 has energy that does not cause an irreversible change in the stacked body from the substrate 7000 to the insulating layer 7010. Specific laser beams are the same as those in the above embodiment, and a description thereof is omitted. In this embodiment, an opening is formed by removing only the insulating layer 7010 by ablation by irradiation with the first laser beam 7032 and the second laser beam 7034. Needless to say, the present invention is not particularly limited, and by appropriately selecting the energy of the first laser beam 7032 and the second laser beam 7034, the upper layer portion of the conductive layer 712b is removed and the lower layer portion remains, or An opening can also be formed so as to penetrate the conductive layer 712b.

  Note that in the case where the substrate 7000, the base insulating layer 7002, and the gate insulating layer 706 are formed using a light-transmitting material, the first laser beam can be irradiated from the substrate 7000 side. The second laser beam absorbed by the insulating layer 7010 is emitted from the insulating layer 7010 side. The first laser beam absorbed by the conductive layer 712b is emitted from the substrate 7000 side. At this time, the first laser beam and the second laser beam are irradiated so as to overlap each other. An opening 7038 is formed in the insulating layer 7010 (or the insulating layer 7010 and the conductive layer 712b) by ablating part or all of the overlapped and irradiated region. In this case, the insulating layer 7010 does not need to transmit the first laser beam, so that a selection range of materials is expanded.

  The opening 7038 may be formed by forming a mask using a photoresist over the insulating layer 7010 and selectively etching the mask using the mask. In addition, a mask may be formed using a droplet discharge method and may be selectively etched using the mask.

  Next, a light-emitting element 7020 that is electrically connected to the transistor 720 is formed. As the light-emitting element 7020, a light-emitting element that emits red (R), green (G), or blue (B) light may be formed. Alternatively, a light-emitting element 7020 that emits white (W) light may be formed, and RGB light emission may be obtained in combination with a color filter. A method for forming the light emitting element 7020 is described below.

  First, a first electrode layer 7012 of a light-emitting element that functions as a pixel electrode is formed in the opening 7038 from which the conductive layer 712b is exposed. The conductive layer 712b and the first electrode layer 7012 are electrically connected (see FIG. 10A).

  The first electrode layer 7012 can be formed using a conductive material such as indium tin oxide (ITO), indium tin oxide containing silicon oxide (ITSO), or zinc oxide (ZnO). For example, indium tin oxide containing silicon oxide can be formed by a sputtering method using a target in which silicon oxide is contained in the range of 2 wt% to 10 wt% in ITO. In addition, a conductive material obtained by doping ZnO with gallium (Ga), and an oxide conductive material formed using a target in which silicon oxide is included and zinc oxide (ZnO) in a range of 2 wt% to 20 wt% is mixed with indium oxide. Alternatively, indium zinc oxide (IZO) may be used.

  As the first electrode layer 7012, a conductive layer formed by a sputtering method, a PVD method (Physical Vapor Deposition), a low pressure CVD method (LPCVD method), or a CVD method (Chemical Vapor Deposition) such as a plasma CVD method is selectively used. It is formed by etching.

  The first electrode layer 7012 can be selectively formed at a desired place using a droplet discharge method, a printing method (a method for forming a pattern such as screen printing or offset printing), a dipping method, a dispenser method, or the like. It can also be formed.

  The first electrode layer 7012 may be cleaned by polishing with a CMP method or a polyvinyl alcohol-based porous body so that the surface thereof is planarized. Further, after the polishing using the CMP method, the surface of the first electrode layer 7012 may be subjected to ultraviolet irradiation, oxygen plasma treatment, or the like.

  Next, a partition layer 7014 is formed so as to have an opening over the first electrode layer 7012 (see FIG. 10B). The partition layer 7014 is formed using an inorganic insulating material such as silicon oxide, silicon nitride, silicon oxynitride, aluminum oxide, aluminum nitride, or aluminum oxynitride, acrylic acid, methacrylic acid, and derivatives thereof, polyimide, aromatic polyamide, or the like. Bonded to silicon, oxygen, and hydrogen containing a heat-resistant polymer such as polybenzimidazole, or a siloxane-based material, an inorganic siloxane containing Si—O—Si bond, and silicon It can be formed of an organic siloxane insulating material in which hydrogen is substituted with an organic group such as methyl or phenyl. You may form using photosensitive and non-photosensitive materials, such as an acryl and a polyimide.

  The partition layer 7014 can be selectively formed by a droplet discharge method, a printing method, a dispenser method, or the like. Alternatively, a partition layer 7014 having a desired shape may be formed by forming a partition layer over the entire surface using an insulating material, forming a resist mask or the like using a lithography process, and performing etching. In addition, a partition layer 7014 having a desired shape can be formed by forming a partition layer on the entire surface using a photosensitive material, and exposing and developing the partition layer made of a photosensitive material. Note that the partition wall layer 7014 preferably has a shape in which the radius of curvature continuously changes. With such a shape of the partition layer, the coverage with the layer 7016 and the second electrode layer 7018 formed above is improved.

  Alternatively, after the partition layer 7014 is formed by discharging a composition by a droplet discharge method, the surface may be pressed and flattened by pressure in order to improve the flatness. As a pressing method, unevenness may be reduced by scanning a roller-shaped object on the surface, or the surface may be pressed vertically with a flat plate-like object. Alternatively, the surface may be softened or melted with a solvent or the like, and the surface irregularities may be removed with an air knife. Further, polishing may be performed using a CMP method. This step can be applied when the surface is flattened when unevenness is generated by the droplet discharge method. When flatness is improved by this step, display unevenness of the display device can be prevented and a high-definition image can be displayed.

  Next, a layer 7016 and a second electrode layer 7018 are stacked over the first electrode layer 7012 and the partition layer 7014. Then, a light-emitting element 7020 having a structure in which the layer 7016 is sandwiched between the first electrode layer 7012 and the second electrode layer 7018 is obtained (see FIG. 10C). The layer 7016 includes a layer containing a light-emitting material that can obtain at least a desired light emission wavelength (hereinafter also referred to as a light-emitting layer). Specifically, the layer 7016 is formed of an organic compound, an inorganic compound, or a layer containing both.

  Through the above steps, a display device including the light-emitting element 7020 can be obtained.

  By applying the present invention, an opening can be formed in a desired region without using a lithography process using a photoresist. Therefore, the lithography process can be reduced and simplified, loss of materials such as a resist material and a developer can be prevented, and the number of necessary photomasks can be reduced. In addition, by irradiating two types of laser beams that are absorbed in different layers so as to overlap, damage to other layers can be reduced and openings can be easily formed. Therefore, in the manufacturing process of the display device, manufacturing cost can be reduced and throughput can be improved. In addition, a highly reliable semiconductor device can be manufactured.

  This embodiment mode can be freely combined with Embodiment Modes 1 to 3.

(Embodiment 5)
In this embodiment mode, a structure of a display panel according to the present invention will be described.

  FIG. 15A is a top view illustrating a structure of a display panel according to the present invention. A pixel portion 2701 in which pixels 2702 are arranged in a matrix over a substrate 2700 having an insulating surface, a scanning line side input terminal 2703, a signal A line side input terminal 2704 is formed. The number of pixels may be provided in accordance with various standards. For full color display using XGA and RGB, 1024 × 768 × 3 (RGB), and for full color display using UXGA and RGB, 1600 × 1200. If it corresponds to x3 (RGB) and full spec high vision and is full color display using RGB, it may be 1920 x 1080 x 3 (RGB).

  The pixels 2702 are arranged in a matrix by a scan line extending from the scan line side input terminal 2703 and a signal line extending from the signal line side input terminal 2704 intersecting. Each of the pixels 2702 includes a switching element and a pixel electrode connected to the switching element. A typical example of a switching element is a transistor, and the gate electrode side of the transistor is connected to a scanning line, and the source electrode or drain electrode side is connected to a signal line, so that each pixel is controlled independently by a signal input from the outside. It is possible.

  FIG. 15A illustrates a structure of a display device in which signals input to the scan lines and the signal lines are controlled by an external driver circuit. As illustrated in FIG. 16A, COG (Chip on The driver IC 2751 may be mounted on the substrate 2700 by a glass method. As another mounting mode, a TAB (Tape Automated Bonding) method as shown in FIG. 16B may be used. The driver IC may be formed on a single crystal semiconductor substrate or may be a circuit in which a transistor is formed on a glass substrate. In FIG. 16, the driver IC 2751 is connected to the FPC 2750.

  In the case where the transistor provided in the pixel is formed using a polycrystalline (microcrystalline) semiconductor with high crystallinity, the scan line driver circuit 3702 may be formed over the substrate 3700 as illustrated in FIG. it can. In FIG. 15B, reference numeral 3701 denotes a pixel portion, and the signal line side driver circuit is controlled by an external driver circuit as in FIG. In the case where the transistor provided in the pixel is formed using a polycrystalline (microcrystalline) semiconductor, a single crystal semiconductor, or the like with high mobility, as illustrated in FIG. 15C, a pixel portion 4701, a scan line driver circuit 4702, and a signal The line driver circuit 4704 can be formed over the substrate 4700 integrally.

  In this embodiment mode, an opening for forming a wiring (conductive layer) for connecting the switching element and the pixel electrode, an opening for forming a wiring (conductive layer) for connecting the gate electrode of the transistor to the scanning line, a source electrode or a drain electrode The present invention using laser ablation as shown in Embodiment Modes 1 to 4 can be applied to an opening or the like for forming a wiring (conductive layer) for connecting the signal line to the signal line.

  By applying the present invention, the lithography process using a photoresist can be reduced and simplified. In the present invention, an opening is formed by utilizing laser ablation that occurs when two types of laser beams absorbed in different layers are irradiated so as to overlap each other. By doing so, it becomes possible to easily ablate while preventing damage to other layers and the substrate. Therefore, manufacturing cost for manufacturing a display panel can be reduced and throughput can be improved.

  This embodiment mode can be freely combined with any of Embodiment Modes 1 to 4 as appropriate.

(Embodiment 6)
In this embodiment, an example of a display device according to the present invention will be described with reference to FIG.

  FIG. 27A is a schematic view of the top surface of the display device described in this embodiment. FIG. 27B is a cross-sectional view taken along the line QR in FIG.

  A display device 900 illustrated in FIG. 27 includes a pixel portion 902 and a driver circuit portion 904 over a substrate 901. A sealing substrate 908 is provided above the substrate 901 with a sealant 910 interposed therebetween. Further, a terminal portion 906 is provided on the substrate 901. A signal for controlling operations of a plurality of elements included in the pixel portion 902 and a power supply potential are input from the outside through the terminal portion 906.

  In the pixel portion 902, a light-emitting element 930, a driving transistor 924, a switching transistor 922, and a capacitor 920 are provided. In the light-emitting element 930, a layer including at least a light-emitting layer is sandwiched between a pair of electrode layers. The light-emitting element 930 is electrically connected to the driving transistor 924.

  An end portion of an electrode layer (an electrode layer electrically connected to the driving transistor 924) below the light-emitting element 930 is covered with a partition wall layer 918. The partition layer 918 is formed using an inorganic insulating material such as silicon oxide or silicon nitride, an organic insulating material such as acrylic, polyimide, or resist, or a siloxane material. A partition layer 918 can be separated from another light-emitting element provided adjacent to the partition layer 918. Note that, as in this embodiment, the partition wall layer 918 having a rounded end portion whose curvature radius continuously changes so that the coverage of the layer formed by stacking upward is provided. Is preferable.

  The driver circuit portion 904 is provided with a plurality of transistors 926 and forms a driver circuit that controls the operation of the pixel portion 902. The drive circuit portion 904 is provided with, for example, a shift register, a decoder, a buffer, a sampling circuit, a latch, and the like.

  The substrate 901 and the sealing substrate 908 are attached to each other with a sealant 910 so that the pixel portion 902 and the driver circuit portion 904 are sealed. The sealing substrate 908 is provided with a color filter 942 and a light shielding layer 944. Note that the present invention is not particularly limited, and the color filter 942 and the light-blocking layer 944 are not necessarily provided.

  This embodiment is different from Embodiment 4 in that the gate electrode layer of the transistor is below or above the semiconductor layer. Other configurations are the same as those in the fourth embodiment.

  Next, a specific example of a manufacturing method will be described.

  Silicon nitride oxide is used as a base insulating layer over the substrate 901 by a sputtering method, a PVD method (Physical Vapor Deposition), a low pressure CVD method (LPCVD method), a CVD method such as a plasma CVD method (Chemical Vapor Deposition), or the like. The base insulating layer 903a is formed with a thickness of 10 nm to 200 nm (preferably 50 nm to 150 nm), and the base insulating layer 903b is stacked with a thickness of 50 nm to 200 nm (preferably 100 nm to 150 nm) using silicon oxynitride. Alternatively, heat-resistant polymers such as acrylic acid, methacrylic acid and derivatives thereof, polyimide, aromatic polyamide, polybenzimidazole, or siloxane resin may be used. Moreover, resin materials such as vinyl resins such as polyvinyl alcohol and polyvinyl butyral, epoxy resins, phenol resins, novolac resins, acrylic resins, melamine resins, and urethane resins may be used. Alternatively, an organic material such as benzocyclobutene, parylene, fluorinated arylene ether, or polyimide, a composition material containing a water-soluble homopolymer and a water-soluble copolymer, or the like may be used. Moreover, an oxazole resin can also be used, for example, photocurable polybenzoxazole or the like can be used.

  Further, a droplet discharge method, a printing method (a method for forming a pattern such as screen printing or offset printing), a coating method such as a spin coating method, a dipping method, a dispenser method, or the like can also be used. In this embodiment, the base insulating layer 903a and the base insulating layer 903b are formed by a plasma CVD method. As the substrate 901, a glass substrate, a quartz substrate, a silicon substrate, a metal substrate, or a stainless substrate on which an insulating layer is formed may be used. Further, a plastic substrate having heat resistance that can withstand the processing temperature of this embodiment may be used, or a flexible substrate such as a film may be used. As the plastic substrate, a substrate made of PET (polyethylene terephthalate), PEN (polyethylene naphthalate), or PES (polyethersulfone) can be used, and as the flexible substrate, a synthetic resin such as acrylic can be used.

  As the base insulating layer, silicon oxide, silicon nitride, silicon oxynitride, silicon nitride oxide, or the like can be used. The base insulating layer may have a single layer structure or a stacked structure of two layers or three layers.

  Next, a semiconductor layer is formed over the base insulating layer. The semiconductor layer may be formed by various means (a sputtering method, an LPCVD method, a plasma CVD method, or the like) with a thickness of 25 nm to 200 nm (preferably 30 nm to 150 nm). In this embodiment mode, it is preferable to use a crystalline semiconductor layer obtained by crystallizing an amorphous semiconductor layer by laser crystallization.

  In order to control the threshold voltage of the transistor, the semiconductor layer obtained in this manner may be doped with a trace amount of an impurity element (boron or phosphorus). This doping of the impurity element may be performed on the amorphous semiconductor layer before the step of crystallizing the semiconductor layer. When the impurity element is doped in the state of the amorphous semiconductor layer, the impurity can be simultaneously activated by heat treatment for subsequent crystallization. In addition, defects and the like generated during doping can be improved.

  The semiconductor layer may be selectively etched and processed into a desired shape. In addition, the semiconductor layer may be formed by various printing methods (screen (stencil) printing, offset (lithographic) printing, a method of forming a desired pattern such as relief printing or gravure printing (intaglio printing)), nanoimprinting method, droplet discharge method, dispenser. It may be formed using a method, a selective coating method, or the like.

  Note that the lower electrode layer constituting the capacitor is also formed in the same process as the semiconductor layer. The lower electrode layer is formed of the same layer as the semiconductor layer constituting the transistor.

  A gate insulating layer is formed to cover the semiconductor layer. The gate insulating layer is formed of an insulating layer containing silicon with a thickness of 10 nm to 150 nm by a plasma CVD method, a sputtering method, or the like. The gate insulating layer may be formed of an inorganic insulating material such as silicon nitride, silicon oxide, silicon oxynitride, or silicon nitride oxide, and may have a stacked structure or a single layer structure. The insulating layer may have a three-layer structure including a silicon nitride layer, a silicon oxide layer, and a silicon nitride layer, or a single layer or two layers of a silicon oxynitride layer.

  Next, a gate electrode layer is formed over the gate insulating layer. The gate electrode layer can be formed by forming a conductive layer by a technique such as sputtering, vapor deposition, or CVD, and selectively etching the conductive layer. The gate electrode layer is formed of a metal element such as tantalum (Ta), tungsten (W), titanium (Ti), molybdenum (Mo), aluminum (Al), copper (Cu), chromium (Cr), neodymium (Nd), or the like What is necessary is just to form with the alloy material or compound material which has a metal element as a main component. Alternatively, a semiconductor layer typified by polycrystalline silicon doped with an impurity element such as phosphorus, or an AgPdCu alloy may be used as the gate electrode layer. The gate electrode layer may have a single layer structure or a stacked structure. At this time, an upper electrode layer of a capacitor element to be completed later is also formed. The upper electrode layer is made of the same material as the gate electrode layer.

  In this embodiment, the side surface of the gate electrode layer is formed to have a tapered shape. The tapered shape of the gate electrode layer can be formed using a wet etching method in the etching process. Alternatively, after the dry etching method, the wet etching method can be performed. Note that a gate electrode layer having a vertical side surface may be formed. Alternatively, the gate electrode layer may have a two-layer structure, and each layer may have a different taper angle. By making the side surface of the gate electrode layer into a tapered shape, coverage with a layer stacked on the upper layer can be improved.

  In addition, the gate electrode layer may be formed by various printing methods (screen (stencil) printing, offset (lithographic) printing, a method of forming a desired pattern such as relief printing or gravure (intaglio printing)), nanoimprinting method, droplet discharge method, You may form using the dispenser method, the selective application method, etc.

  Note that the gate insulating layer may be slightly etched by the etching for forming the gate electrode layer, and the film thickness may be reduced (so-called film reduction).

  An impurity element is added to the semiconductor layer to form a pair of impurity regions. The impurity region formed in the semiconductor layer functions as a source region or a drain region. As the impurity element to be added, an impurity element imparting n-type conductivity or an impurity element imparting p-type conductivity may be appropriately selected and added. As the impurity element imparting n-type conductivity, phosphorus (P), arsenic (As), or the like can be used. As the impurity element imparting p-type conductivity, boron (B), aluminum (Al), gallium (Ga), or the like can be used. At this time, a channel formation region is formed between the pair of impurity regions.

  Note that in the semiconductor layer, an impurity region called an LDD (Light Doped Drain) region may be formed between an impurity region functioning as a source region or a drain region and a channel formation region. The LDD region is an impurity region having a lower concentration than the source region or the drain region. Further, the LDD region may have a structure overlapping with the gate electrode layer or a structure not overlapping.

  In order to activate the impurity element, heat treatment, intense light irradiation, or laser beam irradiation may be performed. Simultaneously with activation, plasma damage to the gate insulating layer and plasma damage to the interface between the gate insulating layer and the semiconductor layer can be recovered.

  Next, a first interlayer insulating layer is formed to cover the gate electrode layer and the gate insulating layer. In this embodiment, a stacked structure of the insulating layer 913 and the insulating layer 914 is employed. As the insulating layer 913 and the insulating layer 914, a silicon nitride layer, a silicon nitride oxide layer, a silicon oxynitride layer, a silicon oxide layer, or the like using a sputtering method or plasma CVD can be used, and other insulating layers containing silicon can be used. A single layer structure or a stacked structure of three or more layers may be used.

  Further, heat treatment is performed at 300 ° C. to 550 ° C. for 1 hour to 12 hours in a nitrogen atmosphere to perform a step of hydrogenating the semiconductor layer. Preferably, it is performed at 400 ° C. to 500 ° C. This step is a step of terminating dangling bonds in the semiconductor layer with hydrogen contained in the insulating layer 913 which is an interlayer insulating layer. In this embodiment, heat treatment is performed at 410 ° C.

  As the insulating layer 913 and the insulating layer 914, aluminum nitride, aluminum oxynitride, aluminum nitride oxide or aluminum oxide whose nitrogen content is higher than oxygen content, diamond-like carbon (DLC), nitrogen-containing carbon, polysilazane, etc. It can be formed of a material selected from substances including inorganic insulating materials. Further, a material containing siloxane may be used. An organic insulating material may be used, and polyimide, acrylic, polyamide, polyimide amide, resist, or benzocyclobutene can be used. Moreover, an oxazole resin can also be used, for example, photocurable polybenzoxazole or the like can be used.

  Next, an opening reaching the source or drain region formed in the semiconductor layer is formed in the insulating layer 913, the insulating layer 914, and the gate insulating layer.

  The opening can be formed using ablation by laser beam irradiation as described in the first to fourth embodiments. Specifically, two types of laser beams that are absorbed by different layers (the layer to be ablated and the layer stacked on top of it) are irradiated so as to overlap, and a part or all of the overlapping irradiated region is ablated. Form an opening. In this embodiment mode, the first laser beam having a wavelength absorbed by the semiconductor layer and the second laser beam having a wavelength absorbed by the gate insulating layer, the insulating layer 913, and the insulating layer 914 are superimposed. The gate insulating layer, the insulating layer 913, and the insulating layer 914 are removed by ablating the overlapping irradiated region, and an opening reaching the semiconductor layer is formed. Note that the first laser beam has energy that can be ablated in a region irradiated with the second laser beam in an overlapping manner. The second laser beam has an energy that does not cause an irreversible change in the irradiated region.

  The opening reaching the source region or the drain region of the semiconductor layer may be formed by forming a mask layer using a photoresist and performing etching using the mask layer.

  A source electrode layer or a drain electrode layer is formed in an opening reaching the source region or the drain region of the semiconductor layer. Through the above steps, the source region or the drain region of the semiconductor layer and the source electrode layer or the drain electrode layer are electrically connected.

  The source electrode layer or the drain electrode layer can be formed by forming a conductive layer by a PVD method, a CVD method, an evaporation method, or the like, and selectively etching the conductive layer. The material of the source electrode layer or the drain electrode layer is Ag, Au, Cu, Ni, Pt, Pd, Ir, Rh, W, Al, Ta, Mo, Cd, Zn, Fe, Ti, Si, Ge, Zr, Ba Or an alloy material containing the element as a main component or a metal nitride containing the element as a main component. The source electrode layer or the drain electrode layer may have a single-layer structure or a stacked structure.

  In addition, the source electrode layer or the drain electrode layer may be formed by various printing methods (a method of forming a desired pattern such as screen (stencil printing), offset (lithographic printing), relief printing or gravure printing (intaglio printing)), nanoimprinting method, liquid A droplet discharge method, a dispenser method, a selective coating method, or the like may be used. Furthermore, a reflow method or a damascene method may be used. When such a method is used, a conductive layer can be selectively formed at a desired place. Note that the terminal electrode layer 950 of the terminal portion 906 is also formed when the source electrode layer or the drain electrode layer is formed.

  Through the above steps, an active matrix substrate including the transistor 922 and the transistor 924 in the pixel portion 902 and the plurality of transistors 926 in the driver circuit portion 904 can be manufactured.

  Note that the present invention is not particularly limited, and the transistor may have a single gate structure in which one channel formation region is formed, a double gate structure in which two channels are formed, or a triple gate structure in which three transistors are formed. .

  Next, an insulating layer 916 is formed as a second interlayer insulating layer. As the insulating layer 916, silicon oxide, silicon nitride, silicon oxynitride, silicon nitride oxide, aluminum nitride, aluminum oxide containing nitrogen (also referred to as aluminum oxynitride), aluminum nitride containing oxygen (also referred to as aluminum nitride oxide), aluminum oxide , Diamond-like carbon (DLC), nitrogen-containing carbon film, PSG (phosphorus glass), BPSG (phosphorus boron glass), alumina, and other materials selected from materials including inorganic insulating materials. A siloxane resin may also be used. An organic insulating material may be used. The organic material may be photosensitive or non-photosensitive, and may be polyimide, acrylic, polyamide, polyimide amide, resist or benzocyclobutene, polysilazane, low dielectric constant (Low-k). ) Materials can be used. Moreover, an oxazole resin can also be used, for example, photocurable polybenzoxazole or the like can be used. As an interlayer insulating layer provided for planarization, a layer having high heat resistance and high insulating property and a high planarization rate is required. Therefore, a method for forming the insulating layer 916 is represented by a spin coat method. It is preferable to use a coating method.

  The insulating layer 916 can employ other dipping methods, spray coating, doctor knife, roll coater, curtain coater, knife coater, CVD method, vapor deposition method, and the like. The insulating layer 916 may be formed by a droplet discharge method. When the droplet discharge method is used, the material liquid can be saved. Further, a method capable of transferring or drawing a pattern, such as a droplet discharge method, for example, a printing method (a method for forming a pattern such as screen printing or offset printing), a dispenser method, or the like can be used.

  An opening reaching the source or drain electrode layer of the transistor 924 is formed in the insulating layer 916 of the pixel portion 902. The opening may be formed in the same manner as the opening for electrically connecting the source or drain electrode layer and the source or drain region of the semiconductor layer described above.

  For example, as shown in the first to fourth embodiments, two types of laser beams that are absorbed in different layers (a layer to be ablated and a layer stacked thereon) are irradiated so as to be superimposed. An opening is formed by ablating part or all of the irradiated region. Specifically, the first laser beam having a wavelength absorbed by the source electrode layer or the drain electrode layer and the second laser beam having a wavelength absorbed by the insulating layer 916 are irradiated and superimposed. Then, the irradiated region can be ablated, and the insulating layer 916 can be removed to form an opening. At this time, the first laser beam has such energy that it can be ablated in the region irradiated with the second laser beam. The second laser beam has an energy that does not cause an irreversible change in the irradiated region. Note that in the case where the opening is formed using ablation by laser beam irradiation, it is preferable to use a low-melting point metal (chromium in this embodiment) that is relatively easily evaporated in the source electrode layer or the drain electrode layer. Of course, without using laser ablation, a mask layer may be formed using a photoresist, and an opening may be formed by etching using the mask layer.

  A light-emitting element 930 is formed over the insulating layer 916 in the pixel portion 902. The light-emitting element 930 is electrically connected to the transistor 924.

  First, the first electrode layer 932 is formed in the opening provided in the insulating layer 916 and exposing the source electrode layer or the drain electrode layer of the transistor 924.

  Next, a partition layer 918 is formed so as to cover an end portion of the first electrode layer 932 and to have an opening over the first electrode layer 932. As the partition layer 918, silicon oxide, silicon nitride, silicon oxynitride, silicon nitride oxide, or the like can be used, and a single-layer structure or a stacked structure including two layers and three layers may be used. As another material for the partition layer 918, aluminum nitride, aluminum oxynitride with an oxygen content higher than the nitrogen content, aluminum nitride oxide or aluminum oxide with a nitrogen content higher than the oxygen content, diamond like carbon (DLC) ), Nitrogen-containing carbon, and materials selected from substances including other inorganic insulating materials can be used. A material containing siloxane may be used. An organic insulating material may be used, and the organic material may be either photosensitive or non-photosensitive, and polyimide, acrylic, polyamide, polyimide amide, resist, benzocyclobutene, or polysilazane can be used. Moreover, an oxazole resin can also be used, for example, photocurable polybenzoxazole or the like can be used.

  The partition layer 918 is formed by a droplet discharge method that can selectively form a pattern, a printing method that can transfer or draw a pattern (a method that forms a pattern such as screen printing or offset printing), a dispenser method, and other spin coating methods. It can be formed using a coating method, a dipping method, or the like. In addition, a partition layer can be formed on the entire surface using a photosensitive material, and the partition layer made of a photosensitive material can be exposed and developed to be processed into a desired shape. Further, a sputtering method, a PVD method (Physical Vapor Deposition), a low pressure CVD method (LPCVD method), a CVD method such as a plasma CVD method (Chemical Vapor Deposition), or the like is formed on the entire surface, and a resist or the like is used using a lithography technique These masks may be formed and etched into a desired shape.

As an etching process for processing into a desired shape, either a dry etching method or a wet etching method may be employed. Plasma etching (a kind of dry etching method) is suitable for processing a large area substrate. As an etching gas, a fluorine-based gas such as CF ₄ , CHF ₃ , or NF ₃ or a chlorine-based gas such as Cl ₂ or BCl ₃ may be used, and an inert gas such as He or Ar may be added as appropriate. Further, if an atmospheric pressure discharge etching process is applied, a local electric discharge process is possible, and it is not necessary to form a mask such as a resist on the entire surface of the substrate.

  The partition layer 918 preferably has a shape in which the radius of curvature continuously changes. By forming the partition layer in such a shape, the coverage of the layer formed on the upper side is improved.

  Next, a layer 934 and a second electrode layer 936 are stacked over the first electrode layer 932 and the partition wall layer 918. Then, a light-emitting element 930 having a structure in which the layer 934 is sandwiched between the first electrode layer 932 and the second electrode layer 936 is obtained. The layer 934 includes a layer containing a light emitting material that can obtain at least a desired light emission wavelength.

  One of the first electrode layer 932 and the second electrode layer 936 functions as an anode, and the other functions as a cathode. The first electrode layer 932 and the second electrode layer 936 include indium tin oxide (ITO), indium tin oxide containing silicon oxide, indium oxide containing 2 wt% to 20 wt% zinc oxide, and gold (Au ), Platinum (Pt), nickel (Ni), tungsten (W), chromium (Cr), molybdenum (Mo), iron (Fe), cobalt (Co), copper (Cu), palladium (Pd), etc. Can be formed. In addition to aluminum, an alloy of magnesium and silver, an alloy of aluminum and lithium, or the like can also be used.

  Note that in order to extract light emitted from the layer 934 to the outside, one or both of the first electrode layer 932 and the second electrode layer 936 uses indium tin oxide or the like, or silver, aluminum, or the like Is preferably formed to have a thickness of several nm to several tens of nm so that visible light can be transmitted.

  The first electrode layer 932 can be formed by selective etching after the above-described material is formed over the entire surface. In addition, the first electrode layer 932 can be formed by various printing methods (screen (stencil) printing, offset (lithographic printing) printing, a method of forming a desired pattern such as letterpress printing or gravure printing (intaglio printing)), nanoimprinting, and droplets. You may form using the discharge method, the dispenser method, the selective application method, etc. Furthermore, a reflow method or a damascene method may be used. When such a method is used, a conductive layer can be selectively formed at a desired place.

  Alternatively, the first electrode layer 932 may be wiped with a CMP method or a polyvinyl alcohol-based porous body and polished so that the surface thereof is planarized. Further, after polishing using the CMP method, the surface of the first electrode layer 932 may be subjected to ultraviolet irradiation, oxygen plasma treatment, or the like.

  Heat treatment may be performed after the first electrode layer 932 is formed. By this heat treatment, moisture contained in the first electrode layer 932 is released. Therefore, the first electrode layer 932 does not cause degassing. Therefore, even when a light-emitting material that easily deteriorates due to moisture is formed over the first electrode layer 932, the light-emitting material is not deteriorated and the display has high reliability. A device can be made.

  The second electrode layer 936 can be formed by an evaporation method, a sputtering method, or the like. Further, an insulating layer may be provided as a passivation layer (protective layer) over the second electrode layer 936. In this way, it is effective to provide a passivation layer so as to cover the second electrode layer 936. As the passivation layer, silicon nitride, silicon oxide, silicon oxynitride, silicon nitride oxide, aluminum nitride, aluminum oxynitride, aluminum nitride oxide or aluminum oxide whose nitrogen content is higher than oxygen content, diamond like carbon (DLC), The insulating layer includes a nitrogen-containing carbon film, and a single layer structure of the insulating layer or a laminated structure in combination can be used. Alternatively, a siloxane resin may be used.

At this time, it is preferable to use a film with good coverage as the passivation layer, and it is effective to use a carbon film, particularly a DLC film. Since the DLC film can be formed in a temperature range from room temperature to 100 ° C., even when the heat resistance of the layer 934 is low, the DLC film can be easily stacked. The DLC film is formed by a plasma CVD method (typically, an RF plasma CVD method, a microwave CVD method, an electron cyclotron resonance (ECR) CVD method, a hot filament CVD method, etc.), a combustion flame method, a sputtering method, or an ion beam evaporation method. It can be formed by laser vapor deposition. The reaction gas used for film formation was hydrogen gas and a hydrocarbon-based gas (for example, CH ₄ , C ₂ H ₂ , C ₆ H _6, etc.), ionized by glow discharge, and negative self-bias was applied. Films are formed by accelerated collision of ions with the cathode. The CN film may be formed using C ₂ H ₄ gas and N ₂ gas as reaction gases. The DLC film has a high blocking effect against oxygen and can suppress oxidation of the layer 934. Therefore, the problem that the layer 934 is oxidized during the subsequent sealing process can be prevented.

  The layer 934 formed over the first electrode layer 932 is a light-emitting layer containing at least a light-emitting material. The light-emitting layer is formed using an organic compound, an inorganic compound, or a layer containing an organic compound and an inorganic compound. A layer 934 is provided between the first electrode layer 932 and the second electrode layer 936, whereby the light-emitting element 930 can be obtained.

  The substrate 901 over which the light-emitting element 930 is formed in this manner and the sealing substrate 908 are fixed with a sealant 910, and the light-emitting element 930 is sealed. As the sealant 910, typically, a visible light curable resin, an ultraviolet curable resin, or a thermosetting resin is preferably used. For example, bisphenol A type liquid resin, bisphenol A type solid resin, bromine-containing epoxy resin, bisphenol F type resin, bisphenol AD type resin, phenol type resin, cresol type resin, novolac type resin, cyclic aliphatic epoxy resin, epibis type epoxy Epoxy resins such as resins, glycidyl ester resins, glycidylamine resins, heterocyclic epoxy resins, and modified epoxy resins can be used. Note that the region 948 surrounded by the sealant may be filled with a filler, or nitrogen or the like may be sealed by sealing in a nitrogen atmosphere. In the case of a structure in which light is extracted through the filler, the filler needs to have translucency. Typically, a visible light curable, ultraviolet curable, or thermosetting epoxy resin may be used. Through the above steps, a display device having a display function using a light-emitting element is completed. Further, the filler can be dropped in a liquid state and filled in the display device. When a hygroscopic substance such as a desiccant is used as the filler, a further water absorption effect can be obtained and deterioration of the light-emitting element 930 can be prevented.

  In order to prevent deterioration of the element due to moisture, a desiccant may be provided so as to surround the pixel portion 902. For example, a desiccant may be installed in the recess formed in the sealing substrate. With such a structure, it is possible to achieve a configuration that does not hinder thinning. Moreover, if a desiccant is formed also in the area | region corresponding to a gate wiring layer and a water absorption area is taken widely, the water absorption effect will be high. Further, when a desiccant is formed on the gate wiring layer that does not emit light directly, the light extraction efficiency is not lowered.

  Note that in this embodiment mode, a case where a light-emitting element is sealed with a glass substrate is shown; however, the sealing process is a process for protecting the light-emitting element from moisture and is mechanically sealed with a cover material. Either a method, a method of encapsulating with a thermosetting resin or an ultraviolet light curable resin, or a method of encapsulating with a thin film having a high barrier ability such as a metal oxide or a nitride is used. As the cover material, glass, ceramics, plastic, or metal can be used. However, when light is extracted to the cover material side, it must be translucent. In addition, the cover material and the substrate on which the light emitting element is formed are bonded together using a sealing material such as a thermosetting resin or an ultraviolet light curable resin, and the resin is cured by heat treatment or ultraviolet light irradiation treatment to form a sealed space. Form. It is also effective to provide a hygroscopic material typified by barium oxide in this sealed space. This hygroscopic material may be provided in contact with the sealing material, or may be provided on or around the partition layer so as not to block light from the light emitting element. Further, the space between the cover material and the substrate on which the light emitting element is formed can be filled with a thermosetting resin or an ultraviolet light curable resin. In this case, it is effective to add a moisture absorbing material typified by barium oxide in the thermosetting resin or the ultraviolet light curable resin.

  Alternatively, the source or drain electrode layer and the first electrode layer 932 may be in direct contact with each other and may not be electrically connected but may be connected through a wiring layer (conductive layer).

  In this embodiment mode, the terminal portion 906 has a structure in which the FPC 954 is connected to the terminal electrode layer 950 through the anisotropic conductive layer 952 and electrically connected to the outside.

  As shown in FIG. 27A, the display device manufactured in this embodiment includes a driver circuit portion 904 over the same substrate as the pixel portion 902. Note that the present invention is not particularly limited, and an IC chip may be mounted as a peripheral driver circuit by the above-described COG method or TAB method.

  In the display device of the present invention, the screen display driving method is not particularly limited. For example, a dot sequential driving method, a line sequential driving method, a surface sequential driving method, or the like may be used. Typically, a line sequential driving method is used, and a time-division gray scale driving method or an area gray scale driving method may be used as appropriate. The video signal input to the source line of the display device may be an analog signal or a digital signal, and a drive circuit or the like may be designed in accordance with the video signal as appropriate.

  By applying the present invention, an opening can be formed in a desired region without using a lithography process using a photoresist. Therefore, the lithography process can be reduced and simplified. Further, according to the present invention, two types of laser beams absorbed in different layers are irradiated so as to be superimposed, and laser ablation can be performed to form an opening. By doing so, it is possible to easily ablate and form an opening while preventing damage to other layers and the substrate. Therefore, in manufacturing a display device, manufacturing cost can be reduced and throughput can be improved.

  This embodiment mode can be freely combined with Embodiment Modes 1 to 5.

(Embodiment 7)
Various element structures can be applied to a light-emitting element having a display function of a display device. Generally, light-emitting elements are distinguished depending on whether the light-emitting material is an organic compound or an inorganic compound. The former is called an organic EL element, and the latter is called an inorganic EL element. Here, examples of light-emitting elements that can be applied to the present invention will be described with reference to FIGS.

  FIG. 12 shows an organic EL element. In the light-emitting element illustrated in FIG. 12, the layer 8260 is interposed between the first electrode layer 8270 and the second electrode layer 8250. One of the first electrode layer 8270 and the second electrode layer 8250 serves as an anode, and the other serves as a cathode. The anode refers to an electrode that injects holes into the light emitting layer, and the cathode refers to an electrode that injects electrons into the light emitting layer. In this embodiment mode, the first electrode layer 8270 is an anode and the second electrode layer 8250 is a cathode. The layer 8260 has a structure in which a hole injection layer 8262, a hole transport layer 8264, a light-emitting layer 8266, an electron transport layer 8268, and an electron injection layer 8269 are sequentially stacked.

  The first electrode layer 8270 and the second electrode layer 8250 include indium tin oxide (ITO), indium tin oxide containing silicon oxide, indium oxide containing 2 wt% to 20 wt% zinc oxide, and gold (Au ), Platinum (Pt), nickel (Ni), tungsten (W), chromium (Cr), molybdenum (Mo), iron (Fe), cobalt (Co), copper (Cu), palladium (Pd), etc. Can be formed. In addition to aluminum, an alloy of magnesium and silver, an alloy of aluminum and lithium, or the like can be used for forming the first electrode layer 8270. A method for forming the first electrode layer 8270 is the same as that of the first electrode layer 7012 in Embodiment 4 and the first electrode layer 932 in Embodiment 6. There is no particular limitation on the method for forming the second electrode layer 8250, and the second electrode layer 8250 can be formed by, for example, a sputtering method or an evaporation method.

  Note that in order to extract the emitted light to the outside, either one or both of the first electrode layer 8270 and the second electrode layer 8250 uses indium tin oxide or the like, or silver, aluminum, or the like is several nm. It is preferably formed so as to have a thickness of several to several tens of nm so that visible light can be transmitted.

The hole injection layer 8262 is a layer having a function of assisting injection of holes from the first electrode layer 8270 to the hole transport layer 8264. By providing the hole-injecting layer 8262, the difference in ionization potential between the first electrode layer 8270 and the hole-transporting layer 8264 is reduced, and holes are easily injected. The hole-injecting layer 8262 has a lower ionization potential than the substance forming the hole-transporting layer 8264 and has a higher ionization potential than the substance forming the first electrode layer 8270, or the hole-transporting layer It is preferable to use a substance whose energy band bends when it is provided as a thin film having a thickness of 1 nm to 2 nm between the 8264 and the first electrode layer 8270. Specific examples of a substance that can be used to form the hole-injecting layer 8262 include phthalocyanine-based compounds such as phthalocyanine (abbreviation: H ₂ Pc) and copper phthalocyanine (CuPC), or poly (ethylenedioxythiophene) / Examples thereof include a polymer such as a poly (styrenesulfonic acid) aqueous solution (PEDOT / PSS). In other words, the hole injection layer 8262 is formed by selecting a substance from which the ionization potential in the hole injection layer 8262 is relatively smaller than the ionization potential in the hole transport layer 8264 from among the hole transport materials. can do. In the case where the hole-injecting layer 8262 is provided, the first electrode layer 8270 is preferably formed using a substance having a high work function such as indium tin oxide. Note that the present invention is not particularly limited, and the hole-injection layer 8262 is not necessarily provided.

The hole-transport layer 8264 is a layer having a function of transporting holes injected from the first electrode layer 8270 side to the light-emitting layer 8266. In this manner, by providing the hole-transport layer 8264, the distance between the first electrode layer 8270 and the light-emitting layer 8266 can be increased, and as a result, the metal contained in the first electrode layer 8270 and the like can be reduced. This can prevent the emission of light from disappearing. The hole-transport layer 8264 is preferably formed using a hole-transport substance, and particularly preferably formed using a substance having a hole mobility of 1 × 10 ⁻⁶ cm ² / Vs or higher. Note that the hole-transporting substance has higher hole mobility than electrons, and the ratio of the hole mobility to the electron mobility (= hole mobility / electron mobility) is preferably 100. Larger than the substance. Specific examples of a substance that can be used for forming the hole-transport layer 8264 include 4,4′-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (abbreviation: NPB), 4, 4′-bis [N- (3-methylphenyl) -N-phenylamino] biphenyl (abbreviation: TPD), 4,4 ′, 4 ″ -tris (N, N-diphenylamino) triphenylamine (abbreviation: TDATA), 4,4 ′, 4 ″ -tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine (abbreviation: MTDATA), 4,4′-bis {N- [4- ( N, N-di-m-tolylamino) phenyl] -N-phenylamino} biphenyl (abbreviation: DNTPD), 1,3,5-tris [N, N-di (m-tolyl) amino] benzene (abbreviation: m -MTDAB), 4, 4 ', 4 " Tris (N- carbazolyl) triphenylamine (abbreviation: TCTA), phthalocyanine _{(abbreviation:} H 2 Pc), copper phthalocyanine (abbreviation: CuPc), or vanadyl phthalocyanine (abbreviation: VOPc), 4,4'-bis [N- ( 4-biphenylyl) -N-phenylamino] biphenyl (abbreviation: BBPB) and the like. Note that the hole-transport layer 8264 may have a single-layer structure or a stacked structure.

  The light-emitting layer 8266 is a layer having a light-emitting function and includes a light-emitting material formed using an organic compound. Moreover, the inorganic compound may be included. The organic compound contained in the light-emitting layer 8266 is not particularly limited as long as it is a light-emitting organic compound, and various low-molecular organic compounds and high-molecular organic compounds can be used. As the light-emitting organic compound, either a fluorescent light-emitting material or a phosphorescent light-emitting material can be used. The light-emitting layer 8266 may be a layer including only a light-emitting organic compound, or may have a structure in which a light-emitting organic compound is dispersed in a host material having an energy gap larger than that of the organic compound. Note that in the case where the light-emitting layer 8266 is a layer in which a plurality of compounds are mixed, such as a layer including a light-emitting material formed using an organic compound and a host material, the light-emitting layer 8266 can be formed by a co-evaporation method. Here, co-evaporation refers to a vapor deposition method in which raw materials are vaporized from a plurality of vapor deposition sources provided in one processing chamber, the vaporized raw materials are mixed in a gas phase state, and deposited on an object to be processed.

The electron-transport layer 8268 is a layer having a function of transporting electrons injected from the second electrode layer 8250 to the light-emitting layer 8266. In this manner, by providing the electron-transport layer 8268, the distance between the second electrode layer 8250 and the light-emitting layer 8266 can be increased, and as a result, the metal is contained in the second electrode layer 8250 and the like. Thus, it is possible to prevent the light emission from disappearing. The electron transporting layer 8268 is preferably formed using an electron transporting substance, and particularly preferably formed using a substance having an electron mobility of 1 × 10 ⁻⁶ cm ² / Vs or higher. Note that the electron transporting substance has higher electron mobility than holes, and the ratio of the electron mobility to the hole mobility (= electron mobility / hole mobility) is preferably from 100. Also refers to a large substance. Specific examples of a substance that can be used for forming the electron-transport layer 8268 include tris (8-quinolinolato) aluminum (abbreviation: Alq ₃ ), tris (4-methyl-8-quinolinolato) aluminum (abbreviation: Almq _3). ), Bis (10-hydroxybenzo [h] -quinolinato) beryllium (abbreviation: BeBq ₂ ), bis (2-methyl-8-quinolinolato) -4-phenylphenolato-aluminum (abbreviation: BAlq), bis [2- In addition to metal complexes such as (2-hydroxyphenyl) benzoxazolate] zinc (abbreviation: Zn (BOX) ₂ ), bis [2- (2-hydroxyphenyl) benzothiazolate] zinc (abbreviation: Zn (BTZ) ₂ ) 2- (4-biphenylyl) -5- (4-tert-butylphenyl) -1,3,4-oxadiazole ( Abbreviation: PBD), 1,3-bis [5- (p-tert-butylphenyl) -1,3,4-oxadiazol-2-yl] benzene (abbreviation: OXD-7), 3- (4- tert-butylphenyl) -4-phenyl-5- (4-biphenylyl) -1,2,4-triazole (abbreviation: TAZ), 3- (4-tert-butylphenyl) -4- (4-ethylphenyl) -5- (4-biphenylyl) -1,2,4-triazole (abbreviation: p-EtTAZ), bathophenanthroline (abbreviation: BPhen), bathocuproin (abbreviation: BCP), 4,4-bis (5-methylbenzoxa) And sol-2-yl) stilbene (abbreviation: BzOs). The electron transport layer 8268 may have a single-layer structure or a stacked structure.

The electron injection layer 8269 has a function of assisting injection of electrons from the second electrode layer 8250 to the electron transport layer 8268. The electron injection layer 8269 has an electron affinity higher than that of a material used for forming the electron transport layer 8268 from among materials which can be used to form the electron transport layer 8268 such as BPhen, BCP, p-EtTAZ, TAZ, and BzOs. It can be formed by selecting and using a substance having a relatively large value. By forming the electron injection layer 8269 in this manner, the difference in electron affinity between the second electrode layer 8250 and the electron transport layer 8268 is alleviated, and electrons are easily injected. The electron injection layer 8269 includes an alkali metal such as lithium (Li) or cesium (Cs), an oxide of alkali metal such as lithium oxide, potassium oxide, or sodium oxide, calcium oxide, or magnesium oxide. Alkali earth metal oxides, fluorides of alkali metals such as lithium fluoride and cesium fluoride, fluorides of alkaline earth metals such as calcium fluoride, or alkalis such as magnesium (Mg) and calcium (Ca) Inorganic materials such as earth metals may be included. Further, the electron injection layer 8269 may include an organic compound such as BPhen, BCP, p-EtTAZ, TAZ, or BzOs, an alkali metal fluoride such as LiF, or an alkaline earth metal such as CaF _2. It may be composed of an inorganic compound such as fluoride. As described above, the electron injection layer 8269 is provided as a 1 nm to 2 nm thin film using an inorganic compound such as an alkali metal fluoride such as LiF or an alkaline earth metal fluoride such as CaF _2. When the energy band is bent or a tunnel current flows through the electron injection layer 8269, electrons can be easily injected from the second electrode layer 8250 into the electron transport layer 8268.

  Note that a hole generation layer may be provided instead of the hole injection layer 8262, or an electron generation layer may be provided instead of the electron injection layer 8269.

  Here, the hole generation layer is a layer that generates holes. The hole generating layer can be formed by mixing at least one substance selected from the hole transporting substances and a substance that exhibits an electron accepting property with respect to the hole transporting substance. Here, as the hole-transporting substance, a substance similar to the substance that can be used for forming the hole-transport layer 8264 can be used. As the substance exhibiting electron accepting properties, it is preferable to use a metal oxide such as molybdenum oxide, vanadium oxide, ruthenium oxide, or rhenium oxide.

  The electron generating layer is a layer that generates electrons. The electron generating layer can be formed by mixing at least one substance selected from electron transporting substances and a substance exhibiting an electron donating property with respect to the electron transporting substance. Here, as the electron transporting substance, a substance similar to the substance that can be used for forming the electron transporting layer 8268 can be used. Moreover, as the substance exhibiting electron donating property, a substance selected from alkali metals and alkaline earth metals, specifically, lithium (Li), calcium (Ca), sodium (Na), potassium (K), Magnesium (Mg) or the like can be used.

  The hole-injection layer 8262, the hole-transport layer 8264, the light-emitting layer 8266, the electron-transport layer 8268, and the electron-injection layer 8269 may be formed using an evaporation method, a droplet discharge method, a coating method, or the like, respectively. The first electrode layer 8270 or the second electrode layer 8250 may be formed by a sputtering method, an evaporation method, or the like.

  In this embodiment mode, the layer 8260 only needs to include at least the light-emitting layer 8266 and have other functions (a hole injection layer 8262, a hole transport layer 8264, an electron transport layer 8268, an electron injection layer 8269, or the like). ) May be provided as appropriate.

  Alternatively, the first electrode layer 8270 may be a cathode and the second electrode layer 8250 may be an anode. In that case, the layer 8260 has a structure in which an electron injection layer, an electron transport layer, a light-emitting layer, a hole transport layer, and a hole injection layer are sequentially stacked from the first electrode layer 8270 side.

  Next, an inorganic EL element will be described with reference to FIGS. Inorganic EL elements are classified into a dispersion-type inorganic EL element and a thin-film inorganic EL element depending on the element structure. The former has a light-emitting layer in which particles of a light-emitting material are dispersed in a binder, and the latter has a light-emitting layer made of a thin film of the light-emitting material. It is common in the point that requires. Note that the obtained light emission mechanism includes donor-acceptor recombination light emission using a donor level and an acceptor level, and localized light emission using inner-shell electron transition of a metal ion. In general, the dispersion-type inorganic EL often has donor-acceptor recombination light emission, and the thin-film inorganic EL element often has localized light emission.

  A light-emitting material that can be used in the present invention includes a base material and an impurity element. The impurity element functions as a light emission center. By changing the impurity element to be contained, light emission of various colors can be obtained. As a method for manufacturing the light-emitting material, various methods such as a solid phase method and a liquid phase method (coprecipitation method) can be used. Also, spray pyrolysis method, metathesis method, precursor thermal decomposition method, reverse micelle method, method combining these methods with high temperature firing, liquid phase method such as freeze-drying method, etc. can be used.

  The solid phase method is a method in which a base material and an impurity element or a compound containing the impurity element are weighed, mixed in a mortar, heated and fired in an electric furnace, reacted, and the base material contains the impurity element. The firing temperature is preferably 700 ° C to 1500 ° C. This is because the solid phase reaction does not proceed when the temperature is too low, and the base material is decomposed when the temperature is too high. In addition, although baking may be performed in a powder state, it is preferable to perform baking in a pellet state. Although firing at a relatively high temperature is required, it is a simple method, so it has high productivity and is suitable for mass production.

  The liquid phase method (coprecipitation method) is a method in which a base material or a compound containing the base material and an impurity element or a compound containing the impurity element are reacted in a solution, dried, and then fired. The particles of the luminescent material are uniformly distributed, and the reaction can proceed even at a low firing temperature with a small particle size.

As a base material used for the light-emitting material, sulfide, oxide, or nitride can be used. Examples of sulfides that can be used include zinc sulfide, cadmium sulfide, calcium sulfide, yttrium sulfide, gallium sulfide, strontium sulfide, and barium sulfide. As the oxide, for example, zinc oxide, yttrium oxide, or the like can be used. As the nitride, for example, aluminum nitride, gallium nitride, indium nitride, or the like can be used. Furthermore, zinc selenide, zinc telluride, and the like can also be used, such as calcium sulfide-gallium sulfide (CaGa ₂ S ₄ ), strontium sulfide-gallium sulfide (SrGa ₂ S ₄ ), barium sulfide-gallium sulfide (BaGa ₂ S ₄ ), and the like. Or a ternary mixed crystal.

  As impurity elements for localized emission, manganese (Mn), copper (Cu), samarium (Sm), terbium (Tb), erbium (Er), thulium (Tm), europium (Eu), cerium (Ce), praseodymium (Pr) or the like can be used. Note that a halogen element such as fluorine (F) or chlorine (Cl) may be added. The halogen element can also function as charge compensation.

  On the other hand, a light-emitting material containing a first impurity element that forms a donor level and a second impurity element that forms an acceptor level can be used as the impurity element for donor-acceptor recombination light emission. As the first impurity element, for example, fluorine (F), chlorine (Cl), aluminum (Al), or the like can be used. For example, copper (Cu), silver (Ag), or the like can be used as the second impurity element.

  In the case where a light-emitting material for donor-acceptor recombination light emission is synthesized using a solid-phase method, a base material, a first impurity element or a compound containing the first impurity element, a second impurity element, or a second impurity element Each compound containing an impurity element is weighed and mixed in a mortar, and then heated and fired in an electric furnace. As the base material, the above-described base material can be used, and as the first impurity element or the compound containing the first impurity element, for example, fluorine (F), chlorine (Cl), aluminum sulfide, or the like is used. As the second impurity element or the compound containing the second impurity element, for example, copper (Cu), silver (Ag), copper sulfide, silver sulfide, or the like can be used. The firing temperature is preferably 700 to 1500 ° C. This is because the solid phase reaction does not proceed when the temperature is too low, and the base material is decomposed when the temperature is too high. In addition, although baking may be performed in a powder state, it is preferable to perform baking in a pellet state.

  In addition, as an impurity element in the case of using a solid phase reaction, a compound including a first impurity element and a second impurity element may be used in combination. In this case, since the impurity element is easily diffused and the solid-phase reaction easily proceeds, a uniform light emitting material can be obtained. Further, since no extra impurity element is contained, a light-emitting material with high purity can be obtained. As the compound constituted by the first impurity element and the second impurity element, for example, copper chloride, silver chloride, or the like can be used.

  Note that the concentration of these impurity elements may be in the range of 0.01 atom% to 10 atom% with respect to the base material, and is preferably in the range of 0.05 atom% to 5 atom%.

In the case of a thin film type inorganic EL element, the light emitting layer is a layer containing the above light emitting material, and a physical vapor deposition method such as a vacuum evaporation method such as a resistance heating vapor deposition method or an electron beam vapor deposition (EB vapor deposition) method, or a sputtering method ( PVD), metal organic chemical vapor deposition (CVD), chemical vapor deposition (CVD) such as hydride transport low pressure CVD, atomic layer epitaxy (ALE), or the like.

  FIGS. 13A to 13C illustrate an example of a thin-film inorganic EL element that can be used as a light-emitting element. 13A to 13C, the light-emitting element includes a first electrode layer 50, a layer 51, and a second electrode layer 53. The layer 51 includes at least the light emitting layer 52.

  In the light-emitting element illustrated in FIG. 13A, a layer 51 including only the light-emitting layer 52 is sandwiched between the first electrode layer 50 and the second electrode layer 53. 13B and 13C is the same as the light-emitting element in FIG. 13A between the first electrode layer 50 or the second electrode layer 53 and the light-emitting layer 52. In this structure, an insulating layer is provided. 13B includes an insulating layer 54 between the first electrode layer 50 and the light-emitting layer 52, and the light-emitting element illustrated in FIG. 13C includes the first electrode layer 50 and the light-emitting element. An insulating layer 54 a is provided between the light emitting layer 52 and an insulating layer 54 b is provided between the second electrode layer 53 and the light emitting layer 52. Thus, the insulating layer may be provided only between one of the pair of electrode layers sandwiching the light emitting layer, or may be provided between both. The insulating layer may have a single layer structure or a laminated structure.

  13B, the insulating layer 54 is provided so as to be in contact with the first electrode layer 50. However, the order of the insulating layer and the light emitting layer is reversed so as to be in contact with the second electrode layer 53. An insulating layer 54 may be provided.

  Next, a dispersion-type inorganic EL element will be described. In the case of a dispersion-type inorganic EL element, a particulate light emitting material is dispersed in a binder to form a film light emitting layer. When particles having a desired size cannot be obtained sufficiently by the method for manufacturing a light emitting material, the particles may be processed into particles by pulverization or the like in a mortar or the like. A binder is a substance for fixing a granular light emitting material in a dispersed state and maintaining the shape as a light emitting layer. The light emitting material is uniformly dispersed and fixed in the light emitting layer by the binder.

  In the case of a dispersion-type inorganic EL element, a light emitting layer can be formed by a droplet discharge method capable of selectively forming a light emitting layer, a printing method (screen printing, offset printing, etc.), a coating method such as a spin coating method, or a dipping method. A dispenser method or the like can also be used. The film thickness is not particularly limited, but is preferably in the range of 10 nm to 1000 nm. In the light-emitting layer including the light-emitting material and the binder, the ratio of the light-emitting material may be 50 wt% or more and 80 wt% or less.

  FIGS. 14A to 14C illustrate an example of a dispersion-type inorganic EL element that can be used as a light-emitting element. 14A to 14C, the light-emitting element includes a first electrode layer 60, a layer 65, and a second electrode layer 63. The layer 65 includes at least a light emitting layer.

  14A has a stacked structure of a first electrode layer 60, a light emitting layer 62, and a second electrode layer 63, and includes a light emitting material 61 held in the light emitting layer 62 by a binder.

  As a binder that can be used in this embodiment mode, an insulating material can be used. Specifically, an organic insulating material or an inorganic insulating material can be used, and a mixed material of an organic insulating material and an inorganic insulating material may be used. As the organic insulating material, a polymer having a relatively high dielectric constant such as a cyanoethyl cellulose resin, or a resin such as polyethylene, polypropylene, polystyrene resin, silicone resin, epoxy resin, or vinylidene fluoride can be used. Alternatively, a heat-resistant polymer such as aromatic polyamide, polybenzimidazole, or siloxane resin may be used. Note that a siloxane resin corresponds to a resin including a Si—O—Si bond. Siloxane has a skeleton structure formed of a bond of silicon (Si) and oxygen (O). As a substituent, an organic group containing at least hydrogen (for example, an alkyl group or an aromatic hydrocarbon) is used. A fluoro group may be used as a substituent. Alternatively, an organic group containing at least hydrogen and a fluoro group may be used as a substituent. Moreover, resin materials such as vinyl resins such as polyvinyl alcohol and polyvinyl butyral, phenol resins, novolac resins, acrylic resins, melamine resins, urethane resins, and oxazole resins (polybenzoxazole) may be used. The dielectric constant can be adjusted by appropriately mixing fine particles having a high dielectric constant such as barium titanate or strontium titanate with these resins.

Examples of the inorganic insulating material contained in the binder include silicon oxide (SiOx), silicon nitride (SiNx), silicon containing oxygen and nitrogen, aluminum nitride, aluminum or aluminum oxide containing oxygen and nitrogen, titanium oxide, BaTiO ₃ , SrTiO _3. , Lead titanate, potassium niobate, lead niobate, tantalum oxide, barium tantalate, lithium tantalate, yttrium oxide, zirconium oxide, and other inorganic insulating materials. By including an inorganic insulating material having a high dielectric constant in the organic insulating material (by addition or the like), the dielectric constant of the light emitting layer made of the light emitting material and the binder can be further controlled, and the dielectric constant can be further increased. it can. When a mixed layer of an inorganic insulating material and an organic insulating material is used for the binder and the dielectric constant is high, a larger charge can be induced in the light emitting material.

  In the manufacturing process, the light-emitting material is dispersed in a solution containing a binder. As a solvent for the solution containing a binder that can be used in this embodiment mode, a method for forming a light-emitting layer by dissolving the binder material (various methods) The wet process) and a solvent capable of producing a solution having a viscosity suitable for a desired film thickness may be selected as appropriate. For example, when a siloxane resin is used as the binder, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate (also referred to as PGMEA), 3-methoxy-3-methyl-1-butanol (also referred to as MMB) can be used. ) Etc. can be used.

  14B and 14C is the same as the light-emitting element in FIG. 14A between the first electrode layer 60 or the second electrode layer 63 and the light-emitting layer 62. In this structure, an insulating layer is provided. 14B includes an insulating layer 64 between the first electrode layer 60 and the light-emitting layer 62, and the light-emitting element illustrated in FIG. 14C includes the first electrode layer 60 and the light-emitting element. An insulating layer 64 a is provided between the light emitting layer 62 and an insulating layer 64 b is provided between the second electrode layer 63 and the light emitting layer 62. Thus, the insulating layer may be provided only between one of the pair of electrode layers sandwiching the light emitting layer, or may be provided between both. The insulating layer may have a single layer structure or a laminated structure.

  14B, the insulating layer 64 is provided so as to be in contact with the first electrode layer 60, but the order of the insulating layer and the light emitting layer is reversed so as to be in contact with the second electrode layer 63. An insulating layer 64 may be provided.

The insulating layers such as the insulating layer 54 in FIG. 13 and the insulating layer 64 in FIG. 14 are not particularly limited, but preferably have a high withstand voltage and a dense film quality. Furthermore, it is preferable that the dielectric constant is high. For example, silicon oxide (SiO _x ), yttrium oxide, titanium oxide, aluminum oxide, hafnium oxide, tantalum oxide, barium titanate, strontium titanate, lead titanate, silicon nitride, zirconium oxide, or a mixed layer or two of these The above lamination can be used. These insulating layers can be formed by a sputtering method, a vapor deposition method, a CVD method, or the like. The insulating layer may be formed by dispersing particles of these insulating materials in a binder. The binder material may be formed using the same material and method as the binder contained in the light emitting layer. The film thickness is not particularly limited, but is preferably in the range of 10 nm to 1000 nm.

  The inorganic EL elements shown in FIGS. 13 and 14 can emit light by applying a voltage between a pair of electrode layers sandwiching the light emitting layer, but can operate in either DC driving or AC driving.

  The light-emitting element described in this embodiment (FIGS. 12 to 14) can be provided as the display element of the display device described in the above embodiment.

  For example, when the organic EL element illustrated in FIG. 12 is applied to the display device illustrated in FIG. 10, the first electrode layer 7012 or the second electrode layer 7018 is the first electrode layer 8270 or the second electrode layer 8250. It corresponds to. The layer 7016 corresponds to the layer 8260. Similarly, in the display device illustrated in FIG. 27, the first electrode layer 932 or the second electrode layer 936 corresponds to the first electrode layer 8270 or the second electrode layer 8250. The layer 934 corresponds to the layer 8260.

  The same applies to the case where the inorganic EL element shown in FIGS. 13 and 14 is applied to the display device shown in FIG. The first electrode layer 7012 or the second electrode layer 7018 corresponds to the first electrode layer 50 or the second electrode layer 53, or the first electrode layer 60 or the second electrode layer 63. The layer 7016 corresponds to the layer 51 or the layer 65. Similarly, in the case of the display device illustrated in FIG. 27, the first electrode layer 932 or the second electrode layer 936 includes the first electrode layer 50 or the second electrode layer 53, or the first electrode layer 60 or This corresponds to the second electrode layer 63. The layer 934 corresponds to the layer 51 or the layer 65.

  The present invention can be applied to formation of an opening for connecting the light-emitting element, the transistor, and the like described in this embodiment mode. By applying the present invention, throughput is improved in the manufacturing process of a display device having a light-emitting element.

  This embodiment mode can be freely combined with Embodiment Modes 4 to 6.

(Embodiment 8)
In this embodiment, a liquid crystal display device is described.

  FIG. 29A is a top view of the liquid crystal display device, and FIG. 29B is a cross-sectional view taken along line GH in FIG.

  As shown in FIG. 29A, a pixel region 606, a driving circuit region 608a which is a scanning line driving circuit, and a driving circuit region 608b which is a scanning line driving region are separated from each other with a substrate 600 and a sealing substrate 695 by a sealant 692. A driving circuit region 607 which is a signal line driving circuit which is sealed between and formed on the substrate 600 by an IC driver is provided. A transistor 622 and a capacitor 623 are provided in the pixel region 606, and a driver circuit including a transistor 620 and a transistor 621 is provided in the driver circuit region 608b. As the substrate 600, a substrate similar to that in the above embodiment can be used. When a substrate made of a synthetic resin is used as the substrate 600, there is a concern that the heat-resistant temperature is lower than that of other substrates. However, the substrate 600 is adopted by transposition after a manufacturing process using a substrate with high heat resistance. It becomes possible.

  In the pixel region 606, a transistor 622 serving as a switching element is provided over the substrate 600 with the base insulating layer 604a and the base insulating layer 604b interposed therebetween. In this embodiment, a multi-gate thin film transistor is used as the transistor 622. The transistor 622 includes a semiconductor layer having impurity regions functioning as a source region and a drain region, a gate insulating layer, a gate electrode layer having a two-layer structure, a source electrode layer, and a drain electrode layer. The source electrode layer or the drain electrode layer is electrically connected to the impurity region of the semiconductor layer. Further, the source electrode layer or the drain electrode layer is electrically connected to the pixel electrode layer 630.

  The source electrode layer or the drain electrode layer has a stacked structure. The source or drain electrode layer is an opening formed in the insulating layer 612, the insulating layer 611, and the gate insulating layer that covers the gate electrode layer, and is in contact with and electrically connected to the impurity region of the semiconductor layer.

  The opening reaching the impurity region of the semiconductor layer can be formed using ablation by laser beam irradiation as described in Embodiment Modes 1 to 4. Specifically, two types of laser beams that are absorbed by different layers (the layer to be ablated and the layer stacked on top of it) are irradiated so as to overlap, and a part or all of the overlapping irradiated region is ablated. Form an opening. In this embodiment mode, the first laser beam having a wavelength absorbed by the semiconductor layer and the second laser beam having a wavelength absorbed by the gate insulating layer, the insulating layer 611, and the insulating layer 612 are superimposed. The gate insulating layer, the insulating layer 611, and the insulating layer 612 are removed by ablating the overlapping irradiated region, and an opening reaching the semiconductor layer is formed. Note that the first laser beam has energy that can be ablated in a region irradiated with the second laser beam in an overlapping manner. The second laser beam has an energy that does not cause an irreversible change in the irradiated region.

  The opening reaching the impurity region of the semiconductor layer may be formed by forming a mask layer using a photoresist and performing etching using the mask layer.

  The source or drain electrode layers 644 a and 644 b are in contact with the pixel electrode layer 630 through openings formed in the insulating layer 615 and are electrically connected to each other. As shown in Embodiment Modes 1 to 4, the opening formed in the insulating layer 615 superimposes two types of laser beams that are absorbed in different layers (the layer to be ablated and the layer stacked thereon). In this way, an opening is formed by ablating a part or all of the region irradiated with overlapping. Specifically, the first laser beam having a wavelength that is absorbed by the source or drain electrode layer 644b and the second laser beam having a wavelength that is absorbed by the insulating layer 615 are irradiated so as to overlap, and superimposition is performed. Then, the irradiated region can be ablated, and the source or drain electrode layer 644b and the insulating layer 615 can be removed to form an opening. At this time, the first laser beam has such energy that it can be ablated in the region irradiated with the second laser beam. The second laser beam has an energy that does not cause an irreversible change in the irradiated region. In this embodiment, a low-melting point metal (chromium in this embodiment) that is relatively easily evaporated is used for the source electrode layer or the drain electrode layer 644b, and the source electrode layer or the drain electrode is used for the source electrode layer or the drain electrode layer 644a. A refractory metal (tungsten in this embodiment) that is harder to evaporate than the layer 644b is used. Note that the opening can be formed by removing only the insulating layer 615 by ablation by appropriately selecting the energy of the laser beam and the material of the source electrode layer or the drain electrode layer. Of course, without using laser ablation, a mask layer may be formed using a photoresist, and an opening may be formed by etching using the mask layer.

  A pixel electrode layer 630 is formed in the opening from which the source or drain electrode layers 644a and 644b are exposed, and the source or drain electrode layers 644a and 644b and the pixel electrode layer 630 are electrically connected.

  Thin film transistors (TFTs) can be manufactured by various methods. For example, a crystalline semiconductor layer is used as the semiconductor layer. A gate electrode layer is provided over the crystalline semiconductor layer with a gate insulating layer interposed therebetween. An impurity element can be added to the crystalline semiconductor layer by using the gate electrode layer. Thus, it is not necessary to form a mask layer for adding an impurity element by adding the impurity element using the gate electrode layer. The gate electrode layer can have a single-layer structure or a stacked structure. The impurity region can be a high concentration impurity region and a low concentration impurity region by controlling the concentration thereof. A thin film transistor having such a low concentration impurity region is referred to as an LDD (Lightly Doped Drain) structure. The low-concentration impurity region can be formed so as to overlap with the gate electrode. Such a thin film transistor is referred to as a GOLD (Gate Overlapped LDD) structure. The polarity of the thin film transistor is n-type by using phosphorus (P) or the like in the impurity region. When p-type is used, boron (B) or the like may be added. After that, an insulating layer 611 and an insulating layer 612 that cover the gate electrode layer and the like are formed. A dangling bond in the crystalline semiconductor layer can be terminated by hydrogen mixed in the insulating layer 611 (and the insulating layer 612).

  In order to further improve the flatness, an insulating layer 615 may be formed as an interlayer insulating layer. The insulating layer 615 can be formed with a single-layer structure or a stacked structure using an organic insulating material or an inorganic insulating material. For example, silicon oxide, silicon nitride, silicon oxynitride, silicon nitride oxide, aluminum nitride, aluminum oxynitride, aluminum nitride oxide or aluminum oxide whose nitrogen content is higher than oxygen content, diamond like carbon (DLC), polysilazane, nitrogen content It can be formed of a material selected from substances including carbon (CN), PSG (phosphorus glass), BPSG (phosphorus boron glass), alumina, and other inorganic insulating materials. An organic insulating material may be used, and the organic material may be either photosensitive or non-photosensitive, and polyimide, acrylic, polyamide, polyimide amide, resist, benzocyclobutene, siloxane resin, or the like can be used. Note that a siloxane resin corresponds to a resin including a Si—O—Si bond. Siloxane has a skeleton structure formed of a bond of silicon (Si) and oxygen (O). As a substituent, an organic group containing at least hydrogen (for example, an alkyl group or an aromatic hydrocarbon) is used. A fluoro group may be used as a substituent. Alternatively, an organic group containing at least hydrogen and a fluoro group may be used as a substituent.

  In addition, by using a crystalline semiconductor layer, the pixel region and the driver circuit region can be formed over the same substrate. In that case, the transistor in the pixel portion and the transistor in the driver circuit region 608b are formed at the same time. Transistors used for the driver circuit region 608b constitute a CMOS circuit. Although the thin film transistor included in the CMOS circuit has a GOLD structure, an LDD structure such as the transistor 622 can also be used.

  Without being limited to this embodiment mode, the thin film transistor in the pixel region 606 may have a single gate structure in which one channel formation region is formed, a double gate structure in which two channel formation regions are formed, or a triple gate structure in which three channel formation regions are formed. . The thin film transistor in the peripheral driver circuit region may have a single gate structure, a double gate structure, or a triple gate structure.

  Note that not only the method for manufacturing the thin film transistor described in this embodiment mode, but a top gate type (for example, a forward staggered type), a bottom gate type (for example, an inverted staggered type), or a gate insulating film above and below a channel region is used. The present invention can also be applied to a dual gate type or other structure having two gate electrode layers arranged.

  Next, an insulating layer 631 called an alignment film is formed by a printing method or a droplet discharge method so as to cover the pixel electrode layer 630. Note that the insulating layer 631 can be selectively formed by a screen printing method or an offset printing method. Thereafter, a rubbing process is performed. This rubbing process may not be performed in the liquid crystal mode, for example, the VA mode. The insulating layer 633 functioning as an alignment film is similar to the insulating layer 631. Subsequently, a sealant 692 is formed in a peripheral region where pixels are formed by a droplet discharge method.

  After that, a sealing substrate provided with an insulating layer 633 that functions as an alignment film, a conductive layer 634 that functions as a counter electrode, a colored layer 635 that functions as a color filter, a polarizer 641 (also referred to as a polarizing plate), and a polarizer 642. 695 and a substrate 600 which is a TFT substrate are attached to each other with a spacer 637, and a liquid crystal layer 632 is provided in the gap. Since the liquid crystal display device in this embodiment is a transmissive type, a polarizer (polarizing plate) 643 is provided on the side opposite to the surface of the substrate 600 having elements. The polarizer can be provided on the substrate by an adhesive layer. A filler may be mixed in the sealing material, and a sealing film (black matrix) or the like may be formed on the sealing substrate 695. Note that the color filter or the like may be formed from a material exhibiting red (R), green (G), and blue (B) when the liquid crystal display device is set to full color display. It may be formed of a material that eliminates or exhibits at least one color.

  When a continuous additive color mixing method (field sequential method) in which RGB light emitting diodes (LEDs) are arranged in the backlight and color display is performed in a time-sharing manner, a color filter may not be provided. The black matrix is preferably provided so as to overlap with the transistor or the CMOS circuit in order to reduce reflection of external light due to the wiring of the transistor or the CMOS circuit. Note that the black matrix may be formed so as to overlap with the capacitor. This is because reflection by the metal film constituting the capacitor element can be prevented.

  As a method for forming the liquid crystal layer, a dispenser method (dropping method) or an injection method in which liquid crystal is injected by using a capillary phenomenon after the substrate 600 having an element and the sealing substrate 695 are bonded to each other can be used. The dropping method is preferably applied when handling a large-area substrate to which it is difficult to apply the implantation method.

  The spacer may be provided by spraying particles of several μm, but in this embodiment, a method of forming a resin film on the entire surface of the substrate and then etching it is employed. After applying such a spacer material with a spinner, it is formed into a predetermined pattern by exposure and development processing. Further, it is cured by heating at 150 ° C. to 200 ° C. in a clean oven or the like. The spacers produced in this way can have different shapes depending on the conditions of exposure and development processing, but preferably, the spacers are columnar and the top is flat, so that the opposite substrate is When combined, the mechanical strength of the liquid crystal display device can be ensured. The shape can be a conical shape, a pyramid shape, or the like, and there is no particular limitation.

  Subsequently, an FPC 694 which is a wiring board for connection is provided on the terminal electrode layers 678a and 678b electrically connected to the pixel region with an anisotropic conductive layer 696 interposed therebetween. The FPC 694 plays a role of transmitting an external signal or potential. Through the above steps, a liquid crystal display device having a display function can be manufactured.

  Note that a wiring layer (conductive layer) included in the transistor, a gate electrode layer, a pixel electrode layer 630, and a conductive layer 634 which is a counter electrode layer are indium tin oxide (ITO), indium oxide mixed with zinc oxide (ZnO). Indium zinc oxide (IZO) formed by using, conductive material in which silicon oxide is mixed with indium oxide, organic indium, organic tin, indium oxide containing tungsten oxide, indium zinc oxide containing tungsten oxide, and titanium oxide Indium oxide, indium tin oxide including titanium oxide, tungsten (W), molybdenum (Mo), zirconium (Zr), hafnium (Hf), vanadium (V), niobium (Nb), tantalum (Ta), chromium ( Cr), cobalt (Co), nickel (Ni), h It can be selected from metal elements such as tan (Ti), platinum (Pt), aluminum (Al), copper (Cu), and silver (Ag), or alloy materials or metal nitrides containing such metal elements as main components.

  You may laminate | stack in the state which had the phase difference plate between the polarizing plate and the liquid-crystal layer.

  Note that although a TN liquid crystal panel is described in this embodiment mode, the above process can be similarly applied to other types of liquid crystal panels. For example, the present embodiment can be applied to a horizontal electric field type liquid crystal panel in which an electric field is applied in parallel with a glass substrate to align liquid crystals. Further, the present embodiment can be applied to a VA (Vertical Alignment) liquid crystal panel.

  17 and 18 show the pixel structure of the VA liquid crystal panel. FIG. 17 is a plan view, and FIG. 18 shows a cross-sectional structure corresponding to the line segment IJ shown in the figure. The following description will be given with reference to both the drawings.

  In this pixel structure, a single pixel has a plurality of pixel electrodes, and a TFT is connected to each pixel electrode. Each TFT is configured to be driven by a different gate signal. In other words, a multi-domain designed pixel has a configuration in which signals applied to individual pixel electrodes are controlled independently.

  The pixel electrode layer 1624 is connected to the TFT 1628 through a wiring layer 1618 through an opening 1623 (contact hole). The pixel electrode layer 1626 is connected to the TFT 1629 through the wiring layer 1619 through an opening 1627 (contact hole). The gate electrode layer 1602 of the TFT 1628 and the gate electrode layer 1603 of the TFT 1629 are separated so that different gate signals can be given. On the other hand, the wiring layer 1616 functioning as a data line is used in common by the TFT 1628 and the TFT 1629.

  The openings 1623 and 1627 can be formed by utilizing ablation by laser beam irradiation as described in Embodiment Modes 1 to 4. Specifically, two types of laser beams that are absorbed by different layers (the layer to be ablated and the layer stacked on top of it) are irradiated so as to overlap, and a part or all of the overlapping irradiated region is ablated. Form an opening. In this embodiment mode, the first laser beam having a wavelength absorbed by the wiring layers 1618 and 1619 and the second laser beam having a wavelength absorbed by the upper insulating layer 1620 and the insulating layer 1622 are superimposed. In this way, the regions irradiated with overlapping are ablated, and the insulating layers 1620 and 1622 are removed to form openings. The first laser beam has energy that can be ablated in the region irradiated with the second laser beam. The second laser beam has an energy that does not cause an irreversible change in the irradiated region. Note that although the openings are formed by removing the insulating layers 1620 and 1622, the wirings can be appropriately selected by appropriately selecting the energy of the first laser beam and the second laser beam, the material forming the wiring layers 1618 and 1619, and the like. The openings may be formed so that the upper layer portions of the layers 1618 and 1619 are removed and the lower layer portion remains or penetrates. Even in this case, the wiring layers 1618 and 1619 are exposed at the side surfaces (or the side surfaces and the bottom surface) of the opening, and thus can be electrically connected to the pixel electrode layers 1624 and 1626.

  The pixel electrode layer 1624 and the pixel electrode layer 1626 can be formed by being selectively etched after a conductive material is formed over the entire surface. The pixel electrode layer 1624 and the pixel electrode layer 1626 have different shapes and are separated by a slit 1625. A pixel electrode layer 1626 is formed so as to surround the outside of the V-shaped pixel electrode layer 1624. The timing of the voltage applied to the pixel electrode layer 1624 and the pixel electrode layer 1626 is varied depending on the TFT 1628 and the TFT 1629, thereby controlling the alignment of the liquid crystal. A counter substrate 1601 is provided with a light-blocking layer 1632, a coloring layer 1636, and a counter electrode layer 1640. In addition, a planarization layer 1637 is formed between the colored layer 1636 and the counter electrode layer 1640 to prevent alignment disorder of the liquid crystal. FIG. 19 shows a structure on the counter substrate side. The counter electrode layer 1640 is a common electrode between different pixels, but a slit 1641 is formed. By arranging the slits 1641 and the slits 1625 on the pixel electrode layer 1624 side and the pixel electrode layer 1626 side to alternately engage with each other, an oblique electric field can be effectively generated to control the alignment of the liquid crystal. Thereby, the direction in which the liquid crystal is aligned can be varied depending on the location, and the viewing angle is widened.

  By applying the present invention, an opening can be formed in a desired region without using a lithography process using a photoresist. Therefore, the lithography process can be reduced and simplified. Further, according to the present invention, two types of laser beams absorbed in different layers are irradiated so as to be superimposed, and laser ablation can be performed to form an opening. By doing so, it is possible to easily ablate and form an opening while preventing damage to other layers and the substrate. Therefore, in the manufacturing process of the display device, it is possible to reduce costs and improve throughput.

  This embodiment mode can be freely combined with any of Embodiment Modes 1 to 4.

(Embodiment 9)
In this embodiment, a liquid crystal display device using a liquid crystal display element as a display element will be described.

  The display device illustrated in FIG. 30 includes a transistor 420 which is an inverted staggered transistor, a pixel electrode layer 451, an insulating layer 452, an insulating layer 453, a liquid crystal layer 454, a spacer 481, an insulating layer 435, and a pixel region. Electrode layer 456, color filter 458, black matrix 457, counter substrate 410, polarizing plate (polarizer) 431, polarizing plate (polarizer) 433, sealing material 482 in the sealing region, terminal electrode layer 487, anisotropic conductive layer 488 and FPC 486 are provided.

  The gate electrode layer, the semiconductor layer, the source electrode layer, the drain electrode layer, and the pixel electrode layer 451 of the transistor 420 manufactured in this embodiment are formed using conductive materials or semiconductors as described in Embodiments 6 and 8 and the like. A material layer made of a material can be formed, and the material layer can be selectively etched as appropriate.

  In this embodiment mode, an amorphous semiconductor layer is used as a semiconductor layer for forming a channel. A semiconductor layer having one conductivity provided between the semiconductor layer forming the channel and the source or drain electrode layer may be formed as necessary. In this embodiment mode, an amorphous n-type semiconductor layer is stacked as a semiconductor layer and a semiconductor layer having one conductivity. In addition, an n-type semiconductor layer is formed as a semiconductor layer having one conductivity, an NMOS structure of an n-channel thin film transistor, a PMOS structure of a p-channel thin film transistor in which a p-type semiconductor layer is formed, an n-channel thin film transistor and a p-channel thin film transistor, The CMOS structure can be manufactured.

In order to impart conductivity, an element imparting conductivity is added by doping, and an impurity region is formed in the semiconductor layer, whereby an n-channel transistor or a P-channel transistor can be formed. Alternatively, conductivity may be imparted to the semiconductor layer by performing plasma treatment with a PH ₃ gas.

  In this embodiment, the transistor 420 is an n-channel inverted staggered thin film transistor. Alternatively, a channel-protective inverted staggered thin film transistor in which a protective layer is provided over the channel region of the semiconductor layer can be used.

  Next, the configuration of the backlight unit 352 will be described. The backlight unit 352 includes a cold cathode tube, a hot cathode tube, a light emitting diode, an inorganic EL, an organic EL, a lamp reflector 362 for efficiently guiding the fluorescence to the light guide plate 365 as a light source 361 that emits fluorescence, while the fluorescence is totally reflected. A light guide plate 365 for guiding light to the entire surface, a diffusion plate 366 for reducing unevenness in brightness, and a reflection plate 364 for reusing light leaked under the light guide plate 365 are provided.

  A control circuit for adjusting the luminance of the light source 361 is connected to the backlight unit 352. The luminance of the light source 361 can be controlled by supplying a signal from the control circuit.

  The source or drain electrode layer and the pixel electrode layer 451 of the transistor 420 are electrically connected to each other through an opening formed in the insulating layer 452. The opening can be formed using ablation by laser beam irradiation as described in Embodiments 1 to 4. Specifically, two types of laser beams that are absorbed by different layers (the layer to be ablated and the layer stacked on top of it) are irradiated so as to overlap, and a part or all of the overlapping irradiated region is ablated. Form an opening. In this embodiment mode, irradiation is performed so that the first laser beam having a wavelength absorbed by the source electrode layer or the drain electrode layer and the second laser beam having a wavelength absorbed by the insulating layer 452 are superimposed. Then, the overlapped and irradiated region is ablated, and the source or drain electrode layer and the insulating layer 452 are removed to form an opening. On the side and bottom surfaces of the opening, the source or drain electrode layer and the semiconductor layer having one conductivity are exposed. The first laser beam has energy that can be ablated in the region irradiated with the second laser beam. The second laser beam has an energy that does not cause an irreversible change in the irradiated region. In the case where the opening is formed by utilizing ablation by laser beam irradiation, it is preferable to use a low-melting point metal (chromium in this embodiment) that is relatively easily evaporated in the source electrode layer or the drain electrode layer. Note that although an example in which an opening is formed so as to penetrate the insulating layer 452 and the source or drain electrode layer is described in this embodiment, the energy of the first laser beam and the second laser beam, the source electrode, By appropriately selecting materials constituting the layer or drain electrode layer, the insulating layer, etc., so as to penetrate only the insulating layer 452, or the upper layer portion of the source electrode layer or drain electrode layer is removed and the lower layer portion remains. It is also possible to form openings in

  A pixel electrode layer 451 is formed in the opening formed in the insulating layer 452, and the pixel electrode layer 451 and the source or drain electrode layer are electrically connected.

  By applying the present invention, an opening can be formed in a desired region without using a lithography process using a photoresist. Therefore, the lithography process can be reduced or simplified. Further, according to the present invention, two types of laser beams absorbed in different layers are irradiated so as to be superimposed, and laser ablation can be performed to form an opening. By doing so, it is possible to easily ablate and form an opening while preventing damage to other layers and the substrate. Therefore, in the manufacturing process of the display device, it is possible to reduce costs and improve throughput.

  This embodiment mode can be freely combined with Embodiment Modes 1 to 4 and 8.

(Embodiment 10)
In this embodiment, an example of a display device which is different from the above embodiment will be described.

  FIG. 20 shows active matrix electronic paper to which the present invention is applied. Note that FIG. 20 illustrates active matrix electronic paper, but the present invention can also be applied to passive matrix electronic paper.

  A twist ball display system can be used as the electronic paper. In the twist ball display system, spherical particles that are separately painted in white and black are arranged between the first electrode layer and the second electrode layer, and a potential difference is generated between the first electrode layer and the second electrode layer. In this method, display is performed by controlling the orientation of the spherical particles.

  The transistor 5801 is an inverse coplanar thin film transistor and includes a gate electrode layer 5802, a gate insulating layer 5804, a wiring layer 5805a, a wiring layer 5805b, and a semiconductor layer 5806. The wiring layer 5805a and the wiring layer 5805b function as a source electrode layer or a drain electrode layer. The wiring layer 5805b is in contact with and electrically connected to the first electrode layer 5807 through an opening formed in the insulating layer 5908. Between the first electrode layer 5807 and the second electrode layer 5808, spherical particles 5809 including a cavity 5904 having a black region 5900a and a white region 5900b and being filled with a liquid are provided. The periphery of the spherical particle 5809 is filled with a filler 5905 such as a resin.

  In this embodiment, the gate electrode layer 5802, the semiconductor layer 5806, the wiring layers 5805a, 5805b, and the like included in the transistor 5801 form a material layer formed using a conductive material or a semiconductor material as described in the above embodiment mode. The material layer can be formed by being selectively etched as appropriate.

  The wiring layer 5805b is electrically connected to the first electrode layer 5807 through an opening formed in the insulating layer 5908. The opening can be formed using ablation by laser beam irradiation as described in Embodiments 1 to 4. Specifically, two types of laser beams that are absorbed by different layers (the layer to be ablated and the layer stacked on top of it) are irradiated so as to overlap, and a part or all of the overlapping irradiated region is ablated. Form an opening. In this embodiment mode, the first laser beam having a wavelength absorbed by the wiring layer 5805b and the second laser beam having a wavelength absorbed by the insulating layer 5908 are irradiated so as to overlap with each other. The irradiated region is ablated, and the insulating layer 5908 and the wiring layer 5805b are removed to form an opening. The first laser beam has energy that can be ablated in the region irradiated with the second laser beam. The second laser beam has an energy that does not cause an irreversible change in the irradiated region. In the case where an opening is formed using ablation by laser beam irradiation, it is preferable to use a low-melting-point metal (chromium in this embodiment mode) that is relatively easy to evaporate for the wiring layer 5805b. Note that although an example in which an opening is formed so as to penetrate the insulating layer 5908 and the wiring layer 5805b is described in this embodiment, the energy of the first laser beam and the second laser beam, the wiring layer, the insulating layer, and the like It is also possible to form the opening so as to penetrate only the insulating layer 5908 or to remove the upper layer portion of the wiring layer 5805b and leave the lower layer portion by appropriately selecting the material constituting the layer.

  A first electrode layer 5807 is formed in the opening formed in the insulating layer 5908, and the wiring layer 5805b and the first electrode layer 5807 are electrically connected.

  By utilizing laser ablation, an opening can be formed in the insulating layer without performing a complicated lithography process.

  Further, instead of the twisting ball, an electrophoretic element can be used. A microcapsule having a diameter of about 10 μm to 200 μm in which transparent liquid, positively charged white fine particles, and negatively charged black fine particles are enclosed is used. In the microcapsule provided between the first electrode layer and the second electrode layer, when an electric field is applied by the first electrode layer and the second electrode layer, the white particles and the black particles are in opposite directions. And can display white or black. A display element using this principle is an electrophoretic display element, and is generally called electronic paper. Since the electrophoretic display element has higher reflectance than the liquid crystal display element, an auxiliary light is unnecessary, power consumption is small, and the display portion can be recognized even in a dim place. In addition, even when power is not supplied to the display unit, it is possible to retain the image once displayed. Therefore, even when the display device with a display function is moved away from the radio wave source, it is displayed. The image can be stored.

  The transistor may have any structure as long as it can function as a switching element. As the semiconductor layer, various semiconductors such as an amorphous semiconductor, a crystalline semiconductor, a polycrystalline semiconductor, and a microcrystalline semiconductor can be used, and an organic transistor may be formed using an organic compound.

  In this embodiment mode, specifically, the case where the structure of the display device is an active matrix type is shown; however, the present invention can also be applied to a passive matrix type display device.

  By applying the present invention, an opening can be formed in a desired region without using a lithography process using a photoresist. Therefore, the lithography process can be reduced and simplified. Further, according to the present invention, two types of laser beams absorbed in different layers are irradiated so as to be superimposed, and laser ablation can be performed to form an opening. By doing so, it is possible to easily ablate and form an opening while preventing damage to other layers and the substrate. Therefore, the manufacturing cost of the display device can be reduced and the throughput can be improved.

  This embodiment mode can be freely combined with any of Embodiment Modes 1 to 4.

(Embodiment 11)
Next, a mode in which a driver circuit for driving is mounted on the display panel manufactured according to Embodiment Modes 4 to 10 will be described.

  First, a display device employing a COG method is described with reference to FIG. A pixel portion 2701 for displaying information such as characters and images is provided over the substrate 2700. A substrate provided with a plurality of drive circuits is divided into a rectangular shape, and a divided drive circuit (also referred to as a driver IC) 2751 is mounted on the substrate 2700. FIG. 16A illustrates a form in which an FPC 2750 is mounted on the tip of a plurality of driver ICs 2751 and driver ICs 2751. Alternatively, the size of the division may be substantially the same as the length of the side of the pixel portion on the signal line side, and a tape may be mounted on the tip of a single driver IC.

  Alternatively, a TAB method may be employed. In that case, a plurality of tapes may be attached and driver ICs may be mounted on the tapes as shown in FIG. As in the case of the COG method, a single driver IC may be mounted on a single tape. In this case, a metal piece or the like for fixing the driver IC may be attached together due to strength problems.

  A plurality of driver ICs mounted on these display panels may be formed on a rectangular substrate having a side of 300 mm to 1000 mm or more from the viewpoint of improving productivity.

  That is, a plurality of circuit patterns having a drive circuit portion and an input / output terminal as one unit may be formed on the substrate, and finally divided and taken out. The long side of the driver IC may be formed in a rectangular shape having a long side of 15 mm to 80 mm and a short side of 1 mm to 6 mm in consideration of the length of one side of the pixel portion and the pixel pitch. Or a length obtained by adding one side of the pixel portion and one side of each driver circuit.

  The advantage of the external dimensions of the driver IC over the IC chip is the length of the long side. When a driver IC having a long side of 15 mm to 80 mm is used, the number necessary for mounting corresponding to the pixel portion is obtained. This is less than when an IC chip is used, and the manufacturing yield can be improved. Further, when a driver IC is formed over a glass substrate, the shape of the substrate used as a base is not limited, and thus productivity is not impaired. This is a great advantage compared with the case where the IC chip is taken out from the circular silicon wafer.

  In the case where the scan line side driver circuit 3702 is formed over the substrate as shown in FIG. 15B, a driver IC in which a signal line side driver circuit is formed is mounted in a region outside the pixel portion 3701. Is done. These driver ICs are drive circuits on the signal line side. In order to form a pixel region corresponding to RGB full color, the number of signal lines in the XGA class is 3072 and the number in the UXGA class is 4800. The signal lines formed in such a number are divided into several blocks at the end of the pixel portion 3701 to form lead lines, and are collected according to the pitch of the output terminals of the driver IC.

  The driver IC is preferably formed using a crystalline semiconductor formed over a substrate, and the crystalline semiconductor is preferably formed by irradiation with a continuous wave laser beam. Therefore, it is preferable to use a continuous wave solid-state laser or a gas laser as an oscillator for generating the laser beam. When a continuous wave laser beam is used, a polycrystalline semiconductor layer having a large grain size with few crystal defects can be obtained. When a transistor is manufactured using such a semiconductor layer, high speed driving is possible because of good mobility and response speed, the operating frequency of the element can be improved as compared with the conventional technology, and there is little variation in characteristics. Reliability can be obtained. Note that for the purpose of further improving the operating frequency, the channel length direction of the transistor and the scanning direction of the laser beam are preferably matched. This is highest in a laser crystallization process using a continuous wave laser beam when the channel length direction of the transistor and the scanning direction of the laser beam with respect to the substrate are substantially parallel (preferably between −30 degrees and 30 degrees). This is because mobility can be obtained. Note that the channel length direction corresponds to the direction in which current flows in the channel formation region, in other words, the direction in which charges move. The transistor manufactured in this manner has a semiconductor layer composed of a polycrystalline semiconductor layer in which crystal grains extend in the channel direction, which means that the crystal grain boundaries are formed substantially along the channel direction. means.

  In order to perform laser crystallization, it is preferable to significantly narrow the laser beam, and the width of the laser beam shape (beam spot) should be about 1 mm to 3 mm, which is the same width as the short side of the driver IC. Is good. In order to ensure a sufficient and efficient energy density for the irradiated object, the laser beam irradiation region is preferably linear. However, the line shape here does not mean a line in a strict sense, but means a rectangle or an ellipse having a large aspect ratio. For example, the aspect ratio is 2 or more (preferably 10 or more and 10,000 or less). In this manner, a method for manufacturing a display device with improved productivity can be provided by setting the width of the shape of the laser beam (beam spot) to the same length as the short side of the driver IC.

  As shown in FIGS. 16A and 16B, driver ICs may be mounted as both the scanning line driver circuit and the signal line driver circuit. In that case, the specifications of the driver ICs used on the scanning line side and the signal line side may be different.

In the pixel region, signal lines and scanning lines intersect to form a matrix, and transistors are arranged corresponding to the respective intersections. This embodiment is characterized in that a TFT having an amorphous semiconductor or a semi-amorphous semiconductor as a channel portion is used as a transistor arranged in a pixel region. The amorphous semiconductor is formed by a method such as a plasma CVD method or a sputtering method. A semi-amorphous semiconductor can be formed at a temperature of 300 ° C. or less by a plasma CVD method. For example, even a non-alkali glass substrate having an outer dimension of 550 mm × 650 mm has a film thickness necessary for forming a transistor. Can be formed in a short time. Such a feature of the manufacturing technique is effective in manufacturing a large-screen display device. Further, a semi-amorphous TFT can obtain field effect mobility of ^{2cm 2} / V · sec to 10cm ² / V · sec by forming a channel formation region using a SAS. Thus, a display panel that realizes system-on-panel can be manufactured.

  By using a TFT in which the semiconductor layer is formed of SAS, the scanning line side driver circuit can also be integrally formed on the substrate. Note that in the case where a TFT in which a semiconductor layer is formed using SAS is used, driver ICs may be mounted on both the scanning line side driver circuit and the signal line side driver circuit.

  In that case, it is preferable that the specifications of the driver ICs used on the scanning line side and the signal line side are different. For example, although a transistor constituting the driver IC on the scanning line side is required to have a withstand voltage of about 30 V, the driving frequency is 100 kHz or less and a relatively high speed operation is not required. Therefore, it is preferable to set the channel length (L) of the transistors forming the driver on the scanning line side to be sufficiently large. On the other hand, it is sufficient for the transistor of the driver IC on the signal line side to have a withstand voltage of about 12V, but the drive frequency is about 65 MHz at 3V, and high speed operation is required. Therefore, it is preferable to set the channel length and the like of the transistors constituting the driver on the micron rule.

  The method for mounting the driver IC is not particularly limited, and a COG method, a wire bonding method, or a TAB method can be used.

  By setting the thickness of the driver IC to the same thickness as that of the counter substrate, the heights of the two are almost the same, which contributes to a reduction in thickness of the entire display device. In addition, since each substrate is made of the same material, thermal stress is not generated even when a temperature change occurs in the display device, and the characteristics of a circuit made of TFTs are not impaired. In addition, the number of driver ICs to be mounted in one pixel region can be reduced by mounting the drive circuit with a driver IC that is longer than the IC chip as shown in this embodiment.

  As described above, a driver circuit can be incorporated in the display panel.

(Embodiment 12)
Examples of display panels (EL display panels and liquid crystal display panels) manufactured according to Embodiment Modes 4 to 11 in which a semiconductor layer is formed using an amorphous semiconductor or SAS and a driver circuit on the scan line side is formed over a substrate. Indicates.

FIG. 22 is a block diagram of a scanning line side driver circuit including n-channel TFTs using SAS that can obtain a field effect mobility of 1 cm ² / V · sec to 15 cm ² / V · sec.

  In FIG. 22, a block denoted by reference numeral 8500 corresponds to a pulse output circuit that outputs a sampling pulse for one stage, and the shift register includes n pulse output circuits. Reference numeral 8501 denotes a buffer circuit to which a pixel 8502 is connected.

  FIG. 23 shows a specific structure of the pulse output circuit 8500. The n-channel TFT 8601, TFT 8602, TFT 8603, TFT 8604, TFT 8605, TFT 8606, TFT 8607, TFT 8608, TFT 8609, TFT 8610, TFT 8611, TFT 8612, and TFT 8613 are shown in FIG. A circuit is configured. At this time, the size of the TFT may be determined in consideration of the operating characteristics of the n-channel TFT using SAS. For example, when the channel length is 8 μm, the channel width can be set in the range of 10 μm to 80 μm.

  A specific structure of the buffer circuit 8501 is shown in FIG. Similarly, the buffer circuit includes n-channel TFTs 8620, TFT 8621, TFT 8622, TFT 8623, TFT 8624, TFT 8625, TFT 8626, TFT 8627, TFT 8628, TFT 8629, TFT 8630, TFT 8631, TFT 8632, TFT 8633, TFT 8634, and TFT 8635. At this time, the size of the TFT may be determined in consideration of the operating characteristics of the n-channel TFT using SAS. For example, if the channel length is 10 μm, the channel width is set in the range of 10 μm to 1800 μm.

  In order to realize such a circuit, it is necessary to connect the TFTs by wiring.

  As described above, a driver circuit can be incorporated in the display panel.

(Embodiment 13)
This embodiment will be described with reference to FIG. FIG. 28 shows an example in which an EL display module is formed using a TFT substrate 2800 manufactured by applying the present invention. In FIG. 28, a pixel portion including pixels is formed over the TFT substrate 2800.

  In FIG. 28, outside the pixel portion and between the driver circuit and the pixel, a TFT similar to that formed in the pixel or a gate electrode layer of the TFT and one of the source electrode layer or the drain electrode layer is provided. A protection circuit portion 2801 that is connected and operated in the same manner as a diode is provided. As the driver circuit 2809, a driver IC formed of a single crystal semiconductor, a stick driver IC formed of a polycrystalline semiconductor layer over a glass substrate, a driver circuit formed of SAS, or the like is applied.

  The TFT substrate 2800 is fixed to the sealing substrate 2820 through spacers 2806a and 2806b formed by a droplet discharge method. The spacer is preferably provided to keep the distance between the two substrates constant even when the substrate is thin and the area of the pixel portion is increased. Resin material having light-transmitting property at least in the visible region in the gap between the TFT substrate 2800 and the sealing substrate 2820 on the light-emitting element 2804 and the light-emitting element 2805 connected to the TFT 2802 and the TFT 2803, respectively. May be solidified by filling, or may be filled with anhydrous nitrogen or inert gas.

  FIG. 28 shows a case where the light-emitting element 2804 and the light-emitting element 2805 are configured as an upward emission type (top emission type), in which light is emitted in the direction of the arrow shown in the drawing. Each pixel can perform multicolor display by changing the emission color of the pixels to red, green, and blue. At this time, by forming the colored layer 2807a, the colored layer 2807b, and the colored layer 2807c corresponding to each color on the sealing substrate 2820 side, the color purity of the emitted light can be increased. Alternatively, the pixel may be combined with a colored layer 2807a, a colored layer 2807b, or a colored layer 2807c as a white light emitting element.

  A driver circuit 2809 which is an external circuit is connected to a scanning line or a signal line connection terminal provided at one end of the external circuit board 2811 through a wiring board 2810. Further, a heat pipe 2813 and a heat radiating plate 2812 which are pipe-like high-efficiency heat conduction devices used for transferring heat to the outside of the device in contact with or close to the TFT substrate 2800 are provided to enhance the heat radiation effect. It is good also as a structure.

  In FIG. 28, the top emission type EL display module is used. However, the configuration of the light emitting element and the arrangement of the external circuit board may be changed to have a bottom emission structure, and of course, a dual emission structure in which light is emitted from both the top and bottom surfaces. . In the case of a top emission type structure, an insulating layer serving as a partition wall may be colored and used as a black matrix. The partition walls can be formed by a droplet discharge method, and may be formed by mixing a resin material such as polyimide with a pigment-based black resin, carbon black, or the like, or may be a laminate thereof.

  In addition, the EL display module may block reflected light of light incident from the outside using a retardation plate or a polarizing plate. In the case of an upward emission display device, an insulating layer serving as a partition wall may be colored and used as a black matrix. This partition wall can also be formed by a droplet discharge method or the like. Carbon black or the like may be mixed with a pigment-based black resin or a resin material such as polyimide, or may be laminated. A different material may be discharged to the same region a plurality of times by a droplet discharge method to form a partition wall. As the retardation plate, a λ / 4 plate or a λ / 2 plate may be used and designed so that light can be controlled. The structure is a light emitting element, a sealing substrate (sealing material), a retardation plate (λ / 4 plate or λ / 2 plate), and a polarizing plate in order from the TFT element substrate side. The emitted light passes through these and is emitted to the outside from the polarizing plate side. The retardation plate and the polarizing plate may be installed on the side from which light is emitted, and may be installed on both in the case of a dual emission type display device that emits both. Further, an antireflection film may be provided outside the polarizing plate. Thereby, it is possible to display a higher-definition and precise image.

  In the TFT substrate 2800, a sealing structure may be formed by attaching a resin film to the side where the pixel portion is formed using a sealing material or an adhesive resin. Although glass sealing using a glass substrate is described in this embodiment mode, various sealing methods such as resin sealing using a resin, plastic sealing using a plastic, and film sealing using a film can be used. A gas barrier film for preventing the permeation of water vapor may be provided on the surface of the resin film. By adopting a film sealing structure, further reduction in thickness and weight can be achieved.

  In a display device including a TFT substrate or the like manufactured by applying the present invention, a part of the process is simplified, and the throughput is improved in manufacturing the display device. Therefore, a display module can be manufactured with high productivity.

  This embodiment mode can be freely combined with any of Embodiment Modes 1 to 7 and Embodiments 11 and 12.

(Embodiment 14)
This embodiment will be described with reference to FIGS. 31A and 31B. FIG. 31A and FIG. 31B illustrate an example in which a liquid crystal display module is formed using a TFT substrate 2600 manufactured by applying the present invention.

  FIG. 31A illustrates an example of a liquid crystal display module. A TFT substrate 2600 and a counter substrate 2601 are fixed to each other with a sealant 2602, and a pixel portion 2603 and a liquid crystal layer 2604 are provided therebetween to form a display region. The colored layer 2605 is necessary for color display. In the case of the RGB method, a colored layer corresponding to each color of red, green, and blue is provided corresponding to each pixel. A polarizing plate 2607 and a diffusion plate 2613 are disposed outside the TFT substrate 2600, and a polarizing plate 2606 is disposed outside the counter substrate 2601. The light source is composed of a cold cathode tube 2610 and a reflection plate 2611. The circuit board 2612 is connected to the TFT substrate 2600 by a flexible wiring board 2609, and an external circuit such as a control circuit or a power supply circuit is incorporated. Moreover, you may laminate | stack in the state which had the phase difference plate between the polarizing plate and the liquid-crystal layer.

  The liquid crystal display module includes a TN (Twisted Nematic) mode, an IPS (In-Plane-Switching) mode, an FFS (Fringe Field Switching) mode, an MVA (Multi-domain Vertical Alignment) mode, and a PVA (Pattern Vertical Alignment) mode. (Axial Symmetrical Aligned Micro-cell) mode, OCB (Optical Compensated Birefringence) mode, FLC (Ferroelectric Liquid Crystal) mode, AFLC (Anti-Ferroelectric Crystal) mode, etc. It is possible to have.

  FIG. 31B is an example in which the OCB mode is applied to the liquid crystal display module of FIG. 31A, and is an FS-LCD (Field sequential-LCD). The FS-LCD emits red light, green light, and blue light in one frame period, and can perform color display by combining images using time division. Further, since each light emission is performed by a light emitting diode or a cold cathode tube, a color filter is unnecessary. Therefore, it is not necessary to arrange the color filters of the three primary colors and limit the display area of each color, and it is possible to display all three colors in any area. On the other hand, since the three colors emit light in one frame period, a high-speed response of the liquid crystal is required. By applying the FLC mode using the FS method and the OCB mode to the display device of the present invention, a high-performance and high-quality display device and a liquid crystal television device can be completed.

  The liquid crystal layer in the OCB mode has a so-called π cell structure. The π cell structure is a structure in which the pretilt angles of liquid crystal molecules are aligned in a plane-symmetric relationship with respect to the center plane between the active matrix substrate and the counter substrate. The alignment state of the π cell structure is splay alignment when no voltage is applied between the substrates, and shifts to bend alignment when a voltage is applied. This bend orientation is white. When a voltage is further applied, the bend-aligned liquid crystal molecules are aligned perpendicularly to both substrates, and light is not transmitted. In the OCB mode, high-speed response that is about 10 times faster than the conventional TN mode can be realized.

  Further, as a mode corresponding to the FS method, HV (Half V) -FLC using a ferroelectric liquid crystal (FLC) capable of high-speed operation, SS (Surface Stabilized) -FLC, or the like can be used. . A nematic liquid crystal having a relatively low viscosity is used for the OCB mode, and a smectic liquid crystal having a ferroelectric phase can be used for HV-FLC and SS-FLC.

  In addition, the high-speed optical response speed of the liquid crystal display module is increased by narrowing the cell gap of the liquid crystal display module. The speed can also be increased by reducing the viscosity of the liquid crystal material. The increase in speed is more effective when the pixel pitch of the pixel region of the TN mode liquid crystal display module is 30 μm or less. Further, the speed can be further increased by the overdrive method in which the applied voltage is increased (or decreased) for a moment.

  The liquid crystal display module in FIG. 31B is a transmissive liquid crystal display module, and is provided with a red light source 2910a, a green light source 2910b, and a blue light source 2910c as light sources. The light source is provided with a controller 2912 for controlling on / off of the red light source 2910a, the green light source 2910b, and the blue light source 2910c. The light emission of each color is controlled by the control unit 2912, light enters the liquid crystal, an image is synthesized using time division, and color display is performed.

  The liquid crystal display module described above can apply the present invention to the manufacture of the TFT substrate 2600. In addition, by applying the present invention, an opening for connecting the TFT substrate 2600 to a pixel portion or the like can be formed. Accordingly, part of the steps can be simplified and the throughput can be improved, so that the liquid crystal display module can be manufactured with high productivity.

  This embodiment mode can be freely combined with Embodiment Modes 1 to 3 and Embodiment Modes 8, 9, 11, and 12 as appropriate.

(Embodiment 15)
With the display device formed according to the present invention, a television device (also simply referred to as a television or a television receiver) can be completed. FIG. 21 is a block diagram illustrating a main configuration of the television device.

  A display panel included in the television device according to this embodiment includes a pixel portion 9011, a signal line side driver circuit 9012, and a scan line side driver circuit 9013. In the display panel, the signal line side driver circuit 9012 and the scan line side driver circuit 9013 may be external driver circuits as shown in FIG. 15A or COG type as shown in FIG. May be separately mounted as a driver IC, or may be mounted as a driver IC by the TAB method as shown in FIG. Further, the scanning line side driver circuit may be formed of TFTs as shown in FIG. 15B and formed integrally with the pixel portion on the substrate, or the signal line side driver circuit as shown in FIG. 15C. Alternatively, the scanning line side driver circuit may be formed of TFTs and formed integrally with the pixel portion on the substrate. The detailed description of FIGS. 15 and 16 has been described in the above embodiment, and is omitted here.

  In FIG. 21, as the configuration of other external circuits, on the video signal input side, among the signals received by the tuner 9014, the video signal amplification circuit 9015 for amplifying the video signal and the signal output therefrom are red, green The video signal processing circuit 9016 converts the color signal into a color signal corresponding to each blue color, and the control circuit 9017 converts the video signal into the input specifications of the driver IC. The control circuit 9017 outputs a signal to each of the scanning line side and the signal line side. In the case of digital driving, a signal dividing circuit 9018 may be provided on the signal line side so that an input digital signal is divided into m pieces and supplied.

  Of the signals received by the tuner 9014, the audio signal is sent to the audio signal amplifier circuit 9019, and the output is supplied to the speaker 9113 through the audio signal processing circuit 9110. The control circuit 9111 receives control information on the receiving station (reception frequency) and volume from the input unit 9112, and sends a signal to the tuner 9014 and the audio signal processing circuit 9110.

  As shown in FIGS. 25A and 25B, these display modules can be incorporated into a housing to complete a television device. If a liquid crystal display module is used as the display module, a liquid crystal television device can be manufactured. If an EL display module is used, an EL television device, plasma television, electronic paper, or the like can be manufactured. In FIG. 25A, a main screen 2403 is formed by a display module, and a speaker portion 2409, operation switches, and the like are provided as accessory equipment. Thus, a television device can be completed according to the present invention.

  In FIG. 25A, a display panel 2402 is incorporated in a housing 2401, and by receiving a general television broadcast by a receiver 2405, it is connected to a wired or wireless communication network through a modem 2404. Information communication can be performed in the direction (from the sender to the receiver) or in both directions (between the sender and the receiver, or between the receivers). The television device can be operated by a switch incorporated in the housing 2401 or a separate remote control device 2406. The remote control device is also provided with a display portion 2407 for displaying information to be output. Also good.

  In addition, the television device may have a configuration in which a sub screen 2408 is formed using the second display panel in addition to the main screen 2403 to display a channel, a volume, and the like. In this structure, the main screen 2403 and the sub screen 2408 may be formed of the liquid crystal display panel or the EL display panel of the present invention, and the main screen 2403 is formed of an EL display panel having an excellent viewing angle. The screen may be formed of a liquid crystal display panel that can display with low power consumption. In order to prioritize low power consumption, the main screen 2403 may be formed of a liquid crystal display panel, the sub screen may be formed of an EL display panel, and the sub screen may be blinkable. When the present invention is used, a display device can be manufactured at a low manufacturing cost even when a large area substrate is used and a large number of TFTs and electronic components are used.

  FIG. 25B illustrates a television device having a large display portion of 20 inches to 80 inches, for example, which includes a housing 2410, a display portion 2411, a remote control device 2412 that is an operation portion, a speaker portion 2413, and the like. The present invention is applied to manufacturing the display portion 2411. The television device in FIG. 25B is a wall-hanging type and does not require a large installation space.

  Of course, the present invention is not limited to a television device, but can be applied to various uses such as a monitor for a personal computer, an information display board in a railway station or airport, an advertisement display board in a street, etc. can do.

  By applying the present invention, an opening or the like for connecting a TFT and a pixel of a display device can be formed. As a result, the process can be simplified, and the throughput can be improved in manufacturing the display device.

  This embodiment mode can be freely combined with any of Embodiment Modes 1 to 14 as appropriate.

(Embodiment 16)
As an electronic apparatus according to the present invention, a television device (also simply referred to as a television or a television receiver), a camera such as a digital camera or a digital video camera, a mobile phone device (also simply referred to as a mobile phone or a mobile phone), a PDA, or the like Portable information terminal devices, portable game machines, computer monitors, computers, sound reproduction apparatuses such as car audio, and image reproduction apparatuses equipped with recording media such as home game machines. A specific example will be described with reference to FIG.

  A portable information terminal device illustrated in FIG. 26A includes a main body 9201, a display portion 9202, and the like. The display device according to the present invention can be applied to the display portion 9202. As a result, the portable information terminal device can be manufactured with high productivity because it can be manufactured through a simplified process and throughput is improved.

  A digital video camera shown in FIG. 26B includes a main body 9700, a display portion 9701, and the like. The display device according to the present invention can be applied to the display portion 9701. As a result, the digital video camera can be manufactured with high productivity because it can be manufactured through a simplified process and throughput is improved.

  A cellular phone shown in FIG. 26C includes a main body 9101, a display portion 9102, and the like. The display device according to the present invention can be applied to the display portion 9102. As a result, the mobile phone can be manufactured with high productivity because it can be manufactured through a simplified process and throughput is improved.

  A portable television device illustrated in FIG. 26D includes a main body 9301, a display portion 9302, and the like. The display device according to the present invention can be applied to the display portion 9302. As a result, manufacturing can be performed with a simplified process and throughput is improved, so that a portable television device can be manufactured with high productivity. In addition, the present invention can be applied to a wide variety of television devices, from a small one mounted on a portable terminal such as a cellular phone to a medium-sized one that can be carried and a large one (for example, 40 inches or more). A display device according to the above can be applied.

  A portable computer shown in FIG. 26E includes a main body 9401, a display portion 9402, and the like. The display device according to the present invention can be applied to the display portion 9402. As a result, manufacturing can be performed with a simplified process and throughput is improved, so that a portable computer can be manufactured with high productivity.

  Thus, by applying the display device according to the present invention, an electronic device can be manufactured with high productivity.

  This embodiment mode can be freely combined with any of Embodiment Modes 1 to 15.

The conceptual diagram explaining this invention. The conceptual diagram explaining this invention. The conceptual diagram explaining this invention. 4A and 4B illustrate an example of a method for manufacturing a semiconductor device of the present invention. 4A and 4B illustrate an example of a method for manufacturing a semiconductor device of the present invention. 4A and 4B illustrate an example of a method for manufacturing a semiconductor device of the present invention. The conceptual diagram explaining this invention. The conceptual diagram explaining this invention. 4A and 4B illustrate an example of a method for manufacturing a semiconductor device of the present invention. 4A and 4B illustrate an example of a method for manufacturing a semiconductor device of the present invention. The figure explaining the laser processing apparatus which concerns on this invention. FIG. 6 illustrates a structure of a light-emitting element that can be applied to the present invention. FIG. 6 illustrates a structure of a light-emitting element that can be applied to the present invention. FIG. 6 illustrates a structure of a light-emitting element that can be applied to the present invention. The top view of the display apparatus of this invention. The top view of the display apparatus of this invention. FIG. 11 illustrates an example of a display device of the present invention. FIG. 11 illustrates an example of a display device of the present invention. FIG. 11 illustrates an example of a display device of the present invention. FIG. 11 illustrates an example of a display device of the present invention. 1 is a block diagram illustrating a main configuration of an electronic device to which the present invention is applied. FIG. 11 illustrates an example of a circuit configuration of a display device of the present invention. FIG. 11 illustrates an example of a circuit configuration of a display device of the present invention. FIG. 11 illustrates an example of a circuit configuration of a display device of the present invention. FIG. 11 illustrates an example of an electronic device to which the present invention is applied. FIG. 11 illustrates an example of an electronic device to which the present invention is applied. FIG. 11 illustrates an example of a display device of the present invention. The figure which shows the structural example of the display module of this invention. FIG. 11 illustrates an example of a display device of the present invention. FIG. 11 illustrates an example of a display device of the present invention. The figure which shows the structural example of the display module of this invention. The figure explaining the laser processing apparatus which concerns on this invention. The figure explaining the laser processing apparatus which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Substrate 12 Conductive layer 14 1st material layer 16 2nd material layer 18 1st laser beam 19 1st beam spot 20 2nd laser beam 21 2nd beam spot 22 Overlapping irradiation area | region 24 Opening 26 Conductive layer 30 1st Laser beam 31 First beam spot 32 Second laser beam 33 Second beam spot 34 Overlapping irradiation region

Claims (2)

Forming a first material layer on the first conductive layer with a material that absorbs the first laser beam;
Forming a second material layer on the first material layer with a material that transmits the first laser beam and absorbs the second laser beam;
By irradiating the first laser beam and the second laser beam from the second material layer side so that the first laser beam and the second laser beam partially overlap each other, A third step of removing the material layer and the second material layer to form an opening;
By forming the second conductive layer in the opening, have a, a fourth step of electrically connecting the first conductive layer and the second conductive layer,
A method for manufacturing a semiconductor device , wherein the wavelength of the first laser beam is longer than the wavelength of the second laser beam . A first step of forming a first material layer with a material that absorbs the first laser beam;
Forming a second material layer on the first material layer with a material that transmits the first laser beam and absorbs the second laser beam;
By irradiating the first laser beam and the second laser beam from the second material layer side so that the first laser beam and the second laser beam partially overlap each other, a third step of removing the material layer and the second material layer, was closed,
A method for manufacturing a semiconductor device , wherein the wavelength of the first laser beam is longer than the wavelength of the second laser beam .

Images