JP2006332314A - Semiconductor device, electro-optical device, electronic device, and manufacturing method of semiconductor device - Google Patents

Abstract

A semiconductor device in which a channel formation region of a semiconductor device is formed with high alignment accuracy in a substantially single crystal grain having a large grain size, an electro-optical device and an electronic device using the semiconductor device, and a method for manufacturing the semiconductor device are provided. With the goal.
A first alignment mark is formed on a substrate. The position of the grain filter 26 that is the starting point of crystal growth is determined with reference to the first alignment mark 21. A semiconductor film is formed on the grain filter 26, and then the semiconductor film is crystallized to form a substantially single crystal semiconductor film. When patterning a substantially single crystal semiconductor film, the position of the first alignment mark 21 is used as a reference.
[Selection] Figure 5

Description

  The present invention relates to a semiconductor device, an electro-optical device, an electronic device, and a method for manufacturing a semiconductor device.

  In an electro-optical device such as a liquid crystal display device or an organic EL (electroluminescence) display device, pixel switching is performed using a thin film circuit including a semiconductor device. In a conventional semiconductor device, an active region such as a channel formation region is formed using an amorphous silicon film. A semiconductor device in which an active region is formed using a polycrystalline silicon film has also been put into practical use. By using the polycrystalline silicon film, electric characteristics such as field effect mobility can be improved and the performance of the semiconductor device can be improved as compared with the case where an amorphous silicon film is used.

  In order to further improve the performance of a semiconductor device, a technique for forming a semiconductor film made of large crystal grains and forming a channel formation region of the semiconductor device with substantially single crystal grains has been studied. For example, a technique has been proposed in which a fine hole (concave portion) is formed on a substrate and a semiconductor film is crystallized using this hole as a starting point for crystal growth to form a substantially single crystal grain having a large grain size. . By forming a semiconductor device using a silicon film having a large crystal grain size formed by using this technique, a single semiconductor device formation region (particularly, a channel formation region) is configured with a single substantially single crystal grain. It becomes possible to do. This makes it possible to realize a semiconductor device having excellent electrical characteristics such as field effect mobility. (For example, see Non-Patent Document 1 or Non-Patent Document 2.)

  The fine holes on the substrate in Non-Patent Documents 1 and 2 are hereinafter referred to as “grain filters”. An example of a method for forming a grain filter is shown below. A silicon oxide film is formed on the substrate, and a photoresist film is applied thereon. The photoresist film is exposed and developed using a mask on which a grain filter pattern is arranged, and an opening for exposing the formation position of the grain filter is formed in the photoresist film. The silicon oxide film is etched using the photoresist film as an etching mask, and then the photoresist film is removed to form a grain filter. Here, the size of the grain filter is preferably about 100 nm in diameter. If it is difficult to form such fine holes by photolithography, after removing the photoresist film in the above step, a silicon oxide film is deposited by a method such as PECVD method or LPCVD method, -The hole diameter of the filter can be reduced.

  After forming the grain filter, a semiconductor film such as an amorphous silicon film or a polycrystalline silicon film is deposited. By irradiating the semiconductor film with laser light to crystallize the semiconductor film, large single crystal grains can be formed. Thereafter, the semiconductor film is processed into a desired pattern by photolithography. Then, a semiconductor device is completed by forming a gate insulating film, a gate electrode, an interlayer insulating film, a source / drain electrode, and the like.

“Single Crystal Thin Film Transistors” (IBM Technical DISCLOSURE BULLETIN Aug. 1993 pp 257-258) “Advanced Excimer-Laser Crystallization Techniques of Si Thin-Film For Location Control of Large Grain on Glass” (R. Ishihara et al., Proc.

  In the semiconductor device manufacturing process described above, in order to form a channel formation region of a semiconductor device in a substantially single crystal grain having a large grain size, an alignment mark formed by a grain filter mask is used when patterning a semiconductor film. It is necessary to align the alignment mark on the mask of the semiconductor film. However, if the hole diameter of the grain filter is reduced by depositing the silicon oxide film as described above, the shape of the alignment mark formed by the mask of the grain filter is different from the shape of the mask. When the alignment mark of the semiconductor film is aligned with an alignment mark that is not the original shape, misalignment of the mask occurs, and the channel formation region of the semiconductor device cannot be formed in a substantially single crystal grain having a large grain size.

  The present invention provides a semiconductor device in which a channel formation region of a semiconductor device is formed with high alignment accuracy in substantially single crystal grains having a large grain size, an electro-optical device and an electronic device using the semiconductor device, and a method for manufacturing the semiconductor device For the purpose.

  In order to achieve the above object, a semiconductor device according to the present invention includes a substrate on which an alignment mark is formed, an insulating film formed on the substrate and the alignment mark, and a large substrate formed on the insulating film. A substantially single crystal semiconductor film having a grain size, and a channel formation region is formed in the substantially single crystal semiconductor film.

  According to the above semiconductor device, since the alignment mark is formed on the substrate, the substantially single crystal semiconductor film is accurately formed at a desired position on the basis of the alignment mark. A channel formation region is formed in the film. Therefore, electrical characteristics of the semiconductor device can be improved.

  In addition to the above configuration, the semiconductor device of the present invention includes a light shielding film formed in the same layer as the alignment mark, and light incident on the semiconductor film through the substrate is shielded by the light shielding film. It is preferable that it is comprised so that.

  According to the above semiconductor device, the light incident on the semiconductor film through the substrate is configured to be shielded by the light shielding film, so that generation of carriers due to light can be suppressed, and light leakage current is reduced. can do. In addition, since the alignment mark is provided in the same layer as the light shielding film, the positions of the light shielding film and the semiconductor film can be accurately aligned, and light incident on the semiconductor film can be efficiently shielded.

  The present invention also provides a liquid crystal device and an electronic device comprising the semiconductor device according to the present invention as described above. These are high-performance liquid crystal devices and electronic devices each including a semiconductor device having excellent electrical characteristics by forming a channel formation region in a substantially single crystal semiconductor film. Further, the present invention is a high-performance liquid crystal device and electronic device including a semiconductor device in which light leakage current is reduced by being configured such that light incident on the semiconductor film through the substrate is shielded by the light shielding film.

  The method for manufacturing a semiconductor device of the present invention includes a step of forming an alignment mark on a substrate, a step of forming an insulating film on the substrate and the alignment mark, and a substantially single particle having a large particle size on the insulating film. The method includes a step of forming a crystalline semiconductor film and a step of forming a channel formation region in the substantially single crystal semiconductor film.

  According to the method for manufacturing a semiconductor device, an alignment mark is formed on a substrate, and a substantially single crystal semiconductor film can be accurately formed at a desired position using the mark as a reference position. A channel formation region can be formed in the film. Therefore, a semiconductor device exhibiting excellent electrical characteristics can be manufactured.

  In the semiconductor device manufacturing method of the present invention, in addition to the above manufacturing method, a light-shielding film for shielding light incident on the semiconductor film through the substrate is formed on the same layer as the alignment mark. It is preferable that the process is included.

  According to the above method for manufacturing a semiconductor device, light incident on the semiconductor film through the substrate is shielded by the light shielding film, so that generation of carriers due to light can be suppressed and light leakage current can be reduced. it can. In addition, since the alignment mark is provided in the same layer as the light shielding film, the positions of the light shielding film and the semiconductor film can be accurately aligned, and light incident on the semiconductor film can be efficiently shielded. In addition, since the alignment mark and the light shielding film can be formed at the same time, the process can be simplified.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Example 1)
FIG. 1 is an explanatory diagram of a semiconductor device as Example 1 of the present invention.

  A first alignment mark 11 patterned in an island shape is formed on a quartz substrate 10 as a substrate. The substrate is not limited to a quartz substrate, and may be a single crystal silicon substrate, a glass substrate, or a plastic substrate. The film thickness of the first alignment mark 11 is preferably about 50 nm to 500 nm, and the material is a semiconductor film such as a silicon film, or a metal or metal silicide film containing at least one of Ti, Cr, W, Ta, Mo, Pd, etc. Is preferred.

  On the quartz substrate 10 and the first alignment mark 11, a silicon oxide film 12 as an insulating film is formed with a film thickness of about 300 nm to about 1.5 μm. The silicon oxide film 12 is formed with a grain filter 13 which is a fine hole (concave portion) having a diameter of about 50 nm to 150 nm, preferably about 100 nm. Further, a hole 14 is formed in the silicon oxide film 12 as a second alignment mark. The position of the second alignment mark 14 is determined based on the position of the first alignment mark 11.

  A silicon film as a semiconductor film is formed in the grain filter 13 and on the silicon oxide film 12 around the grain filter 13, and a source region 15, a drain region 16, and a channel formation region 17 of the semiconductor device are formed on the silicon film. Is formed. The position of a crystal grain boundary (not shown) existing in the silicon film is controlled by the position of the grain filter 13, and the position of the crystal grain boundary is preferably outside the channel formation region 17. That is, the channel formation region 17 is preferably formed of a substantially single crystal semiconductor film. Thereby, the electrical characteristics of the semiconductor device become excellent. A silicon film 18 as a third alignment mark is formed on the silicon oxide film 12. The thickness of the silicon film is preferably about 30 nm to about 300 nm. This is because it is difficult to control the film thickness if it is too thin, and excellent electrical characteristics cannot be obtained if it is too thick. A more preferable film thickness is about 30 nm to 60 nm.

  In the semiconductor device of the present invention, the position of the third alignment mark 18 is determined based on the position of the first alignment mark 11, not the second alignment mark 14. Therefore, even when the shape of the second alignment mark 14 has changed before the formation of the third alignment mark 18, the third alignment mark 18 and the semiconductor film, that is, the substantially single crystal semiconductor film having a large grain size, The first alignment mark 11 can be formed at a desired position with reference to the position. Since the first alignment mark 11 exists, the second alignment mark 14 need not be used after the grain filter 13 is formed.

  A silicon oxide film 19 as a gate insulating film is formed on the source region 15, the drain region 16, and the channel forming region 17 that are substantially single crystal silicon films, and a gate electrode 20 is formed on the silicon oxide film 19 as a gate insulating film. And a fourth alignment mark 21 is formed. The material of the gate electrode 20 is, for example, a metal film or a semiconductor film into which impurities are implanted. The position of the fourth alignment mark 21 is determined based on the position of the first alignment mark 11.

  Thereby, the positional relationship accuracy between the gate electrode 20 and the channel formation region 17 and the grain filter 13 is improved. That is, since the positional relationship accuracy between the channel formation region 17 and the crystal grain boundary of the semiconductor film is improved, the channel formation region 17 does not include a crystal grain boundary, and the channel formation region is formed of a substantially single crystal semiconductor film. Therefore, the semiconductor device has excellent electrical characteristics.

  A silicon oxide film 22 as an interlayer insulating film is formed, and a source electrode 23 and a drain electrode 24 are formed. The material of the source electrode 23 and the drain electrode 24 is, for example, a metal film or a semiconductor film into which impurities are implanted. The source electrode 23 and the drain electrode 24 are connected to a source region 15 and a drain region 16 formed in a substantially single crystal silicon film, respectively.

  As described above, in the semiconductor device of Example 1, the first alignment mark exists on the substrate, and the channel formation region is formed in the substantially single crystal semiconductor film. Therefore, the semiconductor device exhibits excellent electrical characteristics. .

(Example 2)
FIG. 2 is an explanatory diagram of a semiconductor device as a second embodiment of the present invention.

  The difference from the first embodiment is only that the light shielding film 11b exists in the same layer as the first alignment mark 11 on the quartz substrate 10. The light shielding film 11 b has a role of shielding light incident on the semiconductor film through the quartz substrate 10. With this light shielding film 11b, generation of carriers due to light in the semiconductor film can be suppressed, and light leakage current can be reduced.

  The light shielding film 11 b is made of the same material as the first alignment mark 11. The material is preferably a metal or metal silicide film containing at least one of Ti, Cr, W, Ta, Mo, Pd and the like. The film thickness is preferably about 100 nm to 500 nm. When the film thickness is 100 nm or less, the light shielding property is deteriorated, and the light leakage current easily flows through the semiconductor device.

  Further, the first alignment mark 11 is provided in the same layer as the light shielding film 11b, and the position of the third alignment mark 18 is determined based on the position of the first alignment mark 11. That is, the positional relationship accuracy between the light shielding film 11b and the semiconductor film is good, and the light incident on the semiconductor film can be efficiently shielded by the light shielding film 11b.

(Example 3)
FIG. 3 is an explanatory diagram for a method of manufacturing a semiconductor device as a third embodiment of the present invention.

  As shown in FIG. 3A, a metal or metal silicide film containing at least one of Ti, Cr, W, Ta, Mo, Pd, etc. is formed on a quartz substrate 30 as a substrate by sputtering or the like. It is formed to a thickness of about 100 nm to 500 nm. Then, the metal or metal silicide film is processed into an island shape by photolithography to form the first alignment mark 31 and the light shielding film 31b. The light shielding film 31b can be eliminated depending on the application of the semiconductor device.

  A silicon oxide film 32 as a first insulating film is formed on the quartz substrate 30, the first alignment mark 31, and the light shielding film 31b. A silicon oxide film having a thickness of 800 nm is formed using TEOS as a raw material by low pressure chemical vapor deposition (LPCVD). The deposition method may be other than LPCVD, and plasma chemical vapor deposition (PECVD) may be used. The film thickness is preferably about 500 nm to 1.5 μm.

  Next, as shown in FIG. 3B, a recess 33 and a second alignment mark 34 are formed in the first insulating film 32. The position of the second alignment mark 34 is determined based on the position of the first alignment mark 31. The recess 33 has a cylindrical shape with a diameter of 1 μm and a depth of about 800 nm, which is the same as the thickness of the first insulating film. In addition to the above, the recess 33 may have a cylindrical shape or a prism shape with a diameter or one side of about 0.75 μm to 1.5 μm. The depth of the recess 33 is preferably about the thickness of the first insulating film 32 or 1 μm or more. The shape of the second alignment mark 34 is preferably a prismatic shape having a side of 1 μm or more and a depth similar to that of the recess.

  Next, as shown in FIG. 3C, a low pressure chemical vapor deposition method (LPCVD method) or a plasma chemical vapor deposition method (LPCVD method) (on the first insulating film 32, the recess 33, and the second alignment mark 34). A silicon oxide film 35 as a second insulating film is formed by PECVD) or the like. By forming the second insulating film 35, the hole diameter of the recess 33 is reduced, and this is used as the grain filter 36. The grain filter 36 is preferably formed in a cylindrical shape having a diameter of about 50 nm to 150 nm and a depth of about 750 nm. Here, a silicon oxide film having a thickness of 600 nm is formed by LPCVD using TEOS as a raw material, and a cylindrical grain filter having a diameter of about 100 nm and a depth of about 900 nm is formed. The grain filter 36 may have a shape other than a cylindrical shape (for example, a prism shape). The grain filter 36 is a starting point portion to be a starting point when crystallization of a semiconductor film to be performed later, and is a hole for growing only one crystal nucleus. Here, since the second insulating film 35 is formed, the hole diameter of the second alignment mark 34 is reduced. When a concave portion having a diameter of 1 μm becomes a grain filter having a diameter of 100 nm, the diameter is reduced by 0.9 μm. That is, the size of the second alignment mark is also reduced to the same extent. Therefore, if one side of the second alignment mark is 1 μm, one side of the second alignment mark is about 100 nm, and even if the side is about several μm, the shape is small from about several percent to several tens of percent. turn into.

  Next, as shown in FIG. 3D, an amorphous silicon film as a semiconductor film is formed on the second insulating film 35, the grain filter 36, and the second alignment mark 34 by a film forming method such as LPCVD. 37 is formed. The thickness of the semiconductor film 37 is 50 nm or more and 300 nm or less. As the semiconductor film 37, a polycrystalline silicon film may be formed instead of the amorphous silicon film.

  Here, the semiconductor film 37 needs to have a thickness sufficient to embed the grain filter 36. For example, if the diameter of the grain filter is 50 nm, the thickness of the semiconductor film needs to be about 30 nm or more. If a semiconductor film thinner than this is deposited, the grain filter is not sufficiently embedded, and a gap is formed. In addition, when the diameter of the grain filter is made smaller than 50 nm, the thickness of the semiconductor film can be reduced in principle, but it is possible to stably form such a grain filter with a small diameter. The process is very difficult, and further, the semiconductor cannot be sufficiently supplied to the inside of the grain filter when the semiconductor film is deposited. For these reasons, the minimum film thickness of the semiconductor film 37 is 30 nm in order to stably perform substantially single crystal grain growth of the semiconductor film described later. Although the minimum film thickness is 30 nm, the crystal growth of the semiconductor film can be performed better when the semiconductor film is thicker. In the experiments by the present inventors, if the thickness of the semiconductor film 37 is 50 nm or more, good crystallization can be performed.

  When the semiconductor film is thicker, larger single crystal grains can be formed. In the experiments of the present inventors, the maximum crystal grain size was about 3.0 μm when the semiconductor film thickness was 50 nm, but the maximum crystal grain size was about 4.0 μm when the semiconductor film thickness was 100 nm. When the film thickness was 250 nm, the maximum crystal grain size was about 6.5 μm. As described above, larger crystal grains can be formed when the semiconductor film is thicker. However, if the semiconductor film is too thick, a problem arises. First, there is an upper limit to the film thickness that can be deposited due to device limitations. If the film thickness is too thick, the film may be peeled off. Further, when the film thickness is increased, it takes time to form the film, and the productivity is lowered. Furthermore, the heat treatment apparatus for crystallization is burdened, and if it is too thick, crystallization cannot be sufficiently performed due to the restrictions of the apparatus. In the experiments by the present inventors, the maximum film thickness of the semiconductor film 37 is about 300 nm. When the film thickness is 300 nm or less, the above-described problems do not occur, and crystal grains having a size sufficient for manufacturing a semiconductor device can be obtained.

Next, as shown in FIG. 4A, the silicon film 37 as a semiconductor film is irradiated with a laser beam 38 as a heat treatment. This laser irradiation is preferably performed using, for example, an XeCl pulse excimer laser having a wavelength of 308 nm and a pulse width of about 200 ns so that the energy density of the laser light 28 is about 0.4 to 1.5 J / cm ^2. It is. By performing laser irradiation under such conditions, most of the irradiated laser light 38 is absorbed near the surface of the silicon film 37. This is because the absorption coefficient of amorphous silicon at the wavelength of XeCl pulsed excimer laser light (308 nm) is relatively large at 0.139 nm ⁻¹ .

  Here, as the excimer laser light to be irradiated, it is preferable to use an excimer laser light having a pulse width of about 150 ns to 250 ns, rather than an excimer laser light having a pulse width of about 20 ns to 30 ns, which is conventionally used. This is because the melting time of the silicon film is remarkably increased by irradiating the excimer laser light having such a relatively long pulse width. This is reported in “Experimental and numerical narrative of surface melt dynamics in 200 ns-excimer laser crystallisation, in 38 s. Yes. The size of the crystal grains when the molten silicon film is solidified and crystallized depends on the multiplication of the crystal growth rate and the melting time. That is, when the melting time of the silicon film is increased by irradiating the excimer laser beam having a relatively long pulse width, a large substantially single crystal grain can be formed accordingly. For example, in the experiments of the present inventors, by irradiating a silicon film sample at room temperature with the excimer laser light having the relatively long pulse width, for example, in the case of a silicon film thickness of 100 nm, the diameter is about 4 μm. The formation of crystal grains is confirmed. On the other hand, R. mentioned above. In Ishihara et al., A conventional excimer laser having a relatively short pulse width is used, and the maximum grain size of a substantially single crystal grain when the silicon film thickness is 90 nm is about 2.5 μm. Although the silicon film thicknesses of these two are slightly different, by using the excimer laser having a long pulse width, it is possible to realize growth of a crystal grain that is several tens of percent larger.

  Furthermore, in the experiments by the inventors of the present application, the silicon film sample is heated to about 200 ° C. during the irradiation with the excimer laser having a long pulse width, so that the maximum single crystal grain size of about 7 μm is obtained in the sample having a silicon film thickness of 100 nm. In the sample with the same film thickness of 150 nm, formation of large crystal grains of about 8 μm was confirmed. This is because the silicon film was melted for a long time by heating the sample. The heating temperature of the silicon film sample during excimer laser irradiation is preferably about 200 ° C. to about 500 ° C.

  On the other hand, techniques for crystallizing a silicon film using a laser having a long pulse width are also disclosed in, for example, Japanese Patent Application Laid-Open Nos. 2000-36464 and 7-283151. However, in these techniques, the silicon film does not have a starting point as a starting point for crystallization, and the place where crystal growth starts is not controlled. In other words, irradiation with laser light having a long pulse width increases the melting time of the silicon film, but crystal nuclei are generated at random positions and crystal grains grow from the respective crystal nuclei. There is no significant change in the size of the grains compared to the conventional one. On the other hand, in this embodiment, since the starting point of the crystallization of the silicon film is controlled by forming a grain filter, crystal growth starts preferentially from here, and the melting time is increased by laser irradiation with a long pulse width. Due to the effect of increasing the length, as described above, the formation of crystal grains several tens of percent larger than the conventional one is realized.

  By appropriately selecting the laser irradiation conditions described above, the silicon film 37 is left in an unmelted state inside the grain filter 36, particularly in the vicinity of the bottom, and the other portions are substantially completely melted. To be in a state. As a result, the crystal growth of silicon after the laser irradiation starts first in the vicinity of the unmelted silicon in the grain filter 36 and proceeds to the vicinity of the surface of the silicon film 37, that is, the substantially completely melted portion.

  Several crystal grains may be generated inside the grain filter 36 after laser irradiation. At this time, the cross-sectional dimension of the grain filter 36 (in this embodiment, the diameter of a circle) is set to be approximately the same as or slightly smaller than one crystal grain, so that the upper part (opening) of the grain filter 36 is formed. Will reach only one crystal grain. As a result, in the substantially completely melted portion of the silicon film 37, crystal growth proceeds with the crystal grains reaching the upper part of the grain filter 36 as nuclei. As shown in FIG. A substantially single crystal grain 37a of silicon centering on the filter 36 is formed.

  FIG. 6 is a plan view showing substantially single crystal grains 37 a of silicon formed on the substrate 30. As shown in the figure, the substantially single crystal grains 37a of silicon are formed in a range having the grain filter 36 as a substantial center. Using such substantially single crystal grains 37a, a semiconductor device is formed as described below.

  Next, as shown in FIG. 4C, the semiconductor film 37 and the substantially single crystal grains 37a are processed into an island shape by photolithography, and the third alignment mark 37b and the island-like substantially single crystal film are processed. 37c is formed. Here, the position of the third alignment mark 37 b is determined based on the position of the first alignment mark 31. Since the shape of the second alignment mark 34 has changed due to the formation of the second insulating film 35, if the position of the third alignment mark 37b is determined based on the position of the second alignment mark 34, the third alignment mark The position of the mark 37b cannot be accurately formed at a desired position. If the shape of the second alignment mark changes by about 1 μm due to the formation of the second insulating film, the alignment accuracy deteriorates accordingly, and the semiconductor film cannot be formed at a desired position. In the present invention, since the first alignment mark 31 is formed on the substrate, the third alignment mark 37b can be formed with high positional accuracy. That is, the substantially single crystal film 37c can be systematically formed at a desired position.

  Next, as shown in FIG. 5, a silicon oxide film 39 as a gate insulating film is formed. The silicon oxide film may be formed by thermal oxidation or plasma oxidation of a silicon film, or may be deposited by LPCVD or PECVD.

  Next, the gate electrode 40 and the fourth alignment mark 41 are formed using a polycrystalline silicon film into which an impurity element is implanted, a metal film such as tantalum or aluminum, or the like. The position of the fourth alignment mark 41 is determined based on the position of the first alignment mark 31 or the third alignment mark 37b. Since the second alignment mark 34 is not used, the gate electrode 40 is formed with a good position system.

Then, a source region 42, a drain region 43, and a channel formation region 44 are formed in the semiconductor film by implanting an impurity element serving as a donor or acceptor using the gate electrode 40 as a mask, so-called self-aligned ion implantation. For example, in this embodiment, phosphorus (P) is implanted as an impurity element, and then heat treatment is performed to activate the impurity element to form an N-type semiconductor device. Needless to say, a P-type semiconductor device can also be formed. Note that the impurity element may be activated by irradiating the XeCl excimer laser with an energy density of about 200 mJ / cm to 400 mJ / cm ² . Since the gate electrode 40 is formed with high positional accuracy, the channel formation region 44 is also formed at a desired position in the substantially single crystal semiconductor film. FIG. 7 shows a plan view. A cross-sectional view taken along the alternate long and short dash line between AA ′ corresponds to FIG. However, in FIG. 7, the alignment mark, the source electrode, the drain electrode, and the light shielding film are omitted. It can be seen that the channel formation region 44 is formed in the substantially single crystal semiconductor film 37a.

  Thereafter, a silicon oxide film 45 as an interlayer insulating film is formed by LPCVD, PECVD, or the like. Next, contact holes are formed through the interlayer insulating film 45 and the gate insulating film 39 to reach the source region 42 and the drain region 43, and aluminum is formed in these contact holes by a film forming method such as a sputtering method. A source electrode 46 and a drain electrode 47 are formed by embedding and patterning a metal such as tungsten. By the manufacturing method described above, the semiconductor device of Example 2 as shown in FIG. 5 is formed.

  Thus, in the semiconductor device of Example 3, the first alignment mark is formed on the substrate, and the position of the grain filter, the semiconductor film, the gate electrode, and the channel formation region is based on the position of the first alignment mark. Therefore, each layer can be formed at a desired position. Therefore, a channel formation region can be formed in a substantially single crystal semiconductor film, and a semiconductor device having excellent electrical characteristics can be formed.

(Example 4)
FIG. 8 shows a liquid crystal display device 100 as an example of the liquid crystal device according to the present invention.

  As shown in FIG. 8, in the liquid crystal device 100, the element substrate 52 on the side where the TFT 1 is formed and the counter substrate 53 are arranged to face each other, and between these element substrate (active matrix substrate) 52 and the counter substrate 53. A liquid crystal layer (not shown) made of liquid crystal having positive dielectric anisotropy is enclosed.

  The liquid crystal display device 100 includes a display pixel region in which a pixel circuit having a large number of source lines (scanning lines) 54 and a large number of gate lines (data lines) 55 that intersect with each other, and the source lines 54 and the gate lines. And a drive circuit region in which drive circuits for supplying drive signals to 55 are formed.

  At the intersection of each source line 54 and each gate line 55 arranged on the inner surface side of the element substrate 52, a TFT 1 that performs a switching operation of each corresponding pixel electrode 57 (load) is formed. In other words, one TFT 1 and one pixel electrode 57 are provided for each pixel arranged in a matrix. A common electrode 58 is formed on the entire inner surface of the counter substrate 53 over the entire display pixel region in which a large number of pixels are arranged in a matrix.

  On the other hand, the drive circuits (source drivers) 60 and 61 for controlling the drive of the pixels connected to the TFT 1 are formed on the inner surface side of the element substrate 52 like the TFT 1 and include a large number of TFTs (not shown). Has been. The drive circuits 60 and 61 are supplied with a control signal from a control circuit (not shown), and generate a drive signal (scanning signal) for driving each TFT 1 based on the control signal. Also, another drive circuit (gate driver) 62 and 63 for controlling the drive of the pixel connected to the TFT 1 is configured to include a large number of TFTs as in the drive circuits 60 and 61 and is supplied. Drive signals (data signals) for driving the TFTs 1 are generated.

(Example 5)
FIG. 9 is a diagram showing an example of an electronic apparatus according to the present invention. An electronic apparatus according to the present invention includes an active matrix substrate which is a semiconductor device according to the present invention obtained by forming a TFT as described above.

  FIG. 9A shows an example of a mobile phone on which a semiconductor device or the like manufactured by the manufacturing method of the present invention is mounted. The mobile phone 230 includes a liquid crystal display device (display panel) 100, an antenna unit 231, an audio output. A unit 232, a voice input unit 233, and an operation unit 234. The method for manufacturing a semiconductor device of the present invention is applied to the manufacture of a semiconductor device provided in, for example, the display panel 100 or a built-in integrated circuit.

  FIG. 9B shows an example of a video camera on which a semiconductor device or the like manufactured by the manufacturing method of the present invention is mounted. The video camera 240 includes an electro-optical device (display panel) 100, an image receiving unit 241, and an operation unit. 242 and a voice input unit 243 are provided. The method for manufacturing a semiconductor device of the present invention is applied to the manufacture of a semiconductor device provided in, for example, the display panel 100 or a built-in integrated circuit.

  FIG. 9C shows an example of a portable personal computer on which a semiconductor device or the like manufactured by the manufacturing method of the present invention is mounted. The computer 250 includes an electro-optical device (display panel) 100, a camera unit 251, and an operation. Part 252. The method for manufacturing a semiconductor device of the present invention is applied to the manufacture of a semiconductor device provided in, for example, the display panel 100 or a built-in integrated circuit.

  FIG. 9D shows an example of a head-mounted display on which a semiconductor device or the like manufactured by the manufacturing method of the present invention is mounted. The head-mounted display 260 includes an electro-optical device (display panel) 100, a band unit 261, and the like. An optical system storage unit 262 is provided. The method for manufacturing a semiconductor device of the present invention is applied to the manufacture of a semiconductor device provided in, for example, the display panel 100 or a built-in integrated circuit.

  FIG. 9E shows an example of a rear projector on which a semiconductor device or the like manufactured by the manufacturing method of the present invention is mounted. The projector 270 includes an electro-optical device (light modulator) 100, a light source 272, and combined optics. A system 273 and mirrors 274 and 275 are provided in the housing 271. The semiconductor device manufacturing method of the present invention is applied to the manufacture of a semiconductor device provided in, for example, the optical modulator 100 or a built-in circuit.

  FIG. 9F shows an example of a front projector on which a semiconductor device or the like manufactured by the manufacturing method of the present invention is mounted. The projector 280 includes an electro-optical device (image display source) 100 and an optical system 281. It is provided in the body 282 and can display an image on the screen 283. The semiconductor device manufacturing method of the present invention is applied to, for example, the manufacture of a semiconductor device provided in the image display source 100 or an integrated circuit incorporated therein.

  The method for manufacturing a semiconductor device according to the present invention is not limited to the above example, and can be applied to the manufacture of any electronic device. For example, the present invention can be applied to a fax machine with a display function, a digital camera finder, a portable TV, a DSP device, a PDA, an electronic notebook, an electric bulletin board, an advertisement display, an IC card, and the like.

  The present invention is not limited to the above-described embodiments, and various modifications and changes can be made within the scope of the gist of the present invention. For example, in the above-described embodiments, a silicon film is taken as an example of the semiconductor film, but the semiconductor film is not limited to this. In the above-described embodiment, an active matrix substrate including a TFT (semiconductor element) is taken as an example of the semiconductor device according to the present invention. However, the semiconductor device is not limited to this, and other These elements (for example, thin film diodes) may be provided. Further, although a top gate type structure is exemplified as the TFT, a bottom gate type TFT can also be used similarly.

  As described above, according to the present invention, it is possible to provide a semiconductor device in which a channel formation region of a semiconductor device is formed with high alignment accuracy in a substantially single crystal grain having a large grain size, and thus has excellent electrical characteristics. A semiconductor device can be obtained.

  The semiconductor device according to the present invention can be used as a switching element of a liquid crystal display device or a drive element of an organic EL display device.

  These display devices can be applied to various electronic devices. Examples include mobile phone display units, video camera viewfinders and display units, portable personal computer (so-called PDA) display units, head mounted display image display sources, rear and front projector image display sources, and the like. Can be mentioned.

  The display device using the semiconductor device of the present invention is not limited to the above-described example, and can be applied to any electronic apparatus to which an active or passive matrix liquid crystal display device and organic EL display device can be applied. For example, in addition to this, it can also be used for a fax machine with a display function, a finder for a digital camera, a portable TV, an electronic notebook, an electric bulletin board, a display for advertisements, and the like.

It is sectional drawing of the semiconductor device shown in Example 1 of this invention. It is sectional drawing of the semiconductor device shown in Example 2 of this invention. It is sectional drawing explaining the manufacturing method of the semiconductor device shown in Example 3 of this invention. It is sectional drawing explaining the manufacturing method of the semiconductor device shown in Example 3 of this invention. It is sectional drawing explaining the manufacturing method of the semiconductor device shown in Example 3 of this invention. It is a top view explaining the manufacturing method of the semiconductor device shown in Example 3 of this invention. It is a top view explaining the manufacturing method of the semiconductor device shown in Example 3 of this invention. It is a connection diagram of the liquid crystal device shown in Example 4 of the present invention. It is a figure which shows the electronic device shown in Example 5 of this invention.

Explanation of symbols

1 ... TFT
10, 30 ... Substrate 11, 31 ... First alignment mark 11b, 31b ... Light shielding film 12 ... Insulating film 13, 36 ... Grain filter 14, 34 ... Second alignment Marks 15, 42 ... Source regions 16, 43 ... Drain regions 17, 44 ... Channel formation region 18 ... Third alignment marks 19, 39 ... Gate insulating films 20, 40 ... Gate electrodes 21, 41 ... fourth alignment marks 22, 45 ... interlayer insulating films 23, 46 ... source electrodes 24, 47 ... drain electrodes 32 ... first insulating film 33 ... · Recess 35 · · · Second insulating film 37 · · · Semiconductor film 37a · · · substantially single crystal grain 37b · · · third alignment mark 37c · · · island-like substantially single crystal film 38 · · · laser light 52... Element substrate 5 ... counter substrate 54 ... scanning line 55 ... gate line 57 ... pixel electrode 58 ... common electrodes 60, 61, 62, 63 ... drive circuit 100 ... liquid crystal display device 230 .. Mobile phone 231... Antenna unit 232... Audio output unit 233, 243... Audio input unit 234 242 252... Operation unit 240. .. Computer 251... Camera unit 260... Head mounted display 261... Band unit 262... Optical system storage unit 270, 280. 273: Synthetic optical system 274, 275 ... Mirror 281 ... Optical system 283 ... Screen

Claims (6)

A substrate on which an alignment mark is formed;
An insulating film formed on the substrate and the alignment mark;
A substantially single crystal semiconductor film having a large grain size formed on the insulating film,
A semiconductor device, wherein a channel formation region is formed in the substantially single crystal semiconductor film.   The semiconductor according to claim 2, further comprising: a light shielding film formed in the same layer as the alignment mark, and configured to shield light incident on the semiconductor film through the substrate by the light shielding film. apparatus.   A liquid crystal device comprising the semiconductor device according to claim 1.   An electronic device comprising the semiconductor device according to claim 1. Forming alignment marks on the substrate;
Forming an insulating film on the substrate and the alignment mark;
Forming a substantially single crystal semiconductor film having a large grain size on the insulating film;
And a step of forming a channel formation region in the substantially single crystal semiconductor film.   6. The method of manufacturing a semiconductor device according to claim 5, further comprising a step of forming a light shielding film for shielding light incident on the semiconductor film through the substrate on the same layer as the alignment mark. .

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