JP5084340B2 - Method for manufacturing light emitting device - Google Patents

Description

  The present invention relates to a light emitting device and a manufacturing method thereof.

  Development of a light-emitting device using a light-emitting element that has a light-emitting layer between a pair of electrodes and emits light by passing a current between the electrodes is underway. Such a light-emitting device is advantageous in reducing the thickness and weight as compared to other display devices called thin display devices, and since it is self-luminous, it has good visibility and quick response. For this reason, development has been actively promoted as a next-generation display device, and some of the devices have been put into practical use.

  By the way, one of the reasons why such a light emitting device is only in practical use is a problem of deterioration of the light emitting element. Even if the same amount of current is applied to the light emitting element, the luminance decreases with the accumulation of driving time. One of the causes is that there are not yet many materials, structures, and combinations thereof for manufacturing a light-emitting element whose degree of deterioration is acceptable as an actual product.

  As a light-emitting device as described above, light emission in which an organic substance, an inorganic substance, or a mixture containing an organic substance and an inorganic substance that emits light called electroluminescence (hereinafter also referred to as “EL”) is interposed between electrodes. There is a light-emitting display device in which an element and a thin film transistor (TFT) are connected.

Since an electroluminescent element (EL element) can emit light with high luminance, it can display a variety of exciting images. Emission obtained from the light emitting element, for example, high luminance ^{100cd / m 2 ~10000cd / m 2} . The light-emitting display device has an advantage that the display device can be thinned and light-weighted because of its quick response and self-luminous display. A light emitting element using electroluminescence that can be applied in the present invention is distinguished depending on whether the light emitting material is an organic compound or an inorganic compound. Generally, the former is an organic EL element, and the latter is an inorganic EL element. It is called an element.

A resin material is used as a material for partitioning the pixels of the EL element (hereinafter referred to as a partition) (see Patent Document 1). Moisture, gas, and the like generated from this resin material are considered as one of the causes of deterioration of the light emitting characteristics of EL elements, particularly organic EL elements. Therefore, before depositing the EL material, the substrate is heated in air or vacuum at a temperature of about 150 to 300 ° C. and dried.
JP 2000-294378 A

  However, it has been found that merely heating the resin at a temperature of about 150 to 300 ° C. to form the partition walls is insufficient to dry the resin. In order to prevent the deterioration of the EL element, it is necessary to reduce moisture, gas, and the like generated from the resin constituting the partition wall.

  In the present invention, paying attention to the temperature at which the resin is cured, the step of volatilizing the solvent by heating at a first temperature of about 150 ° C. to 200 ° C. and the second temperature of about 300 ° C. to 350 ° C. By combining the steps of curing, a resin with a small amount of outgassing is produced. By using such a resin for the partition, a light-emitting device with a long lifetime can be obtained.

  In the present invention, a first electrode is formed on a substrate, a partition is formed using a resin material on the substrate and the first electrode, and the partition is a first temperature lower than a curing temperature. The temperature is held for a first time, and after being held at the first temperature, the partition is held at a second temperature that is higher than the curing temperature for a second time and at the second temperature. The present invention relates to a method for manufacturing a light-emitting device, in which a light-emitting layer is formed over the first electrode and a second electrode is formed over the light-emitting layer after being held.

  In the present invention, the resin material is polyimide or polybenzoxazole.

  In the present invention, the light emitting layer is an organic compound.

  In the present invention, the light emitting layer is an inorganic compound.

  In the present invention, the first temperature is 150 ° C. or higher and 200 ° C. or lower.

  In the present invention, the second temperature is 300 ° C. or higher and 350 ° C. or lower.

  Note that in this specification, a semiconductor device refers to all elements and devices that function by using a semiconductor, and includes an electro-optical device including a light-emitting device including a semiconductor element and an electronic device including the electro-optical device. Category.

  According to the present invention, generation of gas, moisture and the like from the resin for forming the partition can be suppressed, and adverse effects on the light emitting layer of the EL element can be suppressed. Accordingly, not only the EL element but also the light emitting device and the semiconductor device including the EL element can be extended in life, and the reliability can be improved.

This embodiment will be described with reference to FIGS. 1A to 1D and FIG. However, in FIG. _2, T 1 through T ₃ is the _temperature, H 1 to H ₅ is time. ΔH _a and ΔH _b represent the time taken from H _{1 to} H ₂ and the time taken from H _{3 to} H ₄ , respectively.

  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 are used in common in different drawings.

  First, the first electrode 102 is formed over the substrate 101 (see FIG. 1A). As the substrate 101, for example, glass, quartz, or the like can be used. Note that a base insulating film may be formed over the substrate 101 before the first electrode 102 is formed.

  For the first electrode 102 and the second electrode 105 formed in a later step, a metal, an alloy, a conductive compound, a mixture thereof, or the like can be used. Specifically, for example, indium tin oxide (also referred to as “ITO”), indium oxide-tin oxide containing silicon or silicon oxide, indium zinc oxide (“IZO”). And tungsten oxide-indium oxide containing tungsten oxide and zinc oxide. These conductive metal oxide films are usually formed by sputtering. For example, indium oxide-zinc oxide (IZO) can be formed by sputtering using a target in which 1 to 20 wt% of zinc oxide is added to indium oxide. Further, tungsten oxide-indium oxide containing zinc oxide can be formed by sputtering using a target containing 0.5 to 5 wt% tungsten oxide and 0.1 to 1 wt% zinc oxide with respect to indium oxide.

  In addition to the above, the first electrode 102 and the second electrode 105 include aluminum (Al), silver (Ag), gold (Au), platinum (Pt), nickel (Ni), tungsten (W), chromium (Cr), molybdenum (Mo), iron (Fe), cobalt (Co), copper (Cu), palladium (Pd), a nitride of a metal material (for example, titanium nitride (TiN)), or the like can be used.

  Note that in the case where one of the first electrode 102 and the second electrode 105 or the first electrode 102 and the second electrode 105 is a light-transmitting electrode, the material has low visible light transmittance. Even so, it can be used as a light-transmitting electrode by forming a film with a thickness of about 1 nm to 50 nm, preferably about 5 nm to 20 nm. In addition to sputtering, an electrode can also be produced using vacuum deposition, CDV, or sol-gel method.

  Note that light emission is extracted to the outside through the first electrode 102 or the second electrode 105; therefore, at least one of the first electrode 102 and the second electrode 105 is formed using a light-transmitting material. Need to be. The material is preferably selected so that the work function of the first electrode 102 is higher than that of the second electrode 105. Further, the first electrode 102 and the second electrode 105 do not have to be one layer each, and may have a structure of two or more layers.

  Next, a resin material 107 is formed over the substrate 101 and the first electrode 102 (see FIG. 1B). In this embodiment mode, a polyimide film is formed using a spinner as the resin material 107. As the resin material 107, in addition to polyimide, polybenzoxazole (also referred to as “polybenzoxazole”, but in this specification “polybenzoxazole”) can be used.

  Next, the formed resin material 107 is formed into a predetermined shape, so that the partition wall 103 is formed (see FIG. 1C). As a method of forming a predetermined shape, a method of imparting photosensitivity to a resin material like a resist material is preferable. For a resin that does not have photosensitivity, wet or dry etching may be performed using a resist material.

Next, a step of heating the partition wall 103 is performed by placing the substrate 101 in a hot plate or an oven. As shown in FIG. 2, the temperature is raised to T ₂ is a temperature lower than the curing temperature of T _1. In this embodiment, T ₁ is 100 ° C. and T ₂ is 150 to 200 ° C.

Further retain [Delta] H _a time the substrate 101 at a temperature of _{T 2.} In this embodiment, [Delta] H _a is 0.5 hours.

Next, the temperature is raised again from T ₂ to T _3, and held for ΔH _b time at T ₃ , which is higher than the curing temperature. In the present embodiment, T ₃ is set to a temperature of 300 to 350 ° C., and ΔH _b is set to 0.5 hour.

  Next, the substrate 101 is cooled to room temperature (rt) and taken out from a hot plate or an oven. Alternatively, the substrate 101 is taken out from a hot plate or oven at 100 to 200 ° C., for example, 150 ° C., and is set at room temperature and slowly cooled.

As described above, the method comprising firing at a temperature higher than the normal cure temperatures such as T _3, by being retained [Delta] H _a time at a temperature of T ₂ is a temperature lower than the usual curing temperature, the septum 103 The removal of the solvent contained in the resin material 107 for forming and the generation of moisture from the resin material 107 for forming the partition wall 103 can be suppressed. As a result, a partition wall with less degassing and moisture evaporation can be obtained. Thereby, the advantage that the lifetime of the EL element and the light emitting device having the EL element is increased.

  Next, the light-emitting layer 104 is formed over the partition wall 103 and the first electrode 102. In this embodiment, an organic compound is used for the light-emitting layer 104.

The following materials can be used for the organic compound light-emitting layer 104. For example, a material such as Alq ₃ : DCM or Alq ₃ : rubrene: BisDCJTM is used as a light-emitting material that emits red light. As a light-emitting material that emits green light, a material such as Alq ₃ : DMQD (N, N′-dimethylquinacridone) or Alq ₃ : coumarin 6 is used. As a light-emitting material that emits blue light, a material such as α-NPD or tBu-DNA is used.

  The present invention can also be applied to the case where an inorganic compound is used as the light emitting layer 104. Since generation of moisture from the partition wall 103 is suppressed by the present invention, an inorganic EL element having a long lifetime can be obtained.

  Inorganic EL elements using an inorganic compound as a light emitting material are classified into a dispersion type inorganic EL element and a thin film type inorganic EL element depending on the element structure. The former has an electroluminescent layer in which particles of a luminescent material are dispersed in a binder, and the latter has an electroluminescent layer made of a thin film of luminescent material, but is accelerated by a high electric field. This is common in that it requires more electrons. 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 serving 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 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 the sulfide include zinc sulfide (ZnS), cadmium sulfide (CdS), calcium sulfide (CaS), yttrium sulfide (Y ₂ S ₃ ), gallium sulfide (Ga ₂ S ₃ ), strontium sulfide (SrS), sulfide. Barium (BaS) or the like can be used. As the oxide, for example, zinc oxide (ZnO), yttrium oxide (Y ₂ O ₃ ), or the like can be used. As the nitride, for example, aluminum nitride (AlN), gallium nitride (GaN), indium nitride (InN), or the like can be used. Furthermore, zinc selenide (ZnSe), zinc telluride (ZnTe), and the like can also be used, such as calcium sulfide-gallium sulfide (CaGa ₂ S ₄ ), strontium sulfide-gallium (SrGa ₂ S ₄ ), barium sulfide-gallium (BaGa). _It may be a ternary mixed crystal such as ₂ S ₄ ).

  As emission centers of 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 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 emission center of 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 examples of the first impurity element or the compound containing the first impurity element include fluorine (F), chlorine (Cl), and aluminum sulfide (Al ₂ S). ₃ ) or the like, and examples of the second impurity element or the compound containing the second impurity element include copper (Cu), silver (Ag), copper sulfide (Cu ₂ S), and silver sulfide (Ag). ₂ S) 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 including the first impurity element and the second impurity element, for example, copper chloride (CuCl), silver chloride (AgCl), or the like can be used.

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

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

  Next, the second electrode 105 is formed over the light-emitting layer 104 (see FIG. 1D). The material and manufacturing process of the second electrode 105 are as described in manufacturing the first electrode 102.

  Thus, a light emitting device is manufactured. Since the amount of degassing from the partition wall 103 is small in the light emitting device of this embodiment mode, the influence on the light emitting layer 104 is small. Thus, a light-emitting device with a long lifetime can be obtained.

  Note that this embodiment mode can be combined with any embodiment if necessary.

  In this example, changes in characteristics due to differences in polyimide firing conditions were observed.

  Polyimide (hereinafter abbreviated as “PI”) is a resin having heat resistance and insulating properties, and is widely used in the semiconductor field because it has photosensitivity. Therefore, in a light emitting device having an EL element, it is often used as a partition wall for separating pixels.

  In this example, heat resistance characteristics and optical characteristics were evaluated for the purpose of verifying how much the characteristics (physical properties) of PI depend on the firing conditions.

  Regarding the heat resistance characteristics, mass spectra were measured by thermal desorption spectroscopy (hereinafter referred to as “TDS”), and the types and amounts of generated gases were compared and evaluated.

  The TDS measurement will be described below.

First, PI samples for TDS measurement were prepared under the conditions shown in Table 1. In the present embodiment, the sintering temperature corresponds to the temperature of T ₃ in FIG. 2.

  FIG. 3 shows a sample stage of the TDS measuring apparatus. A quartz column 121 is provided below the sample stage 122, and the temperature is controlled by infrared rays through the quartz column 121. A sample 125 is installed on the sample stage 122.

In the measurement apparatus of FIG. 3, the stage temperature _TST and the sample surface temperature _TSP are monitored using a thermocouple 123 and a thermocouple 124, respectively. Because in a vacuum thermal conductivity is significantly _{decreased, T ST} and _{T SP} is different about 100 to 300 ° C.. A pressure of 10 ⁻⁸ to 10 ⁻⁷ Pa is maintained in the chamber, and the pressure rises to near 10 ⁻⁵ Pa only when the sample is heated to generate gas. The generated gas is subjected to component analysis by a QMS (Quadrupole Mass Spectrometer) and converted into a mass spectrum.

  The TDS spectrum was measured under the conditions shown in Table 2 using the measurement apparatus shown in FIG. In addition, it was confirmed by preliminary measurement that there was no degassed component having a mass number of 100 or more.

The results of the scan measurement are shown in FIGS. Temperature axis is point temperature _{T SP} obtained by monitoring the sample 125 surface thermocouple 124, numbers entered each peak in the spectrum shows the corresponding Mass Number (mass number).

Comparing the TDS spectra of FIGS. 22 to 25, it can be seen that the intensity of the spectrum peak and the shape in the temperature axis direction change depending on the firing temperature. As an overall trend, it appears that the sample fired at high temperature is shifted to the high temperature side of the temperature axis compared to the sample fired at low temperature. Paying particular attention to H ₂ O (mass number: 18), the low-temperature fired sample has two desorption peaks in the low-temperature region and the high-temperature region, and a large amount of degassing is observed even in a relatively low-temperature region of 200 ° C. or lower. However, in the sample fired at high temperature, only degassing in the high temperature range is observed.

  Table 3 summarizes the characteristics of the estimation of the components corresponding to these spectral peaks and the degassing amount change depending on the firing temperature.

When a mass spectrum of a certain molecule is measured, it is almost always decomposed into a plurality of components and detected. For example, even in the case of benzene, decomposition components (fragments) other than mass number 78 corresponding to C ₆ H ₆ are always detected, and the intensity ratio thereof is determined. A component cannot be identified unless the detection intensity ratio of those fragment components completely matches the literature value. Therefore, the chemical species in Table 3 are only estimates and there is no confirmation.

By the way, as shown in Table 3, HF, CO, and CO ₂ have a tendency to generate less gas in the low-temperature fired sample, and this is considered to be important. Only an overview of the spectral data allows only a qualitative evaluation of the firing temperature dependence.

  Therefore, it was decided to perform MID (Multi-ion Detection) measurement with higher quantification under the same conditions. The results of MID measurement are shown below.

  In MID measurement, measurement is performed on the mass number in which the generation of gas is confirmed in the TDS spectra of FIGS. 22 to 25, and the amount of gas generated as the temperature rises is measured. 22 to 25, the scan measurement is performed three-dimensionally, whereas the MID measurement is performed two-dimensionally. In MID measurement, the dimension of measurement is lower than in Scan measurement (although fewer parameters can be measured), but the accuracy is improved instead.

26 to 30 show the results of MID measurement for mass numbers 18, 20, 28, 64, and 94, respectively, and show changes in the degassing amount. The degassing amount change is obtained by plotting the measured data as it is. As described above, the components of each mass number are interpreted as 18 for H ₂ O, 20 for HF, 28 for CO, 64 for SO ₂ , and 94 for C ₄ O ₂ N.

As shown in FIG. 26, the amount of degassing with a mass number of 18 (H ₂ O) is larger for a sample fired at a low temperature. In particular, a sample fired at 260 ° C. has a first desorption component having a peak near 200 ° C., which is greatly different from other samples. In addition, the peak of the second desorption component is around 290 ° C., but the peak value decreases as the firing temperature becomes higher, and almost disappears in the sample fired at 320 ° C. About a 1st desorption component, it can be estimated that the low molecular-weight additive which a content rate falls with the raise of a calcination temperature is adsorb | sucking the water molecule by a hydrogen bond. It can be presumed that the second desorption component is a component generated by a reaction between moisture absorbed in the film and a hydroxyl group (OH group) and hydrogen (H) contained in the film.

  Further, if the density of the film increases with an increase in the firing temperature, the amount of moisture absorbed in the film decreases as the sample with a higher firing temperature. In any case, it can be said that a higher firing temperature is preferable from the viewpoint of generation of moisture.

  As shown in FIG. 27, the amount of degassing with a mass number of 20 (HF) increases as the sample is fired at a high temperature. It is not completely known why HF is generated. However, it seems that a fluorine compound is added to the resin material for forming the partition wall for the purpose of lowering the dielectric constant, and there is no doubt that it originates from this additive.

  It is considered that a single fluorine (F) is not generated in the process of thermal decomposition, but is combined with surrounding hydrogen (H) to become a more stable HF.

  As shown in FIG. 28, the degassing amount of the mass number 28 (CO) is characterized in that the lower temperature region of 300 ° C. or lower has a larger amount of the low-temperature fired sample and the higher temperature region of 300 ° C. or higher has a higher degassing amount. ing. CO is considered to be generated in the process of thermal decomposition of PI and derived from a low molecular component, but the cause of the characteristics as shown in FIG. 28 is unknown.

As shown in FIG. 29, the amount of degassing having a mass number of 64 (SO ₂ ) is larger as the sample is fired at a lower temperature. All have a peak around 300 ° C., and there is no great difference in the shape of the plot, but there is a large difference in the amount of generation. We believe that firing at a high temperature reduces the content of low molecular weight additives such as photosensitizers, or that low molecular weight additives in the resin are structurally difficult to escape from the resin. It is done. Therefore, if attention is paid to degassing of mass number 64 (SO ₂ ), it can be said that a higher firing temperature is preferable.

As shown in FIG. 30, the amount of degassing with a mass number of 94 (C ₄ O ₂ N) is larger as the sample is fired at a lower temperature. Although it cannot be determined that the component is an imide ring, there may be a difference in the fundamental heat resistance of the polyimide main component.

The Figure 44, in the case of using the polyimide in the partition wall, is a result of Scan measurement is obtained by plotting the total value of the mass number of 0 to 100 with respect to the sample surface temperature T _SP. The vertical axis represents the sample surface temperature _{T SP,} the horizontal axis is equivalent to total value of the mass number 0-100 is Li Construct Total Ion Current (Reconstruct Total Ion Current (RTIC) ).

  Regarding FIG. 44, it can be seen that those fired at 260 ° C. are noisy, but the amount of degassing decreases as the firing temperature increases.

  In summary, it can be concluded that in the range of 260 ° C. to 320 ° C., the higher the firing temperature, the better the characteristics such as heat resistance and moisture resistance.

  In this example, changes in characteristics of polybenzoxazole (benzoxazole (also referred to as polybenzoxazole; hereinafter abbreviated as “PBO”)) were observed when the firing conditions were changed.

  Polybenzoxazole is said to have higher heat resistance, higher mechanical properties, lower hygroscopicity, and lower dielectric properties than polyimide (PI). Therefore, the use is expanding as a new surface protective film or interlayer insulating film replacing PI.

  In this example, heat resistance was evaluated for the purpose of investigating how much the physical properties of polybenzoxazole depend on the firing conditions.

  As a method for evaluating heat resistance, thermal desorption spectroscopy (TDS) was adopted. The mass spectrum of the gas generated during vacuum heating was measured by this method, and the type and amount thereof were compared and evaluated.

Samples for TDS measurement were prepared under the conditions shown in Table 4. In the present embodiment, the sintering temperature corresponds to the temperature of T ₃ in FIG. 2.

  In addition, the sample stage of the TDS apparatus was the same as that in Example 1 as shown in FIG. The measurement method is the same as that of the first embodiment.

  Table 5 shows the measurement conditions of this example.

The results of the scan measurement are shown in FIGS. Temperature axis is point temperature T _SP obtained by monitoring a sample surface with a thermocouple, numbers entered each peak in the spectrum shows the corresponding Mass Number (mass number).

  Comparing the spectra of FIGS. 31 to 32, it can be seen that the intensity of the spectrum peak and the shape in the temperature axis direction change depending on the firing temperature.

  Table 6 summarizes the characteristics of the estimation of components corresponding to the spectral peaks in FIGS.

  Next, MID measurement with higher quantitativeness was also performed under the same conditions. The measurement results are shown in FIGS.

  The dependence on the firing temperature of the mass number 18 shown in FIG. 33 and the firing temperature dependence of the mass number 20 shown in FIG. 34 are similar to the results of polyimide (see Example 1), and gas is generated by a common mechanism. It is suggested that

  On the other hand, from FIG. 35 and FIG. 36, a clear difference is recognized in the results of polyimide and polybenzoxazole at mass numbers 28 and 44. These differences are thought to be due to differences in molecular structure or additives. Although it is difficult to estimate the gas generation mechanism, in polybenzoxazole, the gas generation amount of mass numbers 28 and 44 tends to greatly decrease as the firing temperature rises. The improvement is remarkable. This is probably because the film quality (film density, content of low molecular weight components, etc.) varies depending on the firing temperature.

  From the above, in this example, polybenzoxazole was baked under four conditions of 280 ° C. to 340 ° C., and TDS measurement was performed. As a result, it was found that polybenzoxazole baked at high temperature tends to generate less gas.

The Figure 45, in the case of using the polybenzoxazole in the partition wall, is a result of Scan measurement is obtained by plotting the total value of the mass number of 0 to 100 with respect to the sample surface temperature T _SP. The vertical axis represents the sample surface temperature _{T SP,} the horizontal axis is equivalent to total value of the mass number 0-100 is Li Construct Total Ion Current (Reconstruct Total Ion Current (RTIC) ).

  Regarding FIG. 45, it can be seen that the product fired at 260 ° C. has a large noise, but the amount of degassing decreases as the firing temperature increases.

  In this example, organic EL characteristics using polyimide (PI) and polybenzoxazole ((polybenzoxazole (PBO)) for the partition walls were examined.

  Polyimide (PI) and polybenzoxazole (PBO) are both insulating materials having excellent heat resistance. In Example 1 and Example 2, TDS measurement was performed on a single film sample as a heat resistance test for polyimide and polybenzoxazole, and the results were compared.

  However, it was not possible to conclude which heat resistance was superior from the results of TDS measurement alone.

  A plurality of samples were prepared by changing the firing conditions (firing temperature) of both polyimide and polybenzoxazole, and TDS measurement was performed. As a result, it was confirmed that the amount of gas detected in both the samples fired at a high temperature was small.

  Therefore, in this example, in order to verify whether the above-described tendency affects the initial characteristics and reliability of light emission of the organic EL element, a substrate formed with PI and PBO fired at a temperature higher than the standard condition as a partition is used. The organic EL material was vapor-deposited and the characteristics were evaluated.

  First, a silicon oxide film having a thickness of 200 nm was formed as a base film on a substrate. Then, the 1st electrode was formed using the laminated film of aluminum (Al) and titanium (Ti).

  The second electrode was formed using indium tin oxide (also referred to as “ITO”).

Next, polyimide and polybenzoxazole, which are partition walls, are formed on the substrate and formed into a desired shape. And after developing, it baked at the temperature shown in Table 7. In the present embodiment, the sintering temperature corresponds to the temperature of T ₃ in FIG. 2.

  The light-emitting layer was formed using an organic material that emitted green light. From the above, the organic EL element of this example is formed.

  The initial characteristics of the produced organic EL element are shown in FIGS. In any of the figures, the characteristic difference between the elements is small, and in FIGS. 37, 39, and 40, the data are almost overlapped.

  It can be seen from FIG. 37 that the current value and the luminance are directly proportional in a wide range. Accordingly, FIG. 38 also shows that the current efficiency (unit: cd / A) takes a constant value over a wide range. In FIG. 40, it can be seen that the current and the voltage are in a proportional relationship in a wide range of 4 V or more.

Although not remarkable in the current efficiency of FIG. 38, a difference between elements is recognized. However, from FIG. 38, it is difficult to separately consider differences from the partition wall materials, differences due to firing conditions, deposition variations, errors, and the like. Therefore, in FIG. ^38, the average current efficiency in the range of ^{1000cd / m 2 ~3000cd / m 2} , compared with the plot in FIG. 41.

  From FIG. 41, it can be seen that the deposition variation and the error are large, and the difference between the partition wall materials and the difference between the firing conditions are not obvious. It cannot be said that there is a significant difference between PI and PBO depending on the material. Moreover, it cannot be said that there is a significant difference depending on the firing temperature.

  To summarize the above results and discussion, it can be said that the influence of the material of the partition walls and the firing conditions is not significant in the initial characteristics of the device.

  The attenuation curve of the reliability test of the organic EL element of this example is shown in FIG. 42 when polyimide is used for the partition walls, and FIG. 43 when polybenzoxazole is used for the partition walls.

In this example, the organic EL element emitting green light was subjected to a reliability test with an initial luminance of 3000 cd / m ² . Based on FIG. 42 and FIG. 43, Table 8 shows the time for the luminance of each organic EL element to decay to 80% of the initial luminance. 42 and 43, an element obtained by baking the partition wall material at 250 ° C. is used as a standard element.

  The reliability of the elements deposited on the substrate fired at a high temperature of the partition wall material at a temperature of 300 ° C. or higher indicates that 5 elements out of 6 elements exceed the elements fired at 250 ° C. Therefore, it can be said that high temperature firing shows a tendency of high reliability.

  By the way, although it is considered that baking the partition wall material at a high temperature contributes to improving the reliability of the EL element, as shown in the results of the TDS measurement, the decrease in the degassing amount from the partition wall material is caused. I think that.

  PI is said to be imidized at 200 ° C. or higher, and at 250 ° C. or higher, the imidization rate (curing rate) is said to be 100%. Therefore, firing at 250 ° C. should be sufficient as a partition material.

  However, even in the temperature range of 250 ° C. or higher, the film quality is considered to depend on the firing temperature due to the content of low molecular weight components such as a photosensitizer, the average molecular weight, and the film density. As seen in the results of TDS measurement, degassing There is a difference in quantity.

  The amount of gas detected by the TDS measurement is very small, and an actual EL element does not heat at the time of light emission. Therefore, it is difficult to intuitively think that an amount of gas that causes deterioration is generated from the partition wall material.

  However, EL elements incorporated into light-emitting devices are used continuously for hundreds of hours and thousands of hours, so even with very small amounts of gas, some components such as moisture may gradually degrade the elements. Is also possible. Therefore, it can be said that it is desirable that the degassing is as little as possible as a requirement for the partition material of the EL element.

  4A to 4D, FIGS. 5A to 5C, and FIGS. 6A to 6C are examples of using a method for manufacturing a semiconductor device according to the present invention. 7 (A) to FIG. 7 (C) and FIG. 8 (A) to FIG. 8 (B), FIG. 9 (A) to FIG. 9 (B), FIG. 10, FIG. .

  First, as shown in FIG. 4A, a base film 502 is formed over a substrate 501. As the substrate 501, for example, a glass substrate such as barium borosilicate glass or alumino borosilicate glass, a quartz substrate, a stainless steel substrate, or the like can be used. Further, it is also possible to use a substrate made of a plastic such as PET (polyethylene terephthalate), PES (polyethersulfone), or PEN (polyethylene naphthalate), or a flexible synthetic resin such as acrylic.

  The base film 502 is provided to prevent an alkali metal such as Na or an alkaline earth metal contained in the substrate 501 from diffusing into the semiconductor film and adversely affecting the characteristics of the semiconductor element.

  As the base film 502, silicon oxide, silicon nitride, silicon oxide containing nitrogen, silicon nitride containing oxygen, or the like can be used, and a single layer or a stacked structure of two layers or three layers may be used. In addition, when using a substrate containing an alkali metal or alkaline earth metal, such as a glass substrate, a stainless steel substrate, or a plastic substrate, it is effective to provide a base film from the viewpoint of preventing impurity diffusion. However, when diffusion of impurities does not cause any problem, such as a quartz substrate, it is not necessarily provided.

In this embodiment, a silicon nitride film containing oxygen is formed as a lower base film 502a on the substrate using SiH ₄ , NH ₃ , N ₂ O, N ₂ and H ₂ as reaction gases, and SiH ₄ is formed thereon. Then, a silicon oxide film containing nitrogen is formed as an upper base film 502b with a film thickness of 100 nm using N ₂ O as a reaction gas. The thickness of the silicon nitride film containing oxygen may be 140 nm, and the thickness of the silicon oxide film containing nitrogen to be stacked may be 100 nm.

  Next, a semiconductor film 503 is formed over the base film 502. The thickness of the semiconductor film 503 is 25 nm to 100 nm (preferably 30 nm to 60 nm). As the semiconductor, not only silicon (Si) but also silicon germanium (SiGe) can be used. When silicon germanium is used, the concentration of germanium is preferably about 0.01 to 4.5 atomic%.

  The semiconductor film 503 is formed using an amorphous semiconductor (hereinafter also referred to as “amorphous semiconductor”) or a semi-amorphous semiconductor (microcrystalline or microcrystalline) manufactured by a vapor deposition method or a sputtering method using a semiconductor material gas such as silane or germane. Also referred to as a crystal.

A semi-amorphous semiconductor (SAS) is a semiconductor having an intermediate structure between amorphous and crystalline structures (including single crystal and polycrystal) and having a third state that is stable in terms of free energy, It includes a crystalline region with distance order and lattice distortion. A crystal region of 0.5 to 20 nm can be observed in at least a part of the film, and when silicon is a main component, the Raman spectrum is shifted 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. Hydrogen or halogen is contained at least 1 atomic% or more as a terminal for dangling bonds (dangling bonds).

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, or 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 is in the range of 2 to 1000 times, the pressure is in the range of 0.1 Pa to 133 Pa, and the power supply frequency is 1 MHz to 120 MHz, preferably 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 of 100 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 film.

  A typical example of the amorphous semiconductor is hydrogenated amorphous silicon. Further, as described above, a semi-amorphous semiconductor or a semiconductor containing a crystal phase in part of a semiconductor film can also be used.

  In this embodiment, an amorphous silicon film with a thickness of 54 nm is formed as the semiconductor film 503 by plasma CVD.

  Next, a metal element that promotes crystallization of the semiconductor is introduced into the semiconductor film 503. A method for introducing a metal element into the semiconductor film 503 is not particularly limited as long as the metal element can be present on the surface of the semiconductor film 503 or inside thereof. For example, a sputtering method, a CVD method, a plasma treatment method (plasma) A CVD method), an adsorption method, and a method of adding 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 semiconductor film 503 and to spread the aqueous solution over the entire surface of the amorphous semiconductor film, irradiation with UV light in an oxygen atmosphere, thermal oxidation, ozone containing hydroxy radicals It is desirable to form an oxide film by treatment with water or hydrogen peroxide.

  Examples of metal elements that promote semiconductor crystallization include nickel (Ni), germanium (Ge), iron (Fe), palladium (Pd), tin (Sn), lead (Pb), cobalt (Co), and platinum (Pt ), Copper (Cu), gold (Au), or a single element or a plurality of elements. In this embodiment, nickel (Ni) is used as a metal element, and a liquid nickel acetate solution is added to the surface of the semiconductor film 503 as a solution 504 containing the metal element by a spin coating method (see FIG. 4A).

  Next, hydrogen in the semiconductor film 503 is released by holding at 450 to 500 ° C. for 1 hour in a nitrogen atmosphere. This is because the threshold energy for subsequent crystallization is lowered by intentionally forming a dangling bond in the semiconductor film 503.

  Then, by performing heat treatment at 550 to 600 ° C. for 4 to 8 hours in a nitrogen atmosphere, the semiconductor film 503 is crystallized to obtain a crystalline semiconductor film 505. With this metal element, the crystallization temperature of the semiconductor film 503 can be set to a relatively low temperature of 550 to 600 ° C.

  Next, the crystalline semiconductor film 505 is irradiated with a linear laser beam 500 to further improve crystallinity (see FIG. 4B).

  In the case of performing laser crystallization, heat treatment for one hour at 500 ° C. may be applied to the crystalline semiconductor film 505 in order to increase resistance of the crystalline semiconductor film 505 to the laser before laser crystallization.

  For laser crystallization, a pulsed laser having an oscillation frequency of 10 MHz or more, preferably 80 MHz or more can be used as a continuous wave laser or a pseudo CW laser.

Specifically, as a continuous wave laser, Ar laser, Kr laser, CO ₂ laser, YAG laser, YVO ₄ laser, YLF laser, YAlO ₃ laser, GdVO ₄ laser, Y ₂ O ₃ laser, ruby laser, alexandrite laser Ti: sapphire laser, helium cadmium laser, and the like.

As a pseudo CW laser, an Ar laser, a Kr laser, an excimer laser, a CO ₂ laser, a YAG laser, a Y ₂ O ₃ laser, a YVO can be used as long as it can oscillate a pulse having an oscillation frequency of 10 MHz or more, preferably 80 MHz or more. _A pulsed laser such as a ₄ laser, a YLF laser, a YAlO ₃ laser, a GdVO ₄ laser, a glass laser, a ruby laser, an alexandrite laser, a Ti: sapphire laser, a copper vapor laser, or a gold vapor laser can be used.

  Such a pulsed laser has an effect equivalent to that of a continuous wave laser as the oscillation frequency is increased.

For example, when a solid-state laser capable of continuous oscillation is used, a crystal having a large grain size can be obtained by irradiating laser light of second to fourth harmonics. Typically, it is desirable to use the second harmonic (532 nm) or the third harmonic (355 nm) of a YAG laser (fundamental wave 1064 nm). For example, laser light emitted from a continuous wave YAG laser is converted into a harmonic by a non-linear optical element, and irradiated to the semiconductor film 505. Energy density may be about 0.01 to 100 MW / cm ² (preferably 0.1~10MW / cm ^2).

  Note that laser light irradiation may be performed in an atmosphere containing an inert gas such as a rare gas or nitrogen. Thereby, roughness of the semiconductor surface due to laser light irradiation can be suppressed, and variation in threshold voltage caused by variation in interface state density can be suppressed.

  By irradiation of the semiconductor film 505 with the laser beam 500, the crystalline semiconductor film 506 with higher crystallinity is formed (see FIG. 4C).

  Next, as illustrated in FIG. 4D, an island-shaped semiconductor film 507, an island-shaped semiconductor film 508, an island-shaped semiconductor film 509, and an island-shaped semiconductor film 510 are formed using the crystalline semiconductor film 506. The island-shaped semiconductor film 507 to the island-shaped semiconductor film 510 serve as an active layer of a TFT formed in the subsequent steps.

Next, impurities for threshold control are introduced into the island-shaped semiconductor film 507 to the island-shaped semiconductor film 510. In this embodiment, boron (B) is introduced into each of the island-shaped semiconductor films 507 to 510 by doping with diborane (B ₂ H ₆ ).

  Next, an insulating film 511 is formed so as to cover the island-shaped semiconductor film 507 to the island-shaped semiconductor film 510. For the insulating film 511, for example, silicon oxide, silicon nitride, silicon oxide containing nitrogen, or the like can be used. As a film formation method, a plasma CVD method, a sputtering method, or the like can be used.

  Next, after a conductive film is formed over the insulating film 511, a first conductive film 512 and a second conductive film 513 are formed, and these are used to form a gate electrode 515, a gate electrode 516, a gate electrode 517, and a gate electrode. A gate electrode 519 is formed 518.

  The gate electrodes 515 to 519 are formed using a structure in which a single conductive film or two or more conductive films are stacked. In the case where two or more conductive films are stacked, an element selected from tantalum (Ta), tungsten (W), titanium (Ti), molybdenum (Mo), and aluminum (Al), or the element as a main component Alternatively, the gate electrode 515 to the gate electrode 519 may be formed by stacking alloy materials or compound materials to be stacked. Alternatively, the gate electrode may be formed using a semiconductor film typified by a polycrystalline silicon film doped with an impurity element such as phosphorus (P).

  In this embodiment, first, as the first conductive film 512, for example, a tantalum nitride (TaN) film is formed with a thickness of 10 to 50 nm, for example, 30 nm. Then, as the second conductive film 513, for example, a tungsten (W) film is formed to a thickness of 200 to 400 nm, for example, 370 nm, over the first conductive film 512, and the first conductive film 512 and the second conductive film 513 are formed. (See FIG. 5A).

  Next, the second conductive film and the first conductive film are successively anisotropically etched, and then the second conductive film is isotropically etched, so that the upper gate electrode 515b to the upper gate electrode 519b, the lower gate An electrode 515a to a lower gate electrode 519a are formed. Through the above steps, the gate electrode 515 to the gate electrode 519 are formed (see FIG. 5B).

  The gate electrodes 515 to 519 may be formed as part of the gate wiring, or a gate wiring may be formed separately and the gate electrodes 515 to 519 may be connected to the gate wiring.

  Further, when the gate electrodes 515 to 519 are formed, part of the insulating film 511 is also etched to form the gate insulating film 514.

  Then, an impurity imparting one conductivity (n-type or p-type conductivity) is added to each of the island-shaped semiconductor film 507 to the island-shaped semiconductor film 510 by using the gate electrode 515 to the gate electrode 519 or a resist as a mask. Then, a source region, a drain region, a low-concentration impurity region, and the like are formed.

First, phosphorous (P) is introduced into the island-shaped semiconductor film using phosphine (PH ₃ ) with an acceleration voltage of 60 to 120 keV and a dose of 1 × 10 ¹³ to 1 × 10 ¹⁵ cm ⁻² . When this impurity is introduced, a channel formation region 525 and channel formation regions 528 and 531 of the n-channel TFT 543 are formed in the n-channel TFT 542.

In order to manufacture the p-channel TFT 541 and the p-channel TFT 544, diborane (B ₂ H ₆ ) is applied with an applied voltage of 60 to 100 keV, for example, 80 keV, and a dose amount of 1 × 10 ^{13 to} 5 × 10 ¹⁵ cm ⁻² , for example, 3 Boron (B) is introduced into the island-shaped semiconductor film under the condition of × 10 ¹⁵ cm ⁻² . Accordingly, the source region or drain region 521 of the p-channel TFT 541, the source region or drain region 533 of the p-channel TFT 544, and the channel formation region 522 of the p-channel TFT 541 and the p-channel TFT 544 when this impurity is introduced. A channel formation region 534 is formed.

Further, a phosphine (PH ₃ ) is used in the island-shaped semiconductor film 508 of the n-channel TFT 542 and the island-shaped semiconductor film 509 of the n-channel TFT 543, and an applied voltage of 40 to 80 keV, for example, 50 keV, a dose amount of 1.0 × Phosphorus (P) is introduced at 10 ^{15 to} 2.5 × 10 ¹⁶ cm ⁻² , for example, 3.0 × 10 ¹⁵ cm ⁻² . Thus, the low concentration impurity region 524 and the source or drain region 523 of the n-channel TFT 542, the low concentration impurity regions 527 and 530 of the n-channel TFT 543, and the source or drain regions 526, 529 and 532 are formed (FIG. 5 (see C)).

In this embodiment, each of the source region or drain region 523 of the n-channel TFT 542 and the source region or drain regions 526, 529, and 532 of the n-channel TFT 543 has a size of 1 × 10 ^{19 to} 5 × 10 ²¹ cm ^−. Phosphorus (P) will be contained at a concentration of ³ .

In addition, phosphorus (P) is present at a concentration of 1 × 10 ^{18 to} 5 × 10 ¹⁹ cm ⁻³ in each of the low-concentration impurity region 524 of the n-channel TFT 542 and the low-concentration impurity regions 527 and 530 of the n-channel TFT 543. included.

Further, boron (B) is contained in the source region or drain region 521 of the p-channel TFT 541 and the source region or drain region 533 of the p-channel TFT 544 at a concentration of 1 × 10 ^{19 to} 5 × 10 ²¹ cm ⁻³ , respectively. included.

  Next, a first interlayer insulating film 551 is formed to cover the island-shaped semiconductor film 507 to the island-shaped semiconductor film 510, the gate insulating film 514, and the gate electrode 515 to the gate electrode 519.

  As the first interlayer insulating film 551, an insulating film containing silicon, for example, a silicon oxide film, a silicon nitride film, a silicon oxide film containing nitrogen, or a stacked film thereof is formed using a plasma CVD method or a sputtering method. Needless to say, the first interlayer insulating film 551 is not limited to a silicon oxide film or silicon nitride film containing nitrogen, or a laminated film thereof, and other insulating films containing silicon may be used as a single layer or a laminated structure. .

  In this embodiment, after introducing impurities, a silicon oxide film containing nitrogen is formed to a thickness of 50 nm by a plasma CVD method. After the laser irradiation method or the silicon oxide film containing nitrogen is formed, the silicon oxide film is heated in a nitrogen atmosphere at 550 ° C. for 4 hours. , Activate the impurities.

  Next, a silicon nitride film is formed to a thickness of 50 nm by plasma CVD, and a silicon oxide film containing nitrogen is further formed to a thickness of 600 nm. The stacked film of the silicon oxide film containing nitrogen, the silicon nitride film, and the silicon oxide film containing nitrogen is the first interlayer insulating film 551.

  Next, the whole is heated at 410 ° C. for 1 hour, and hydrogen is released by releasing hydrogen from the silicon nitride film.

  Next, a second interlayer insulating film 552 which functions as a planarization film is formed so as to cover the first interlayer insulating film 551 (see FIG. 6A).

  As the second interlayer insulating film 552, a photosensitive or non-photosensitive organic material (polyimide, acrylic, polyamide, polyimide amide, resist, or benzocyclobutene), siloxane, and a stacked structure thereof can be used. As the organic material, a positive photosensitive organic resin or a negative photosensitive organic resin can be used.

  Siloxane has a skeletal structure with a bond of silicon (Si) and oxygen (O), and an organic group containing at least hydrogen (for example, an alkyl group or aromatic hydrocarbon) is used as a substituent. . 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 this embodiment, siloxane is formed as the second interlayer insulating film 552 by a spin coating method.

  Note that a third interlayer insulating film may be formed over the second interlayer insulating film 552. As the third interlayer insulating film, a film that hardly transmits moisture, oxygen, or the like as compared with other insulating films is used. Typically, a silicon nitride film, a silicon oxide film, a silicon nitride film containing oxygen (composition ratio N> O) or a silicon oxide film containing nitrogen (composition ratio N <O)) obtained by a sputtering method or a CVD method, A thin film mainly containing carbon (for example, a diamond-like carbon film (DLC film) or a carbon nitride film (CN film)) can be used.

  Next, a transparent conductive film 553 is formed over the second interlayer insulating film 552 (see FIG. 6B). As the transparent conductive film used in the present invention, indium tin oxide containing silicon (Si) (also referred to as indium tin oxide containing Si) is used.

In addition to indium tin oxide containing Si, a conductive material formed using a target in which zinc oxide (ZnO), tin oxide (SnO ₂ ), indium oxide, and indium oxide are mixed with ₂ to 20 wt% zinc oxide (ZnO). A transparent conductive film such as a film may be used. In this embodiment, indium tin oxide containing Si is formed to a thickness of 110 nm as the transparent conductive film 553 by sputtering.

  Next, a pixel electrode 554 is formed using the transparent conductive film 553 (see FIG. 6C). In order to form the pixel electrode 554, the transparent conductive film 553 may be etched by a wet etching method.

  The first interlayer insulating film 551 and the second interlayer insulating film 552 are etched to form contact holes reaching the island-shaped semiconductor film 507 to the island-shaped semiconductor film 510 in the first interlayer insulating film 551 and the second interlayer insulating film 552. It is formed (see FIG. 7A).

  A third conductive film 555 and a fourth conductive film 556 are formed over the second interlayer insulating film 552 through contact holes (see FIG. 7B).

  In this embodiment, the third conductive film 555 may be a film made of molybdenum (Mo), tungsten (W), tantalum (Ta), or chromium (Cr) or an alloy film using these elements. In this embodiment, molybdenum (Mo) is deposited to a thickness of 100 nm by a sputtering method.

  As the fourth conductive film 556, a film containing aluminum as a main component is formed by a sputtering method. The film containing aluminum as a main component is an aluminum alloy film containing at least one element selected from aluminum, nickel, cobalt, and iron, or an aluminum alloy film including at least one element selected from nickel, cobalt, and iron and carbon. Can be used. In this embodiment, an aluminum film is formed to 700 nm by sputtering.

  Next, the fourth conductive film 556 is etched, so that the electrode 561b, the electrode 562b, the electrode 563b, the electrode 564b, the electrode 565b, the electrode 566b, and the electrode 567b are formed (see FIG. 8A).

Etching of the fourth conductive film 556 is performed by dry etching using a mixed gas of BCl ₃ and Cl ₂ . In this embodiment, dry etching is performed by flowing BCl ₃ and Cl ₂ at flow rates of 60 sccm and 20 sccm, respectively.

At this time, the third conductive film 555 serves as an etching stopper, and the pixel electrode 554 is not in contact with the mixed gas of BCl ₃ and Cl ₂ . As a result, generation of particles can be prevented.

Next, the third conductive film 555 is etched to form an electrode 561a, an electrode 562a, an electrode 563a, an electrode 564a, an electrode 565a, an electrode 566a, and an electrode 567a. In this embodiment, dry etching of the third conductive film 555 is performed by flowing CF ₄ and O ₂ at 30 to 60 sccm and 40 to 70 sccm, respectively.

At this time, since the pixel electrode 554 does not react with CF ₄ and O ₂ , fine particles are not formed. In addition, the pixel electrode 554 serves as an etching stopper for etching the third conductive film 555 to form the electrode 567a.

  As described above, the electrode 561, the electrode 562, the electrode 563, the electrode 564, the electrode 565, the electrode 566, and the electrode 567 are formed. In each of the electrodes 561 to 567, the electrode and the wiring may be formed using the same material and the same process, or the electrode and the wiring may be separately formed and connected to each other.

  Through the above series of steps, an n-channel TFT 542, an n-channel TFT 543, a p-channel TFT 541, and a p-channel TFT 544 are formed. The n-channel TFT 542 and the p-channel TFT 541 are connected by an electrode 562 to form a CMOS circuit 571 (see FIG. 8B).

  From the above, the TFT substrate of the dual emission display device is formed. 8B, a driver circuit portion 595 and a pixel portion 596 are provided over a substrate 501, and a CMOS circuit 571 including an n-channel TFT 542 and a p-channel TFT 541 is formed in the driver circuit portion 595. ing.

  In the pixel portion 596, a p-channel TFT 544 serving as a pixel TFT and an n-channel TFT 543 for driving the pixel TFT are formed. In this embodiment, the pixel electrode 554 serves as an anode of the light emitting element.

  After the electrodes 561 to 567 are formed, an insulator 581 (referred to as a partition wall, a barrier, or the like) that covers an end portion of the pixel electrode 554 is formed. As the insulator 581, polyimide or polybenzoxazole is used.

  A method for baking the insulator 581 may be performed as described in Embodiment Mode. The solvent can be removed by heating at a temperature lower than the curing temperature, for example, 150 to 200 ° C. Then, by baking at a temperature higher than the curing temperature, for example, 300 to 350 ° C., it is possible to obtain an insulator (partition) with less degassing.

  After the insulator 581 is formed, an organic compound layer 582 is formed. Next, the second electrode 583, that is, the cathode of the light-emitting element is formed with a thickness of 10 nm to 800 nm (see FIG. 9B). As the second electrode 583, in addition to indium tin oxide (ITO), for example, an electrode formed using a target in which 2 to 20 wt% zinc oxide (ZnO) is mixed with indium oxide containing Si element is used. Can be used.

  The organic compound layer 582 includes a hole injection layer 601, a hole transport layer 602, a light emitting layer 603, an electron transport layer 604, and an electron injection layer 605 that are formed using a vapor deposition method or a coating method. Note that deaeration is preferably performed by vacuum heating before the formation of the organic compound layer 582 in order to improve the reliability of the light-emitting element. For example, before vapor deposition of the organic compound material, it is desirable to perform a heat treatment at 200 ° C. to 300 ° C. in a reduced pressure atmosphere or an inert atmosphere in order to remove gas contained in the substrate.

  Next, molybdenum oxide (MoOx) and 4,4′-bis [N- (1-naphthyl) -N-phenyl-amino] -biphenyl (α-) are selectively formed over the pixel electrode 554 using an evaporation mask. NPD) and rubrene are co-evaporated to form the hole injection layer 601.

  In addition to MoOx, a material having a high hole injection property such as copper phthalocyanine (CuPc), vanadium oxide (VOx), ruthenium oxide (RuOx), or tungsten oxide (WOx) can be used. In addition, a material in which a high hole-injection polymer material such as a polyethylene dioxythiophene aqueous solution (PEDOT) or a polystyrene sulfonic acid aqueous solution (PSS) is formed by a coating method may be used as the hole injection layer 601.

  Next, α-NPD is selectively deposited using a deposition mask to form a hole transport layer 602 on the hole injection layer 601. In addition to α-NPD, 4,4′-bis [N- (3-methylphenyl) -N-phenyl-amino] -biphenyl (abbreviation: TPD), 4,4 ′, 4 ″ -tris (N , N-diphenyl-amino) -triphenylamine (abbreviation: TDATA), 4,4 ′, 4 ″ -tris [N- (3-methylphenyl) -N-phenyl-amino] -triphenylamine (abbreviation: A material having a high hole transporting property typified by an aromatic amine compound such as MTDATA) can be used.

  Next, the light-emitting layer 603 is selectively formed. In order to obtain a full-color display device, the vapor deposition mask is aligned for each of the emission colors (R, G, B) to selectively deposit each.

Next, Alq ₃ (tris (8-quinolinolato) aluminum) is selectively vapor-deposited using an evaporation mask to form an electron transport layer 604 over the light-emitting layer 603. In addition to Alq ₃ , tris (4-methyl-8-quinolinolato) aluminum (abbreviation: Almq ₃ ), bis (10-hydroxybenzo [h] -quinolinato) beryllium (abbreviation: BeBq ₂ ), bis (2-methyl) A material having a high electron transport property typified by a metal complex having a quinoline skeleton such as -8-quinolinolato) -4-phenylphenolato-aluminum (abbreviation: BAlq) or a benzoquinoline skeleton can be used.

In addition, bis [2- (2-hydroxyphenyl) -benzoxazolate] zinc (abbreviation: Zn (BOX) ₂ ), bis [2- (2-hydroxyphenyl) -benzothiazolate] zinc (abbreviation: Zn ( A metal complex having an oxazole-based or thiazole-based ligand such as BTZ) ₂ ) can also be used.

  In addition to metal complexes, 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 1, 4-triazole (abbreviation: p-EtTAZ), bathophenanthroline (abbreviation: BPhen), bathocuproin (abbreviation: BCP), and the like can also be used as the electron-transport layer 604 because of their high electron-transport properties.

  Next, 4,4-bis (5-methylbenzoxazol-2-yl) stilbene (abbreviation: BzOs) and lithium (Li) are co-evaporated to cover the electron transport layer 604 and the insulator 581 and inject electrons onto the entire surface. Layer 605 is formed. By using a benzoxazole (also referred to as benzoxazole) derivative (BzOS), damage due to a sputtering method at the time of forming the second electrode 583 performed in a later step is suppressed.

In addition to BzOs: Li, a material having a high electron-injection property such as an alkali metal or alkaline earth metal compound such as CaF ₂ , lithium fluoride (LiF), and cesium fluoride (CsF) can be used. . In addition, a mixture of Alq ₃ and magnesium (Mg) can also be used.

  Next, the second electrode 583, that is, the cathode of the organic light-emitting element is formed over the electron injecting layer 605 in a thickness range of 10 nm to 800 nm. As the second electrode 583, in addition to indium tin oxide (ITO), for example, a conductive film formed using indium tin oxide containing Si or a target containing 2 to 20% zinc oxide (ZnO) in indium oxide is used. Can be used.

  Note that this embodiment describes an example of manufacturing a dual emission display device, and thus a light-transmitting electrode is used for the second electrode 583. However, in the case of manufacturing a single emission display device, The second electrode 583 may be formed using a conductive material that reflects. As such a conductive material, a metal, an alloy, an electrically conductive compound, a mixture thereof, or the like having a low work function (work function of 3.8 eV or less) is preferably used.

Note that specific examples of the material of the second electrode 583 include elements belonging to Group 1 or Group 2 of the periodic table, that is, alkali metals such as Li and Cs, and alkaline earth metals such as Mg, Ca, and Sr. In addition to alloys containing these (Mg: Ag, Al: Li) and compounds (LiF, CsF, CaF ₂ ), transition metals including rare earth metals can be used, but metals such as Al and Ag ( It can also be formed by lamination with an alloy.

  As described above, the light-emitting element 584 is manufactured. The materials for the anode 554, the organic compound layer 582, and the cathode 583 included in the light-emitting element 584 are appropriately selected, and the film thicknesses are also adjusted. It is desirable that the same material is used for the anode and the cathode, and the film thickness is approximately the same, preferably approximately 100 nm.

  If necessary, as shown in FIG. 9B, a transparent protective layer 585 which covers the light-emitting element 584 and prevents moisture from entering is formed. As the transparent protective layer 585, a silicon nitride film, a silicon oxide film, a silicon nitride film containing oxygen (composition ratio N> O) or a silicon oxide film containing nitrogen (composition ratio N <O) obtained by sputtering or CVD is used. A thin film mainly containing carbon (for example, a diamond-like carbon film (DLC film), a carbon nitride film (CN film)), or the like can be used. FIG. 10 shows an enlarged view of a part of FIG.

  FIG. 12 shows an example in which the pixel TFTs in the pixel portion are separately formed by RGB. In the pixel for red (R), a pixel TFT 544R is connected to the pixel electrode 554R, and a hole injection layer 601R, a hole transport layer 602R, a light emitting layer 603R, an electron transport layer 604R, an electron injection layer 605R, and a cathode 583. A transparent protective layer 585 is formed.

  In the pixel for green (G), a pixel TFT 544G is connected to the pixel electrode 554G, and a hole injection layer 601G, a hole transport layer 602G, a light emitting layer 603G, an electron transport layer 604G, an electron injection layer 605G, a cathode 583 and a transparent protective layer 585 are formed.

  Further, the pixel TFT 544B is connected to the pixel electrode 554B in the blue (B) pixel, and the hole injection layer 601B, the hole transport layer 602B, the light emitting layer 603B, the electron transport layer 604B, the electron injection layer 605B, the cathode 583 and a transparent protective layer 585 are formed.

For the light-emitting layer 603R that emits red light, a material such as Alq ₃ : DCM or Alq ₃ : rubrene: BisDCJTM is used. For the light-emitting layer 603G that emits green light, a material such as Alq ₃ : DMQD (N, N′-dimethylquinacridone) or Alq ₃ : coumarin 6 is used. For the light-emitting layer 603B that emits blue light, a material such as α-NPD or tBu-DNA is used.

  Next, a sealant 593 containing a gap material for securing a substrate interval is provided over the driver circuit portion 595 including the CMOS circuit 571, and the second substrate 591 and the substrate 501 are attached to each other. As the second substrate 591, a light-transmitting glass substrate or quartz substrate may be used.

  Note that in the gap between the substrates 501 and 591, a desiccant may be disposed as a gap (inert gas) in a region 592 where the pixel portion 596 is provided, or a transparent sealing material (ultraviolet curing or heat treatment). A cured epoxy resin or the like may be filled.

  In the light-emitting element, since the pixel electrode 554 and the second electrode 583 are formed using a light-transmitting material, light can be collected from one light-emitting element in two directions, that is, from both sides.

  With the panel configuration described above, light emission from the upper surface and light emission from the lower surface can be made substantially the same.

  Further, optical films (polarizing plates or circularly polarizing plates) 597 and 598 may be provided on the substrates 501 and 591 to improve contrast (see FIG. 11).

  In this embodiment, the top gate type TFT is used as the TFT. However, the present invention is not limited to this structure, and a bottom gate type (reverse stagger type) TFT or a forward stagger type TFT can be used as appropriate. . Further, the TFT is not limited to a single-gate TFT, and may be a multi-gate TFT having a plurality of channel formation regions, for example, a double-gate TFT.

  The light-emitting device of this embodiment can suppress generation of moisture, gas, and the like from the insulator 581 and can manufacture a favorable display device with high reliability and a long lifetime.

  In addition, this embodiment can be freely combined with the embodiment mode and Embodiments 1 to 3 if necessary.

  In this embodiment, an example in which the present invention is applied to an inorganic EL element will be described with reference to FIGS. 13 (A) to 13 (C) and FIGS. 14 (A) to 14 (C).

  A light-emitting element utilizing electroluminescence is distinguished depending on whether the light-emitting material is an organic compound or an inorganic compound. Generally, the former is called an organic EL element and the latter is called an inorganic EL element. An example in which the organic EL element is used in the present invention is described in Example 4.

  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 an electroluminescent layer in which particles of a luminescent material are dispersed in a binder, and the latter has an electroluminescent layer made of a thin film of luminescent material, but is accelerated by a high electric field. This is common in that it requires more electrons.

  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 serving 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 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 the sulfide include zinc sulfide (ZnS), cadmium sulfide (CdS), calcium sulfide (CaS), yttrium sulfide (Y ₂ S ₃ ), gallium sulfide (Ga ₂ S ₃ ), strontium sulfide (SrS), sulfide. Barium (BaS) or the like can be used. As the oxide, for example, zinc oxide (ZnO), yttrium oxide (Y ₂ O ₃ ), or the like can be used. As the nitride, for example, aluminum nitride (AlN), gallium nitride (GaN), indium nitride (InN), or the like can be used.

Further, as a base material used for a light emitting material, zinc selenide (ZnSe), zinc telluride (ZnTe), or the like can be used. Calcium sulfide-gallium (CaGa ₂ S ₄ ), strontium sulfide-gallium (SrGa ₂ S ₄ ) Or a ternary mixed crystal such as barium-gallium sulfide (BaGa ₂ S ₄ ).

  As emission centers of 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 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 emission center of 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 examples of the first impurity element or the compound containing the first impurity element include fluorine (F), chlorine (Cl), and aluminum sulfide (Al ₂ S). ₃ ) or the like, and examples of the second impurity element or the compound containing the second impurity element include copper (Cu), silver (Ag), copper sulfide (Cu ₂ S), and silver sulfide (Ag). ₂ S) 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 including the first impurity element and the second impurity element, for example, copper chloride (CuCl), silver chloride (AgCl), or the like can be used.

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

  In the case of a thin-film inorganic EL, the electroluminescent layer is a layer containing the above-described luminescent material, and is a physical vapor deposition method such as a resistance heating vapor deposition method, a vacuum vapor deposition method such as 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 250, an electroluminescent layer 252, and a second electrode layer 253.

  In order to fabricate a light-emitting device using the light-emitting elements of FIGS. 13A to 13C, the light-emitting device of FIG. The light-emitting element may be replaced with the light-emitting element 584 in FIG.

  13B and 13C has a structure in which an insulating layer is provided between the electrode layer and the electroluminescent layer in the light-emitting element in FIG. 13A. 13B includes an insulating layer 254 between the first electrode layer 250 and the electroluminescent layer 252, and the light-emitting element illustrated in FIG. 13C includes the first electrode layer 250. And an electroluminescent layer 252, and an insulating layer 254 b is provided between the second electrode layer 253 and the electroluminescent layer 252. Thus, the insulating layer may be provided only between one of the pair of electrode layers sandwiching the electroluminescent layer, or may be provided between both. Further, the insulating layer may be a single layer or a stacked layer including a plurality of layers.

  In FIG. 13B, the insulating layer 254 is provided so as to be in contact with the first electrode layer 250; however, the order of the insulating layer and the electroluminescent layer is reversed so as to be in contact with the second electrode layer 253. An insulating layer 254 may be provided.

  In the case of a dispersion-type inorganic EL, a particulate luminescent material is dispersed in a binder to form a film-like electroluminescent 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 an electroluminescent layer. The light emitting material is uniformly dispersed and fixed in the electroluminescent layer by the binder.

  In the case of a dispersion-type inorganic EL, the electroluminescent layer can be formed by a droplet discharge method capable of selectively forming an electroluminescent layer, a printing method (screen printing, offset printing, etc.), a coating method such as a spin coating method, dipping, etc. It is also possible to use a method or a dispenser method. The film thickness is not particularly limited, but is preferably in the range of 10 to 1000 nm. In the electroluminescent 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.

  14A to 14C illustrate an example of a dispersion-type inorganic EL element that can be used as a light-emitting element. The light-emitting element in FIG. 14A has a stacked structure of a first electrode layer 260, an electroluminescent layer 262, and a second electrode layer 263, and a light-emitting material 261 held in a binder in the electroluminescent layer 262. Including.

  In order to fabricate a light-emitting device using the light-emitting elements of FIGS. 14A to 14C, the light-emitting device of FIG. 11 described in Example 4 can be manufactured using FIGS. 14A to 14C. The light-emitting element may be replaced with the light-emitting element 584 in FIG.

  As a binder that can be used in this embodiment, an organic material or an inorganic material can be used, and a mixed material of an organic material and an inorganic material may be used. As the organic 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.

Alternatively, a resin material such as a vinyl resin such as polyvinyl alcohol or polyvinyl butyral, a phenol resin, a novolac resin, an acrylic resin, a melamine resin, a urethane resin, or an oxazole resin (polybenzoxazole) may be used. The dielectric constant can be adjusted by appropriately mixing fine particles of high dielectric constant such as barium titanate (BaTiO ₃ ) and strontium titanate (SrTiO ₃ ) with these resins.

Examples of the inorganic material contained in the binder include silicon oxide (SiOx), silicon nitride (SiN _x ), silicon containing oxygen and nitrogen, aluminum nitride (AlN), aluminum containing oxygen and nitrogen, or aluminum oxide (Al ₂ O ₃ ). , Titanium oxide (TiO ₂ ), BaTiO ₃ , SrTiO ₃ , lead titanate (PbTiO ₃ ), potassium niobate (KNbO ₃ ), lead niobate (PbNbO ₃ ), tantalum oxide (Ta ₂ O ₅ ), barium tantalate (BaTa ₂ O ₆ ), lithium tantalate (LiTaO ₃ ), yttrium oxide (Y ₂ O ₃ ), zirconium oxide (ZrO ₂ ), zinc sulfide (ZnS), and other materials selected from inorganic materials Can be formed. By including an inorganic material having a high dielectric constant in the organic material (by addition or the like), the dielectric constant of the electroluminescent layer made of the light emitting material and the binder can be further controlled, and the dielectric constant can be further increased. .

  In the manufacturing process, the light emitting material is dispersed in a solution containing a binder, but as a solvent of the solution containing the binder that can be used in this embodiment, a method of forming an electroluminescent layer by dissolving the binder material (various wet types) A solvent capable of producing a solution having a viscosity suitable for the process) and a desired film thickness may be appropriately selected. 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 has a structure in which an insulating layer is provided between the electrode layer and the electroluminescent layer in the light-emitting element in FIG. 14A. The light-emitting element illustrated in FIG. 14B includes an insulating layer 264 between the first electrode layer 260 and the electroluminescent layer 262, and the light-emitting element illustrated in FIG. 14C includes the first electrode layer 260. And an electroluminescent layer 262, and an insulating layer 264b is provided between the second electrode layer 263 and the electroluminescent layer 262. Thus, the insulating layer may be provided only between one of the pair of electrode layers sandwiching the electroluminescent layer, or may be provided between both. Further, the insulating layer may be a single layer or a stacked layer including a plurality of layers.

  In FIG. 14B, the insulating layer 264 is provided so as to be in contact with the first electrode layer 260; however, the order of the insulating layer and the electroluminescent layer is reversed so as to be in contact with the second electrode layer 263. An insulating layer 264 may be provided on the substrate.

  Insulating layers such as the insulating layer 254 in FIG. 13B, the insulating layers 254a and 254b in FIG. 13C, the insulating layer 264 in FIG. 14B, and the insulating layers 264a and 264b in FIG. Although not particularly limited, it is preferable that the withstand voltage is high and the film quality is dense, and further, the dielectric constant is preferably high.

For example, silicon oxide (SiO ₂ ), yttrium oxide (Y ₂ O ₃ ), titanium oxide (TiO ₂ ), aluminum oxide (Al ₂ O ₃ ), hafnium oxide (HfO ₂ ), tantalum oxide (Ta ₂ O ₅ ), Barium titanate (BaTiO ₃ ), strontium titanate (SrTiO ₃ ), lead titanate (PbTiO ₃ ), silicon nitride (Si ₃ N ₄ ), zirconium oxide (ZrO ₂ ), etc., a mixed film thereof, or two or more kinds thereof A laminated film can be used.

  These insulating films can be formed by sputtering, vapor deposition, CVD, 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 electroluminescent layer. The film thickness is not particularly limited, but is preferably in the range of 10 to 1000 nm.

  The light-emitting element described in this embodiment can emit light by applying a voltage between a pair of electrode layers sandwiching an electroluminescent layer, but can operate in either DC driving or AC driving.

  By applying the present invention to an inorganic EL element, generation of gas and moisture from a partition wall (insulator) can be suppressed. In particular, by preventing generation of moisture that adversely affects the inorganic EL element, it is possible to extend the life of the inorganic EL element and a light-emitting device using the inorganic EL element more than usual.

  Further, this embodiment can be freely combined with the embodiment mode and other embodiments if necessary.

  Electronic devices to which the present invention is applied include cameras such as video cameras and digital cameras, goggle-type displays, navigation systems, sound playback devices (car audio components, etc.), computers, game devices, and portable information terminals (mobile computers, mobile phones). An image playback apparatus (specifically, a digital versatile disc (DVD)) such as a telephone, a portable game machine, or an electronic book), and an apparatus including a display that can display the image. ) And the like.

  Specific examples of these electronic devices are shown in FIGS. 15, 16, 17A to 17B, 18, 19, 20, 21A to 21E.

  FIG. 15 shows an EL module in which a display panel 301 and a circuit board 311 are combined. A control circuit 312, a signal dividing circuit 313, and the like are formed on the circuit board 311, and are electrically connected to the display panel 301 by connection wiring 314.

  The display panel 301 includes a pixel portion 302 provided with a plurality of pixels, a scanning line driving circuit 303, and a signal line driving circuit 304 for supplying a video signal to the selected pixel. The display panel 301 of the EL module may be manufactured using the method for manufacturing a display device described in Embodiment 4 or Embodiment 5.

  A television receiver can be completed with the EL module shown in FIG. FIG. 16 is a block diagram showing the main configuration of the receiver. The tuner 321 receives video signals and audio signals. The video signal includes a video signal amplifying circuit 322, a video signal processing circuit 323 that converts a signal output from the video signal into a color signal corresponding to each color of red, green, and blue, and the video signal as input specifications of the driver IC. Processing is performed by the control circuit 312 for conversion. The control circuit 312 outputs signals to the scanning line side and the signal line side, respectively. In the case of digital driving, a signal dividing circuit 313 may be provided on the signal line side, and an input digital signal may be divided into m pieces and supplied.

  Of the signals received by the tuner 321, the audio signal is sent to the audio signal amplifier circuit 325, and the output is supplied to the speaker 327 via the audio signal processing circuit 326. The control circuit 328 receives control information on the receiving station (reception frequency) and volume from the input unit 329 and sends a signal to the tuner 321 and the audio signal processing circuit 326.

  As shown in FIG. 17A, an EL module can be incorporated into a housing 331 to complete a television receiver. A display screen 332 is formed by the EL module. In addition, a speaker 333, an operation switch 334, and the like are provided as appropriate.

  FIG. 17B illustrates a television receiver that can carry only a display wirelessly. A battery and a signal receiver are incorporated in the housing 342, and the display portion 343 and the speaker portion 347 are driven by the battery. The battery can be repeatedly charged by the charger 340. In addition, the charger 340 can transmit and receive a video signal, and can transmit the video signal to a signal receiver of the display. The housing 342 is controlled by operation keys 346.

  The device illustrated in FIG. 17B can also be referred to as a video / audio two-way communication device because a signal can be sent from the housing 342 to the charger 340 by operating the operation key 346. Further, by operating the operation key 346, a signal is transmitted from the housing 342 to the charger 340, and further, a signal that can be transmitted by the charger 340 is received by another electronic device, so that communication control of the other electronic device can be performed. It can be said to be a general-purpose remote control device. The present invention can be applied to the display portion 343.

  By using the present invention for the television receiver shown in FIGS. 15, 16, 17A to 17B, a highly reliable and excellent television receiver can be obtained.

  Of course, the present invention is not limited to a television receiver, and is applied to various uses as a display medium of a particularly large area such as a monitor of a personal computer, an information display board in a railway station or airport, an advertisement display board in a street, etc. can do.

  18 and 19 show a module in which a display panel 351 and a printed wiring board 352 are combined. The display panel 351 includes a pixel portion 353 provided with a plurality of pixels, a first scan line driver circuit 354, a second scan line driver circuit 355, and a signal line driver circuit that supplies a video signal to the selected pixel. 356.

  The printed wiring board 352 includes a controller 357, a central processing unit (CPU) 358, a memory 359, a power supply circuit 360, an audio processing circuit 361, a transmission / reception circuit 362, and the like. The printed wiring board 352 and the display panel 351 are connected by a flexible wiring board (FPC) 363. The printed wiring board 352 may be provided with a capacitor, a buffer circuit, or the like so that noise is added to the power supply voltage or the signal or the rise of the signal is not slowed. The controller 357, the audio processing circuit 361, the memory 359, the CPU 358, the power supply circuit 360, and the like can be mounted on the display panel 351 by using a COG (Chip On Glass) method. The scale of the printed wiring board 352 can be reduced by the COG method.

  Various control signals are input and output through an interface 364 provided on the printed wiring board 352. An antenna port 365 for transmitting and receiving signals to and from the antenna is provided on the printed wiring board 352.

  FIG. 19 shows a block diagram of the module shown in FIG. This module includes a VRAM 366, a DRAM 367, a flash memory 368, and the like as the memory 359. The VRAM 366 stores image data to be displayed on the panel, the DRAM 367 stores image data or audio data, and the flash memory stores various programs.

  The power supply circuit 360 supplies power for operating the display panel 351, the controller 357, the CPU 358, the sound processing circuit 361, the memory 359, and the transmission / reception circuit 362. Depending on the panel specifications, the power supply circuit 360 may be provided with a current source.

  The CPU 358 includes a control signal generation circuit 370, a decoder 371, a register 372, an arithmetic circuit 373, a RAM 374, an interface 379 for the CPU 358, and the like. Various signals input to the CPU 358 via the interface 379 are once held in the register 372 and then input to the arithmetic circuit 373, the decoder 371, and the like. The arithmetic circuit 373 performs an operation based on the input signal and designates a place to send various commands. On the other hand, the signal input to the decoder 371 is decoded and input to the control signal generation circuit 370. The control signal generation circuit 370 generates a signal including various instructions based on the input signal, and a location designated by the arithmetic circuit 373, specifically, a memory 359, a transmission / reception circuit 362, an audio processing circuit 361, a controller 357, and the like. Send to.

  The memory 359, the transmission / reception circuit 362, the sound processing circuit 361, and the controller 357 operate according to the received commands. The operation will be briefly described below.

  A signal input from the input unit 375 is sent to the CPU 358 mounted on the printed wiring board 352 via the interface 364. The control signal generation circuit 370 converts the image data stored in the VRAM 366 into a predetermined format in accordance with a signal sent from the input unit 375 such as a pointing device or a keyboard, and sends the image data to the controller 357.

  The controller 357 performs data processing on a signal including image data sent from the CPU 358 according to the specifications of the panel and supplies the processed signal to the display panel 351. The controller 357 generates an Hsync signal, a Vsync signal, a clock signal CLK, an AC voltage (AC Cont), and a switching signal L / R based on the power supply voltage input from the power supply circuit 360 and various signals input from the CPU 358. It is generated and supplied to the display panel 351.

  The transmission / reception circuit 362 processes signals transmitted and received as radio waves in the antenna 378. Specifically, high-frequency signals such as isolators, bandpass filters, VCOs (Voltage Controlled Oscillators), LPFs (Low Pass Filters), couplers, and baluns are used. Includes circuitry. A signal including audio information among signals transmitted and received in the transmission / reception circuit 362 is sent to the audio processing circuit 361 in accordance with a command from the CPU 358.

  A signal including audio information sent in accordance with a command from the CPU 358 is demodulated into an audio signal by the audio processing circuit 361 and sent to the speaker 377. The audio signal sent from the microphone 376 is modulated by the audio processing circuit 361 and sent to the transmission / reception circuit 362 in accordance with a command from the CPU 358.

  The controller 357, the CPU 358, the power supply circuit 360, the sound processing circuit 361, and the memory 359 can be mounted as a package of this embodiment. This embodiment can be applied to any circuit other than a high-frequency circuit such as an isolator, a band pass filter, a VCO (Voltage Controlled Oscillator), an LPF (Low Pass Filter), a coupler, and a balun.

  FIG. 20 shows one mode of a mobile phone including the module shown in FIGS. The display panel 351 is incorporated in the housing 380 so as to be detachable. The shape and dimensions of the housing 380 can be changed as appropriate in accordance with the size of the display panel 351. The housing 380 to which the display panel 351 is fixed is fitted on the printed circuit board 381 and assembled as a module.

  The display panel 351 is connected to the printed board 381 through the FPC 363. A signal processing circuit 385 including a speaker 382, a microphone 383, a transmission / reception circuit 384, a CPU, a controller, and the like is formed on the printed board 381. Such a module is combined with the input means 386, the battery 387, and the antenna 390 and stored in the housing 389. The pixel portion of the display panel 351 is arranged so that it can be seen from an opening window formed in the housing 389.

  The mobile phone according to the present embodiment can be transformed into various modes according to the function and application. For example, the above-described effects can be obtained even when a plurality of display panels are provided, or the housing is divided into a plurality of cases and is opened and closed by a hinge.

  By using the present invention for the mobile phone shown in FIGS. 18, 19, and 20, it is possible to obtain a good mobile phone having a long life and high reliability.

  FIG. 21A illustrates an EL display which includes a housing 401, a support base 402, a display portion 403, and the like. The present invention can be applied to the display portion 403 by using the structure of the EL module shown in FIG. 15 and the display panel shown in FIG.

  By using the present invention, a good display with a long lifetime and high reliability can be obtained.

  FIG. 21B illustrates a computer, which includes a main body 411, a housing 412, a display portion 413, a keyboard 414, an external connection port 415, a pointing device 416, and the like. The present invention can be applied to the display portion 413 using the structure of the EL module shown in FIG. 15 and the display panel shown in FIG.

  By using the present invention, a good computer with a long lifetime and high reliability can be obtained.

  FIG. 21C illustrates a portable computer, which includes a main body 421, a display portion 422, a switch 423, operation keys 424, an infrared port 425, and the like. The present invention can be applied to the display portion 422 by using the structure of the EL module shown in FIG. 15 and the display panel shown in FIG.

  By using the present invention, a good computer with a long lifetime and high reliability can be obtained.

  FIG. 21D illustrates a portable game machine including a housing 431, a display portion 432, a speaker portion 433, operation keys 434, a recording medium insertion portion 435, and the like. The present invention can be applied to the display portion 432 using the structure of the EL module shown in FIG. 15 and the display panel shown in FIG.

  By using the present invention, a reliable game machine with a long lifetime can be obtained.

  FIG. 21E illustrates a portable image playback device (specifically, a DVD playback device) including a recording medium, which includes a main body 441, a housing 442, a first display portion 443, a second display portion 444, A recording medium reading unit 445, operation keys 446, a speaker unit 447, and the like are included. Note that the recording medium includes a DVD or the like.

  The first display unit 443 mainly displays image information, and the second display unit 444 mainly displays character information. The present invention can be applied to the first display portion 443 and the second display portion 444 by using the structure of the EL module shown in FIG. 15 and the display panel shown in FIG. Note that an image reproducing device provided with a recording medium includes a home game machine and the like.

  By using the present invention, it is possible to obtain a good and reliable image reproducing apparatus having a long lifetime.

  Display devices used in these electronic devices can use not only a glass substrate but also a heat-resistant plastic substrate depending on the size, strength, or purpose of use. As a result, the weight can be further reduced.

  In addition, the example shown in the present embodiment is only an example, and is not limited to these applications.

  In addition, this embodiment can be freely combined with the embodiment mode and other embodiments.

  The present invention can be used for light emitting devices and semiconductor devices using EL elements. Since the generation of gas and moisture is suppressed, the partition wall of the present invention can prevent adverse effects on the light emitting layer of the EL element. Accordingly, it is possible to obtain a light-emitting device and a semiconductor device with a long lifetime and high reliability.

FIG. 11 illustrates a semiconductor device of the present invention. 10A and 10B illustrate a manufacturing process of a semiconductor device of the present invention. 10A and 10B illustrate a manufacturing process of a semiconductor device of the present invention. 10A and 10B illustrate a manufacturing process of a semiconductor device of the present invention. 10A and 10B illustrate a manufacturing process of a semiconductor device of the present invention. 10A and 10B illustrate a manufacturing process of a semiconductor device of the present invention. 10A and 10B illustrate a manufacturing process of a semiconductor device of the present invention. 10A and 10B illustrate a manufacturing process of a semiconductor device of the present invention. 10A and 10B illustrate a manufacturing process of a semiconductor device of the present invention. 10A and 10B illustrate a manufacturing process of a semiconductor device of the present invention. 10A and 10B illustrate a manufacturing process of a semiconductor device of the present invention. 10A and 10B illustrate a manufacturing process of a semiconductor device of the present invention. 10A and 10B illustrate a manufacturing process of a semiconductor device of the present invention. 10A and 10B illustrate a manufacturing process of a semiconductor device of the present invention. FIG. 6 shows a manufacturing process of an EL module of the present invention. 1 is a block diagram illustrating a configuration of a receiver according to the present invention. FIG. 11 illustrates an example of an electronic device to which the present invention is applied. The figure which shows the manufacturing process of the module of this invention. The figure which shows the manufacturing process of the module of this 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. The figure which shows the measurement result of the light emitting element of this invention. The figure which shows the measurement result of the light emitting element of this invention. The figure which shows the measurement result of the light emitting element of this invention. The figure which shows the measurement result of the light emitting element of this invention. The figure which shows the measurement result of the light emitting element of this invention. The figure which shows the measurement result of the light emitting element of this invention. The figure which shows the measurement result of the light emitting element of this invention. The figure which shows the measurement result of the light emitting element of this invention. The figure which shows the measurement result of the light emitting element of this invention. The figure which shows the measurement result of the light emitting element of this invention. The figure which shows the measurement result of the light emitting element of this invention. The figure which shows the measurement result of the light emitting element of this invention. The figure which shows the measurement result of the light emitting element of this invention. The figure which shows the measurement result of the light emitting element of this invention. The figure which shows the measurement result of the light emitting element of this invention. The figure which shows the measurement result of the light emitting element of this invention. The figure which shows the measurement result of the light emitting element of this invention. The figure which shows the measurement result of the light emitting element of this invention. The figure which shows the measurement result of the light emitting element of this invention. The figure which shows the measurement result of the light emitting element of this invention. The figure which shows the measurement result of the light emitting element of this invention. The figure which shows the measurement result of the light emitting element of this invention. The figure which shows the measurement result of the light emitting element of this invention. The figure which shows the measurement result of the light emitting element of this invention.

Explanation of symbols

101 Substrate 102 Electrode 103 Partition 104 Light emitting layer 105 Electrode 107 Resin material 121 Quartz pillar 122 Sample stage 123 Thermocouple 124 Thermocouple 125 Sample 250 Electrode layer 252 Electroluminescent layer 253 Electrode layer 254 Insulating layer 254a Insulating layer 254b Insulating layer 260 Electrode layer 261 Luminescent material 262 Electroluminescent layer 263 Electrode layer 264 Insulating layer 264a Insulating layer 264b Insulating layer 301 Display panel 302 Pixel portion 303 Scan line driver circuit 304 Signal line driver circuit 311 Circuit board 312 Control circuit 313 Signal dividing circuit 314 Connection wiring 321 Tuner 322 Video signal amplification circuit 323 Video signal processing circuit 325 Audio signal amplification circuit 326 Audio signal processing circuit 327 Speaker 328 Control circuit 329 Input unit 331 Housing 332 Display screen 333 Speaker 334 Operation switch 340 charger 342 housing 343 display unit 346 operation keys 347 speaker 351 display panel 352 printed circuit board 353 a pixel portion 354 the scan line driver circuit 355 scanning-line drive circuit 356 the signal line driver circuit 357 controller 358 CPU
359 Memory 360 Power supply circuit 361 Audio processing circuit 362 Transmission / reception circuit 363 FPC
364 Interface 365 Antenna port 366 VRAM
367 DRAM
368 Flash memory 370 Control signal generation circuit 371 Decoder 372 Register 373 Arithmetic circuit 374 RAM
375 Input means 376 Microphone 377 Speaker 378 Antenna 379 Interface 380 Housing 381 Printed circuit board 382 Speaker 383 Microphone 384 Transmission / reception circuit 385 Signal processing circuit 386 Input means 387 Battery 389 Case 390 Antenna 401 Case 402 Support base 403 Display unit 411 Main body 412 Case Body 413 Display unit 414 Keyboard 415 External connection port 416 Pointing device 421 Main unit 422 Display unit 423 Switch 424 Operation key 425 Infrared port 431 Case 432 Display unit 433 Speaker unit 434 Operation key 435 Recording medium insertion unit 441 Main unit 442 Case 443 Display Unit 444 display unit 445 recording medium reading unit 446 operation key 447 speaker unit 500 laser beam 501 substrate 502 base film 5 2a lower base film 502b upper base film 503 semiconductor film 504 solution 505 semiconductor film 506 crystalline semiconductor film 507 island-like semiconductor film 508 island-like semiconductor film 509 island-like semiconductor film 510 island-like semiconductor film 511 insulating film 512 conductive film 513 conductive film 514 Gate insulating film 515 Gate electrode 515a Lower gate electrode 515b Upper gate electrode 516 Gate electrode 516a Lower gate electrode 516b Upper gate electrode 517 Gate electrode 517a Lower gate electrode 517b Upper gate electrode 518 Gate electrode 518a Lower gate electrode 518b Upper gate electrode 519 Gate Electrode 519a Lower gate electrode 519b Upper gate electrode 521 Source region or drain region 522 Channel formation region 523 Source region or drain region 524 Low concentration impurity region 525 Channel formation Frequency 526 source and drain regions 527 lightly doped regions 528 channel forming region 529 source region and a drain region 530 the low concentration impurity regions 531 channel forming region 532 source region or drain region 533 source and drain regions 534 a channel forming region 541 TFT
542 TFT
543 TFT
544 TFT
544R pixel TFT
544G pixel TFT
544B pixel TFT
551 insulating film 552 insulating film 553 transparent conductive film 554 pixel electrode 554R pixel electrode 554G pixel electrode 554B pixel electrode 555 conductive film 556 conductive film 561 electrode 561a electrode 561b electrode 562 electrode 562a electrode 562b electrode 563 electrode 563a electrode 563b electrode 564 electrode 564 electrode 564b Electrode 565a Electrode 565a Electrode 565b Electrode 566 Electrode 566a Electrode 566b Electrode 567 Electrode 567a Electrode 567b Electrode 571 CMOS circuit 581 Insulator 582 Organic compound layer 583 Electrode 584 Light emitting element 585 Transparent protective layer 591 Substrate 592 Region 593 Drive circuit 595 Drive circuit 596 Pixel portion 597 Optical film 598 Optical film 601 Hole injection layer 601R Hole injection layer 601G Hole injection layer 601B Hole injection layer 602 Hole transport 602R hole transport layer 602G hole transport layer 602B hole transport layer 603 light emitting layer 603R light emitting layer 603G light emitting layer 603B light emitting layer 604 electron transport layer 604R electron transport layer 604G electron transport layer 604B electron transport layer 605 electron injection layer 605R electron injection Layer 605G Electron injection layer 605B Electron injection layer

Claims (6)

Forming a first electrode on a substrate;
A partition wall is formed using a resin material on the substrate and the first electrode,
The partition is raised at a constant rate of temperature from a temperature lower than the curing temperature and higher than room temperature to a first temperature that is lower than the curing temperature using a heating means , and then at the first temperature, Hold for the first time,
After holding at the first temperature, the partition wall, until said second temperature is higher than the curing temperature the temperature is increased at a constant heating rate, a subsequent second temperature, and held a second time And the second time is set equal to the first time,
After being held at the second temperature, it is taken out from the heating means at a temperature higher than room temperature, allowed to cool slowly by being left at the room temperature,
Thereafter, a light emitting layer is formed on the partition and the first electrode,
A method for manufacturing a light-emitting device, wherein a second electrode is formed over the light-emitting layer. Forming a first electrode on a substrate;
A partition wall is formed using a resin material on the substrate and the first electrode,
In order to volatilize the solvent from the partition wall, the partition wall is heated at a constant rate from a temperature lower than the curing temperature and higher than room temperature to a first temperature that is lower than the curing temperature using a heating unit. And then hold at the first temperature for a first time,
After holding at the first temperature, to cure the partition wall, the partition wall is raised until said second temperature is higher than the curing temperature the temperature at a constant heating rate, then the second temperature And hold for a second time, and the second time is set equal to the first time,
After being held at the second temperature, it is taken out from the heating means at a temperature higher than room temperature, allowed to cool slowly by being left at the room temperature,
Thereafter, a light emitting layer is formed on the partition and the first electrode,
A method for manufacturing a light-emitting device, wherein a second electrode is formed over the light-emitting layer. In claim 1 or claim 2 ,
The method for manufacturing a light-emitting device, wherein the resin material is polyimide or polybenzoxazole. In any one of Claim 1 thru | or 3 ,
The method for manufacturing a light-emitting device, wherein the light-emitting layer is an organic compound. In any one of Claims 1 thru | or 4 ,
The method for manufacturing a light-emitting device, wherein the first temperature is 150 ° C. or higher and 200 ° C. or lower. In any one of Claims 1 thru | or 5 ,
The method for manufacturing a light-emitting device, wherein the second temperature is 300 ° C. to 350 ° C.

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