JP4704004B2 - LIGHT EMITTING DEVICE AND ELECTRONIC DEVICE - Google Patents

Description

  The present invention relates to a light emitting device having a light emitting element in each pixel and a method for manufacturing the light emitting device.

  Since the light emitting element emits light by itself, it has high visibility, is not required for a backlight necessary for a liquid crystal display device (LCD), is optimal for thinning, and has a feature that a viewing angle is wider than that of an LCD. Therefore, a light-emitting device using a light-emitting element has attracted attention as a display device that replaces a CRT or an LCD, and is being put into practical use. An OLED (Organic Light Emitting Diode), which is one of the light-emitting elements, includes a layer containing an electroluminescent material (hereinafter referred to as an electroluminescent layer) that can obtain luminescence (Electroluminescence) by applying an electric field, an anode, a cathode, have. Light emission can be obtained by combining holes injected from the anode and electrons injected from the cathode in the electroluminescent layer.

  The injection property of holes and electrons into the electroluminescent layer is based on the size of the work function of the material forming the electrode, and the electrode (anode) on the hole injecting side has a high work function, It is desired to use a material having a low work function for the electrode (cathode) on the electron injection side. Specifically, indium tin oxide (ITO) having a work function of about 5 eV is generally used for the anode.

  By the way, since the light emitting device does not use the backlight, the power consumption of the entire light emitting device tends to depend on the performance of the light emitting element of each pixel. That is, the higher the external quantum efficiency (number of photons extracted outside / number of injected carriers) of the light-emitting element, the lower the power consumption can be realized. The external quantum efficiency is improved by improving the light extraction efficiency (number of photons extracted outside / number of emitted photons) or internal quantum efficiency (number of photons emitted / number of injected carriers). Can be enhanced. In particular, the improvement in internal quantum efficiency means that the energy converted into heat among the power applied to the light emitting element is suppressed, so that not only the power consumption is reduced, but also the reliability caused by heat generation is reduced. It is thought that it leads to restraint.

  One factor that determines the high internal quantum efficiency is the carrier injection balance (the ratio of injected electrons and holes). The injection balance is determined by the work function of the electrode, the work function of the electroluminescent layer in contact with the electrode, and the mobility of carriers in the electroluminescent layer. The closer the injection balance is to 1, the more The quantum efficiency can be increased.

  However, it is not easy to find a combination of an electrode material and an electroluminescent material that can increase the injection balance, and it has been difficult to obtain sufficient luminance for the conventional light emitting element instead of power consumption. The conventional light-emitting element has a short half life of luminance and has a problem to be improved with respect to reliability. In particular, in order to extract light from the light-emitting element, at least one of the electrodes must have a light-transmitting property. However, the material of the light-transmitting conductive film is limited, and the selectivity of the material is limited. poor. In many cases, ITO is used as the light-transmitting conductive film. When the ITO is used for the anode, it is necessary to optimize the material in the layer having a hole transporting property in contact with the anode. However, the development of new materials has the problem of cost and time.

  In view of the above problems, it is an object of the present invention to provide a light-emitting device having a light-emitting element that improves internal quantum efficiency, is bright with low power consumption, and has high reliability, and a method for manufacturing the light-emitting device.

  The present inventors have a light-transmitting conductive layer containing an oxide used as an anode (hereinafter abbreviated as a light-transmitting oxide conductive layer or CTO), and are in contact with the anode and have a hole transporting property. When both of them contact with the layer (hole injection layer or hole transport layer), carriers move so that the Fermi levels coincide with each other. As a result, the energy band of the hole injection layer or the hole transport layer is bent. It was thought that the bending and the bending hindered the improvement of the hole injection property and contributed to lowering the injection balance.

FIG. 2 shows a band model in a state where the light-transmitting oxide conductive layer and the hole injection layer (HIL) (in contact with the CTO) are in contact with each other. When HIL and CTO exist apart from each other, the Fermi levels of HIL and CTO are different, and the energy band of HIL is flat. However, the CTO and HIL as shown in FIG. 2 contact, the HIL energy band as the Fermi level E _F is coincident bent in a direction making a barrier against electrons, holes near the interface of the CTO and HIL It will be accumulated. For this reason, it is presumed that the hole injection property and mobility are suppressed, and it is difficult to increase the carrier injection balance, and as a result, the improvement of the internal quantum efficiency is hindered.

  Therefore, in the present invention, a highly insulating layer (hereinafter referred to as a barrier layer) having a thickness that allows a tunnel current to flow in a region of the anode closest to the hole injection layer or the hole transport layer. ). The material used for the barrier layer is more than the material used for the layer other than the barrier layer in the anode and the layer having a hole transporting property in contact with the barrier layer (hole injection layer or hole transport layer). High resistance material. With the above structure, the width of the energy band of the barrier layer can be made wider than that of the light-transmitting oxide conductive layer and the layer having hole transportability. Specifically, the present invention uses a conductive material having a light-transmitting property and containing an oxide (translucent oxide conductive material) as an anode, and a barrier layer corresponding to a part of the anode is formed of silicon oxide. And a light-transmitting conductive material or a thin insulating or semi-insulating material containing silicon oxide.

FIGS. 1A and 1B show band models in a state where the barrier layer of the CTO is in contact with the HIL. The barrier layer contains silicon oxide and exhibits insulating properties or semi-insulating properties. The barrier layer is formed to a thickness that allows carriers to tunnel, that is, a thickness of 0.5 to 5 nm. By forming the barrier layer, it is possible to separate the CTO and HIL physically, as shown in FIG. 1 (A), CTO, barrier layer, even if the Fermi level E _F coincides with the HIL, The CTO energy band is flat. Therefore, the hole injection property is improved and the hole mobility is increased, so that the carrier injection balance can be increased, and as a result, the internal quantum efficiency can be increased.

  Note that the energy band of the HIL is not necessarily completely flat as shown in FIG. 1 (A), and it may be assumed that the energy band is bent toward a lower energy as shown in FIG. 1 (B). The However, unlike the energy band bend shown in FIG. 2, the energy band bend shown in FIG. 1B acts to prevent the accumulation of holes. As a result, the hole injection property is improved and the hole mobility is increased, so that the carrier injection balance can be increased, and as a result, the internal quantum efficiency can be increased.

  Silicon oxide has a characteristic that water molecules are easily adsorbed by chemical bonds. Therefore, it is considered that CTO containing silicon oxide is likely to adsorb moisture on the surface thereof as compared with normal CTO. FIG. 3 shows the amount of degassing from the substrate with respect to the temperature, measured using a temperature programmed desorption method (TDS: Thermal Desorption Spectroscopy). The substrate corresponds to a state after forming the anode and before forming a layer having a hole transporting property.

  FIG. 3A shows the amount of degassing with respect to temperature when silicon oxide and ITO are used as the anode. FIG. 3B shows the amount of degassing with respect to temperature when ITO is used as the anode. In FIGS. 3A and 3B, after the anode is formed, heat treatment is performed at 200 ° C. for 1 hour in an air atmosphere. Note that in the substrate used in FIG. 3A, the composition of the anode is O: Si: In: Sn = 61: 3: 34: 2.

  In FIG. 3, the temperature shown on the horizontal axis indicates the temperature of the heater used in the heat treatment. The actual temperature of the substrate is lower than the temperature of the heater, and the tendency is more remarkable as the temperature of the heater is higher.

  As shown in FIG. 3 (A) and FIG. 3 (B), the desorption of physically adsorbed water occurs when the temperature of the horizontal axis is about 120 ° C. (the temperature of the substrate is also about 120 ° C.). This is common in that the peak shown is observed. However, as shown in FIG. 3A, when silicon oxide and ITO are used as the anode, unlike the case where only ITO is used as the anode, the temperature on the horizontal axis is about 350 ° C. to 370 ° C. A peak indicating desorption of water is observed again at a temperature of about 300 ° C. to 320 ° C.). The peak observed at 350 ° C. to 370 ° C. is considered to indicate desorption of moisture adsorbed on silicon oxide by chemical bonding.

  From the above TDS measurement results, it can be seen that moisture is more easily adsorbed on the surface of the barrier layer containing silicon oxide than when only CTO is used. When the surface of the anode is contaminated with moisture or the like, the work function is reduced, so that the hole injectability is lowered. Therefore, the injection balance is deteriorated, and as a result, the internal quantum efficiency is reduced. In addition, the moisture adsorbed on the surface of the anode may cause deterioration of the electroluminescent layer.

  Therefore, in the present invention, after forming an anode having a barrier layer and before forming a layer having hole transportability, the anode is subjected to heat treatment in an air atmosphere or heat treatment (vacuum bake) in a vacuum atmosphere. And removing moisture adsorbed on the surface of the barrier layer. With the above-described configuration, it is possible to prevent the carrier injection balance from being deteriorated or the reliability from being lowered due to moisture adsorbed on the barrier layer.

  In the present invention, the electroluminescent layer is composed of a plurality of layers, and these layers are a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer, etc. from the viewpoint of carrier transport properties. Can be classified. The distinction between a hole injection layer and a hole transport layer is not necessarily strict, and these are the same in that hole transportability (hole mobility) is a particularly important characteristic. In this specification, for convenience, the hole injection layer is a layer in contact with the anode, and the layer in contact with the hole injection layer is referred to as a hole transport layer to be distinguished. The same applies to the electron transport layer and the electron injection layer. The layer in contact with the cathode is called an electron injection layer, and the layer in contact with the electron injection layer is called an electron transport layer. The light emitting layer may also serve as an electron transport layer, and is also referred to as a light emitting electron transport layer.

  In addition, the electroluminescent layer can be substituted if the same function can be obtained by using not only an organic material but also a material obtained by combining an organic material and an inorganic material, or a material obtained by adding a metal complex to an organic material. can do.

  Note that the boundary between the barrier layer and the light-transmitting oxide conductive layer is not necessarily clear. For example, there may be a case where the concentration of silicon contained in the anode changes with a gradient so as to become higher as it is closer to the electroluminescent layer. In this case, the boundary between the barrier layer and the translucent oxide conductive layer is not clear, but there is no change in that the region closer to the electroluminescent layer functions as a barrier layer.

  In the above-described present invention, the light-transmitting oxide conductive layer includes other light-transmitting properties such as indium tin oxide (ITO), zinc oxide (ZnO), indium zinc oxide (IZO), and zinc oxide (GZO) to which gallium is added. An oxide conductive material can be used. Preferably, the anode is formed by a sputtering method using a target containing the light-transmitting oxide conductive material and silicon oxide.

  In the present invention, by forming a barrier layer, the hole injection property can be improved and the hole mobility can be increased, so that the carrier injection balance can be increased, resulting in an increase in internal quantum efficiency. Can be increased. In addition, since the moisture adsorbed on the silicon oxide contained in the barrier layer is removed by vacuum baking, a layer having hole transportability is formed, thereby preventing deterioration of the injection property due to moisture and deterioration of the electroluminescent layer. be able to. Therefore, a light-emitting element with low power consumption and brightness and high reliability can be manufactured.

  Embodiments of the present invention will be described below. In the light-emitting element of the present invention, a layer containing an organic compound is stacked between an anode formed using a light-transmitting oxide conductive material and silicon oxide, and a cathode containing an alkali metal or an alkaline earth metal. An electroluminescent layer is formed. The layer containing an organic compound can be classified into a hole transport layer, a light emitting layer, and an electron transport layer from the carrier transport property. Further, a hole injection layer may be provided between the anode and the hole transport layer, or an electron injection layer may be provided between the cathode and the electron transport layer. The distinction between a hole injection layer and a hole transport layer, and an electron injection layer and an electron transport layer is not necessarily strict, and they have a hole transport property (hole mobility) and an electron transport property (electron mobility). It is the same in that it is particularly important (an important characteristic). Alternatively, a hole blocking layer may be provided between the electron transport layer and the light emitting layer. The light emitting layer may have a different emission color by adding a guest material such as a pigment or a metal complex to the host material. That is, the light emitting layer may be formed by including a fluorescent material or a phosphorescent material.

  As the anode, a light-transmitting oxide conductive material selected from indium tin oxide (ITO), zinc oxide (ZnO), indium zinc oxide (IZO), zinc oxide to which gallium is added (GZO), and the like is used. Use one containing atomic%. Then, a barrier layer having an insulating property or a semi-insulating property in which the silicon density is higher than the other regions of the anode is provided in a region of the anode in contact with the electroluminescent layer. The barrier layer is formed to a thickness that allows carriers to move from the anode to the electroluminescent layer, that is, a thickness that allows a current to flow due to a tunnel current. The barrier layer can physically separate the light-transmitting oxide conductive layer that is a part of the anode and is in contact with the barrier layer from the electroluminescent layer, and can move carriers. .

  The anode including the light-transmitting oxide conductive material can be formed by a sputtering method using a target including the light-transmitting oxide conductive material and silicon oxide. The content of silicon oxide in the target with respect to the light-transmitting oxide conductive material may be 1 to 20% by weight, preferably 2 to 10% by weight. When the proportion of silicon oxide is increased, the resistivity of the anode is increased. Therefore, it may be appropriately formed within this range. Accordingly, an anode containing a light-transmitting oxide conductive material and 1 to 10 atomic percent, preferably 2 to 5 atomic percent of silicon oxide can be obtained. Of course, if a similar composition can be obtained, it may be formed by co-evaporation by a vacuum deposition method. Note that co-evaporation is an evaporation method in which an evaporation source is heated at the same time and different substances are mixed in a film formation stage.

  The barrier layer is formed by selectively removing the light-transmitting oxide conductive material from the surface of the anode containing silicon oxide and the light-transmitting oxide conductive material and increasing the density of the added silicon. be able to. For example, a method of treating a surface with a solution capable of selectively removing a light-transmitting oxide conductive material, plasma treatment using one or more kinds of gases selected from hydrogen, oxygen, and fluorine, nitrogen The barrier layer can be formed by plasma treatment using an inert gas such as argon.

  In the case of forming a barrier layer by selectively removing the light-transmitting oxide conductive material from the surface of the anode, the barrier layer is difficult to be formed when the light-transmitting oxide conductive layer is densely formed. It is preferable to make it roughly at a level. With the above structure, when the light-transmitting oxide conductive material is selectively removed, the density of added silicon can be efficiently increased with respect to the light-transmitting oxide conductive material.

  The barrier layer may be formed by intentionally increasing the density of (oxide) silicon in a region close to the surface when forming the translucent oxide conductive layer. Specifically, after the formation of the light-transmitting oxide conductive layer, the composition of the sputtering target is changed so that the density of (oxide) silicon is increased, so that the weight percent of (oxide) silicon is higher. A barrier layer may be newly formed on the previously formed translucent oxide conductive layer.

In the present invention, before forming the electroluminescent layer, the temperature of the substrate is 200 ° C. to 450 ° C., preferably 250 ° C. in an air atmosphere or a vacuum atmosphere (preferably about 10 ⁻⁴ to 10 ⁻⁸ Pa). ˜300 ° C., and heat treatment is performed on the anode. Moreover, in order to clean and improve flatness, you may perform a wiping process and a grinding | polishing process.

  In the light-emitting element having the above structure, since the anode and the hole injection layer or the hole transport layer are physically separated, the effect of the original work function of the anode can be obtained. That is, the hole injection efficiency with respect to the hole injection layer can be increased and the injection balance can be increased. As a result, the internal quantum efficiency can be increased.

  FIG. 4A shows a structure of a light-emitting element obtained by the present invention. A light-emitting element illustrated in FIG. 4A includes an anode 101, an electroluminescent layer 102 formed on the anode 101, and a cathode 103 formed on the electroluminescent layer 102 over a substrate 100. .

  The anode 101 includes a barrier layer 109a and a light-transmitting oxide conductive layer 109b, and the light-transmitting oxide conductive layer 109b and the electroluminescent layer 102 are physically separated by the barrier layer 109a. ing.

  As the cathode 103, a metal, an alloy, an electrically conductive compound, a mixture thereof, or the like having a low work function, which is generally used for a cathode of a light emitting element, can be used. Specifically, in addition to alkaline metals such as Li and Cs, alkaline earth metals such as Mg, Ca and Sr, and alloys containing these (Mg: Ag, Al: Li, etc.), rare earths such as Yb and Er It can also be formed using a metal. In addition, a normal conductive film using aluminum, a light-transmitting oxide conductive material, or the like can be used by forming a layer containing a material having a high electron-injecting property so as to be in contact with the cathode 103.

  In FIG. 4A, the electroluminescent layer 102 includes first to fifth layers 104 to 108.

Since the first layer 104 formed over the barrier layer 109a functions as a hole injection layer, a material having a hole transporting property, a relatively low ionization potential, and a high hole injecting property is used. Is desirable. Broadly divided into metal oxides, low-molecular organic compounds, and high-molecular organic compounds. As the metal oxide, for example, vanadium oxide, molybdenum oxide, ruthenium oxide, aluminum oxide, or the like can be used. If low molecular weight organic compound, for example, starburst amine typified by m-MTDATA, copper phthalocyanine (abbreviation: Cu-Pc) in the metal phthalocyanine represented, phthalocyanine (abbreviation: H ₂ -Pc), _2, A 3-dioxyethylenethiophene derivative or the like can be used. A film in which a low molecular organic compound and the metal oxide are co-evaporated may be used. As a high molecular organic compound, for example, a polymer such as polyaniline (abbreviation: PAni), polyvinyl carbazole (abbreviation: PVK), or a polythiophene derivative can be used. Polyethylene dioxythiophene (abbreviation: PEDOT), which is one of polythiophene derivatives, doped with polystyrene sulfonic acid (abbreviation: PSS) may be used. Further, a benzoxazole derivative and any one or more materials of TCQn, FeCl ₃ , C _60, or F ₄ TCNQ may be used in combination.

  Since the second layer 105 formed over the first layer 104 functions as a hole transport layer, it is preferable to use a known material having high hole transportability and low crystallinity. Specifically, an aromatic amine-based compound (that is, a compound having a benzene ring-nitrogen bond) is suitable, for example, 4,4-bis [N- (3-methylphenyl) -N-phenylamino]. Biphenyl (TPD) and its derivative 4,4′-bis [N- (1-naphthyl) -N-phenyl-amino] biphenyl (α-NPD) are examples. Starburst aromatic amine compounds such as 4,4 ', 4 "-tris (N, N-diphenylamino) triphenylamine (TDATA) and MTDATA can also be used. Alternatively, 4,4 ′, 4 ″ -tris (N-carbazolyl) triphenylamine (abbreviation: TCTA) may be used. As the polymer material, poly (vinyl carbazole) or the like exhibiting good hole transportability can be used.

Since the third layer 106 formed over the second layer 105 functions as a light-emitting layer, it is preferable to use a material having a large ionization potential and a large band gap. Specifically, for example, tris (8-quinolinolato) aluminum (Alq ₃ ), tris (4-methyl-8-quinolinolato) aluminum (Almq ₃ ), bis (10-hydroxybenzo [η] -quinolinato) beryllium (BeBq) ₂ ), bis (2-methyl-8-quinolinolato)-(4-hydroxy-biphenylyl) -aluminum (BAlq), bis [2- (2-hydroxyphenyl) -benzoxazolate] zinc (Zn (BOX) ₂ ), Bis [2- (2-hydroxyphenyl) -benzothiazolate] zinc (Zn (BTZ) ₂ ), and the like. Various fluorescent dyes (coumarin derivatives, quinacridone derivatives, rubrene, 4,4-dicyanomethylene, 1-pyrone derivatives, stilbene derivatives, various condensed aromatic compounds, etc.) can also be used. Phosphorescent materials such as platinum octaethylporphyrin complex, tris (phenylpyridine) iridium complex, tris (benzylideneacetonato) phenanthrene europium complex can also be used.

  As the host material used for the third layer 106, a hole transport material or an electron transport material typified by the above example can be used. Alternatively, a bipolar material such as 4,4′-N, N′-dicarbazolylbiphenyl (abbreviation: CBP) can be used.

Since the fourth layer 107 formed over the third layer 106 functions as an electron transporting layer, it is preferable to use a material having a high electron transporting property. Specifically, a metal complex having a quinoline skeleton or a benzoquinoline skeleton represented by Alq ₃ or a mixed ligand complex thereof can be used. Specifically, metal complexes such as Alq ₃ , Almq ₃ , BeBq ₂ , BAlq, Zn (BOX) ₂ , and Zn (BTZ) ₂ can be given. In addition to metal complexes, 2- (4-biphenylyl) -5- (4-tert-butylphenyl) -1,3,4-oxadiazole (PBD), 1,3-bis [5- (p Oxadiazole derivatives such as -tert-butylphenyl) -1,3,4-oxadiazol-2-yl] benzene (OXD-7), 3- (4-tert-butylphenyl) -4-phenyl-5 -(4-biphenylyl) -1,2,4-triazole (TAZ), 3- (4-tert-butylphenyl) -4- (4-ethylphenyl) -5- (4-biphenylyl) -1,2, Triazole derivatives such as 4-triazole (p-EtTAZ), imidazole derivatives such as TPBI, phenanthroyl such as bathophenanthroline (BPhen) and bathocuproin (BCP) It can be used derivatives.

Since the fifth layer 108 formed over the fourth layer 107 functions as an electron injection layer, it is preferable to use a material having a high electron injection property. Specifically, an ultra-thin film of an insulator such as an alkali metal halide such as LiF or CsF, an alkaline earth halide such as CaF ₂ , or an alkali metal oxide such as Li ₂ O is often used. In addition, alkali metal complexes such as lithium acetylacetonate (abbreviation: Li (acac) and 8-quinolinolato-lithium (abbreviation: Liq) are also effective. Molybdenum oxide (MoOx), vanadium oxide (VOx), A metal oxide such as ruthenium oxide (RuOx) or tungsten oxide (WOx) or a benzoxazole derivative, and one or more materials of alkali metal, alkaline earth metal, or transition metal may be included.

  In the light-emitting element having the above structure, light is generated from the third layer 106 by applying a voltage between the anode 101 and the cathode 103 and supplying a forward bias current to the electroluminescent layer 102. Can be taken out from the anode 101 side. Note that the electroluminescent layer 102 does not necessarily need to include all of the first to fifth layers. In the present invention, it is sufficient that at least one of the electron transport layer and the electron injection layer and the light emitting layer are provided. Further, light emission is not necessarily obtained only from the third layer 106, and light emission may be obtained from layers other than the third layer 106 depending on a combination of materials used for the first to fifth layers.

  Note that depending on the color, the phosphorescent material can have a lower driving voltage and higher reliability than the fluorescent material. Therefore, when full-color display is performed using light-emitting elements corresponding to the three primary colors, a combination of a light-emitting element using a fluorescent material and a light-emitting element using a phosphorescent material can reduce the deterioration of the light-emitting element of each color. You may make it arrange | equalize a degree.

  Next, a structure of a light-emitting element that can extract light from the cathode side will be described. FIG. 4B shows a structure of a light-emitting element obtained by the present invention. A light-emitting element illustrated in FIG. 4B includes an anode 111, an electroluminescent layer 112 formed over the anode 111, and a cathode 113 formed over the electroluminescent layer 112 over a substrate 110. .

  As the anode 111, for example, a single layer film made of one or more of TiN, ZrN, Ti, W, Ni, Pt, Cr, Ag, etc., as well as a lamination of a titanium nitride film and a film containing aluminum as a main component, nitriding A three-layer structure of a titanium film, a film containing aluminum as its main component, and a titanium nitride film can be used. In addition, a light-transmitting oxide conductive layer using ITO, indium tin oxide containing silicon oxide (hereinafter referred to as ITSO), IZO, or the like on a material that can reflect light, and a barrier layer. They may be stacked and used as the anode 111. In FIG. 4B, an anode 111 is formed by stacking an Al—Si layer 114, a Ti layer 115, a light-transmitting oxide conductive layer 116, and a barrier layer 117 from the side closer to the substrate 110. Yes.

  The light-transmitting oxide conductive layer 116 is formed using a light-transmitting oxide conductive material and silicon oxide. The barrier layer 117 is formed using silicon oxide, or a light-transmitting oxide conductive material and silicon oxide. The density of (oxide) silicon is higher in the barrier layer 117 than in the light-transmitting oxide conductive layer 116.

  Moreover, the cathode 103 has translucency. Specifically, a light-transmitting oxide conductive material selected from indium tin oxide (ITO), zinc oxide (ZnO), indium zinc oxide (IZO), zinc oxide added with gallium (GZO), and the like is used. Alternatively, silicon oxide may be used together with the light-transmitting oxide conductive material. In this case, it is desirable to provide an electron injection layer in the electroluminescent layer 112 so as to be in contact with the cathode 103.

  Further, a metal, an alloy, an electrically conductive compound, a mixture thereof, or the like having a low work function can be formed to have a thickness enough to transmit light and used as the cathode 103. Specifically, in addition to alkaline metals such as Li and Cs, alkaline earth metals such as Mg, Ca and Sr, and alloys containing these (Mg: Ag, Al: Li, etc.), rare earths such as Yb and Er The cathode 103 can be formed with a film thickness of about 5 nm to 30 nm using metal. In the case where an electron injection layer is provided, another conductive layer such as Al can be formed with a thickness enough to transmit light and used as the cathode 103. Note that in the case where the cathode 103 is formed with a thickness enough to transmit light, a light-transmitting conductive layer is formed over the cathode using a light-transmitting oxide conductive material so as to suppress the sheet resistance of the cathode. Anyway.

  The electroluminescent layer 112 may have the same structure as the electroluminescent layer 102 illustrated in FIG. However, when the work function of the material used for the cathode is not sufficiently small, it is desirable to provide an electron injection layer.

  Next, a specific method for manufacturing the light-emitting device of the present invention will be described. Note that in this embodiment, an example in which an n-channel TFT and a p-channel TFT are formed over the same substrate will be described.

  First, as shown in FIG. 5A, a base film 202 is formed over a substrate 201. As the substrate 201, for example, a glass substrate such as barium borosilicate glass or alumino borosilicate glass, a quartz substrate, a ceramic substrate, or the like can be used. Alternatively, a metal substrate including a stainless steel substrate or a silicon substrate with an insulating film formed on the surface thereof may be used. A substrate made of a synthetic resin having flexibility such as plastic generally tends to have a lower heat resistant temperature than the above substrate, but can be used as long as it can withstand the processing temperature in the manufacturing process. .

  The base film 202 is provided to prevent alkali metal such as Na or alkaline earth metal contained in the substrate 201 from diffusing into the semiconductor film and adversely affecting the characteristics of the semiconductor element such as TFT. Therefore, the insulating film is formed using an insulating film such as silicon oxide, silicon nitride, or silicon nitride oxide that can suppress diffusion of alkali metal or alkaline earth metal into the semiconductor film. In this embodiment, a silicon nitride oxide film is formed to a thickness of 10 to 400 nm (preferably 50 to 300 nm) by a plasma CVD method.

  Note that the base film 202 may be a single layer or a stack of a plurality of insulating films. 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.

  Next, island-shaped semiconductor films 203 and 204 used as active layers are formed over the base film 202. The film thickness of the island-shaped semiconductor films 203 and 204 is 25 to 100 nm (preferably 30 to 60 nm). Note that the island-shaped semiconductor films 203 and 204 may be an amorphous semiconductor, a semi-amorphous semiconductor (microcrystalline semiconductor), or a polycrystalline semiconductor. As the semiconductor, not only silicon but also silicon germanium can be used. When silicon germanium is used, the concentration of germanium is preferably about 0.01 to 4.5 atomic%.

  In the case of using a polycrystalline semiconductor, an amorphous semiconductor is first formed, and the amorphous semiconductor may be crystallized using a known crystallization method. Known crystallization methods include crystallization by heating with a heater, crystallization by laser light irradiation, crystallization using a catalytic metal, and crystallization using infrared light. The method of performing etc. are mentioned.

For example, when crystallization is performed using laser light, a pulsed or continuous wave excimer laser, YAG laser, YVO ₄ laser, or the like may be used. For example, when a YAG laser is used, it is desirable to use a second harmonic wavelength that is easily absorbed by the semiconductor film. The oscillation frequency 30～300KHz, the energy density was 300~600mJ / cm ² (typically 350~500mJ / cm ^2), it may be set the scanning speed to be irradiated by several shots to any point.

  Next, a TFT is formed using the island-shaped semiconductor films 203 and 204. Note that in this embodiment mode, the top gate TFTs 205 and 206 are formed using island-shaped semiconductor films 203 and 204 as shown in FIG. 5B; however, the TFT is not limited to the top gate type. For example, a bottom gate type may be used.

  Specifically, a gate insulating film 207 is formed so as to cover the island-shaped semiconductor films 203 and 204. Then, a conductive film is formed over the gate insulating film 207 and patterned to form gate electrodes 208 and 209. Then, gate electrodes 208 and 209 or a resist film formed and patterned are used as masks, and an impurity imparting n-type or p-type is added to the island-shaped semiconductor films 203 and 204 to form source and drain regions. Further, an LDD region or the like is formed. Here, the TFT 205 is n-type and the TFT 206 is p-type.

Note that for the gate insulating film 207, for example, silicon oxide, silicon nitride, silicon nitride oxide, or the like can be used. As a film formation method, a plasma CVD method, a sputtering method, or the like can be used. For example, in the case where a gate insulating film using silicon oxide is formed by a plasma CVD method, a gas in which TEOS (Tetraethyl Orthosilicate) and O ₂ are mixed is used, a reaction pressure is 40 Pa, a substrate temperature is 300 to 400 ° C., and a high frequency (13. 56 MHz) The power density is 0.5 to 0.8 W / cm ² and the film is formed.

  Aluminum nitride can be used for the gate insulating film 207. Aluminum nitride has a relatively high thermal conductivity and can efficiently dissipate heat generated in the TFT. In addition, after forming silicon oxide or silicon oxynitride which does not contain aluminum, a laminate of aluminum nitride may be used as the gate insulating film.

  Through the above series of steps, an n-channel TFT 205 and a p-channel TFT 206 that controls current supplied to the light-emitting element can be formed. Note that a method for manufacturing a TFT is not limited to the above-described steps. A gate electrode or a wiring may be manufactured by a droplet discharge method.

  Next, a passivation film 210 is formed so as to cover the TFTs 205 and 206. As the passivation film 210, an insulating film such as silicon oxide containing silicon, silicon nitride, or silicon oxynitride can be used, and the thickness thereof is about 100 to 200 nm.

  Next, heat treatment is performed to activate the impurity element added to the island-shaped semiconductor films 203 and 204. In this step, a thermal annealing method using a furnace annealing furnace, a laser annealing method, or a rapid thermal annealing method (RTA method) can be used. For example, when activation is performed by thermal annealing, it is performed at 400 to 700 ° C. (preferably 500 to 600 ° C.) in a nitrogen atmosphere having an oxygen concentration of 1 ppm or less, preferably 0.1 ppm or less. Further, a heat treatment is performed at 300 to 450 ° C. for 1 to 12 hours in an atmosphere containing 3 to 100% hydrogen to perform a step of hydrogenating the island-shaped semiconductor film. This step is performed for the purpose of terminating the dangling bonds with thermally excited hydrogen. As another means of hydrogenation, plasma hydrogenation (using hydrogen excited by plasma) may be performed. The activation process may be performed before the passivation film 210 is formed.

Next, as shown in FIG. 5C, a first interlayer insulating film 211 and a second interlayer insulating film 212 are formed so as to cover the passivation film 210. As the first interlayer insulating film 211, an organic resin film, an inorganic insulating film, an insulating film including a Si—O bond and a Si—CH _X bond formed using a siloxane-based material as a starting material, or the like can be used. In this embodiment, an insulating film formed using a siloxane-based material is used. As the second interlayer insulating film 212, a film that hardly transmits a substance that causes deterioration of the light-emitting element such as moisture or oxygen as compared with other insulating films is used. Typically, a silicon nitride film formed by an RF sputtering method is used, but a diamond-like carbon (DLC) film, an aluminum nitride film, or the like can also be used.

  Next, the passivation film 210, the first interlayer insulating film 211, and the second interlayer insulating film 212 are etched to form contact holes. Then, wirings 213 to 216 connected to the island-shaped semiconductor films 203 and 204 are formed.

  Next, a light-transmitting oxide conductive layer 217 is formed so as to cover the second interlayer insulating film 212 and the wirings 213 to 216. In this embodiment, the light-transmitting oxide conductive layer 217 is formed by ITSO using a sputtering method. Note that in addition to ITSO, indium oxide containing silicon oxide may be mixed with 2 to 20% of zinc oxide (ZnO) and used as the light-transmitting oxide conductive layer 217.

When ITSO is used, an ITO containing 2 to 10% by weight of silicon oxide can be used as a target. Specifically, in this embodiment, a target containing In ₂ O ₃ , SnO ₂ , and SiO ₂ at a ratio of 85: 10: 5 wt% is used, the flow rate of Ar is 50 sccm, and the flow rate of O ₂ is The light-transmitting oxide conductive layer 217 was formed to a thickness of 105 nm at 3 sccm, a sputtering pressure of 0.4 Pa, a sputtering power of 1 kW, and a deposition rate of 30 nm / min.

In this embodiment, the barrier layer 218 having a higher density of Si (O ₂ ) than the light-transmitting oxide conductive layer 217 is formed over the light-transmitting oxide conductive layer 217. Specifically, in this embodiment, a barrier layer 218 having a thickness of 5 nm is formed by sputtering using a target containing In ₂ O ₃ , SnO ₂ , and SiO ₂ at a ratio of 83: 7: 10 wt%. It is formed to be thick.

  Before forming the barrier layer 218, the surface of the light-transmitting oxide conductive layer 217 is polished by CMP or wiping with a polyvinyl alcohol-based porous body so that the surface of the light-transmitting oxide conductive layer 217 is planarized. You can keep it.

  In addition, by selectively removing the light-transmitting oxide conductive material from the surface of the light-transmitting oxide conductive layer and increasing the density of the added (oxide) silicon, the barrier layer is formed. Also good. In this case, the barrier layer may be formed after the light-transmitting oxide conductive layer is patterned, or may be formed after the partition walls are formed.

  Next, as illustrated in FIG. 6A, the light-transmitting oxide conductive layer 217 and the barrier layer 218 are patterned, whereby the anode 219 connected to the wiring 216 is formed. Note that 220 represents a light-transmitting oxide conductive layer after patterning, and 221 corresponds to a barrier layer after patterning.

A partition 222 is formed on the second interlayer insulating film 212. As the partition 222, an organic resin film, an inorganic insulating film, an insulating film including a Si—O bond and a Si—CH _x bond formed using a siloxane-based material as a starting material, or the like can be used. The partition 222 covers an end portion of the anode 219 and has an opening in a region overlapping with the anode 219. It is desirable that the end of the opening of the partition wall 222 be rounded so that there is no hole in the electroluminescent layer to be formed later at the end. Specifically, it is desirable that the curvature radius of the curve drawn by the cross section of the partition 222 in the opening is about 0.2 to 2 μm.

  FIG. 6A illustrates an example in which a positive photosensitive acrylic resin is used for the partition 222. The photosensitive organic resin includes a positive type in which a portion exposed to energy rays such as light, electrons, and ions is removed, and a negative type in which the exposed portion remains. In the present invention, a negative organic resin (film) may be used. Alternatively, the partition 222 may be formed using photosensitive polyimide. When the partition 222 is formed using negative acrylic, the end portion in the opening has an S-shaped cross-sectional shape. At this time, it is desirable that the radius of curvature at the upper end and the lower end of the opening is 0.2 to 2 μm.

  With the above structure, coverage of an electroluminescent layer and a cathode to be formed later can be improved, and a short circuit between the anode 219 and the cathode in a hole formed in the electroluminescent layer can be prevented. Further, by relaxing the stress of the electroluminescent layer, a defect called “shrink” in which the light emitting region decreases can be reduced, and reliability can be improved.

Next, in the present invention, before the electroluminescent layer is formed, in order to remove moisture, oxygen, and the like adsorbed on the partition 222 and the anode 219, heat treatment is performed in an air atmosphere or heat treatment (vacuum baking) in a vacuum atmosphere. ). Specifically, heat treatment is performed in a vacuum atmosphere at a substrate temperature of 200 ° C. to 450 ° C., preferably 250 to 300 ° C., for about 0.5 to 20 hours. It is desirably 3 × 10 ⁻⁷ Torr or less, and if possible, 3 × 10 ⁻⁸ Torr or less is most desirable. In the case where an electroluminescent layer is formed after heat treatment in a vacuum atmosphere, reliability can be further improved by placing the substrate in a vacuum atmosphere until just before the electroluminescent layer is formed. it can. Further, before or after vacuum baking, the anode 219 may be irradiated with ultraviolet rays.

  Next, as illustrated in FIG. 6B, an electroluminescent layer 223 is formed over the anode 219. The electroluminescent layer 223 includes one or a plurality of layers, and each layer may contain an inorganic material as well as an organic material. For the specific structure of the electroluminescent layer 223, the above description of FIG. 4 can be referred to. Next, a cathode 224 is formed so as to cover the electroluminescent layer 223. The anode 219, the electroluminescent layer 223, and the cathode 224 overlap with each other in the opening portion of the partition wall 222, and the overlapping portion corresponds to the light emitting element 225.

  Note that after the light-emitting element 225 is formed, a protective film may be formed over the cathode 224. Similar to the second interlayer insulating film 212, the protective film is a film that hardly transmits a substance that causes deterioration of the light-emitting element, such as moisture and oxygen, as compared with other insulating films. Typically, it is desirable to use, for example, a DLC film, a carbon nitride film, a silicon nitride film formed by an RF sputtering method, or the like. In addition, the above-described film that hardly transmits a substance such as moisture or oxygen and a film that easily allows a substance such as moisture or oxygen to pass through can be stacked to be used as a protective film.

  Note that FIG. 6B illustrates a structure in which light emitted from the light-emitting element is emitted to the substrate 201 side; however, a light-emitting element having a structure in which light is directed to the side opposite to the substrate may be used.

  Actually, when completed up to FIG. 6B, a protective film (laminate film, ultraviolet curable resin film, etc.) or a translucent cover material with high air tightness and low outgassing so as not to be exposed to the outside air. It is preferable to package (enclose). At that time, if the inside of the cover material is made an inert atmosphere or a hygroscopic material (for example, barium oxide) is arranged inside, the reliability of the light emitting element is improved.

  Note that the method for manufacturing a light-emitting device of the present invention is not necessarily limited to the above-described embodiment. The manufacturing method described above is only a specific description of one embodiment of the present invention, and the present invention is not limited to the above-described embodiment, and various modifications that do not exceed the technical scope of the invention are possible. .

  In this example, one mode of a pixel of a light-emitting device obtained by a manufacturing method of the present invention will be described.

  FIG. 8 shows a cross-sectional view of the light emitting device of this example. In FIG. 8, transistors 7001 to 7003 are formed over a substrate 7000. The transistors 7001 to 7003 are covered with a first interlayer insulating film 7004, and wirings 7005 to 7007 connected to the transistors 7001 to 7003 through contact holes are formed over the first interlayer insulating film 7004. ing.

A second interlayer insulating film 7008 and a third interlayer insulating film 7009 are stacked on the first interlayer insulating film 7004 so as to cover the wirings 7005 to 7007. Note that the first interlayer insulating film 7004 and the second interlayer insulating film 7008 include Si—O bonds and Si—CH _X bonds formed using an organic resin film, an inorganic insulating film, and a siloxane-based material as starting materials. An insulating film or the like can be used. In this embodiment, non-photosensitive acrylic is used. As the third interlayer insulating film 7009, a film that hardly transmits a substance that causes deterioration of the light-emitting element, such as moisture or oxygen, compared to other insulating films is used. Typically, it is desirable to use, for example, a DLC film, a carbon nitride film, a silicon nitride film formed by an RF sputtering method, or the like.

  Over the third interlayer insulating film 7009, wirings 7010 to 7012 that are electrically connected to the wirings 7005 to 7007 through contact holes are formed. The wirings 7010 to 7012 are made of a material that does not transmit light. Then, light-transmitting oxide conductive layers 7013 to 7015 and barrier layers 7016 to 7018 are stacked over the wirings 7010 to 7012. Anodes 7019 to 7021 are formed by part of the wirings 7010 to 7012, the light-transmitting oxide conductive layers 7013 to 7015, and the barrier layers 7016 to 7018.

  In FIG. 8, since the anodes 7019 to 7021 and the wirings 7010 to 7012 directly connected to the TFTs are formed in different layers, the layout area of the anodes 7019 to 7021 can be increased. As a result, the area where light can be obtained can be expanded.

In addition, an insulating film including a Si—O bond and a Si—CH _X bond formed using a siloxane-based material as a starting material, an organic resin film, an inorganic insulating film, or the like is used over the third interlayer insulating film 7009. A partition wall 7040 is formed. A partition 7040 has an opening, and light-emitting elements 7026 to 7028 are formed by overlapping anodes 7019 to 7021, electroluminescent layers 7022 to 7024, and a cathode 7025 in the openings. The electroluminescent layers 7022 to 7024 have a structure in which a plurality of layers are stacked. The cathode 7025 is formed using a material or a film thickness that transmits light. Note that a protective film may be formed over the partition wall 7040 and the cathode 7025.

  7030 is a cover material for sealing the light emitting elements 7026 to 7028 and has translucency. A color filter 7035 including a shielding film 7031 for shielding visible light and colored layers 7032 to 7034 corresponding to pixels of each color is formed on the cover material 7030. In FIG. 8, in the colored layer 7032, light in the red wavelength region is selectively transmitted among the light emitted from the light emitting element 7026. In the colored layer 7033, light in the green wavelength region out of light emitted from the light emitting element 7027 is selectively transmitted. In the colored layer 7034, light in the blue wavelength region out of light emitted from the light emitting element 7028 is selectively transmitted.

  In FIG. 8, a black pigment and a desiccant are dispersed in the shielding film 7031 in a resin. With the above structure, deterioration of the light-emitting element can be prevented.

  The shielding film 7031 is laid out so as to overlap between the light emitting elements 7026 to 7028, and the shielding film 7031 prevents light from the light emitting element from being transmitted through a colored layer corresponding to an adjacent pixel. Can do.

  In FIG. 8, electroluminescent layers 7022 to 7024 having different electroluminescent materials or element configurations are used for each pixel corresponding to each color, but the present invention is not necessarily limited to this configuration. At least in the pixels corresponding to the two colors, it is only necessary to use electroluminescent layers having different electroluminescent materials or element configurations.

  By using a color filter, even if the color purity of light emitted from each light-emitting element is somewhat inferior, the color purity of light extracted from a pixel can be increased. Note that the light-emitting element of the pixel corresponding to each color has a relatively strong peak in the spectrum of light emitted from the light-emitting element in the wavelength region of the corresponding color compared to other wavelength regions. desirable. For example, in the case of a red pixel, the spectrum of light emitted from the light-emitting element may have a relatively strong peak in the red wavelength region. With the above configuration, the amount of light shielded can be suppressed for each color pixel, and light can be extracted more efficiently than in the case of using a white light emitting element.

  Note that the sealed space formed by the cover material 7030 and the substrate 7000 may be filled with an inert gas or a resin, or a hygroscopic material (eg, barium oxide) may be disposed therein. good.

  In FIG. 8, the cover material is provided with a color filter, but the present invention is not limited to this configuration. For example, the coloring layer may be formed using a droplet discharge method or the like so as to overlap with the light-emitting element. In this case, since the resin can be used instead of the cover material for sealing the light emitting element, the light extraction efficiency can be increased as compared with the case where the cover material is provided.

  Note that the light-emitting device of the present invention is not limited to the above-described manufacturing method, and can be manufactured using a known method.

  Next, a circuit diagram of a pixel of a light-emitting device using the manufacturing method of the present invention is described with reference to FIGS. FIG. 9A shows an equivalent circuit diagram of a pixel, which includes a signal line 6114, power supply lines 6115 and 6117, a scanning line 6116, a light emitting element 6113, a TFT 6110 for controlling input of a video signal to the pixel, and light emission. A TFT 6111 for controlling a current value flowing between both electrodes of the element 6113 and a capacitor element 6112 for holding a gate-source voltage of the TFT 6111 are provided. Note that the capacitor 6112 is illustrated in FIG. 5B; however, the capacitor 6112 is not necessarily provided when it can be covered by the gate capacitance of the TFT 6111 or other parasitic capacitance.

  FIG. 9B illustrates a pixel circuit in which a TFT 6118 and a scanning line 6119 are newly provided in the pixel illustrated in FIG. The arrangement of the TFT 6118 can forcibly create a state in which no current flows to the light-emitting element 6113. Therefore, the lighting period is started immediately after or immediately after the writing period without waiting for signal writing to all pixels. be able to. Therefore, the duty ratio is improved, and moving images can be displayed particularly well.

FIG. 9C illustrates a pixel circuit in which a TFT 6125 and a wiring 6126 are newly provided in the pixel illustrated in FIG. In this structure, the gate electrode of the TFT 6125 is connected to the wiring 6126 that is held at a constant potential, so that the potential of the gate electrode is fixed and the TFT 6125 is operated in the saturation region. In addition, a video signal that transmits information on lighting or non-lighting of a pixel is input to the gate electrode of the TFT 6111 that is connected in series with the TFT 6125 and operates in a linear region through the TFT 6110. Since the value of the source-drain voltage of the TFT 6111 operating in the linear region is small, a slight variation in the gate-source voltage of the TFT 6111 does not affect the value of the current flowing through the light emitting element 6113. Therefore, the value of current flowing through the light emitting element 6113 is determined by the TFT 6125 operating in the saturation region. In the present invention having the above structure, luminance unevenness of the light-emitting element 6113 due to variation in characteristics of the TFT 6125 can be improved and image quality can be improved. Note that the channel length L ₁ and channel width W _{1 of} the TFT 6125 and the channel length L ₂ and channel width W ₂ of the TFT 6111 are set so as to satisfy L ₁ / W ₁ : L ₂ / W ₂ = 5 to 6000: 1. Good. Further, it is preferable in the manufacturing process that both TFTs have the same conductivity type. Further, as the TFT 6125, not only an enhancement type but also a depletion type TFT may be used.

  Note that a light-emitting device formed using the present invention may use either an analog video signal or a digital video signal. However, when a digital video signal is used, there are a video signal using a voltage and a video signal using a current. That is, when the light emitting element emits light, a video signal input to the pixel includes a constant voltage signal and a constant current signal. A video signal having a constant voltage includes a constant voltage applied to the light emitting element and a constant current flowing through the light emitting element. In addition, a video signal having a constant current includes a constant voltage applied to the light emitting element and a constant current flowing in the light emitting element. When the voltage applied to the light emitting element is constant, constant voltage driving is performed. When the current flowing through the light emitting element is constant, constant current driving is performed. In constant current driving, a constant current flows regardless of the resistance change of the light emitting element. In the light emitting device and the driving method thereof according to the present invention, either a constant voltage video signal or a constant current video signal may be used, and either constant voltage driving or constant current driving may be used. This embodiment can be freely combined with the above embodiment modes and embodiments.

  A structure of a light-emitting device to which the present invention is applied will be described with reference to FIG. FIG. 10A is a top view illustrating an outline of a light-emitting device, which includes a pixel portion 6201, a signal line driver circuit 6202, and a scan line driver circuit 6203 over a substrate 6200. 6204 corresponds to an input terminal for supplying a signal or a power supply potential to various circuits formed over the substrate 6200. Reference numerals 6205 to 6207 denote protection circuits which have a function of preventing elements from being destroyed by signal noise or static electricity. Note that all of the protection circuits 6205 to 6207 are not necessarily provided, and any one or more of the protection circuits may be provided.

  In FIG. 10A, the signal line driver circuit 6202 and the scan line driver circuit 6203 are formed over the same substrate 6200 as the pixel portion 6201; however, the present invention is not limited to this structure. For example, in the case where an amorphous semiconductor or a microcrystalline semiconductor is used as a semiconductor element included in the pixel portion 6201, the signal line driver circuit 6202 and the scan line driver circuit 6203 which are separately formed are formed by a known method such as a COG method or a TAB method. You may mount on the board | substrate 6200. FIG. Note that in the case where a microcrystalline semiconductor is used as an element included in the pixel portion 6201, the scan line driver circuit and the pixel portion may be formed using a microcrystalline semiconductor over the same substrate, and the signal line driver circuit may be mounted. . Further, a part of the scan line driver circuit or a part of the signal line driver circuit is formed over the same substrate together with the pixel portion, and the other part of the scan line driver circuit or the other part of the signal line driver circuit is mounted. Anyway. That is, there are various forms of the drive circuit, and any configuration may be used in the present invention.

  Next, an example of the protection circuits 6205 to 6207 used in the light emitting device using the present invention will be described. The protection circuit is composed of one or a plurality of elements selected from a TFT, a diode, a resistance element, a capacitance element, and the like, and the configurations and operations of some protection circuits will be described below.

  First, a structure of the protection circuit 6205 provided between the input terminal and various circuits formed over the substrate will be described with reference to an equivalent circuit diagram illustrated in FIG. The protection circuit illustrated in FIG. 10B includes p-channel TFTs 7220 and 7230, capacitor elements 7210 and 7240, and a resistance element 7250. The resistance element 7250 is a two-terminal resistor, and an input potential Vin applied from an input terminal is applied to one end, and a low-potential power supply potential VSS is applied to the other end. The resistance element 7250 is provided to drop the potential of the wiring to VSS when Vin is no longer applied to the input terminal, and the resistance value is set to be sufficiently larger than the wiring resistance of the wiring.

  When Vin is higher than the high power supply potential VDD, the TFT 7220 is turned on and the TFT 7230 is turned off because of the gate-source voltage. Then, VDD is supplied to the wiring through the TFT 7220. Therefore, even if Vin is higher than VDD due to noise or the like, the potential applied to the wiring does not become higher than VDD. On the other hand, when Vin is lower than VSS, the TFT 7220 is turned off and the TFT 7230 is turned on because of the gate-source voltage. Then, VSS is given to the wiring. Therefore, even if Vin is lower than VSS due to noise or the like, the potential applied to the wiring does not become lower than VSS. Further, the capacitor elements 7210 and 7240 can damp pulsed noise to the potential from the input terminal, and abrupt changes in potential due to noise can be reduced to some extent.

  With the arrangement of the protection circuit having the above structure, the potential of the wiring is kept between VSS and VDD, and the subsequent circuit can be protected from application of an abnormally high or low potential outside this range. Further, by providing a protective circuit at an input terminal to which a signal is input, the potentials of all wirings to which a signal is supplied can be kept constant (here, VSS) when no signal is input. it can. In other words, when a signal is not input, it also has a function as a short ring that can make the wirings short-circuited. Therefore, electrostatic breakdown due to a potential difference between wirings can be prevented. Further, when a signal is input, the resistance value of the resistance element 7250 is sufficiently large, so that a signal applied to the wiring is not pulled by VSS.

  FIG. 10C is an equivalent circuit diagram of a protection circuit in which p-channel TFTs 7220 and 7230 are substituted with rectifying diodes 7260 and 7270. FIG. 10D is an equivalent circuit diagram of a protection circuit in which the p-channel TFTs 7220 and 7230 are substituted with TFTs 7350, 7360, 7370, and 7380.

  FIG. 10E and FIG. 10F illustrate protection circuits having different structures from the above. A protection circuit illustrated in FIG. 10E includes resistors 7280 and 7290 and an n-channel TFT 7300. The protection circuit illustrated in FIG. 10F includes resistors 7280 and 7290, a p-channel TFT 7310, and an n-channel TFT 7320. 10E and 10F, a wiring or the like is connected to the terminal 7330, and when the potential of the wiring or the like changes abruptly, the n-channel TFT 7300 or the p-channel TFT 7310 and When the n-channel TFT 7320 is turned on, current flows in the direction from the terminals 7330 to 7340. Then, rapid fluctuations in the potential connected to the terminal 7330 can be reduced, and damage or destruction of the element can be prevented. Note that the element forming the protection circuit is preferably formed using an amorphous semiconductor with excellent withstand voltage. This embodiment can be freely combined with the above embodiment modes.

  Note that although the signal line driver circuit 6202 and the pixel portion 6201 are connected by a signal line, the protection circuit 6206 can prevent the potential of the signal line from rapidly changing due to noise, static electricity, or the like. In addition, the scan line driver circuit 6203 and the pixel portion 6201 are connected by a scan line, but the protection circuit 6207 can prevent the potential of the scan line from abruptly changing due to noise, static electricity, or the like. Similarly to the protection circuit 6205, the circuit configurations illustrated in FIGS. 10B to 10F can be used for the protection circuits 6206 and 6207.

  In this example, the appearance of a panel corresponding to one mode of a light-emitting device using the present invention will be described with reference to FIGS. FIG. 11 is a top view of a panel in which a transistor and a light-emitting element formed over a substrate are sealed with a sealing material between the cover material and FIG. 11B is a top view of FIG. 11A. This corresponds to a cross-sectional view at −A ′.

  A sealant 4005 is provided so as to surround the pixel portion 4002, the signal line driver circuit 4003, and the scan line driver circuit 4004 provided over the substrate 4001. A cover member 4006 is provided over the pixel portion 4002, the signal line driver circuit 4003, and the scan line driver circuit 4004. Accordingly, the pixel portion 4002, the signal line driver circuit 4003, and the scan line driver circuit 4004 are sealed together with the filler 4007 by the substrate 4001, the sealant 4005, and the cover member 4006.

  In addition, the pixel portion 4002, the signal line driver circuit 4003, and the scan line driver circuit 4004 provided over the substrate 4001 include a plurality of transistors, and are included in the signal line driver circuit 4003 in FIG. Transistors 4008 and 4009 and a transistor 4010 included in the pixel portion 4002 are shown.

  Reference numeral 4011 corresponds to a light-emitting element and is electrically connected to the transistor 4010.

  The lead wiring 4014 corresponds to a wiring for supplying a signal or a power supply voltage to the pixel portion 4002, the signal line driver circuit 4003, and the scan line driver circuit 4004. The lead wiring 4014 is connected to the connection terminal 4016 through the lead wiring 4015. The connection terminal 4016 is electrically connected to a terminal included in the FPC 4018 through an anisotropic conductive film 4019.

  Note that as the substrate 4001, a flexible material typified by plastic can be used in addition to glass, metal (typically stainless steel), ceramics, and the like. As the plastic, an FRP (Fiberglass-Reinforced Plastics) plate, a PVF (polyvinyl fluoride) film, a mylar film, a polyester film, or an acrylic resin film can be used. A sheet having a structure in which an aluminum foil is sandwiched between PVF films or mylar films can also be used. The cover material 4006 is formed using a light-transmitting material such as a glass plate, a plastic plate, a polyester film, or an acrylic film.

  As the filler 4007, in addition to an inert gas such as nitrogen or argon, an ultraviolet curable resin or a thermosetting resin can be used. PVC (polyvinyl chloride), acrylic, polyimide, epoxy resin, silicon resin, PVB (Polyvinyl butyral) or EVA (ethylene vinyl acetate) can be used. In this example, nitrogen was used as the filler.

  Alternatively, the filler 4007 may be exposed to a hygroscopic substance (preferably barium oxide) or a substance that can adsorb oxygen.

  The light emitting device of the present invention has high external quantum efficiency for power consumption, and can increase the contrast of an image. Therefore, even if external light such as sunlight is irradiated, a clear image can be displayed while suppressing power consumption. Therefore, the advantage is that it can be used without relatively selecting a place of use. Therefore, it is very suitable for portable electronic devices as well as televisions.

  Specifically, as an electronic device using the light emitting device of the present invention, a video camera, a digital camera, a goggle type display (head mounted display), a navigation system, a sound reproduction device (car audio, audio component, etc.), a notebook type personal computer, Plays back recording media such as game machines, portable information terminals (mobile computers, mobile phones, portable game machines, electronic books, etc.), and image playback devices (specifically DVDs (Digital Versatile Disc)) equipped with recording media. And a device provided with a display capable of displaying the image). Specific examples of these electronic devices are shown in FIGS.

  FIG. 12A illustrates a display device, which includes a housing 2001, a support base 2002, a display portion 2003, a speaker portion 2004, a video input terminal 2005, and the like. The light emitting device of the present invention can be used for the display portion 2003. Since the light-emitting device is a self-luminous type, a backlight is not necessary and a display portion thinner than a liquid crystal display can be obtained. Note that display devices using light emitting elements include all information display devices for personal computers, TV broadcast reception, advertisement display, and the like.

  FIG. 12B illustrates a laptop personal computer, which includes a main body 2201, a housing 2202, a display portion 2203, a keyboard 2204, an external connection port 2205, a mouse 2206, and the like. The light emitting device of the present invention can be used for the display portion 2203.

  FIG. 12C illustrates a personal digital assistant (PDA), which includes a main body 2101, a display portion 2102, operation keys 2103, a modem 2104, and the like. The modem 2104 may be built in the main body 2101. The light emitting device of the present invention can be used for the display portion 2102.

  As described above, the applicable range of the present invention is so wide that it can be used for electronic devices in various fields. In addition, the electronic device of this embodiment may use the light emitting device having any structure shown in Embodiments 1 to 4.

  The transistor used in the light emitting device of the present invention may be a TFT using a polycrystalline semiconductor, or a TFT using an amorphous semiconductor or a semi-amorphous semiconductor. In this embodiment, a structure of a TFT formed using an amorphous semiconductor or a semi-amorphous semiconductor will be described.

  FIG. 7A shows a cross-sectional view of a TFT used for a driver circuit and a cross-sectional view of a TFT used for a pixel portion. 1001 corresponds to a cross-sectional view of a TFT used in a driver circuit, 1002 corresponds to a cross-sectional view of a TFT used in a pixel portion, and 1003 corresponds to a cross-sectional view of a light-emitting element to which current is supplied by the TFT 1002. The TFTs 1001 and 1002 are inverted stagger type (bottom gate type).

  The TFT 1001 of the driver circuit is a semi-amorphous layer which overlaps with the gate electrode 1010 formed over the substrate 1000, the gate insulating film 1011 covering the gate electrode 1010, and the gate electrode 1010 with the gate insulating film 1011 interposed therebetween. And a first semiconductor film 1012 formed of a semiconductor or an amorphous semiconductor. Further, the TFT 1001 includes a pair of second semiconductor films 1013 functioning as a source region or a drain region, and a third semiconductor film 1014 provided between the first semiconductor film 1012 and the second semiconductor film 1013. is doing.

  In FIG. 7A, the gate insulating film 1011 is formed of two layers of insulating films; however, the present invention is not limited to this structure. The gate insulating film 1011 may be formed of a single layer or three or more layers of insulating films.

  The second semiconductor film 1013 is formed using an amorphous semiconductor or a semi-amorphous semiconductor, and an impurity imparting one conductivity type is added to the semiconductor film. The pair of second semiconductor films 1013 are opposed to each other with a region where the channel of the first semiconductor film 1012 is formed therebetween.

  The third semiconductor film 1014 is formed of an amorphous semiconductor or a semi-amorphous semiconductor, has the same conductivity type as the second semiconductor film 1013, and has lower conductivity than the second semiconductor film 1013. It has special characteristics. Since the third semiconductor film 1014 functions as an LDD region, an electric field concentrated on an end portion of the second semiconductor film 1013 functioning as a drain region can be relaxed and a hot carrier effect can be prevented. The third semiconductor film 1014 is not necessarily provided, but the provision of the third semiconductor film 1014 can increase the withstand voltage of the TFT and improve the reliability. Note that in the case where the TFT 1001 is n-type, an n-type conductivity type can be obtained without adding an impurity imparting n-type in particular when the third semiconductor film 1014 is formed. Therefore, when the TFT 1001 is n-type, it is not always necessary to add n-type impurities to the third semiconductor film 1014. However, an impurity imparting p-type conductivity is added to the first semiconductor film in which the channel is formed, and the conductivity type is controlled so as to be as close to the I-type as possible.

  In addition, two wirings 1015 are formed so as to be in contact with the pair of second semiconductor films 1013.

  The TFT 1002 of the driver circuit is an amorphous semiconductor that overlaps the gate electrode 1020 formed on the substrate 1000, the gate insulating film 1011 covering the gate electrode 1020, and the gate electrode 1020 with the gate insulating film 1011 interposed therebetween. Alternatively, the first semiconductor film 1022 formed of a semi-amorphous semiconductor is included. Further, the TFT 1002 includes a pair of second semiconductor films 1023 functioning as a source region or a drain region, and a third semiconductor film 1024 provided between the first semiconductor film 1022 and the second semiconductor film 1023. is doing.

  The second semiconductor film 1023 is formed using an amorphous semiconductor or a semi-amorphous semiconductor, and an impurity imparting one conductivity type is added to the semiconductor film. The pair of second semiconductor films 1023 face each other with a region where the channel of the first semiconductor film 1022 is formed therebetween.

  The third semiconductor film 1024 is formed using an amorphous semiconductor or a semi-amorphous semiconductor, has the same conductivity type as the second semiconductor film 1023, and has lower conductivity than the second semiconductor film 1023. It has special characteristics. Since the third semiconductor film 1024 functions as an LDD region, an electric field concentrated on an end portion of the second semiconductor film 1023 functioning as a drain region can be relaxed and a hot carrier effect can be prevented. The third semiconductor film 1024 is not necessarily provided; however, by providing the third semiconductor film 1024, the pressure resistance of the TFT can be increased and the reliability can be improved. Note that in the case where the TFT 1002 is n-type, an n-type conductivity type can be obtained without adding an impurity imparting n-type in particular when the third semiconductor film 1024 is formed. Therefore, when the TFT 1002 is n-type, it is not always necessary to add n-type impurities to the third semiconductor film 1024. However, an impurity imparting p-type conductivity is added to the first semiconductor film in which the channel is formed, and the conductivity type is controlled so as to be as close to the I-type as possible.

  A wiring 1025 is formed so as to be in contact with the pair of second semiconductor films 1023.

  A first passivation film 1040 and a second passivation film 1041 made of an insulating film are formed so as to cover the TFTs 1001 and 1002 and the wirings 1015 and 1025. The passivation film that covers the TFTs 1001 and 1002 is not limited to two layers, and may be a single layer or three or more layers. For example, the first passivation film 1040 can be formed using silicon nitride, and the second passivation film 1041 can be formed using silicon oxide. By forming the passivation film using silicon nitride or silicon nitride oxide, it is possible to prevent the TFTs 1001 and 1002 from being deteriorated by the influence of moisture, oxygen, or the like.

  One end of the wiring 1025 is connected to the anode 1030 of the light emitting element 1003. Further, an electroluminescent layer 1031 is formed so as to be in contact with the anode 1030, and a cathode 1032 is formed so as to be in contact with the electroluminescent layer 1031.

  The anode 1030 includes a light-transmitting oxide conductive layer 1030a and a barrier layer 1030b, and the barrier layer 1030b is in contact with the electroluminescent layer 1031.

  Next, a mode different from that in FIG. 7A of the TFT included in the light-emitting device of the present invention is described. FIG. 7B shows a cross-sectional view of a TFT used for a driver circuit and a cross-sectional view of a TFT used for a pixel portion. 1101 corresponds to a cross-sectional view of a TFT used in a driver circuit, 1102 corresponds to a cross-sectional view of a TFT used in a pixel portion, and 1103 corresponds to a cross-sectional view of a light-emitting element to which current is supplied by the TFT 1102.

  The TFT 1101 of the driver circuit and the TFT 1102 of the pixel portion include a gate electrode 1110, 1120 formed on the substrate 1100, a gate insulating film 1111 covering the gate electrode 1110, 1120, and a gate insulating film 1111 sandwiched therebetween. The first semiconductor films 1112 and 1122, which are formed of an amorphous semiconductor or a semi-amorphous semiconductor, overlap with the electrodes 1110 and 1120, respectively. Then, channel protective films 1133 and 1134 formed of an insulating film are formed so as to cover the channel formation regions of the first semiconductor films 1112 and 1122. The channel protective films 1133 and 1134 are provided to prevent the channel formation regions of the first semiconductor films 1112 and 1122 from being etched in the manufacturing process of the TFTs 1101 and 1102. Further, the TFTs 1101 and 1102 are provided between a pair of second semiconductor films 1113 and 1123 functioning as a source region or a drain region, and between the first semiconductor films 1112 and 1122 and the second semiconductor films 1113 and 1123. 3 semiconductor films 1114 and 1124, respectively.

  In FIG. 7B, the gate insulating film 1111 is formed of two layers of insulating films; however, the present invention is not limited to this structure. The gate insulating film 1111 may be formed of a single layer or three or more layers of insulating films.

  The second semiconductor films 1113 and 1123 are formed of an amorphous semiconductor or a semi-amorphous semiconductor, and an impurity imparting one conductivity type is added to the semiconductor film. The pair of second semiconductor films 1113 and 1123 face each other with a region where the channel of the first semiconductor films 1112 and 1122 is formed therebetween.

  In addition, the third semiconductor films 1114 and 1124 are formed of an amorphous semiconductor or a semi-amorphous semiconductor, have the same conductivity type as the second semiconductor films 1113 and 1123, and more than the second semiconductor films 1113 and 1123. It has the characteristic that conductivity becomes low. Since the third semiconductor films 1114 and 1124 function as LDD regions, an electric field concentrated on the end portions of the second semiconductor films 1113 and 1123 functioning as drain regions can be relaxed and the hot carrier effect can be prevented. The third semiconductor films 1114 and 1124 are not necessarily provided, but the provision of the third semiconductor films 1114 and 1124 can increase the pressure resistance of the TFT and improve the reliability. Note that in the case where the TFTs 1101 and 1102 are n-type, an n-type conductivity type can be obtained without adding an impurity imparting n-type in particular when the third semiconductor films 1114 and 1124 are formed. Therefore, when the TFTs 1101 and 1102 are n-type, it is not always necessary to add n-type impurities to the third semiconductor films 1114 and 1124. However, an impurity imparting p-type conductivity is added to the first semiconductor film in which the channel is formed, and the conductivity type is controlled so as to be as close to the I-type as possible.

  In addition, two wirings 1115 and two wirings 1125 are formed so as to be in contact with the pair of second semiconductor films 1113 and 1123.

  A first passivation film 1140 and a second passivation film 1141 made of an insulating film are formed so as to cover the TFTs 1101 and 1102 and the wirings 1115 and 1125. The passivation film that covers the TFTs 1101 and 1102 is not limited to two layers, and may be a single layer or three or more layers. For example, the first passivation film 1140 can be formed using silicon nitride, and the second passivation film 1141 can be formed using silicon oxide. By forming the passivation film using silicon nitride or silicon nitride oxide, the TFTs 1101 and 1102 can be prevented from being deteriorated by the influence of moisture, oxygen, or the like.

  One end of the wiring 1125 is connected to the anode 1130 of the light emitting element 1103. An electroluminescent layer 1131 is formed so as to be in contact with the anode 1130, and a cathode 1132 is formed so as to be in contact with the electroluminescent layer 1131.

  The anode 1130 includes a light-transmitting oxide conductive layer 1130 a and a barrier layer 1130 b, and the barrier layer 1130 b is in contact with the electroluminescent layer 1131.

  Note that in this embodiment, an example in which a driver circuit of a light-emitting device and a pixel portion are formed over the same substrate using a TFT using an amorphous semiconductor or a semi-amorphous semiconductor is described; however, the present invention is not limited to this structure. A pixel portion may be formed using a TFT using an amorphous semiconductor or a semi-amorphous semiconductor, and a separately formed driver circuit may be attached to a substrate on which the pixel portion is formed.

  Further, a gate electrode, a wiring, or the like may be formed by a droplet discharge method. FIG. 13A illustrates a cross-sectional view of a pixel formed using a droplet discharge method as an example. In FIG. 13A, reference numeral 1201 denotes a bottom gate type TFT which is electrically connected to the light emitting element 1202. The TFT 1201 is formed on the gate electrode 1203, the gate insulating film 1204 formed on the gate electrode 1203, the first semiconductor film 1205 formed on the gate insulating film 1204, and the first semiconductor film 1205. And a second semiconductor film 1206. Note that the first semiconductor film 1205 functions as a channel formation region. An impurity imparting a conductivity type is added to the second semiconductor film 1206 and functions as a source region or a drain region.

  A wiring 1208 is formed so as to be in contact with the second semiconductor film 1206, and the wiring 1208 is connected to an anode 1209 included in the light-emitting element 1202. The light emitting element 1202 includes an anode 1209, an electroluminescent layer 1210 formed on the anode 1209, and a cathode 1211 formed on the electroluminescent layer 1210. The anode 1209 includes a light-transmitting oxide conductive layer 1209a and a barrier layer 1209b.

  In the light-emitting device illustrated in FIG. 13A, the gate electrode 1203, the wiring 1208, the anode 1209, the electroluminescent layer 1210, a mask used for pattern formation, and the like can be formed by a droplet discharge method.

  FIG. 13B illustrates an example of a cross-sectional view of a pixel formed using a droplet discharge method. In FIG. 13B, the first semiconductor film 1221 is etched when the second semiconductor film 1222 and the wiring 1223 are patterned over the first semiconductor film 1221 included in the bottom-gate TFT 1220. An insulating film (etching stopper) 1224 that can prevent the above is formed.

  In this embodiment, a combination of an insulating film and an anode formed over the insulating film will be described.

FIG. 14A shows the luminance L (cd / m ² ) of a light-emitting element in which silicon nitride oxide is used as an insulating film and an anode is formed using ITSO containing 5% by weight of silicon oxide on the insulating film. The measured value of current efficiency η (cd / A) is shown. For comparison, FIG. 14A also shows current efficiency η (for luminance L (cd / m ² ) of a light-emitting element in which silicon nitride oxide is also used as an insulating film and an anode is formed on the insulating film using ITO. The actual measurement value of cd / A) is shown.

Note that the sample used in the measurement illustrated in FIG. 14A is an insulating film using silicon nitride oxide, which includes a Si—O bond and a Si—CH _X bond formed using a siloxane-based material as a starting material. It is formed on an insulating film having a thickness of 0.8 μm. The insulating film using silicon nitride oxide is formed with a thickness of 100 nm by a CVD method.

  As shown in FIG. 14A, it was found that the sample using ITSO for the anode had higher current efficiency than the sample using ITO for the anode.

Next, FIG. 14B shows luminance L (cd / m ² ) of a light-emitting element in which silicon nitride is used as an insulating film and an anode is formed on the insulating film using ITSO containing 5 wt% silicon oxide. The measured value of the current efficiency η (cd / A) with respect to is shown. For comparison, FIG. 14B shows a current efficiency η (cd) with respect to luminance L (cd / m ² ) of a light-emitting element in which silicon nitride is also used as an insulating film and an anode is formed on the insulating film using ITO. / A) shows the actual measured value.

  Note that in the sample used in the measurement illustrated in FIG. 14B, an insulating film using silicon nitride is formed over an insulating film containing acrylic with a thickness of 0.8 μm. The insulating film using silicon nitride is formed with a thickness of 100 nm by sputtering.

  As shown in FIG. 14B, as in FIG. 14A, the sample using ITSO for the anode was found to have higher current efficiency than the sample using ITO for the anode.

Next, FIG. 14C illustrates a luminance L (cd / m ² ) of a light-emitting element in which silicon oxide is used as an insulating film and an anode is formed using ITSO containing 5 wt% silicon oxide on the insulating film. The measured value of the current efficiency η (cd / A) with respect to is shown. For comparison, FIG. 14C shows a current efficiency η (cd) with respect to luminance L (cd / m ² ) of a light-emitting element in which silicon oxide is also used as an insulating film and an anode is formed using ITO on the insulating film. / A) shows the actual measured value.

  Note that in the sample used in the measurement illustrated in FIG. 14C, an insulating film using silicon oxide is formed with a thickness of 100 nm.

  14A and 14B are compared with FIG. 14C, when ITSO is used for the anode, silicon nitride oxide or silicon nitride is used rather than silicon oxide as the insulating film. However, it can be seen that high current efficiency is obtained, and as a result, high internal quantum efficiency is obtained.

  Note that FIG. 14 illustrates the case of a single-layer anode using ITSO, but it is considered that the internal quantum efficiency of the light-emitting device can be further increased by combining the above structure with the structure of the present invention. That is, by stacking an anode having a light-transmitting oxide conductive layer and a barrier layer, an electroluminescent layer, and a cathode in this order on an insulating film containing silicon nitride or silicon nitride oxide, higher internal quantum efficiency can be obtained. Obtainable.

The figure which shows the band model explaining the state in which the insulating or semi-insulating barrier film containing silicon or silicon oxide was formed in the interface of a translucent oxide conductive layer and a hole injection layer. The figure which shows the band model which shows the contact state of the conventional translucent oxide conductive layer and hole injection layer. The figure which shows the measurement result of TDS. FIG. 11 illustrates a structure of a light-emitting element in a light-emitting device using the present invention. 4A and 4B illustrate a method for manufacturing a light-emitting device according to the present invention. 4A and 4B illustrate a method for manufacturing a light-emitting device according to the present invention. Sectional drawing of the light-emitting device using this invention. Sectional drawing of the light-emitting device using this invention. FIG. 6 is a circuit diagram of a pixel of a light-emitting device. The top view of a light-emitting device and the figure which shows the structure of a protection circuit. 4A and 4B are a top view and a cross-sectional view of a light-emitting device using the present invention. FIG. 16 illustrates an electronic device using a light-emitting device. Sectional drawing of the light-emitting device using this invention. The graph which shows the measured value of a brightness | luminance and current efficiency.

Explanation of symbols

100 substrate 101 anode 102 electroluminescent layer 103 cathode 104 first layer 105 second layer 106 third layer 107 fourth layer 108 fifth layer 109a barrier layer 109b translucent oxide conductive layer 110 substrate 111 anode 112 Electroluminescent layer 113 Cathode 114 Al-Si layer 115 Ti layer 116 Translucent oxide conductive layer 117 Barrier layer 201 Substrate 202 Base film 203 Semiconductor film 204 Semiconductor film 205 N-channel TFT
206 p-channel TFT
207 Gate insulating film 208 Gate electrode 209 Gate electrode 210 Passivation film 211 First interlayer insulating film 212 Second interlayer insulating film 213 Wiring 214 Wiring 215 Wiring 216 Wiring 217 Translucent oxide conductive layer 218 Barrier layer 219 Anode 220 Patterning Subsequent translucent oxide conductive layer 221 Patterned barrier layer 222 Partition 223 Electroluminescent layer 224 Cathode 225 Light emitting element 7000 Substrate 7001 Transistor 7002 Transistor 7003 Transistor 7004 First interlayer insulating film 7005 Wiring 7006 Wiring 7007 Wiring 7008 Second Interlayer insulating film 7009 Third interlayer insulating film 7010 Wiring 7011 Wiring 7012 Wiring 7013 Translucent oxide conductive layer 7014 Translucent oxide conductive layer 7015 Translucent oxide conductive layer 7016 Barrier layer 701 Barrier layer 7018 Barrier layer 7019 Anode 7020 Anode 7021 Anode 7022 Electroluminescent layer 7023 Electroluminescent layer 7024 Electroluminescent layer 7025 Cathode 7026 Light emitting element 7027 Light emitting element 7028 Light emitting element 7030 Cover material 7031 Shielding film 7032 Colored layer 7033 Colored layer 7034 Colored layer 7035 Color filter 7040 Bulkhead 6110 TFT
6111 TFT
6112 Capacitor element 6113 Light emitting element 6114 Signal line 6115 Power line 6116 Scan line 6117 Power line 6118 TFT
6119 Scan Line 6125 TFT
6126 Wiring 6200 Substrate 6201 Pixel portion 6202 Signal line driver circuit 6203 Scan line driver circuit 6204 Input terminal 6205 Protection circuit 6206 Protection circuit 6207 Protection circuit 7210 Capacitance element 7220 p-channel TFT
7230 TFT
7240 Capacitor 7250 Resistor 7260 Diode 7270 Diode 7280 Resistor 7290 Resistor 7300 n-channel TFT
7310 p-channel TFT
7320 n-channel TFT
7330 Terminal 7340 Terminal 7350 TFT
7360 TFT
7370 TFT
7380 TFT
4001 Substrate 4002 Pixel portion 4003 Signal line driver circuit 4004 Scan line driver circuit 4005 Seal material 4006 Cover material 4007 Filler 4008 Transistor 4009 Transistor 4010 Transistor 4011 Light emitting element 4014 Wiring 4015 Wiring 4016 Connection terminal 4018 FPC
4019 Anisotropic conductive film 2001 Case 2002 Support base 2003 Display unit 2004 Speaker unit 2005 Video input terminal 2201 Main unit 2202 Case 2203 Display unit 2204 Keyboard 2205 External connection port 2206 Mouse 2101 Main unit 2102 Display unit 2103 Operation key 2104 Modem 1000 Substrate 1001 TFT
1002 TFT
1003 Light emitting element 1010 Gate electrode 1011 Gate insulating film 1012 First semiconductor film 1013 Second semiconductor film 1014 Third semiconductor film 1015 Wiring 1020 Gate electrode 1022 First semiconductor film 1023 Second semiconductor film 1024 Third semiconductor Film 1025 Wiring 1030 Anode 1030a Translucent oxide conductive layer 1030b Barrier layer 1031 Electroluminescent layer 1032 Cathode 1040 Passivation film 1041 Passivation film 1100 Substrate 1101 TFT
1102 TFT
1103 Light emitting element 1110 Gate electrode 1111 Gate insulating film 1112 First semiconductor film 1113 Second semiconductor film 1114 Third semiconductor film 1115 Wiring 1120 Gate electrode 1122 First semiconductor film 1123 Second semiconductor film 1124 Third semiconductor Film 1125 Wiring 1130 Channel protective film 1131 Channel protective film 1132 Cathode 1133 Anode 1133a Translucent oxide conductive layer 1133b Barrier layer 1134 Electroluminescent layer 1140 Passivation film 1141 Passivation film 1201 TFT
1202 Light emitting element 1203 Gate electrode 1204 Gate insulating film 1205 First semiconductor film 1206 Second semiconductor film 1208 Wiring 1209 Anode 1210 Electroluminescent layer 1211 Cathode 1209a Translucent oxide conductive layer 1209b Barrier layer 1220 TFT
1221 First semiconductor film 1222 Second semiconductor film 1223 Wiring 1224 Insulating film

Claims (3)

An anode formed in contact with an insulating film using silicon nitride oxide;
An electroluminescent layer formed on the anode;
A cathode formed on the electroluminescent layer,
The insulating film contains nitrogen and silicon;
The anode has a light-transmitting oxide conductive layer in contact with the insulating film, and a barrier layer having a thickness of 0.5 to 5 nm in contact with the electroluminescent layer,
The translucent oxide conductive layer and the barrier layer contain indium tin oxide and silicon oxide,
The silicon density in the barrier layer is higher than the silicon density in the translucent oxide conductive layer,
The light-emitting device, wherein the barrier layer is in contact with a hole injection layer included in the electroluminescent layer. An electronic apparatus comprising the light emitting device according to claim 1.   3. The video camera, digital camera, goggle type display, navigation system, sound playback device, notebook personal computer, game machine, portable information terminal, or image playback device including a recording medium according to claim 2. Electronics.

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