JP2005196225A - Light emitting device and method of manufacturing light emitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a means for preventing a deterioration in a light emitting element caused by a difference in the temperature characteristics between an interlayer insulating film and an anode in a light emitting device having the anode, an organic compound layer, and a cathode. <P>SOLUTION: The light emitting device having a TFT formed on an insulator, a first insulating film formed on the TFT, a second insulating film composed of an inorganic insulating material and formed on the first insulating film, and the anode formed on the second insulating film and a method of manufacturing the same are provided. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing a light-emitting device using a light-emitting element that includes a film containing an organic compound that can emit light by applying an electric field (hereinafter referred to as an “organic compound layer”), an anode, and a cathode. . In particular, the present invention relates to a light-emitting device using a light-emitting element whose driving voltage is lower than that of a conventional element and whose lifetime is long. Note that a light-emitting device in this specification refers to an image display device or a light-emitting device that uses a light-emitting element as a light-emitting element. In addition, connectors such as anisotropic conductive film ((FPC: flexible printed circuit) or TAB (Tape Automated Bonding) tape or TCP (Tape Carrier Package)) are attached to the light emitting element, printed on the end of TAB tape or TCP. It is assumed that the light emitting device includes all modules provided with a wiring board or modules in which an IC (integrated circuit) is directly mounted on a light emitting element by a COG (Chip On Glass) method.

  A light-emitting element is an element that emits light when an electric field is applied. The mechanism of light emission is that molecular excitation occurs when electrons are injected from the cathode and holes injected from the anode are recombined at the emission center in the organic compound layer by applying a voltage across the organic compound layer between the electrodes. It is said that when a molecular exciton returns to the ground state, it emits energy and emits light.

  Note that the type of molecular exciton formed by the organic compound can be a singlet excited state or a triplet excited state, but in this specification, it includes light emission from one of the excited states or both. .

  In such a light emitting device, the organic compound layer is usually formed as a thin film having a thickness of less than 1 μm. Further, since the light emitting element is a self-luminous element in which the organic compound layer itself emits light, a backlight as used in a conventional liquid crystal display is not necessary. Therefore, it is a great advantage that the light-emitting element can be manufactured to be extremely thin and light.

  Also, for example, in an organic compound layer of about 100 to 200 nm, the time from carrier injection to recombination is about several tens of nanoseconds considering the carrier mobility of the organic compound layer. Even if the process from light emission to light emission is included, light emission occurs in the order of microseconds or less. Therefore, one of the features is that the response speed is very fast.

  Due to these characteristics such as thin and light weight, high-speed response, and direct current low voltage drive, the light emitting element is attracting attention as a next-generation flat panel display element. Further, since it is a self-luminous type and has a wide viewing angle, the visibility is relatively good, and it is considered to be effective as an element used for a display screen of an appliance.

  Such a light emitting element is classified into a passive matrix type (simple matrix type) and an active matrix type depending on the driving method. However, an active matrix type is particularly attracting attention because high-definition display having a number of pixels equal to or greater than QVGA is possible.

  An active matrix light-emitting device having a light-emitting element has an element structure as shown in FIG. 18, in which a TFT 1902 is formed over a substrate 1901, and an interlayer insulating film 1903 is formed over the TFT 1902. Note that the interlayer insulating film 1903 can be formed using an inorganic material containing silicon such as silicon oxide or silicon nitride, or an organic material such as an organic resin material such as polyimide, polyamide, or acrylic. However, organic materials are more suitable for planarizing the substrate surface.

An anode (pixel electrode) 1905 that is electrically connected to the TFT 1902 by a wiring 1904 is formed over the interlayer insulating film 1903. As a material for forming the anode 1905, a transparent conductive material having a large work function is suitable. An alloy composed of indium tin oxides (ITO), tin oxide (SnO ₂ ), indium oxide and zinc oxide (ZnO), gold Semipermeable membranes and polyaniline have been proposed. Of these, ITO is most often used because it has a band gap of about 3.75 eV and high transparency in the visible light region.

  ITO film formation methods include chemical vapor deposition, spray pyrolysis, vacuum deposition, electron beam deposition, sputtering, ion beam sputtering, ion plating, and ion assist deposition. In many cases, sputtering is used.

  An organic compound layer 1906 is formed on the anode 1905. In the present specification, all layers provided between the anode and the cathode are defined as organic compound layers. Specifically, the organic compound layer 1906 includes a light emitting layer, a hole injection layer, an electron injection layer, a hole transport layer, an electron transport layer, and the like. Basically, the light-emitting element has a structure in which an anode / light-emitting layer / cathode is laminated in order, and in addition to this structure, an anode / hole injection layer / light-emitting layer / cathode and an anode / hole injection layer. In some cases, the light emitting layer / the electron transporting layer / the cathode are laminated in this order.

  Note that there are film formation methods such as an evaporation method, a printing method, an inkjet method, and a spin coating method as a method for forming an organic compound for forming the organic compound layer 1906. In particular, a vapor deposition method that can be applied separately using a metal mask is often used for forming a low molecular weight organic material.

  After the organic compound layer 1906 is formed, the cathode 1907 is formed, whereby the light emitting element 1908 is formed. Note that FIG. 18 illustrates only light-emitting elements formed in one pixel; however, in actuality, an active matrix light-emitting device is formed by forming a plurality of these in the pixel portion.

  In manufacturing a light-emitting device, improvement of an electrode is an important element for improving element characteristics of a light-emitting element.

  However, it has several problems with anode formation. First, in the case of the active matrix type element structure as described above, since the anode is formed in contact with the interlayer insulating film, the following two problems arise.

  First, there is a problem caused by the difference in temperature characteristics between the organic resin material forming the interlayer insulating film and the transparent conductive film (ITO) forming the anode. Specifically, since the two materials formed in contact with each other have different coefficients of thermal expansion, the material with the smaller coefficient of thermal expansion when the temperature is applied generates cracks at the interface. It is easy to do.

FIG. 2A shows the relationship of the thermal expansion coefficient with respect to temperature. Here, the horizontal axis represents temperature and the vertical axis represents the coefficient of thermal expansion. 201 indicates the thermal expansion coefficient of the organic resin material (PI: polyimide) forming the interlayer insulating film, and 202 indicates the thermal expansion coefficient of the transparent conductive film (ITO) forming the anode. In this graph, when the temperature is Tx, the organic resin material (PI) has a coefficient of thermal expansion of a ₁ , but the coefficient of thermal expansion of ITO is a ₂ .

Since the relationship of a ₁ > a _{2 with} respect to these coefficients of thermal expansion, when the organic resin material 212 and ITO 213 are laminated on the substrate 211 as shown in FIG. As indicated by 214 in 2 (B), cracks occur in the ITO 213 at the interface.

  ITO is the anode of the light-emitting element and is an electrode that injects holes involved in light emission. Therefore, if a crack occurs in the ITO, it affects the generation of holes or the number of injected holes decreases. Furthermore, it may cause deterioration of the light emitting element.

  The other is a problem of gas generated from an interlayer insulating film formed of an organic resin material such as polyimide, polyamide and acrylic. In general, it is known that a light-emitting element is easily deteriorated by oxygen or water. Therefore, the problem is that deterioration of the light-emitting element is promoted by a gas such as oxygen generated from an interlayer insulating film.

  Furthermore, there is a problem due to the flatness of the anode surface. This is a problem common to both the passive matrix type and the active matrix type. However, when the flatness of the anode surface is poor, the film thickness of the organic compound layer formed on the anode becomes nonuniform. Thus, when the film thickness of the organic compound layer of a light emitting element is non-uniform | heterogenous, an electric field will be added nonuniformly and the current density in an organic compound layer will also become non-uniform | heterogenous. As a result, not only the luminance of the light emitting element is lowered, but also the element life is shortened because the deterioration of the element is accelerated.

  Accordingly, an object of the present invention is to provide a light-emitting element having a longer lifetime than that of the conventional element by solving these problems.

  It is another object of the present invention to provide a light-emitting device having a longer lifetime than the conventional one by using such a light-emitting element. It is another object of the present invention to provide an electric appliance that is kept longer than before by producing the electric appliance using the light emitting device.

  A method for solving the above problem will be described below. That is, as shown in FIG. 1, a TFT (current control TFT) 102 is formed on a substrate 101, an interlayer insulating film 103 made of an organic resin material is formed thereon, and an inorganic insulating film is formed on the interlayer insulating film 103. An insulating film 104 made of a material is formed.

  Note that the insulating film 104 includes silicon oxide, silicon nitride (SiN), silicon oxynitride (SiON), silicon nitride oxide (SiNO), aluminum nitride (AlN), aluminum nitride oxide (AlNO), and aluminum oxynitride (AlNO). An inorganic insulating material containing silicon or aluminum is used.

  Here, the insulating film 104 is formed on the interlayer insulating film 103 in order to prevent degassing from the interlayer insulating film 103 and between the interlayer insulating film 103 and the anode (ITO) 106 formed thereon. This is to alleviate the occurrence of cracks in part of the anode (ITO) 106 in the vicinity of the interface due to the difference in thermal expansion coefficient.

  Note that the thermal expansion coefficient of the inorganic insulating material forming the insulating film 104 is as indicated by 203 in FIG. That is, it can be seen that the thermal expansion coefficient of the inorganic insulating material takes a value between the organic resin material (PI) 201 and the transparent conductive film (ITO) 202.

Specifically, the thermal expansion coefficient of the organic resin material (PI) at temperature Tx is a ₁ , the thermal expansion coefficient of ITO forming the anode is a ₃ , and the thermal expansion coefficient of the insulating material is a ₂ . The relationship between these thermal expansion coefficients is a ₁ > a ₂ > a ₃ . Therefore, when an insulating film 223 made of an inorganic insulating material is formed between the interlayer insulating film 222 and the anode 224 as shown in FIG. 2C, the tension (displacement) applied to the anode (ITO) 224 due to the difference in thermal expansion coefficient. Stress) can be relaxed.

  In addition, the organic resin material contains a gas such as oxygen and may be released from the inside of the organic resin with time. However, by providing the insulating film 223 made of an inorganic insulating material on the interlayer insulating film made of an organic resin material as described above, it is possible to prevent gas from being released from the inside of the organic resin.

  Thereby, deterioration of the light emitting element formed on the interlayer insulating film made of the organic resin material due to gas can be prevented, so that the life of the light emitting element can be extended.

  After the insulating film 104 is formed, a contact hole is opened in the interlayer insulating film 103 and the insulating film 104 to form a wiring 105 with the current control TFT 102. Then, an anode 106 made of a transparent conductive material is formed so as to be in contact with the wiring 105.

  Then, the organic compound layer 107 and the cathode 108 are formed over the anode 106, whereby the light-emitting element 109 including the anode 106, the organic compound layer 107, and the cathode 108 is formed, and the active matrix light-emitting device is completed.

  However, since the surface of the transparent conductive film serving as the anode is rough and uneven, it is necessary to flatten the surface of the transparent conductive film in order to increase the light emission luminance of the light emitting element 109 and to extend the life. The

  The flatness of the surface, that is, the surface roughness is related to the contact angle. When the surface has a fine concavo-convex structure, the surface free energy per unit area changes accordingly. This is illustrated by the Wenzel equation (Equation 1).

Here, θ is a contact angle on a smooth surface, and θ ′ is a contact angle on a surface having an uneven structure. Γ _S represents the surface free energy on the solid surface, γ _L represents the surface free energy on the liquid surface, and γ _SL represents the surface free energy on the interface between the solid and the liquid. R is a parameter indicating how many times the surface area of the surface having the concavo-convex structure is larger than the smooth surface. That is, it can be said from this formula that the contact angle changes according to the surface area.

  Specifically, when the contact angle θ ′ on the surface of the transparent conductive film having a concavo-convex structure is θ ′ <90 °, the contact angle θ after the treatment is related to θ ′ <θ by flattening. Fulfill. If θ ′> 90 °, the contact angle θ after processing satisfies the relationship θ ′> θ by flattening.

  Therefore, in the present invention, in the production of a light emitting device, after forming a transparent conductive film, the surface is wiped with a cleaning liquid and a PVA (polyvinyl alcohol) -based porous material that is a wiping property. The surface of the surface is flattened by changing the contact angle with water and changing the contact angle.

  Although the method of directly wiping and flattening the anode surface formed after wiring formation has been described, in the present invention, a flattening film of about 1 to 50 mm is formed on the anode surface to improve the flatness. Thereafter, the planarizing film can be wiped off in the same manner.

  Further, after the wiring is formed, it can be wiped before patterning with the transparent conductive film as an anode. Furthermore, the wiring may be formed after forming the anode first and wiping the surface of the anode.

  After wiping the surface of the anode 106, the bank 110 made of an insulating material is formed. Note that the shape of the bank 110 can be controlled by the insulating material and etching conditions used here. After the bank 110 is formed, an organic compound layer 107 containing an organic compound is formed, and a cathode 108 is further formed. Through the above steps, the light-emitting element 109 including the anode 106, the organic compound layer 107, and the cathode 108 can be formed.

  Further, in the case of an element structure in which an organic compound layer is formed and an anode is formed after the cathode is formed, the cathode surface is wiped by the method described above after the cathode is formed. You can also.

  By the way, in recent years, light-emitting elements that can convert energy emitted when returning from a triplet excited state to a ground state (hereinafter referred to as “triplet excited energy”) into light emission have been announced one after another, and the light emission efficiency is high. (Reference 1: DF O'Brien, MA Baldo, ME Thompson and SR Forrest, "Improved energy transfer in electrophosphorescent devices", Applied Physics Letters, vol. 74, No. 3, 442-444 (1999)) (Reference 2: Tetsuo TSUTSUI, Moon-Jae YANG, Masayuki YAHIRO, Kenji NAKAMURA, Teruichi WATANABE, Taishi TSUJI, Yoshinori FUKUDA, Takeo WAKIMOTO and Satoshi MIYAGUCHI, "High Quantum Efficiency in Organic Light-Emitting Devices with Iridium-Complex as a Triplet Emissive Center ", Japanese Journal of Applied Physics, Vol. 38, L1502-L1504 (1999)).

  Document 1 uses a metal complex having platinum as a central metal, and Document 2 uses a metal complex having iridium as a central metal. A light-emitting element (hereinafter, referred to as a “triplet light-emitting element”) formed using an organic compound (hereinafter referred to as a triplet light-emitting material) capable of converting these triplet excitation energy into light emission emits light with higher brightness than before. -High luminous efficiency can be achieved.

However, according to the report example of Document 2, the luminance half-life is about 170 hours when the initial luminance is set to 500 cd / m ² , and there is a problem in the element lifetime. Therefore, by applying the present invention to a triplet light-emitting element, it is possible to realize a very high-performance light-emitting element in which the lifetime of the element is long in addition to high luminance light emission and high light emission efficiency by light emission from a triplet excited state. .

  Therefore, the present invention also includes a case where the concept of the present invention in which an insulating film is formed on the interlayer insulating film as described above and the anode surface is planarized is applied to a triplet light emitting element.

  As described above, the anode of a light-emitting element is formed over the insulating film using the present invention, and further, the anode surface is wiped and planarized, whereby deterioration of the light-emitting element can be prevented. Furthermore, since the current density in the organic compound layer can be increased by planarizing the anode surface, the light emission luminance can be increased and the driving voltage can be reduced, so that a light emitting element with a long lifetime can be formed. .

  A method for manufacturing the light-emitting element of the present invention will be described below. Note that only a part of a pixel portion where a light emitting element is formed will be described here in order to simplify the description.

[Embodiment 1]
First, a TFT 302 is formed over a substrate 301 as shown in FIG. Note that what is shown here is a TFT that controls a current flowing through the light emitting element, and is referred to as a current control TFT 302 in this specification.

  Next, an interlayer insulating film 303 is formed on the current control TFT 302 for the purpose of planarizing the substrate surface. Here, a material such as an organic resin such as polyimide, acrylic, polyamide, polyimide amide, or BCB (benzocyclobutene) is used, and an average film thickness of 1.0 to 2.0 μm is formed (FIG. 3B )).

  Thus, by forming the interlayer insulating film 303 with an organic resin material, the surface can be satisfactorily planarized. Moreover, since the organic resin material generally has a low dielectric constant, parasitic capacitance can be reduced. In order to prevent degassing from the interlayer insulating film, an insulating film 304 is formed over the interlayer insulating film 303 as shown in FIG.

The insulating film 304 includes silicon such as silicon oxide, silicon nitride (SiN), silicon oxynitride (SiON), silicon nitride oxide (SiNO), aluminum nitride (AlN), aluminum nitride oxide (AlNO), and aluminum oxynitride (AlNO). What is necessary is just to form with the inorganic insulating material containing aluminum, or the laminated film which combined these. In any case, the insulating film 304 is formed from an inorganic insulating material. The thickness of the insulating film 304 is 100 to 200 nm. In the case of forming the insulating film 304, a plasma CVD method is used, with a reaction pressure of 20 to 200 Pa, a substrate temperature of 300 to 400 ° C., and a high frequency (13.56 MHz) power density of 0.1 to 1.0 W / cm ² . It can be formed by discharging.

  Thereafter, a resist mask having a predetermined pattern is formed, and contact holes reaching the drain regions of the respective current control TFTs 302 are formed. A contact hole can be formed by first etching the insulating film 304 and then etching the interlayer insulating film 303 made of an organic resin material.

  Then, a conductive metal film is formed by a sputtering method or a vacuum evaporation method, patterned with a mask, and then etched to form a wiring 305 (FIG. 3D). In addition to Al and Ti, these alloy films can also be used as the wiring material.

  Next, a transparent conductive film is formed thereon, and an anode 306 to be a pixel electrode is formed by patterning (FIG. 3E). As the transparent electrode, an indium tin oxide (ITO) film or a transparent conductive film in which indium oxide is mixed with 2 to 20% zinc oxide (ZnO) can be used.

  When the anode 306 is formed, heat treatment is performed. Here, the transparent conductive film forming the anode is crystallized by heating at 230 to 350 ° C.

  Next, the planarization treatment of the present invention is performed on the anode surface. As a treatment method, the surface of the anode 306 is planarized by wiping the surface of the anode 306 using a PVA (polyvinyl alcohol) -based porous material.

In addition, since the contact angle θ _{1 on the} surface of the transparent conductive film in Embodiment 1 is θ ₁ <90 °, the relationship with the contact angle θ ₂ after the treatment is θ by performing the wiping treatment. ₁ <made to be theta _2.

  As a wiping method using the PVA-based porous body 308, there is a method in which the PVA-based porous body 308 is wound around the shaft 307, and this is brought into contact with the surface of the anode 306 and the shaft 307 is rotated. However, in the present invention, the anode surface may be wiped and flattened by the frictional force generated between the PVA-based porous body 308 and the anode surface, and is not limited to this method.

  A cleaning liquid is used when wiping with the PVA-based porous body 308. As the cleaning liquid used at this time, in addition to pure water, a neutral detergent such as alkylbenzene sulfonate using higher alcohol or alkylbenzene as a raw material, or an aqueous solution containing weakly acidic and weakly alkaline chemicals can be used. In addition to polar solvents such as ethanol, methanol, toluene, and acetone, nonpolar solvents such as benzene and carbon tetrachloride can be used.

  The processing speed and the flatness of the surface can be adjusted by the rotational speed of the shaft 307 and the indentation value. In the present specification, the indentation value refers to the vertical direction of the substrate as the Y direction, and the position of the axis when the PVA-based porous body 308 is in contact with the treatment surface as a reference value (Y = 0) The direction in which the PVA-based porous body is pressed against the substrate is a positive direction, and is a value indicating how much the axis moves in the substrate direction when wiping. In the present invention, the rotational speed of the shaft 307 is desirably 100 to 300 rpm, and the indentation value is desirably 0.1 to 1.0 mm.

  After the surface of the anode 306 is planarized as described above, the bank 309, the organic compound layer 310, and the cathode 311 are formed as shown in FIG.

  Note that the bank 309 is formed to fill a gap between the anodes, and is formed into a desired shape by etching after forming a film using an organic material such as an organic resin. In this embodiment, the organic compound layer 310 includes a plurality of layers such as a hole transport layer, a hole blocking layer, an electron transport layer, an electron injection layer, and a buffer layer as a hole injection layer in addition to the light emitting layer. It is formed by combining and laminating. Note that the thickness of the organic compound layer 310 may be 10 to 400 [nm].

  After the organic compound layer 310 is formed, the cathode 311 is formed by an evaporation method. As the conductive film to be the cathode 311, in addition to MgAg or an Al—Li alloy film (aluminum / lithium alloy film), an element belonging to Group 1 or Group 2 of the periodic table and aluminum were formed by a co-evaporation method. A membrane can be used. The film thickness of the cathode 311 may be 80 to 200 [nm]. Through the above steps, the light-emitting element of the present invention can be formed.

  In this embodiment mode, the method of forming the bank 309 after wiping the anode 306 is described; however, the anode surface may be wiped after the bank is formed. However, when this method is used, there arises a problem that an organic material such as an organic resin formed on the uneven anode surface is difficult to be etched on the anode surface during patterning of the bank.

[Embodiment 2]
The planarization treatment in the present invention is not limited to the formation of the anode as shown in the first embodiment, and the planarization can be performed after the transparent conductive film is formed (before the anode patterning).

  Thus, a method for forming a light-emitting element by a method different from that described in Embodiment Mode 1 is described with reference to FIGS.

  Note that after the current control TFT 502 is formed over the substrate 501 and the interlayer insulating film 503 and the insulating film 504 are formed, contact holes are formed in the insulating film 504 and the interlayer insulating film 503, and the current control TFT 502 is electrically connected. 5A to 5C, a method similar to that described in Embodiment Mode 1 is used.

  When the wiring 505 is formed, a transparent conductive film 506 is formed with a thickness of 80 to 200 nm as shown in FIG. Note that as the transparent conductive film 506, an indium tin oxide (ITO) film or a material in which indium oxide and zinc oxide (ZnO) are mixed can be used.

  Then, when the transparent conductive film 506 is formed, the planarization process of the present invention is performed. As a treatment method, the surface of the transparent conductive film 506 is wiped using a PVA (polyvinyl alcohol) -based porous material to flatten the surface.

  As a wiping method using a PVA-based porous body, the same method as described in Embodiment 1 may be used, and the shaft 507 around which the PVA-based porous body 508 is wound is rotated. The surface of the transparent conductive film 506 is flattened by the frictional force when the PVA-based porous body 508 comes into contact with the surface of the transparent conductive film 506.

  A cleaning liquid is used in the wiping process. As the cleaning liquid used at this time, in addition to pure water, a neutral detergent such as alkylbenzene sulfonate using higher alcohol or alkylbenzene as a raw material, or an aqueous solution containing weakly acidic and weakly alkaline chemicals can be used. Furthermore, in addition to polar solvents such as ethanol, methanol, acetone, and toluene, nonpolar solvents such as benzene and carbon tetrachloride can be used. In this embodiment, pure water or a neutral detergent is used as a cleaning liquid. Is desirable.

  Further, it is desirable that the rotational speed of the shaft 507 is 100 to 300 rpm, and the indentation value is 0.1 to 1.0 mm.

  After the surface of the transparent conductive film 506 is planarized, an anode 509 is formed by patterning as shown in FIG. When the anode 509 is formed, heat treatment is performed. Here, the transparent conductive film forming the anode is crystallized by heating at 230 to 350 ° C. When the anode 509 is formed, the bank 510, the organic compound layer 511, and the cathode 512 are formed. Note that the bank 510, the organic compound layer 511, and the cathode 512 may be formed in the same manner as described in Embodiment Mode 1.

  Through the above, a light-emitting device having the light-emitting element of the present invention can be formed.

[Embodiment 3]
Furthermore, in this Embodiment 3, after forming the planarization film | membrane which consists of organic resin materials on an anode surface and making the uneven surface on an anode small, the wiping process by a PVA-type porous body is performed. A method for planarization will be described.

  After the current control TFT 602 is formed over the substrate 601 in FIG. 6A and the interlayer insulating film 603 and the insulating film 604 are formed, contact holes are formed in the insulating film 604 and the interlayer insulating film 603 to control the current. As a manufacturing method until the wiring 605 that is electrically connected to the TFT for use 602 is formed, the same method as that described in Embodiment Mode 1 is used.

  When the wiring 605 is formed, a transparent conductive film 606 is formed with a thickness of 80 to 120 nm. Note that as the transparent conductive film 606, an indium tin oxide (ITO) film or a material in which indium oxide is mixed with zinc oxide (ZnO) can be used.

  In Embodiment 3, after forming the transparent conductive film 606, the anode 607 is formed by patterning the transparent conductive film 606. Then, heat treatment is performed when the anode 607 is formed. Note that here, the transparent conductive film which forms the anode 607 is crystallized by heating at 230 to 350 ° C. (FIG. 6B). Then, when the anode 607 is formed, a planarization film 608 is formed (FIG. 6C).

  Next, the planarization process of the present invention is performed. As a treatment method, the surface of the planarizing film 608 is wiped using a PVA (polyvinyl alcohol) -based porous body to planarize the surface (FIG. 6D).

  As a wiping method using a PVA-based porous body, a method similar to that described in Embodiment 1 may be used, and a shaft 609 around which a PVA-based porous body 610 is wound is rotated. The surface of the planarizing film 608 is wiped and planarized by the frictional force when the PVA-based porous body 610 comes into contact with the surface of the planarizing film 608.

  A cleaning liquid is used for wiping with a PVA-based porous material. As the cleaning liquid used at this time, in addition to pure water, a neutral detergent such as alkylbenzene sulfonate using higher alcohol or alkylbenzene as a raw material, or an aqueous solution containing weakly acidic and weakly alkaline chemicals can be used. Furthermore, in addition to polar solvents such as ethanol, methanol, acetone, and toluene, nonpolar solvents such as benzene and carbon tetrachloride can be used. However, in this embodiment, the polar solvent or the nonpolar solvent is used as a cleaning liquid. It is desirable to use it.

  Further, it is desirable that the rotational speed of the shaft 507 is 100 to 300 rpm, and the indentation value is 0.1 to 1.0 mm.

  After the surface of the planarization film 608 is planarized, a bank 611, an organic compound layer 612, and a cathode 613 are formed as shown in FIG. Note that the bank 611, the organic compound layer 612, and the cathode 613 may be formed in the same manner as described in Embodiment Mode 1.

  Through the above, a light-emitting device having the light-emitting element of the present invention can be formed. In addition, since the unevenness on the anode surface is flattened to some extent with an organic resin material having high flatness by performing this Embodiment 3, the anode surface is directly flattened by performing a flattening process using Berglin. Compared to this, processing can be performed in a shorter time, which is effective in improving throughput during production.

  As described above, by forming a light emitting device having a light emitting element using the present invention, the insulating film formed at the interface between the interlayer insulating film and the anode is removed from the organic resin material forming the interlayer insulating film. Gas can be prevented, and furthermore, the difference in thermal expansion coefficient between the interlayer insulating film and the anode can be relaxed by this insulating film, so that cracks generated at the interface with the anode can be prevented.

  Furthermore, by flattening the anode surface by wiping with a PVA-based porous material, the luminance characteristics of the light emitting element can be improved, the drive voltage can be reduced, and the lifetime of the element can be increased.

  In this example, a light-emitting element manufactured by the manufacturing method described in Embodiment Mode 1 will be described. This embodiment will be described with reference to FIG.

  First, as shown in FIG. 3A, a plurality of current control TFTs 302 are formed over a substrate 301. Note that a glass substrate is used as the substrate. In addition, a method for manufacturing a TFT including a current control TFT formed over a substrate will be described in detail in Embodiment 3.

  Next, an interlayer insulating film 303 is formed on the current control TFT 302. Note that in this embodiment, polyimide is used and an average film thickness of 1.0 to 2.0 μm is formed (FIG. 3B).

  Next, an insulating film 304 is formed over the interlayer insulating film 303. In this embodiment, a silicon oxynitride film is used as the inorganic insulating material for forming the insulating film. The film thickness is 100 to 200 nm.

In this example, the plasma CVD method is used to discharge at a reaction pressure of 20 to 200 Pa, a substrate temperature of 300 to 400 ° C., a high frequency (13.56 MHz) power density of 0.1 to 1.0 W / cm ² , and SiH ₄ , It is formed using NH ₃ and N ₂ O as reaction gases.

Thereafter, a resist mask having a predetermined pattern is formed, and contact holes reaching the drain regions of the respective current control TFTs 302 are formed. The contact hole is formed by a dry etching method. In this case, the insulating film 304 is first etched using a mixed gas of CF ₄ and O ₂ as an etching gas, and then the interlayer insulating film 303 made of an organic resin material is etched using a mixed gas of CF ₄ , O ₂ and He. Thus, a contact hole can be formed.

  Then, a conductive metal film is formed by a sputtering method or a vacuum evaporation method, patterned with a mask, and then etched to form a wiring 305 (FIG. 3D). In this embodiment, Al is used as the wiring material.

  Next, a transparent conductive film is formed thereon with a thickness of 80 to 120 nm, and an anode 306 to be a pixel electrode is formed by patterning (FIG. 3E). Note that an indium tin oxide (ITO) film is used as the transparent conductive material.

  When the anode 306 is formed, heat treatment is performed. In this embodiment, heating is performed at 230 to 350 ° C., and crystallization of ITO forming the anode is performed. Then, the anode surface is planarized after the heat treatment. As a treatment method, the surface of the anode 306 is flattened by wiping the surface of the anode 306 using PVA (polyvinyl alcohol) -based porous material, specifically, Berglin (manufactured by Ozu Sangyo). .

  In this embodiment, as a wiping method using the Berglin 308, as shown in FIG. 4A, the Bergrin 308 is wound around the shaft 307, and this is brought into contact with the surface of the anode 306, and the shaft 307 is rotated. The surface of the anode 306 can be flattened as shown in FIG. 4B by the frictional force generated between the surface of the anode 306 and the Berglin 308.

4C shows a contact angle θ ₁ with respect to water on the anode surface before the planarization treatment as shown in FIG. 4A, and FIG. 4D shows FIG. The contact angle θ ₂ with respect to water on the anode surface after the flattening treatment shown in FIG. In the present embodiment, since the contact angle θ ₁ is θ ₁ <90 °, a magnitude relationship of θ ₁ <θ ₂ is established between these contact angles.

  Here, the result of measuring the contact angle before and after the flattening treatment is shown in FIG. The measurement is performed by measuring the contact angle when the surface of the transparent conductive film formed on the glass substrate is wiped with Berglin. From the above, it is shown that the contact angle of the transparent conductive film surface is increased by wiping.

  In addition, a cleaning liquid is used for wiping with Berglin 308, but pure water is used in this embodiment. In addition, the rotation speed of the axis | shaft 307 in a present Example shall be 100-300 rpm, and an indentation value shall be 0.1-1.0 mm.

  After the surface of the anode 306 is planarized, a bank 309, an organic compound layer 310, and a cathode 311 are formed as shown in FIG.

Note that the bank 309 is formed to fill a gap between the anodes, and is formed into a desired shape by etching after forming a film using an organic material such as an organic resin. In this embodiment, the organic compound layer 310 is formed by forming copper phthalocyanine (hereinafter referred to as CuPc) with a thickness of 20 nm as a hole injection layer and 4,4′-bis [ After forming N- (1-naphthyl) -N-phenyl-amino] -biphenyl (hereinafter referred to as α-NPD) with a thickness of 20 nm, 4,4′-dicarbazole-biphenyl (hereinafter referred to as CBP) was formed as a light-emitting layer. And tris (2-phenylpyridine) iridium (hereinafter referred to as Ir (ppy) ₃ ) to a thickness of 20 nm by a co-evaporation method, and bathocuproin (hereinafter referred to as BCP) as a hole blocking layer to a thickness of 10 nm. And a laminated structure in which tris (8-quinolinolato) aluminum (hereinafter referred to as Alq ₃ ) is formed to a thickness of 40 nm as an electron transport layer.

  After the organic compound layer 310 is formed, the cathode 311 is formed by an evaporation method. As the conductive film to be the cathode 311, in addition to an alloy film such as Mg: Ag (magnesium and silver alloy film) and Al: Li (aluminum and lithium alloy film), the first and second groups of the periodic table are included. It is possible to use a film in which the element and aluminum belong to each other by a co-evaporation method. Note that the thickness of the cathode 311 may be 80 to 200 [nm] (typically 100 to 150 [nm]).

  Through the above steps, the light-emitting element of the present invention can be formed.

  In this example, a light-emitting element manufactured by the manufacturing method described in Embodiment Mode 3 will be described. This embodiment will be described with reference to FIG.

  In this embodiment, a planarizing film 608 is formed on the anode surface with a film thickness of 50 nm using polyimide as an organic resin material (FIG. 6C).

  After the planarization film 608 is formed, the surface of the planarization film 608 is wiped with Berglin (manufactured by Ozu Sangyo) to planarize the surface (FIG. 6D).

  This will be specifically described with reference to FIG. The reference numerals used in FIG. 7 are the same as those used in FIG. The surface of the anode 607 formed over the insulating film 604 has an uneven shape as shown in FIG.

  However, the planarity of the surface can be increased as shown in FIG. 7B by forming the planarization film 608 using an organic resin material having planarity. And the surface planarized more by the flattening film | membrane can be obtained by wiping off the surface which increased flatness with Berglin.

  Note that a wiping method using Berglin may be performed using a method similar to that described in Embodiment 3, and the shaft 609 around which the Berglin 610 is wound is rotated so that the Berglin 610 is the surface of the planarization film 608. The surface of the flattening film 608 is wiped and flattened by the frictional force at the time of contact.

  In the present embodiment, ethanol or methanol is used as a cleaning liquid when wiping with Berglin. The rotation speed of the shaft 507 is 100 to 300 rpm, and the indentation value is 0.1 to 1.0 mm.

  After the surface of the planarization film 608 is planarized, the bank 611, the organic compound layer 612, and the cathode 613 are formed. Note that the bank 611, the organic compound layer 612, and the cathode 613 may be manufactured using the same method as in Example 1.

  Furthermore, the planarization of the anode surface of the present invention can be made by changing the order of the treatment of the production method shown in Example 1. That is, after forming the interlayer insulating film and insulating film, before forming the wiring with the current control TFT, the anode is formed, and after flattening this, the contact hole is formed in the insulating film and the interlayer insulating film However, wiring can also be formed. In this case, since the wiring is formed on the planarized anode surface, the adhesion between the anode and the wiring can be improved.

  In this example, a light-emitting element manufactured using the present invention will be described. Note that here, an example of a method for simultaneously manufacturing a pixel portion including the light-emitting element of the present invention over the same substrate and TFTs (n-channel TFT and p-channel TFT) of a driver circuit provided around the pixel portion is shown. This will be described with reference to FIGS.

  First, in this embodiment, a substrate 900 made of glass such as barium borosilicate glass represented by Corning # 7059 glass or # 1737 glass or aluminoborosilicate glass is used. Note that the substrate 900 is not limited as long as it is a light-transmitting substrate, and a quartz substrate may be used. Further, a plastic substrate having heat resistance that can withstand the processing temperature of this embodiment may be used.

Next, as illustrated in FIG. 8A, a base film 901 formed of an insulating film such as a silicon oxide film, a silicon nitride film, or a silicon oxynitride film is formed over a substrate 900. Although a two-layer structure is used as the base film 901 in this embodiment, a single-layer film of the insulating film or a structure in which two or more layers are stacked may be used. As a first layer of the base film 901, a silicon oxynitride film 901 a formed by using a plasma CVD method and using SiH ₄ , NH ₃ , and N ₂ O as a reaction gas is formed to 10 to 200 nm (preferably 50 to 100 nm). To do. In this embodiment, a silicon oxynitride film 901a (composition ratio Si = 32%, O = 27%, N = 24%, H = 17%) having a thickness of 50 nm is formed. Next, as a second layer of the base film 901, a silicon oxynitride film 901 b formed using SiH ₄ and N ₂ O as a reaction gas is formed by using a plasma CVD method to a thickness of 50 to 200 nm (preferably 100 to 1).
50 nm). In this embodiment, a silicon oxynitride film 901b (composition ratio Si = 32%, O = 59%, N = 7%, H = 2%) having a thickness of 100 nm is formed.

Next, semiconductor layers 902 to 905 are formed over the base film 901. The semiconductor layers 902 to 905 are formed by forming a semiconductor film having an amorphous structure by a known means (sputtering method, LPCVD method, plasma CVD method, or the like), and then known crystallization treatment (laser crystallization method, heat A crystalline semiconductor film obtained by performing a crystallization method or a thermal crystallization method using a catalyst such as nickel) is formed by patterning into a desired shape. The semiconductor layers 902 to 905 are formed with a thickness of 25 to 80 nm (preferably 30 to 60 nm). There is no limitation on the material of the crystalline semiconductor film, but it is preferably formed of silicon (silicon) or a silicon germanium (Si _x Ge _1-x (X = 0.0001 to 0.02)) alloy. In this example, a 55 nm amorphous silicon film was formed by plasma CVD, and then a solution containing nickel was held on the amorphous silicon film. This amorphous silicon film is dehydrogenated (500 ° C., 1 hour), then thermally crystallized (550 ° C., 4 hours), and further laser annealed to improve crystallization. Thus, a crystalline silicon film was formed. Then, semiconductor layers 902 to 905 are formed by patterning the crystalline silicon film using a photolithography method.

  Further, after the semiconductor layers 902 to 905 are formed, the semiconductor layers 902 to 905 may be doped with a small amount of impurity elements (boron or phosphorus) in order to control the threshold value of the TFT.

When a crystalline semiconductor film is formed by a laser crystallization method, a pulse oscillation type or continuous emission type excimer laser, YAG laser, or YVO ₄ laser can be used. When these lasers are used, it is preferable to use a method in which laser light emitted from a laser oscillator is linearly collected by an optical system and irradiated onto a semiconductor film. The crystallization conditions are appropriately selected by the practitioner. When an excimer laser is used, the pulse oscillation frequency is 300 Hz, and the laser energy density is 100 to 400 mJ / cm ² (typically 200 to 300 mJ / cm ^2). ). When a YAG laser is used, the second harmonic is used and the pulse oscillation frequency is set to 30 to 300 kHz, and the laser energy density is set to 300 to 600 mJ / cm ² (typically 350 to 500 mJ / cm ² ). Then, when the laser beam condensed linearly with a width of 100 to 1000 μm, for example, 400 μm is irradiated over the entire surface of the substrate, the superposition ratio (overlap ratio) of the linear laser light at this time is 50 to 90%. Good.

  Next, a gate insulating film 906 that covers the semiconductor layers 902 to 905 is formed. The gate insulating film 906 is formed of an insulating film containing silicon with a thickness of 40 to 150 nm by a plasma CVD method or a sputtering method. In this embodiment, a silicon oxynitride film (composition ratio: Si = 32%, O = 59%, N = 7%, H = 2%) with a thickness of 110 nm is formed by plasma CVD. Needless to say, the gate insulating film is not limited to the silicon oxynitride film, and another insulating film containing silicon may be used as a single layer or a stacked structure.

When a silicon oxide film is used, TEOS (Tetraethyl Orthosilicate) and O ₂ are mixed by a plasma CVD method to obtain a reaction pressure of 40 Pa, a substrate temperature of 300 to 400 ° C., and a high frequency (13.56 MHz) power density of 0. It can be formed by discharging at 5 to 0.8 W / cm ² . The silicon oxide film thus manufactured can obtain good characteristics as a gate insulating film by thermal annealing at 400 to 500 ° C. thereafter.

Then, a heat-resistant conductive layer 907 for forming a gate electrode is formed over the gate insulating film 906 with a thickness of 200 to 400 nm (preferably 250 to 350 nm). The heat-resistant conductive layer 907 may be formed as a single layer, or may have a laminated structure including a plurality of layers such as two layers or three layers as necessary. The heat-resistant conductive layer includes an element selected from Ta, Ti, and W, an alloy containing the element as a component, or an alloy film combining the elements. These heat-resistant conductive layers are formed by a sputtering method or a CVD method, and it is preferable to reduce the concentration of impurities contained in order to reduce the resistance. Particularly, the oxygen concentration is preferably 30 ppm or less. In this embodiment, a tungsten (W) film is formed with a thickness of 300 nm. The W film may be formed by sputtering using W as a target, or may be formed by thermal CVD using tungsten hexafluoride (WF ₆ ). In any case, in order to use as a gate electrode, it is necessary to reduce the resistance, and the resistivity of the W film is desirably 20 μΩcm or less. The resistivity of the W film can be reduced by increasing the crystal grains. However, when there are many impurity elements such as oxygen in W, crystallization is hindered and the resistance is increased. Therefore, in the case of sputtering, the resistivity is obtained by using a W target with a purity of 99.9999% and forming a W film with sufficient consideration so that impurities are not mixed in the gas phase during film formation. 9-20 μΩcm can be realized.

On the other hand, when a Ta film is used for the heat-resistant conductive layer 907, it can be similarly formed by sputtering. The Ta film uses Ar as a sputtering gas. In addition, when an appropriate amount of Xe or Kr is added to the gas during sputtering, the internal stress of the film to be formed can be relaxed and the film can be prevented from peeling. The resistivity of the α-phase Ta film is about 20 μΩcm and can be used as a gate electrode, but the resistivity of the β-phase Ta film is about 180 μΩcm and is not suitable for a gate electrode. Since the TaN film has a crystal structure close to an α phase, an α phase Ta film can be easily obtained by forming a TaN film under the Ta film. Although not shown, it is effective to form a silicon film doped with phosphorus (P) with a thickness of about 2 to 20 nm under the heat-resistant conductive layer 907. This improves adhesion and prevents oxidation of the conductive film formed thereon, and at the same time, the alkali metal element contained in a trace amount in the heat-resistant conductive layer 907 diffuses into the gate insulating film 906 having the first shape. Can be prevented. In any case, the heat resistant conductive layer 907 preferably has a resistivity in the range of 10 to 50 μΩcm.

Next, a resist mask 908 is formed using a photolithography technique. Then, a first etching process is performed. In this embodiment, an ICP etching apparatus is used, Cl ₂ and CF ₄ are used as etching gases, and 3.2 W / cm ² RF (13.56 MHz) power is applied at a pressure of 1 Pa to form plasma. . 224 mW / cm ² of RF (13.56 MHz) power is also applied to the substrate side (sample stage), thereby applying a substantially negative self-bias voltage. Under this condition, the etching rate of the W film is about 100 nm / min. In the first etching process, the time during which the W film is just etched is estimated based on this etching rate, and the time obtained by increasing the etching time by 20% is used as the etching time.

  Conductive layers 909 to 912 having a first tapered shape are formed by the first etching process. The angle of the tapered portion of the conductive layers 909 to 912 is formed to be 15 to 30 °. In order to perform etching without leaving a residue, overetching that increases the etching time at a rate of about 10 to 20% is performed. Since the selection ratio of the silicon oxynitride film (gate insulating film 906) to the W film is 2 to 4 (typically 3), the surface on which the silicon oxynitride film is exposed is etched by about 20 to 50 nm by overetching. (FIG. 8B).

Then, a first doping process is performed to add an impurity element of one conductivity type to the semiconductor layer. Here, a step of adding an impurity element imparting n-type is performed. The mask 908 having the first shape conductive layer is left as it is, and an impurity element imparting n-type is added by ion doping in a self-aligning manner using the first tapered conductive layers 909 to 912 as a mask. In order to add an impurity element imparting n-type through the tapered portion at the end of the gate electrode and the gate insulating film 906 so as to reach the semiconductor layer located thereunder, the dose is set to 1 × 10 ^{13 to} 5 × 10 6. ¹⁴ atoms / cm ² and an acceleration voltage of 80 to 160 keV. As an impurity element imparting n-type, an element belonging to Group 15, typically phosphorus (P) or arsenic (As), is used here, but phosphorus (P) is used. By such ion doping, an impurity element imparting n-type is added to the first impurity regions 914 to 917 in a concentration range of 1 × 10 ²⁰ to 1 × 10 ²¹ atomic / cm ³ (FIG. 8C )).

  In this step, depending on doping conditions, impurities may flow under the first shape conductive layers 909 to 912, and the first impurity regions 914 to 917 may overlap with the first shape conductive layers 909 to 912. Can also happen.

Next, a second etching process is performed as shown in FIG. The etching process is performed similarly by ICP etching device, using a mixed gas of CF ₄ and Cl ₂ as etching gas, RF power 3.2W / cm ² (13.56MHz), bias power 45mW / cm ² (13.56MHz) Etching is performed at a pressure of 1.0 Pa. Conductive layers 918 to 921 having the second shape formed under these conditions are formed. A tapered portion is formed at the end, and a taper shape is formed in which the thickness gradually increases from the end toward the inside. Compared to the first etching process, the ratio of isotropic etching is increased by reducing the bias power applied to the substrate side, and the angle of the tapered portion is 30 to 60 °. The mask 908 is etched to scrape the end portion, thereby forming a mask 922. 8D, the surface of the gate insulating film 906 is etched by about 40 nm.

Then, an impurity element imparting n-type conductivity is doped under a condition of a high acceleration voltage with a dose amount lower than that in the first doping treatment. For example, the acceleration voltage is set to 70 to 120 keV and the dose is 1 × 10 ¹³ / cm ² , and the first impurity regions 924 to 927 having a high impurity concentration and the first impurity regions 924 to 927 are in contact with each other. Second impurity regions 928 to 931 are formed. In this step, depending on the doping conditions, impurities may flow under the second shape conductive layers 918 to 921, and the second impurity regions 928 to 931 may overlap with the second shape conductive layers 918 to 921. Can also happen. The impurity concentration in the second impurity region is set to 1 × 10 ¹⁶ to 1 × 10 ¹⁸ atoms / cm ³ (FIG. 9A).

As shown in FIG. 9B, impurity regions 933 (933a, 933b) and 934 (934a, 934a, 934a, 934a, 934a, 933a, 933b, 934a, 934a, 933a, 933b, and 934a) 934b). Also in this case, an impurity element imparting p-type is added using the second shape conductive layers 918 and 921 as a mask, and an impurity region is formed in a self-aligning manner. At this time, the semiconductor layers 903 and 904 forming the n-channel TFT are covered with a resist mask 932 so as to cover the entire surface. The impurity regions 933 and 934 formed here are formed by an ion doping method using diborane (B ₂ H ₆ ). The concentration of the impurity element imparting p-type in the impurity regions 933 and 934 is set to 2 × 10 ²⁰ to 2 × 10 ²¹ atoms / cm ³ .

However, the impurity regions 933 and 934 can be divided into two regions containing an impurity element imparting n-type in detail. The third impurity regions 933a and 934a contain an impurity element imparting n-type at a concentration of 1 × 10 ²⁰ to 1 × 10 ²¹ atoms / cm ³ , and the fourth impurity regions 933b and 934b are 1 × 10 ¹⁷ to 1 It contains an impurity element imparting n-type at a concentration of × 10 ²⁰ atoms / cm ³ . However, the concentration of the impurity element imparting p-type in these impurity regions 933b and 934b is set to 1 × 10 ¹⁹ atoms / cm ³ or more, and p-type is imparted in the third impurity regions 933a and 934a. In order to function as a source region and a drain region of the p-channel TFT in the third impurity region by making the concentration of the impurity element 1.5 to 3 times the concentration of the impurity element imparting n-type. There is no problem.

After that, as shown in FIG. 9C, a first interlayer insulating film 937 is formed over the conductive layers 918 to 921 and the gate insulating film 906 having the second shape. The first interlayer insulating film 937 may be formed using a silicon oxide film, a silicon oxynitride film, a silicon nitride film, or a stacked film in which these are combined. In any case, the first interlayer insulating film 937 is formed from an inorganic insulating material. The thickness of the first interlayer insulating film 937 is 100 to 200 nm. In the case where a silicon oxide film is used as the first interlayer insulating film 937, TEOS and O ₂ are mixed by plasma CVD to have a reaction pressure of 40 Pa, a substrate temperature of 300 to 400 ° C., and a high frequency (13.56 MHz) power density. It can be formed by discharging at 0.5 to 0.8 W / cm ² . In the case where a silicon oxynitride film is used as the first interlayer insulating film 937, a silicon oxynitride film manufactured from SiH ₄ , N ₂ O, and NH ₃ by plasma CVD, or SiH ₄ and N ₂ O is used. What is necessary is just to form with the silicon oxynitride film | membrane produced. The production conditions in this case are a reaction pressure of 20 to 200 Pa, a substrate temperature of 300 to 400 ° C., and a high frequency (60 MHz) power density of 0.1 to 1.0 W / cm ² . Alternatively, a silicon oxynitride silicon film formed from SiH ₄ , N ₂ O, and H ₂ may be used as the first interlayer insulating film 937. Similarly, the silicon nitride film can be formed from SiH ₄ and NH ₃ by plasma CVD.

  Then, a step of activating the impurity element imparting n-type or p-type added at each concentration is performed. This step is performed by a thermal annealing method using a furnace annealing furnace. In addition, a laser annealing method or a rapid thermal annealing method (RTA method) can be applied. In the thermal annealing method, the oxygen concentration is 1 ppm or less, preferably 0.1 ppm or less in a nitrogen atmosphere at 400 to 700 ° C., typically 500 to 600 ° C. In this example, the temperature is 550 ° C. for 4 hours. Heat treatment is performed. In the case where a plastic substrate having a low heat resistant temperature is used as the substrate 501, it is preferable to apply a laser annealing method.

Subsequent to the activation step, the step of hydrogenating the semiconductor layer is performed by changing the atmosphere gas and performing heat treatment at 300 to 450 ° C. for 1 to 12 hours in an atmosphere containing 3 to 100% hydrogen. This step is a step of terminating dangling bonds of 10 ¹⁶ to 10 ¹⁸ / cm ^{3 in} the semiconductor layer by thermally excited hydrogen. As another means of hydrogenation, plasma hydrogenation (using hydrogen excited by plasma) may be performed. In any case, it is desirable that the defect density in the semiconductor layers 902 to 905 be 10 ¹⁶ / cm ³ or less. For that purpose, hydrogen may be added at about 0.01 to 0.1 atomic%.

  Then, a second interlayer insulating film 939 made of an organic insulating material is formed with an average film thickness of 1.0 to 2.0 μm. As the organic resin material, polyimide, acrylic, polyamide, polyimide amide, BCB (benzocyclobutene), or the like can be used. For example, when using a type of polyimide that is thermally polymerized after being applied to the substrate, it is formed by baking at 300 ° C. in a clean oven. When acrylic is used, a two-component type is used, and after mixing the main material and the curing agent, applying the entire surface of the substrate using a spinner, preheating at 80 ° C. for 60 seconds with a hot plate. It can be formed by baking at 250 ° C. for 60 minutes in a clean oven.

  Thus, the surface can be satisfactorily planarized by forming the second interlayer insulating film 939 from an organic insulating material. Moreover, since the organic resin material generally has a low dielectric constant, parasitic capacitance can be reduced. However, since it is hygroscopic and not suitable as a protective film, it is preferably used in combination with a silicon oxide film, a silicon oxynitride film, a silicon nitride film, or the like formed as the first interlayer insulating film 937 as in this embodiment. .

  Further, an insulating film 940 is formed over the second interlayer insulating film 939 made of an organic insulating material. Note that the insulating film 940 includes silicon oxide, silicon nitride (SiN), silicon oxynitride (SiON), silicon nitride oxide (SiNO), aluminum nitride (AlN), aluminum nitride oxide (AlNO), aluminum oxynitride (AlNO), and the like. It is formed using an inorganic insulating material containing silicon or aluminum. Note that the insulating film formed here can be formed using a method similar to that of the first interlayer insulating film 937.

Thereafter, a resist mask having a predetermined pattern is formed, and contact holes are formed in the respective semiconductor layers to reach impurity regions serving as source regions or drain regions. The contact hole is formed by a dry etching method. In this case, the insulating film 940 is first etched using a mixed gas of CF ₄ and O ₂ as an etching gas, and then the second interlayer insulating film 939 made of an organic resin material is used using a mixed gas of CF ₄ , O ₂ , and He. After that, the first interlayer insulating film 937 is etched again using CF ₄ and O ₂ as etching gases. Further, in order to increase the selectivity with respect to the semiconductor layer, the contact hole can be formed by etching the third shape gate insulating film 570 while switching the etching gas to CHF ₃ .

  Then, a conductive metal film is formed by a sputtering method or a vacuum deposition method, patterned with a mask, and then etched to form source wirings 941 to 944 and drain wirings 945 to 947. Although not shown, in this embodiment, this wiring is formed by a laminated film of a Ti film having a thickness of 50 nm and an alloy film (alloy film of Al and Ti) having a thickness of 500 nm.

  Next, a transparent conductive film is formed thereon with a thickness of 80 to 120 nm and patterned to form an anode 948 (FIG. 10A). In this embodiment, an indium tin oxide (ITO) film or a transparent conductive film in which 2 to 20% zinc oxide (ZnO) is mixed with indium oxide is used as the transparent electrode.

  In addition, the anode 948 is formed in contact with the drain wiring 947 so as to be electrically connected to the drain region of the current control TFT.

  Next, as shown in FIG. 10B, a third interlayer insulating film 949 having an opening at a position corresponding to the anode 948 is formed. The third interlayer insulating film 949 has insulating properties, functions as a bank, and has a role of separating organic compound layers of adjacent pixels. In this embodiment, a third interlayer insulating film 949 is formed using a resist.

  In this embodiment, the thickness of the third interlayer insulating film 949 is set to about 1 μm, and the opening is formed so as to have a so-called reverse taper shape that becomes wider as the anode 947 is closer. This is formed by depositing a resist, covering the portion other than the portion where the opening is to be formed with a mask, irradiating with UV light and exposing, and removing the exposed portion with a developer.

  As in this example, by forming the third interlayer insulating film 949 in a reverse taper shape, when the organic compound layer is formed in a later step, the organic compound layer is divided between adjacent pixels. Even if the organic compound layer and the third interlayer insulating film 949 have different coefficients of thermal expansion, the organic compound layer can be prevented from cracking or peeling.

  In this embodiment, a film made of a resist is used as the third interlayer insulating film. However, in some cases, a polyimide, polyamide, acrylic, BCB (benzocyclobutene), silicon oxide film, or the like may be used. it can. The third interlayer insulating film 949 may be either an organic material or an inorganic material as long as it is an insulating material. At this time, the anode 948 is heat-treated at 230 to 350 ° C., and the transparent conductive film forming the anode 948 is crystallized.

  Next, the anode surface is planarized. In this embodiment, the surface of the anode 948 is flattened by wiping the surface of the anode 948 using Berglin (manufactured by Ozu Sangyo).

  Here, pure water is used as the cleaning liquid. Moreover, the rotation speed of the shaft around which the Berclin is wound is 100 to 300 rpm, and the indentation value is 0.1 to 1.0 mm.

  Next, as shown in FIG. 10B, an organic compound layer 950, a cathode 951 protective electrode 952, and a passivation film 953 are formed by an evaporation method. In this embodiment, the Mg: Ag electrode is used as the cathode of the light emitting element, but other known materials may be used.

  Note that the organic compound layer 950 is formed by stacking a plurality of layers such as a hole injection layer, a hole transport layer, an electron transport layer, an electron injection layer, and a buffer layer in addition to the light-emitting layer. The structure of the organic compound layer used in this example will be described in detail below.

  In this embodiment, CuPc is used as the hole injection layer, and α-NPD is used as the hole transport layer by vapor deposition.

  Next, a light emitting layer is formed. In this embodiment, an organic compound layer showing different light emission is formed by using different materials for the light emitting layer. In this embodiment, an organic compound layer that emits red, green, and blue light is formed. Moreover, since vapor deposition is used as a film formation method, a light emitting layer can be formed using a different material for each pixel by using a metal mask at the time of film formation.

Emitting layer coloring in red, the Alq ₃ 4-dicyanomethylene-2-methyl-6-(p-dimethylamino - styryl) -4H- pyran (hereinafter referred to as "DCM1") and 4-dicyanomethylene - It is formed using a material doped with 2-methyl-6- (julolidin-4-yl-vinyl) -4H-pyran (hereinafter referred to as “DCM2”) or the like. In addition, (1,10-phenanthroline) tris (1,3-diphenyl-fluorophenyl), which is an Eu complex with N, N'-disalicylidene-1,6-hexanediaminato) zinc (II) (Zn (salhn)) A material doped with 1,3-diolato) europium (III) (Eu (DBM) ₃ (Phen) or the like can be used, but other known materials can also be used.

In addition, the light emitting layer that emits green color can be formed by co-evaporation of CBP and Ir (ppy) ₃ . At this time, it is preferable to laminate the hole blocking layer using BCP. In addition, Alq ₃ and a benzoquinolinolatoberyl complex (BeBq) can be used. Further, Alq ₃ using a material such as coumarin 6 or quinacridone as a dopant can be used, but other known materials can also be used.

  In addition, the light emitting layer that develops a blue color is a zinc complex having a ligand of 4,4′-bis (2,2-diphenyl-vinyl) -biphenyl (hereinafter referred to as DPVBi), which is a distyryl derivative, or an azomethine compound. N, N'-disalicylidene-1,6-hexanediaminato) zinc (II) (Zn (salhn)) and 4,4'-bis (2,2-diphenyl-phenyl) -biphenyl (DPVBi) However, other known materials may be used.

  Next, an electron transport layer is formed. For the electron transport layer, a material such as a 1,3,4-oxadiazole derivative or a 1,2,4-triazole derivative (TAZ) can be used. In this embodiment, 1,2,4- It forms with a film thickness of 30-60 nm by a vapor deposition method using a triazole derivative (TAZ).

  Thus, an organic compound layer having a laminated structure is formed. In this embodiment, the thickness of the organic compound layer 950 is 10 to 400 [nm] (typically 60 to 150 [nm]), and the thickness of the cathode 951 is 80 to 200 [nm] (typically 100-150 [nm]).

  After the organic compound layer is formed, the cathode 951 of the light emitting element is formed by an evaporation method. In this embodiment, Mg: Ag is used as the conductive film serving as the cathode of the light-emitting element, but Al: Li or a film formed by co-evaporation with an element belonging to Group 1 or 2 of the periodic table and aluminum. It is also possible to use.

  Further, after the cathode 951 is formed, a protective electrode 952 is formed. Although the protective electrode 952 can protect the organic compound layer 950 from moisture and oxygen, it is more preferable to provide a passivation film 953. In this embodiment, a 300 nm thick silicon nitride film is provided as the protective film 953. This protective film may be continuously formed after the protective electrode 952 without being released to the atmosphere.

  The protective electrode 952 is provided in order to prevent the cathode 951 from being deteriorated, and a metal film mainly composed of aluminum is typically used. Of course, other materials may be used. In addition, since the organic compound layer 950 and the cathode 951 are very sensitive to moisture, it is desirable to form the protective electrode 952 continuously without being released to the atmosphere to protect the organic compound layer from the outside air.

  Thus, a light emitting device having a structure as shown in FIG. 10B is completed. Note that a portion 954 where the anode 947, the organic compound layer 950, and the cathode 951 overlap corresponds to the light-emitting element.

  A p-channel TFT 960 and an n-channel TFT 961 are TFTs included in the driver circuit and form a CMOS. The switching TFT 962 and the current control TFT 963 are TFTs included in the pixel portion, and the driver circuit TFT and the pixel portion TFT can be formed over the same substrate.

  Note that in the case of a light-emitting device using a light-emitting element, the power supply voltage of the drive circuit is about 5 to 6 V, and the maximum is about 10 V. Therefore, deterioration due to hot electrons in the TFT is not a problem. Further, since it is necessary to operate the driving circuit at high speed, it is preferable that the gate capacitance of the TFT is small. Therefore, as in this embodiment, in the driving circuit of the light emitting device using the light emitting element, the second impurity region 929 and the fourth impurity region 933b included in the semiconductor layer of the TFT are gate electrodes 918 and 919, respectively. It is preferable to have a configuration that does not overlap.

  In this example, a method for manufacturing a light-emitting device, which is different from that in Example 4, will be described.

  The steps until the second interlayer insulating film 939 is formed are the same as those in the first embodiment. As shown in FIG. 11A, after the second interlayer insulating film 939 is formed, the insulating film 940 is formed so as to be in contact with the second interlayer insulating film 939.

  The insulating film 940 is effective in preventing moisture contained in the second interlayer insulating film 939 from entering the organic compound layer 950 through the anode 948 and the third interlayer insulating film 982. In the case where the second interlayer insulating film 939 includes an organic resin material, it is particularly effective to provide the insulating film 940 because the organic resin material contains a large amount of moisture. Note that in this embodiment, a silicon nitride film is used as the insulating film 940.

Thereafter, a resist mask having a predetermined pattern is formed, and contact holes are formed in the respective semiconductor layers to reach impurity regions serving as source regions or drain regions. The contact hole is formed by a dry etching method. In this case, the insulating film 940 is first etched using a mixed gas of CF ₄ and O ₂ as an etching gas, and then the second interlayer insulating film 939 made of an organic resin material is used using a mixed gas of CF ₄ , O ₂ , and He. After that, the first interlayer insulating film 937 is etched again using CF ₄ and O ₂ as etching gases. Further, in order to increase the selectivity with respect to the semiconductor layer, the contact hole can be formed by etching the third shape gate insulating film 570 while switching the etching gas to CHF ₃ .

  Then, a conductive metal film is formed by a sputtering method or a vacuum deposition method, patterned with a mask, and then etched to form source wirings 941 to 944 and drain wirings 945 to 947. Although not shown, in this embodiment, this wiring is formed by a laminated film of a Ti film having a thickness of 50 nm and an alloy film (alloy film of Al and Ti) having a thickness of 500 nm.

  Next, a transparent conductive film is formed thereover with a thickness of 80 to 120 nm and patterned to form an anode 948 (FIG. 11A). In this embodiment, an indium tin oxide (ITO) film or a transparent conductive film in which 2 to 20% zinc oxide (ZnO) is mixed with indium oxide is used as the transparent electrode.

  In addition, the anode 948 is formed in contact with the drain wiring 947 so as to be electrically connected to the drain region of the current control TFT.

  Next, as shown in FIG. 11B, a third interlayer insulating film 982 having an opening at a position corresponding to the anode 948 is formed. In this embodiment, when the opening is formed, a tapered side wall is formed by using a wet etching method. Unlike the case shown in Example 4, since the organic compound layer formed on the third interlayer insulating film 982 is not divided, the deterioration of the organic compound layer due to the step is caused when the side wall of the opening is not sufficiently gentle. Because it becomes a remarkable problem, attention is necessary.

  In this embodiment, a film made of silicon oxide is used as the third interlayer insulating film 982, but an organic resin film such as polyimide, polyamide, acrylic, or BCB (benzocyclobutene) is used in some cases. You can also.

  Here, heat treatment is performed at 230 to 350 ° C., and the transparent conductive film forming the anode 948 is crystallized.

  Next, the anode surface is planarized. In this embodiment, the surface of the anode 948 is flattened by wiping the surface of the anode 948 using Berglin (manufactured by Ozu Sangyo).

  Here, pure water is used as the cleaning liquid. Moreover, the rotation speed of the shaft around which the Berclin is wound is 100 to 300 rpm, and the indentation value is 0.1 to 1.0 mm.

  Then, before forming the organic compound layer 950 over the third interlayer insulating film 982, the surface of the third interlayer insulating film 982 is subjected to plasma treatment using argon, and the surface of the third interlayer insulating film 982 is formed. It is preferable to make it dense. With the above structure, moisture can be prevented from entering the organic compound layer 950 from the third interlayer insulating film 982.

  Next, an organic compound layer 950 is formed by an evaporation method, and a cathode (Mg: Ag electrode) 951 and a protective electrode 952 are further formed by an evaporation method. At this time, it is desirable to perform heat treatment on the anode 947 and completely remove moisture before forming the organic compound layer 950 and the cathode 951. In this embodiment, the Mg: Ag electrode is used as the cathode of the light emitting element, but other known materials may be used.

  Note that as the organic compound layer 950, a known low molecular weight or high molecular weight organic material can be used. In this example, a case where an organic compound layer is formed using a polymer material will be described. However, needless to say, low molecular weight materials as shown in Examples 1 to 4 can be used. The material for forming the organic compound layer can be the same for all pixels. For example, a material that can emit red light, a material that can emit green light, and blue light can be obtained. When the material to be applied is separately applied for each pixel, there are a plurality of organic compound layers formed of different materials, and full color display is possible. In addition, there exist the following as a combination of the material from which blue, green, and red light emission is obtained.

  First, for the formation of an organic compound layer from which red light emission can be obtained, 2- (4-biphenylyl) -5--5 which is an electron transporting material is added to polyvinylcarbazole (hereinafter referred to as PVK) which is a hole transporting material. Spin coating is applied to a coating solution in which 30 to 40% of (4-tert-butylphenyl) -1,3,4-oxadiazole (hereinafter referred to as PBD) is molecularly dispersed and about 1% of DCM2 is added as a dopant. The organic compound layer from which green light emission is obtained can be formed by apply | coating by.

  Moreover, for the formation of the organic compound layer from which green light emission can be obtained, by applying a coating liquid in which PBD is dispersed in 30-40% of PVK and about 1% of coumarin 6 is further added as a dopant by spin coating, An organic compound layer from which green light emission can be obtained can be formed.

  In order to form an organic compound layer that can emit blue light, a coating solution in which 30 to 40% of PBD is dispersed in PVK and about 1% of perylene is added as a dopant is applied by spin coating. It is possible to form an organic compound layer capable of obtaining the above light emission.

  Note that these materials can be used in common for all pixels, or these materials can be used so as to be different for each pixel.

  In addition, the protective electrode 952 can protect the organic compound layer 950 from moisture and oxygen; however, a protective film 953 is more preferably provided. In this embodiment, a 300 nm thick silicon nitride film is provided as the protective film 953. This protective film may be continuously formed after the protective electrode 952 without being released to the atmosphere.

  The protective electrode 952 is provided in order to prevent the cathode 951 from being deteriorated, and a metal film mainly composed of aluminum is typically used. Of course, other materials may be used. In addition, since the organic compound layer 950 and the cathode 951 are very sensitive to moisture, it is desirable to form the protective electrode 952 continuously without being released to the atmosphere to protect the organic compound layer from the outside air. Note that the cathode 951 and the protective electrode 952 are formed by vapor deposition using a metal mask.

  Note that the thickness of the organic compound layer 950 is 10 to 400 [nm] (typically 60 to 150 [nm]), and the thickness of the cathode 951 is 80 to 200 [nm] (typically 100 to 150 [nm]. nm]).

  Thus, a light emitting device having a structure as shown in FIG. 11B is completed. Note that a portion 954 where the anode 948, the organic compound layer 950, and the cathode 951 overlap corresponds to the light-emitting element.

  A p-channel TFT 960 and an n-channel TFT 961 are TFTs included in the driver circuit and form a CMOS. The switching TFT 962 and the current control TFT 963 are TFTs included in the pixel portion, and the driver circuit TFT and the pixel portion TFT can be formed over the same substrate. Note that the manufacturing method of the light-emitting device of the present invention is not limited to the manufacturing method described in this embodiment.

  In this example, a method for completing the light-emitting panel manufactured up to FIG. 10B in Example 4 or the light-emitting panel manufactured up to FIG. 11B in Example 5 as a light-emitting device will be described in detail with reference to FIGS. Explained.

  12A is a top view of a light-emitting panel in which an element substrate is sealed, and FIG. 12B is a cross-sectional view taken along line A-A ′ in FIG. 801 indicated by a dotted line is a source side driver circuit, 802 is a pixel portion, and 803 is a gate side driver circuit. Reference numeral 804 denotes a sealing substrate, 805 denotes a sealing agent, and a space 807 is surrounded by the sealing agent 805.

  Note that a video signal or a clock signal is received from an FPC (flexible printed circuit) 809 serving as an external input terminal by wiring (not shown) for transmitting a signal input to the source side driver circuit 801 and the gate side driver circuit 803. receive. Note that although a state in which an FPC is connected to the light-emitting panel is shown here, a module in which an IC (integrated circuit) is directly mounted via the FPC is referred to as a light-emitting device in this specification.

  Next, a cross-sectional structure will be described with reference to FIG. Over the substrate 810, a pixel portion 802 and a source side driver circuit 801 are formed. The pixel portion 802 is formed by a plurality of pixels including a current control TFT 811 and an anode 812 electrically connected to a drain thereof. . The source side driver circuit 801 is formed using a CMOS circuit in which an n-channel TFT 813 and a p-channel TFT 814 are combined.

  In addition, after the banks 815 are formed on both ends of the anode 812, the organic compound layer 816 and the cathode 817 are formed on the anode 812, and the light emitting element 818 is formed.

  Note that the cathode 817 functions as a wiring common to all pixels, and is electrically connected to the FPC 809 via a connection wiring 808.

  After the light emitting element 818 is formed, a passivation film 821 is formed. This is to prevent the sealant 805 from being directly formed on the connection wiring 808. Thereby, the adhesiveness of the sealing agent 805 can be improved.

  Note that a sealing substrate 804 made of glass is attached to a sealing agent 805. Note that an ultraviolet curable resin or a thermosetting resin is preferably used as the sealant 805. In addition, a spacer made of a resin film may be provided as necessary in order to secure a space between the sealing substrate 804 and the light emitting element 818. A space 807 inside the sealant 805 is filled with an inert gas such as nitrogen or a rare gas. Further, the sealant 805 is desirably a material that does not transmit moisture and oxygen as much as possible.

  By enclosing the light-emitting element in the space 807 with the above structure, the light-emitting element can be completely blocked from the outside, and deterioration of the light-emitting element due to moisture or oxygen entering from the outside can be prevented. Therefore, a highly reliable light-emitting device can be obtained.

  The configuration in the present embodiment can be implemented by freely combining with any configuration in Embodiment 4 or Embodiment 5.

  Here, FIG. 13A shows a more detailed top surface structure of the pixel portion of the light-emitting device described in Embodiments 4 and 5 formed using the present invention, and FIG. 13B shows a circuit diagram thereof. . In FIG. 13, a switching TFT 704 is formed using the switching (n-channel) TFT 962 in FIG. Accordingly, the description of the switching (n-channel type) TFT 962 may be referred to for the description of the structure. A wiring denoted by 703 is a gate wiring that electrically connects the gate electrodes 704a and 704b of the switching TFT 704.

  Note that although a double gate structure in which two channel formation regions are formed is used in this embodiment, a single gate structure in which one channel formation region is formed or a triple gate structure in which three channel formation regions are formed may be used.

  The source of the switching TFT 704 is connected to the source wiring 715, and the drain is connected to the drain wiring 705. The drain wiring 705 is electrically connected to the gate electrode 707 of the current control TFT 706. Note that the current control TFT 706 is formed using the current control (p-channel) TFT 963 of FIG. Therefore, the description of the structure may be referred to the description of the current control (p-channel type) TFT 963. In this embodiment, a single gate structure is used, but a double gate structure or a triple gate structure may be used.

  The source of the current control TFT 706 is electrically connected to the current supply line 716, and the drain is electrically connected to the drain wiring 717. The drain wiring 717 is electrically connected to an anode (pixel electrode) 718 indicated by a dotted line.

  At this time, a storage capacitor (capacitor) is formed in a region indicated by 719. The capacitor 719 is formed between the semiconductor film 720 electrically connected to the current supply line 716, the insulating film (not shown) in the same layer as the gate insulating film, and the gate electrode 707. A capacitor formed by the gate electrode 707, the same layer (not shown) as the first interlayer insulating film, and the current supply line 716 can also be used as the storage capacitor.

  Note that the configuration of this embodiment can be implemented in combination with any of the configurations of Embodiment 4 and Embodiment 5.

  Since a light-emitting device using a light-emitting element is a self-luminous type, it is superior in visibility in a bright place and has a wide viewing angle as compared with a liquid crystal display device. Therefore, various electric appliances can be completed using the light-emitting device of the present invention.

  As an electric appliance using a light emitting device manufactured according to 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 personal computer, a game A device, a portable information terminal (mobile computer, mobile phone, portable game machine, electronic book, etc.), an image playback device equipped with a recording medium (specifically, a recording medium such as a digital video disc (DVD)) And a device provided with a display device capable of displaying an image). In particular, a portable information terminal that frequently sees a screen from an oblique direction emphasizes the wide viewing angle, and thus a light emitting device having a light emitting element is preferably used. Specific examples of these electric appliances are shown in FIG.

  FIG. 14A 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. It is manufactured by using the light emitting device manufactured according to the present invention for the display portion 2003. Since a light-emitting device having a light-emitting element is a self-luminous type, a backlight is not necessary and a display portion thinner than a liquid crystal display device can be obtained. The display devices include all information display devices for personal computers, for receiving TV broadcasts, for displaying advertisements, and the like.

  FIG. 14B shows a digital still camera, which includes a main body 2101, a display portion 2102, an image receiving portion 2103, operation keys 2104, an external connection port 2105, a shutter 2106, and the like. It is manufactured by using the light emitting device manufactured according to the present invention for the display portion 2102.

  FIG. 14C 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 pointing mouse 2206, and the like. It is manufactured by using the light emitting device manufactured according to the present invention for the display portion 2203.

  FIG. 14D illustrates a mobile computer, which includes a main body 2301, a display portion 2302, a switch 2303, operation keys 2304, an infrared port 2305, and the like. It is manufactured by using the light emitting device manufactured according to the present invention for the display portion 2302.

  FIG. 14E) is a portable image reproducing apparatus (specifically, a DVD reproducing apparatus) provided with a recording medium, and includes a main body 2401, a housing 2402, a display unit A2403, a display unit B2404, and a recording medium (DVD etc.) reading unit. 2405, operation keys 2406, speaker unit 2407, and the like. The display portion A 2403 mainly displays image information and the display portion B 2404 mainly displays character information. The light-emitting device manufactured according to the present invention is used for the display portions A, B 2403 and 2404. Note that an image reproducing device provided with a recording medium includes a home game machine and the like.

  FIG. 14F illustrates a goggle type display (head mounted display), which includes a main body 2501, a display portion 2502, and an arm portion 2503. It is manufactured by using the light emitting device manufactured according to the present invention for the display portion 2502.

  FIG. 14G illustrates a video camera, which includes a main body 2601, a display portion 2602, a housing 2603, an external connection port 2604, a remote control reception portion 2605, an image receiving portion 2606, a battery 2607, an audio input portion 2608, operation keys 2609, and an eyepiece. Part 2610 and the like. It is manufactured by using the light emitting device manufactured according to the present invention for the display portion 2602.

  Here, FIG. 14H shows a mobile phone, which includes a main body 2701, a housing 2702, a display portion 703, an audio input portion 2704, an audio output portion 2705, operation keys 2706, an external connection port 2707, an antenna 2708, and the like. It is manufactured by using the light emitting device manufactured according to the present invention for the display portion 2703. Note that the display portion 2703 can reduce power consumption of the mobile phone by displaying white characters on a black background.

  If the emission luminance of the organic material is increased in the future, the light including the output image information can be enlarged and projected by a lens or the like and used for a front type or rear type projector.

  In addition, the electric appliances often display information distributed through electronic communication lines such as the Internet or CATV (cable television), and in particular, opportunities to display moving image information are increasing. Since the response speed of the organic material is very high, the light-emitting device is preferable for displaying moving images.

  In addition, since the light emitting portion of the light emitting device consumes power, it is preferable to display information so that the light emitting portion is minimized. Therefore, when a light emitting device is used for a display unit mainly including character information, such as a portable information terminal, particularly a mobile phone or a sound reproduction device, it is driven so that character information is formed by the light emitting part with the non-light emitting part as the background. It is preferable to do.

  As described above, the applicable range of the light-emitting device manufactured using the present invention is so wide that the light-emitting device can be used for electric appliances in various fields. In addition, the electric appliance of this embodiment can be completed by using a light emitting device manufactured by performing the method shown in Embodiments 1 to 7.

  In this example, the surface state of the transparent conductive film obtained by performing the wiping treatment of the present invention was observed using an atomic force microscope (AFM). The result is shown in FIG.

  Note that, in the surface observation in this example, an ITO film formed with a film thickness of 110 nm on a glass substrate and crystallized by heat treatment at 250 ° C. is used as a measurement surface.

  In FIG. 16, the average surface roughness (Ra) before and after the wiping process using Berglin is shown. Here, the average surface roughness is a three-dimensional extension of the centerline average roughness defined in JIS B0601 so that it can be applied to the surface.

  From this result, it can be seen that after the wiping treatment, the average surface roughness on the measurement surface decreases and the flatness increases. Furthermore, in FIG. 17, the maximum height difference (PV) of the mountain valley before and after the wiping process using Berglin is shown. In addition, the maximum height difference of a mountain valley here shows the difference of the height of a mountain top and a valley bottom. In addition, the summit and valley floor here are three-dimensional extensions of the “mountain peak” and “valley floor” defined in JIS B0601, and the summit is the highest altitude of the designated mountain. Expressed as the lowest elevation in the valley of the designated surface.

  In addition, it can be seen that the flatness on the measurement surface is increased by the wiping treatment even in the maximum height difference (P-V) of Yamaya. 19 and 20 show the uneven shape of the substrate surface observed by AFM. In addition, the result of having observed the measurement surface before a wiping process is shown in FIG. 19, and the result of having observed the measurement surface after a wiping process is shown in FIG.

  From the above, the fact that the treatment surface is flattened in the wiping treatment in the present invention is shown not only by the measurement of the contact angle but also by the measurement result of the average surface roughness by AFM.

  The production method of the present invention can be similarly performed when a light emitting device having a structure in which an organic compound layer is formed on a cathode and an anode is formed on the organic compound layer is formed.

  That is, after the cathode of the light emitting element is formed first, the surface of the cathode is wiped, an organic compound layer is formed on the cathode, and then the anode is formed to form the light emitting element.

  In addition, it can implement by combining the content described in the other Example except the part from which the laminated structure of a light emitting element differs.

3A and 3B each illustrate an element structure in the present invention. The figure explaining a thermal expansion coefficient. 4A and 4B illustrate a method for manufacturing a light-emitting element of the present invention. The figure explaining the wiping process of this invention. 4A and 4B illustrate a method for manufacturing a light-emitting element of the present invention. 4A and 4B illustrate a method for manufacturing a light-emitting element of the present invention. The figure explaining the wiping process of this invention. FIG. 6 illustrates a manufacturing process. FIG. 6 illustrates a manufacturing process. FIG. 6 illustrates a manufacturing process. FIG. 6 illustrates a manufacturing process. 4A and 4B illustrate a sealing structure of a light-emitting device. FIG. 6 illustrates a structure of a pixel portion. The figure which shows an example of an electric appliance. The figure which shows the measurement result of a contact angle. The figure which shows the measurement result by AFM. The figure which shows the measurement result by AFM. The figure explaining a prior art example. The figure which shows the measurement result by AFM. The figure which shows the measurement result by AFM.

Claims (32)

A TFT formed on an insulator;
A first insulating film formed on the TFT;
A second insulating film made of an inorganic insulating material formed on the first insulating film;
A light emitting device comprising: an anode formed on the second insulating film. A TFT formed on an insulator;
A first insulating film formed on the TFT;
A second insulating film made of an inorganic insulating material formed on the first insulating film;
A light emitting device comprising: a cathode formed on the second insulating film. A TFT formed on an insulator;
A first insulating film formed on the TFT;
A second insulating film made of an inorganic insulating material formed on the first insulating film;
An anode formed on the second insulating film;
A wiring for electrically connecting the TFT and the anode;
A third insulating film formed to cover the end of the anode;
A film containing an organic compound formed on the anode;
And a cathode formed on the film containing the organic compound. A TFT formed on an insulator;
A first insulating film formed on the TFT;
A second insulating film made of an inorganic insulating material formed on the first insulating film;
A cathode formed on the second insulating film;
Wiring for electrically connecting the TFT and the cathode;
A third insulating film formed to cover the end of the cathode;
A film containing an organic compound formed on the cathode;
And a positive electrode formed on the film containing the organic compound. A TFT formed on an insulator;
A first insulating film formed on the TFT;
A second insulating film made of an inorganic insulating material formed on the first insulating film;
An anode formed on the second insulating film;
A wiring for electrically connecting the TFT and the anode;
A third insulating film formed to cover the end of the anode;
A fourth insulating film formed on the anode;
A film containing an organic compound formed on the fourth insulating film;
And a cathode formed on the film containing the organic compound. A TFT formed on an insulator;
A first insulating film formed on the TFT;
A second insulating film made of an inorganic insulating material formed on the first insulating film;
A cathode formed on the second insulating film;
Wiring for electrically connecting the TFT and the cathode;
A third insulating film formed to cover the end of the cathode;
A fourth insulating film formed on the cathode;
A film containing an organic compound formed on the fourth insulating film;
And a positive electrode formed on the film containing the organic compound.   The light-emitting device according to claim 1, wherein the anode uses a transparent conductive film.   The light-emitting device according to claim 1, wherein the anode is made of a transparent conductive film or ITO in which indium oxide and zinc oxide are mixed.   7. The light emitting device according to claim 2, wherein the cathode uses an alloy film of magnesium and silver or an alloy film of aluminum and lithium.   7. The light-emitting device according to claim 3, wherein the third insulating film is made of an organic resin material.   11. The light-emitting device according to claim 1, wherein the first insulating film is made of an organic resin material.   11. The light-emitting device according to claim 1, wherein the first insulating film is made of polyimide, acrylic, polyamide, polyimide amide, or benzocyclobutene.   13. The light-emitting device according to claim 1, wherein the second insulating film is formed using an inorganic insulating material containing silicon or aluminum.   13. The second insulating film according to claim 1, wherein the second insulating film is made of silicon oxide, silicon nitride, silicon oxynitride, silicon nitride oxide, aluminum nitride, aluminum nitride oxide, or aluminum oxynitride. A light emitting device characterized by the above.   A digital camera using the light-emitting device according to claim 1.   A mobile phone using the light-emitting device according to claim 1.   A mobile computer using the light-emitting device according to claim 1.   A video camera, a goggle-type display, a navigation system, a sound reproduction device, a personal computer, a game device, a portable game machine, an electronic book, wherein the light-emitting device according to claim 1 is used. Or an image playback device. TFT is formed on the insulator,
Forming a first insulating film on the TFT;
Forming a second insulating film made of an inorganic insulating material on the first insulating film;
A method for manufacturing a light-emitting device, wherein an anode is formed over the second insulating film. TFT is formed on the insulator,
Forming a first insulating film on the TFT;
Forming a second insulating film made of an inorganic insulating material on the first insulating film;
A method for manufacturing a light-emitting device, wherein a cathode is formed over the second insulating film. TFT is formed on the insulator,
Forming a first insulating film on the TFT;
Forming a second insulating film made of an inorganic insulating material on the first insulating film;
Forming an anode on the second insulating film;
Forming a wiring for electrically connecting the TFT and the anode;
Forming a third insulating film covering the end of the anode;
Forming a film containing an organic compound on the anode;
A method for manufacturing a light-emitting device, comprising forming a cathode over a film containing the organic compound. TFT is formed on the insulator,
Forming a first insulating film on the TFT;
Forming a second insulating film made of an inorganic insulating material on the first insulating film;
Forming a cathode on the second insulating film;
Forming a wiring for electrically connecting the TFT and the cathode;
Forming a third insulating film covering the end of the cathode;
Forming a film containing an organic compound on the cathode;
A method for manufacturing a light-emitting device, comprising forming an anode over a film containing the organic compound. TFT is formed on the insulator,
Forming a first insulating film on the TFT;
Forming a second insulating film made of an inorganic insulating material on the first insulating film;
Forming an anode on the second insulating film;
Forming a wiring for electrically connecting the TFT and the anode;
Forming a third insulating film covering the end of the anode;
Forming a fourth insulating film on the anode;
Forming a film containing an organic compound on the fourth insulating film;
A method for manufacturing a light-emitting device, comprising forming a cathode over a film containing the organic compound. TFT is formed on the insulator,
Forming a first insulating film on the TFT;
Forming a second insulating film made of an inorganic insulating material on the first insulating film;
Forming a cathode on the second insulating film;
Forming a wiring for electrically connecting the TFT and the cathode;
Forming a third insulating film covering the end of the cathode;
Forming a fourth insulating film on the cathode;
Forming a film containing an organic compound on the fourth insulating film;
A method for manufacturing a light-emitting device, comprising forming an anode over a film containing the organic compound.   25. The method for manufacturing a light-emitting device according to any one of claims 19, 21, 22, 23, and 24, wherein a transparent conductive film is used as the anode.   25. The method for manufacturing a light-emitting device according to claim 19, wherein a transparent conductive film or ITO in which indium oxide and zinc oxide are mixed is used as the anode.   25. The method for manufacturing a light-emitting device according to any one of claims 20 to 24, wherein an alloy film of magnesium and silver or an alloy film of aluminum and lithium is used as the cathode.   25. The method for manufacturing a light-emitting device according to claim 21, wherein an organic resin material is used for the third insulating film.   30. The method for manufacturing a light-emitting device according to claim 19, wherein an organic resin material is used for the first insulating film.   29. The method for manufacturing a light-emitting device according to claim 19, wherein polyimide, acrylic, polyamide, polyimide amide, or benzocyclobutene is used as the first insulating film.   31. The method for manufacturing a light-emitting device according to claim 19, wherein an inorganic insulating material containing silicon or aluminum is used for the second insulating film.   31. The method according to claim 19, wherein the second insulating film is made of silicon oxide, silicon nitride, silicon oxynitride, silicon nitride oxide, aluminum nitride, aluminum nitride oxide, or aluminum oxynitride. A method for manufacturing a light-emitting device.

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