JP4777380B2 - Light emitting device - Google Patents

Description

  The present invention relates to a light emitting device using an element (hereinafter referred to as a light emitting element) in which a light emitting material is sandwiched between electrodes. Specifically, the present invention relates to an improvement in light extraction efficiency from the light emitting element.

  In recent years, development of light-emitting devices using light-emitting elements has progressed. In the light emitting device, since the light emitting element itself has a light emitting capability, a backlight as used in a liquid crystal display is unnecessary. Therefore, it is possible to reduce the thickness and weight.

  There are two types of light emitting devices, a passive type (simple matrix type) and an active type (active matrix type), both of which are actively developed. In particular, active light emitting devices are currently attracting attention. In addition, materials used for the organic layer of the light-emitting element include an organic material and an inorganic material, and the organic material is further classified into a low molecular (monomer) organic material and a high molecular (polymer) organic material. Both are actively studied, and low molecular weight organic materials are mainly formed by vacuum deposition, and high molecular weight organic materials are mainly formed by spin coating.

  Organic materials are characterized by higher luminous efficiency than inorganic materials and can be driven at a low voltage. In addition, since it is an organic compound, various new substances can be designed and manufactured. Therefore, there is a possibility that a device that emits light with higher efficiency may be developed due to progress in molecular design of future materials.

  An example of the light-emitting device is shown in FIG. FIG. 22 is a cross-sectional view of the light emitting device. The light-emitting element 1707 includes an anode (pixel electrode) 1702, an organic layer 1703, and a cathode 1704, and is formed so that the organic layer 1703 is sandwiched between the anode 1702 and the cathode 1704. The first substrate may be formed from the anode or the cathode, but it is generally formed from the anode on the substrate for ease of production. In the light-emitting element, electrons injected from the cathode and holes injected from the anode recombine at the emission center of the organic film to form excitons, which emit light when the excitons return to the ground state. To do.

In this manner, the light-emitting element 1707 is formed over the first substrate 1701. Next, the first substrate 1701 is attached to the second substrate 1700 with a sealant 1705 interposed therebetween. The light-emitting element 1707 is in a sealed space surrounded by the substrate 1701, the sealing substrate 1700, and the sealant 1705. Since the light emitting element is deteriorated by moisture or oxygen, the sealed space is an inert gas 1706 (nitrogen molecule or rare gas).
Is satisfied by. In this specification, a region surrounded by the first substrate, the second substrate, and the sealant is referred to as a sealed space. Reference numeral 1708 denotes a switching TFT, 1709 denotes a current control TFT, and 1710, 1711 and 1712 denote insulating films.

  A stacked body including the organic layer 1703 and the cathode 1704 needs to be formed individually for each pixel. However, since the organic layer 1703 is extremely weak against moisture, a normal photolithography technique cannot be used. Accordingly, it is preferable to use a physical mask material such as a metal mask and selectively form the film by a vapor phase method such as a vacuum deposition method, a sputtering method, or a plasma CVD method.

  Further, a protective electrode (not shown) for connecting the cathode 1704 of each pixel may be provided at the same time that the cathode 1704 is protected from external moisture or the like. As the protective electrode, it is preferable to use a low-resistance material containing aluminum (Al), copper (Cu), or silver (Ag). The protective electrode can also be expected to have a heat dissipation effect that alleviates the heat generation of the organic layer 1703. It is also effective to form the protective electrode continuously after the organic layer 1703 and the cathode 1704 are formed without being released to the atmosphere.

  The light emitting device is roughly divided into four color display methods, a method of forming three types of light emitting elements corresponding to R (red), G (green), and B (blue), a white light emitting element and a color. A combination of filters, a combination of blue or blue-green light-emitting elements and a phosphor (fluorescent color conversion layer: CCM), and light emission corresponding to RGB using a transparent electrode for the cathode (counter electrode) There is a method of stacking elements.

  As described above, development of a light-emitting device having a light-emitting element is in progress. The light-emitting device has a current-driven light-emitting element that utilizes light emission generated by recombination of electrons and holes injected from the electrodes on both sides into the organic layer by applying a voltage. Light emission is extracted as planar light emission. However, the light extraction efficiency when the light generated in the organic layer is extracted as planar light emission to the outside of the light emitting element is extremely low, and is usually 20% or less.

  The light generated in the organic layer 1703 is guided in the substrate depending on the incident angle of the light. The light guided in this way is called guided light. A part of the guided light 1713 is absorbed by the substrate and disappears, and the remaining light propagates through the first substrate 1701 and escapes to the end face. In, only a part of the light is extracted as planar light emission, and in some cases, light leakage to the adjacent pixel may be considered.

  In order to solve the above-described problem, the structure of the present invention is shown in FIG. 8 in which the first metal film 102a to the third metal film 102c are formed on the first recess 101a to the third recess 101c of the first substrate 100. A structure is provided. The metal film provided on the first substrate only needs to be provided on the light shielding portion as viewed from the side where the display portion is visible.

  Therefore, the configuration of the invention disclosed in this specification includes a first substrate having a first recess formed on the surface and a second recess adjacent to the first recess, the first recess, and the first recess. A first metal film and a second metal film respectively formed along the second recess; a first insulating film on the first metal film and the second metal film; and the first metal film. The light-emitting device includes a light-emitting element above the first insulating film between the metal film and the second metal film. When this light-emitting device is used, a part of light is confined in the first substrate and is less likely to be lost.

  According to another aspect of the invention, there is provided a first substrate having a first recess formed on a surface thereof and a second recess adjacent to the first recess, the first recess and the second recess. A first metal film and a second metal film respectively formed along the first metal film, a first insulating film on the first metal film and the second metal film, and an upper side of the first insulating film A TFT, an anode, a cathode, and a light emitting element sandwiched between the anode and the cathode above the TFT between the first metal film and the second metal film. The light emitting device is characterized. Since the light emitting element and the metal film do not overlap, the aperture ratio does not decrease.

  In another aspect of the present invention, a gate wiring, a source wiring, or a drain wiring formed in the TFT is formed above the first metal film and the second metal film. It is. Since the metal film overlaps with the gate wiring, the source wiring, or the drain wiring as viewed from the direction in which the display can be seen, the aperture ratio does not decrease.

  According to another aspect of the invention, there is provided a light emitting device characterized in that the concave portion has a depth of 25 to 200 μm.

  Another aspect of the invention is a light-emitting device in which a second insulating film is formed over the first insulating film.

  According to another aspect of the invention, the first metal film and the second metal film are made of W, Ta, Ag, Ti, Al, Cu, Pd alone or a laminate selected from them or selected from them. A light-emitting device comprising the above-described alloy. The metal employed here preferably has a higher light reflectance in the visible light region than the material of the substrate, preferably 60% or more. Further, it is desirable that the metal employed here has sufficient heat resistance characteristics for the TFT manufacturing process.

  Another aspect of the invention is a light-emitting device in which the first insulating film is mainly composed of silicon dioxide.

  According to another aspect of the invention, the second insulating film is a light emitting device characterized in that the second insulating film is made of DLC or silicon nitride alone or a laminate selected from them.

  According to another aspect of the invention, there is provided a pixel electrode and a third insulating film, the third insulating film is overlapped on the pixel electrode, an organic layer is formed on the pixel electrode, and the third electrode An end portion of the organic layer is formed on the insulating film, and a fourth insulating film having an upper surface and a slope is formed on the third insulating film and in a lateral direction of the organic layer and the pixel electrode. A cathode is formed on the upper surface and the slope of the fourth insulating film, on a part of the third insulating film, and on the organic layer, and the surface of the cathode is formed on the fourth insulating film. The light emitting device has a convex shape surrounded by an inclined surface of the first insulating film, a part of the third insulating film, and an end of the organic layer. The convex portion formed on the cathode prevents light leakage to the adjacent pixels. The third insulating film and the fourth insulating film are referred to as a third interlayer insulating film and a fourth interlayer insulating film, respectively.

  According to another aspect of the invention, there is provided an anode and a third insulating film, the third insulating film is overlapped on the anode, an organic layer is formed on the anode, and the third insulating film is formed. An end portion of the organic layer is formed thereon, a cathode is formed on the organic layer, an upper surface and a slope are formed on the third insulating film and in a lateral direction of the organic layer and the cathode. A fourth insulating film is formed, and is in contact with an end portion of the cathode, an upper surface and a slope of the fourth insulating film, a part of the third insulating film, and an end portion of the organic layer. 5 is formed, a metal film is formed on the fifth insulating film, an end of the cathode, an end of the organic layer, a slope of the fourth insulating film, and a third By forming a recess in the fifth insulating film formed on a part of the insulating film, the surface of the metal film in contact with the fifth insulating film has a shape of a protrusion. A light emitting device according to claim Rukoto. The third insulating film, the fourth insulating film, and the fifth insulating film are referred to as a third interlayer insulating film, a fourth interlayer insulating film, and a fifth interlayer insulating film, respectively. The convex portions formed on the surface of the metal film prevent light leakage to the adjacent pixels. Furthermore, by forming the metal film 251 above the cathode via the fifth interlayer insulating film, the light emitted upward can be reflected and the light extracted below.

  According to another aspect of the invention, there is provided a light-emitting device in which the fifth insulating film is made of SiNO or DLC or a laminate selected from them.

  Another aspect of the invention is a light-emitting device in which the metal film contains Al as a main component.

  The light emitting device of the present invention can be used for a personal computer, a video camera, a portable information terminal, a digital camera, a digital video disk player, an in-vehicle rear confirmation monitor, a video phone, a car navigation, or an electronic game machine.

  By using a light emitting device in which a concave portion is formed in the first substrate and a metal film is formed along the concave portion, loss of light in the first substrate can be prevented.

  Further, by providing a convex portion on the cathode of the light emitting element, light leakage to the adjacent pixel can be reduced.

  By forming a metal film above the light-emitting element through the insulating film, light emitted upward can be reflected and light can be extracted downward.

  When the light emitting device of the present invention as described above is used, the light extraction efficiency can be improved.

Embodiments of the present invention will be described below. FIG. 10 shows a top view (pixel portion) of the light emitting device of this embodiment. However, for simplification, the first substrate, the base film, the insulating film, the pixel electrode, the organic layer, the cathode, the second substrate, and the like are omitted. FIG. 8 shows a cross-sectional view of the light emitting device of the present embodiment taken along dotted line AA ′ and dotted line BB ′ in FIG.
Here, a method for simultaneously manufacturing a switching TFT 162 and a current control TFT 163 in the pixel portion and TFTs of a driving circuit (a p-channel TFT 160 and an n-channel TFT 161) provided around the pixel portion will be described with reference to FIGS. Will be described.

  The material of the first substrate 100 used in this embodiment is preferably an insulating material such as amorphous glass (borosilicate glass, quartz, etc.), crystallized glass, ceramic glass, glass, polymer, or the like. Insulating substances such as organic resins (acrylic resins, styrene resins, polycarbonate resins or epoxy resins) and silicone resin polymers may also be used. Ceramics may be used.

  In the first substrate 100, first to third recesses 101a to 101c are formed. As a method for forming the recess, a sand blast method is used. The width is about 4.5 to 5.5 μm and the depth is about 25 to 200 μm. In this specification, the surface on which the first to third recesses 101a to 101c are formed is the surface of the substrate. (FIG. 1 (A) Formation of recess)

  A metal film 102 is formed on the surface of the first substrate 100 by a sputtering method or an evaporation method. The material of the metal film 102 is preferably a highly reflective material such as a simple substance of W, Ta, Ag, Ti, Al, Cu, or Pd, a laminate selected from them, or an alloy selected from them. (FIG. 1 (B) Formation of Metal Film 102)

  Next, etching using a mask is performed, and the metal film 102 remaining on the surface is polished by chemical mechanical polishing (CMP), and each of the first recesses 101a to 101c is followed by the first recesses 101c. The metal film 102a to the third metal film 102c are formed. (FIG. 1C: Etching / polishing of the metal film 102)

  Next, the insulating film 103a is formed. (FIG. 2A: Formation of first insulating film)

  Next, the surface is planarized by CMP to form a first insulating film 103b. (FIG. 2 (B) after planarization)

  A second insulating film 104 is formed over the first insulating film 103b. You may form the thin film (DLC; Diamond Like Carbon) which has carbon as a main component, the simple substance of silicon nitride, or the lamination | stacking chosen from them.

  Next, as illustrated in FIG. 3A, first, semiconductor layers 105 to 108 are formed over the second insulating film 104. The semiconductor layers 105 to 108 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 105 to 108 are formed to a thickness of 25 to 80 nm (preferably 30 to 60 nm).

  Next, a gate insulating film 109 that covers the semiconductor layers 105 to 108 is formed by plasma CVD or sputtering.

  Then, a heat-resistant conductive layer 110 for forming a gate electrode is formed over the gate insulating film 109 with a thickness of 200 to 400 nm (preferably 250 to 350 nm).

  Next, a resist mask 111 is formed using a photolithography technique.

  Conductive layers 112 to 115 having a first tapered shape are formed by the first etching treatment. (FIG. 3 (B) first etching process)

Then, a first doping process is performed and an impurity element of one conductivity type is added to the semiconductor layer to form impurity regions 116 to 119 (FIG. 4A, first doping process).
.

  Next, as shown in FIG. 4B, a second etching process is performed to form the conductive layers 120 to 123 and the mask 124 having the second shape with the edges cut off. The surface of the gate insulating film 109 is also etched by about 40 nm.

  Then, the first impurity regions 125 to 128 and the second impurity regions 129 to 132 are formed by doping an impurity element that imparts n-type under a condition of a lower acceleration amount and a higher acceleration voltage than in the first doping process. . (FIG. 5 (A) Second doping)

  Then, as shown in FIG. 5B, the impurity regions 133 (133a, 133b) and 134 (134a, 134a, 134b) of the conductivity type opposite to the one conductivity type are formed in the semiconductor layer 106 and the semiconductor layer 107 forming the p-channel TFT. 134b). Also in this case, an impurity element imparting p-type conductivity is added using the second shape conductive layer 120 and the second shape conductive layer 124 as masks to form impurity regions in a self-aligning manner. At this time, a resist mask 135 is formed above the semiconductor layer for forming the n-channel TFT. (FIG. 5 (B) Third doping)

After that, as illustrated in FIG. 6A, a first interlayer insulating film 136 is formed over the conductive layers 120 to 123 having the second shape and the gate insulating film 109. 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. (Fig. 6 (A)
(Formation / activation process of first interlayer insulating film)

  Next, 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.

  First, a second interlayer insulating film 137 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.

  Thus, by forming the second interlayer insulating film 137 with an organic insulating material, the surface can be satisfactorily flattened. Moreover, since the organic resin material generally has a low dielectric constant, parasitic capacitance can be reduced.

  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.

  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 138 to 141 and drain wirings 142 to 144.

  Next, a transparent conductive film is formed thereon with a thickness of 80 to 120 nm and patterned to form a pixel electrode 145 (FIG. 7A: formation of a pixel electrode).

  Further, the pixel electrode 145 is formed in contact with the drain wiring 144 so as to be electrically connected to the drain region of the current control TFT 163.

  Next, as shown in FIG. 7B, a third interlayer insulating film 146 is formed so as to overlap with the pixel electrode 145. The film thickness may be about 100 nm. The formation method and material of the first interlayer insulating film may be used.

  Next, a fourth interlayer insulating film 147 having an opening at a position corresponding to the pixel electrode 145 and having an upper surface and a slope is formed. The fourth interlayer insulating film 147 has insulating properties, functions as a bank, and has a role of separating organic layers of adjacent pixels. In the fourth interlayer insulating film 147, a surface on the light emitting element side manufactured in a process described later is referred to as a slope.

  Next, an organic layer 148 is formed on the third interlayer insulating film 146 and the pixel electrode 145 by vapor deposition using a metal mask. An end portion of the organic layer 148 is formed on the third interlayer insulating film 146. Therefore, a fourth interlayer insulating film is formed on the third interlayer insulating film and in the lateral direction of the organic layer and the pixel electrode.

  Next, a cathode (MgAg electrode) 149 is formed on the upper surface and the slope of the fourth interlayer insulating film 147, a part of the third interlayer insulating film 146, and the organic layer 148 by ion plating. By using the ion plating method, the cathode is formed so as to be in contact with the inclined surface of the fourth interlayer insulating film 147. Therefore, like the round dotted line portion, the cathode is a convex portion 149a of the cathode surrounded by a part of the third interlayer insulating film 146, the inclined surface of the fourth interlayer insulating film 147, and the edge of the organic layer 148. FIG. 9).

  In the case of forming a cathode, when the cathode 149 is formed on the organic layer 148 while moving the substrate on which the organic layer 148 is formed on a circular orbit, it is possible to reduce variations in film thickness at the cathode.

  At this time, it is preferable that the pixel electrode 145 is heat-treated before the organic layer 148 and the cathode 149 are formed to completely remove moisture. The subsequent steps are performed in an inert gas (nitrogen or noble gas) atmosphere. Keep the moisture concentration in the atmosphere as low as possible. Specifically, the water concentration is desirably 1 ppm or less.

  In this embodiment, an MgAg electrode is used as the cathode of the light emitting element, but other known materials may be used.

  Note that a known material can be used for the organic layer 148. Note that a known material can be used for the organic layer 147. The organic layer 147 is used in a single layer or a stacked structure, but the light emitting efficiency is better when used in a stacked structure. The organic layer is formed using a hole injection material, a hole transport material, a light emitting layer material, an electron transport material, an electron injection material, or the like. Alternatively, a material that can convert energy when returning from the triplet excited state to the ground state into light emission may be used for the light-emitting layer.

Note that the thickness of the organic layer 148 may be 10 to 400 nm, typically 60 to 150 nm, and the thickness of the cathode 151 may be 80 to 200 nm, typically 100 to 150 nm.
Further, when the thickness of the cathode 151 is 2000 nm, shrinkage of the light emitting element can be suppressed as viewed from the direction in which the display can be seen.

  Note that a portion where the pixel electrode 145, the organic layer 148, and the cathode 149 overlap corresponds to the light-emitting element 150.

  The material of the second substrate 153 is preferably an insulating material such as amorphous glass (borosilicate glass, quartz, or the like), crystallized glass, ceramic glass, glass, or polymer. Insulating substances such as organic resins (acrylic resins, styrene resins, polycarbonate resins or epoxy resins) and silicone resin polymers may also be used. Ceramics may be used. Further, if the sealing material is an insulator, a metal material such as a stainless alloy can be used.

  As a material of the sealing material, a sealing material such as an epoxy resin or an acrylate resin can be used. A thermosetting resin or a photocurable resin can also be used as the sealing material. However, it is desirable that the sealing material is a material that does not transmit moisture as much as possible.

Through the above steps, the light-emitting device of FIG. 8 is completed. A region surrounded by the first substrate 100, the second substrate 153, a sealant (not shown), the pixel electrode 145, the light emitting element 150, the third acid interlayer insulating film 147, and the like is filled with an inert gas 152. It is.
If it is after bonding, it may be opened to the atmosphere.

  The p-channel TFT 160 and the n-channel TFT 161 are TFTs included in the drive circuit, and form a complementary metal-oxide semiconductor (CMOS). The switching TFT 162 and the current control TFT 163 are TFTs included in the pixel portion, and the TFT of the driver circuit and the TFT of the pixel portion can be formed over the same substrate.

  As described above, the light-emitting device of this embodiment includes the first recesses 101a to the third recesses 101c, and the first metal films 102a to the third recesses along the first recesses 101a to the third recesses 101c. The metal film 102c is formed. Therefore, part of the light generated from the organic layer 148 of the light emitting device of this embodiment is reflected by the first metal film 102a to the third metal film 102c, and the reflected light is emitted to the outside of the light emitting device of this embodiment. The In addition, for a part of light emission that has caused light leakage to adjacent pixels, light having the light emission direction as shown in FIG. 9 is reflected by the convex portion 149a of the cathode of this embodiment, and the light emitting device of this embodiment The reflected light can be emitted to the outside. Therefore, when the light emitting device of this embodiment is used, the light extraction efficiency can be improved.

  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 the present embodiment, in the driving circuit of the light emitting device using the light emitting element, the second impurity region 130 and the fourth impurity region 133b included in the semiconductor layer of the TFT include the gate electrode 120 and the gate, respectively. A structure that does not overlap with the electrode 121 is preferable.

  As shown in FIG. 10, since the gate wiring 159, the source wiring 140, the source wiring 141, the drain wiring 143, and the drain wiring 144 are formed so as to overlap with the first metal film 102a to the third 102c, the reflected light is transmitted. Suppressing and preventing reflection. 121 is a conductive layer having the second shape, 122 is a conductive layer having the second shape, 150 is a light emitting element, 158 is an anode power supply wiring, 162 is a switching TFT, and 163 is a current control TFT. .

  In addition, as illustrated in FIG. 11, a recess may be formed between the light emitting element 351 and the light emitting element 352 adjacent to the light emitting element 351, and the metal film 302 may be formed along the recess. At the same time, a recess is formed between the light emitting element 351 and the light emitting element 353 adjacent to the light emitting element 351, and the metal film 302 is formed along the recess.

  In addition, although the 1st recessed part 101a-the 3rd recessed part 101c showed the curve-shaped thing in FIG. 10, the shape in particular is not limited, For example, it showed by FIG. 12 (a)-(c) Any of the shapes may be used.

When glass is used for the first substrate as a method for forming the recess, the sand blast method is used, but it may be performed by an etching method, glass formation by a mold, or the like.
The recess may be formed by scraping the surface of the substrate with a blade such as a dicer.

  Although the sealed space is filled with the inert gas 152, it may be filled with an organic resin.

  Although the second substrate 153 of the light-emitting device of the present invention is a sheet, the present invention can also be applied to a light-emitting device in which a desiccant is sealed in the concave portion in the second substrate having the concave portion.

  The present invention can be applied not only to an active light-emitting device but also to a passive light-emitting device. In the case of manufacturing a passive light-emitting device, the cathode may be formed by the ion plating method used in this embodiment, or the ion beam method may be used.

  The present invention having the above-described configuration will be described in more detail with the following examples.

  Embodiments of the present invention will be described below. A top view (pixel portion) of the light emitting device of this example is shown in FIG. However, for simplification, the first substrate, the base film, the insulating film, the pixel electrode, the cathode, the second substrate, and the like are omitted. FIG. 8 shows a cross-sectional view of the light emitting device of the present embodiment taken along dotted line AA ′ and dotted line BB ′ in FIG. Here, a method for simultaneously manufacturing the switching TFT 162 and the current control TFT 163 in the pixel portion and the TFTs (p-channel TFT 160 and n-channel TFT 161) in the driver circuit provided around the pixel portion will be described in detail.

  In this embodiment, a substrate made of glass such as barium borosilicate glass represented by Corning # 7059 glass or # 1737 glass or aluminoborosilicate glass is used. The substrate is not limited as long as it has a light transmitting property, 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.

  In the first substrate 100, first to third recesses 101a to 101c are formed. As a method for forming the recess, a sand blast method is used. The width is about 4.5 to 5.5 μm and the depth is about 25 to 200 μm. (FIG. 1 (A) Formation of recess)

A metal film 102 is formed on the surface of the first substrate 100 by a sputtering method.
The thickness of the metal film 102 is about 0.4 to 0.6 μm. The material of the metal film 102 is preferably a material having high reflectivity 102 such as W, Ta, Ag, and Ti. In this embodiment, an alloy containing Ag as a main component and 1% of Pd and Cu is used. A metal film is formed. (FIG. 1 (B) Formation of metal film)

  Next, etching using a mask is performed, and the metal film 102 remaining on the surface is polished by chemical mechanical polishing (CMP), and each of the first recesses 101a to 101c is followed by the first recesses 101c. The metal film 102a to the third metal film 102c are formed. (FIG. 1C: Etching / polishing of the metal film 102)

Next, the insulating film 103a is formed. In this embodiment, silicon dioxide is applied.
The film thickness is about 1.5 to 2.0 μm. (FIG. 2A: Formation of first insulating film)

  Further, the surface of the first insulating film 103a (portion above the dotted line portion) is removed by chemical mechanical polishing (CMP), and the surface is planarized to form the first insulating film 103b. Form. The film thickness is about 1.3 to 1.8 μm (after planarization in FIG. 2B).

  A second insulating film 104 is formed over the first insulating film 103b. You may form the thin film (DLC; Diamond Like Carbon) which has carbon as a main component, the simple substance of silicon nitride, or the lamination | stacking chosen from them.

Next, semiconductor layers 105 to 108 are formed. The semiconductor layers 105 to 108 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 102 to 105 are formed to have 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 preferable that the crystalline semiconductor film be 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 then laser annealing treatment is performed to improve crystallization. Thus, a crystalline silicon film was formed. Then, semiconductor layers 105 to 108 are formed by patterning the crystalline silicon film using a photolithography method.

  Further, after the semiconductor layers 105 to 108 are formed, the semiconductor layers 105 to 108 may be doped with a trace 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 109 that covers the semiconductor layers 105 to 108 is formed. The gate insulating film 109 is formed of an insulating film containing silicon with a thickness of 40 to 150 nm by using 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 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 subsequent thermal annealing at 400 to 500 ° C.

Then, a heat-resistant conductive layer 110 for forming a gate electrode is formed over the gate insulating film 109 with a thickness of 200 to 400 nm (preferably 250 to 350 nm). The heat-resistant conductive layer 110 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, the 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 110, 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 110. This improves the adhesion of the conductive film formed thereon and prevents oxidation, and at the same time, the alkali metal element contained in a trace amount in the heat-resistant conductive layer 107 diffuses into the gate insulating film 106 having the first shape. Can be prevented. In any case, the heat resistant conductive layer 107 preferably has a resistivity in the range of 10 to 50 μΩcm.

Next, a resist mask 111 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 was just etched was estimated based on this etching rate, and the time when the etching time was increased by 20% was used as the etching time.

  Conductive layers 112 to 115 having a first tapered shape are formed by the first etching treatment. The angle of the taper part of the conductive layers 112 to 115 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 109) 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. Is done. (FIG. 3 (B) first etching)

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 111 on which the first shape conductive layer is formed is left as it is, and an impurity element imparting n-type is added by ion doping in a self-aligned manner using the first tapered conductive layers 112 to 115 as a mask. In order to add the impurity element imparting n-type through the tapered portion at the end of the gate electrode and the gate insulating film 109 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 116 to 119 in a concentration range of 1 × 10 ²⁰ to 1 × 10 ²¹ atoms / cm ³ . (FIG. 4 (A) First doping process)

  In this step, depending on the doping conditions, impurities may flow under the first shape conductive layers 112 to 115, and the first impurity regions 116 to 119 may overlap with the first shape conductive layers 112 to 115. 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 120 to 123 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 108 is etched to scrape the end portion to form a mask 124. 4B, the surface of the gate insulating film 109 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 125 to 128 having an increased impurity concentration are in contact with the first impurity regions 125 to 128. Second impurity regions 129 to 132 are formed. In this step, depending on the doping conditions, impurities may wrap under the second shape conductive layers 120 to 123, and the second impurity regions 129 to 132 overlap with the second shape conductive layers 120 to 123. 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. 5 (A) Second doping process)

Then, as shown in FIG. 5B, the impurity regions 133 (133a, 133b) and 134 (134a, 134a, 134b) of the conductivity type opposite to the one conductivity type are formed in the semiconductor layer 106 and the semiconductor layer 107 forming the p-channel TFT. 134b). Also in this case, an impurity element imparting p-type conductivity is added using the second shape conductive layer 118 and the second shape conductive layer 121 as masks, and impurity regions are formed in a self-aligning manner. At this time, a resist mask 135 is formed above the semiconductor layer 106 and the semiconductor layer 107 forming the n-channel TFT. The impurity regions 133 and 134 formed here are formed by ion doping using diborane (B ₂ H ₆ ). The concentration of the impurity element imparting p-type in the impurity regions 133 and 134 is set to be 2 × 10 ²⁰ to 2 × 10 ²¹ atoms / cm ³ .

However, the impurity region 133 and the impurity region 134 can be divided into two regions containing an impurity element imparting n-type in detail. The third impurity region 133a and the third impurity region 134a 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 region 133b and the fourth impurity region The impurity region 134b contains an impurity element imparting n-type at a concentration of 1 × 10 ¹⁷ to 1 × 10 ²⁰ atoms / cm ³ . However, in the third impurity region 133a and the third impurity region 134a, the concentration of the impurity element imparting p-type in these impurity regions 133b and 134b is set to 1 × 10 ¹⁹ atoms / cm ³ or more. The source region and the drain region of the p-channel TFT are formed in the third impurity region by setting the concentration of the impurity element imparting p-type to 1.5 to 3 times the concentration of the impurity element imparting n-type. No problem arises to function as.

After that, as shown in FIG. 6A, first, a first interlayer insulating film 136 is formed over the conductive layers 120 to 123 having the second shape and the gate insulating film 109. The first interlayer insulating film 136 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 136 is formed of an inorganic insulating material. The film thickness of the first interlayer insulating film 136 is 100 to 200 nm. In the case where a silicon oxide film is used as the first interlayer insulating film 136, TEOS and O ₂ are mixed by a plasma CVD method to 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 136, a silicon oxynitride film manufactured from SiH ₄ , N ₂ O, and NH ₃ by a plasma CVD method, 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 136. 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 was performed. Further, when a plastic substrate having a low heat resistant temperature is used for the substrate 100, it is preferable to apply a laser annealing method.

Next, 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 to set the defect density in the semiconductor layer to 10 ¹⁶ / cm ³ or less, and for that purpose, hydrogen may be added at about 0.01 to 0.1 atomic%.

  First, a second interlayer insulating film 137 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 resin is used, a two-component resin is used, the main material and the curing agent are mixed, and then applied to the entire surface of the substrate using a spinner, followed by preheating at 80 ° C. for 60 seconds on a hot plate. And then baked at 250 ° C. for 60 minutes in a clean oven.

  Thus, by forming the second interlayer insulating film 137 with an organic insulating material, the surface can be satisfactorily flattened. 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 136 as in this embodiment. .

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 second interlayer insulating film 137 made of an organic resin material is first etched using a mixed gas of CF ₄ , O ₂ , and He as an etching gas, and then the first etching gas is changed to CF ₄ and O ₂ . The interlayer insulating film 136 is etched. Further, in order to increase the selection ratio with the semiconductor layer, the contact hole can be formed by etching the gate insulating film 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 138 to 141 and drain wirings 142 to 144. 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 a pixel electrode 145 (FIG. 7A: formation of a pixel electrode). In this embodiment, as the transparent electrode, 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.

  Further, the pixel electrode 145 is formed in contact with the drain wiring 144 so as to be electrically connected to the drain region of the current control TFT 163.

  Next, as shown in FIG. 7B, a third interlayer insulating film 146 is formed so as to overlap with the pixel electrode 145. The film thickness may be about 100 nm. The formation method and material of the first interlayer insulating film may be used.

  Next, a fourth interlayer insulating film 147 having an opening at a position corresponding to the pixel electrode 145 and having an upper surface and a slope is formed. The fourth interlayer insulating film 147 has insulating properties, functions as a bank, and has a role of separating organic layers of adjacent pixels. In this embodiment, a fourth interlayer insulating film 147 is formed using a resist.

  In this embodiment, the thickness of the fourth interlayer insulating film 147 is set to about 1 μm, and the opening is formed to have a so-called reverse taper shape that becomes wider as the pixel electrode 145 is closer. This is formed by depositing a negative resist, covering a portion where an opening is to be formed with a mask, irradiating with UV light and exposing, and removing the exposed portion with a developer. The negative resist preferably contains a light-absorbing agent.

  In this embodiment, a resist film is used as the fourth interlayer insulating film. However, depending on the case, photosensitive polyimide, photosensitive acrylic, or the like can be used.

  Next, an organic layer 148 is formed on the third interlayer insulating film 146 and the pixel electrode 145 by vapor deposition using a metal mask. An end portion of the organic layer 148 is formed in the third interlayer insulating film 146. Therefore, a fourth interlayer insulating film is formed on the third interlayer insulating film and in the lateral direction of the organic layer and the pixel electrode.

  Next, a cathode (MgAg electrode) 149 is formed on the upper surface and the slope of the fourth interlayer insulating film, a part of the third interlayer insulating film, and the organic layer by ion plating. By using the ion plating method, the cathode is formed in contact with the inclined surface of the fourth interlayer insulating film. Therefore, like the round dotted line portion, the cathode has a part of the third interlayer insulating film, the slope of the fourth interlayer insulating film, and the convex portion 149a of the cathode surrounded by the organic layer (FIG. 9).

  At this time, it is preferable that the pixel electrode 145 is heat-treated before the organic layer 148 and the cathode 149 are formed to completely remove moisture. The subsequent steps are performed in an inert gas (nitrogen or noble gas) atmosphere. Keep the moisture concentration in the atmosphere as low as possible. Specifically, the water concentration is desirably 1 ppm or less.

  In this embodiment, an MgAg electrode is used as the cathode of the light emitting element, but other known materials may be used.

  Note that a known material can be used for the organic layer 148. In this embodiment, the organic layer has a two-layer structure consisting of a hole transporting layer and a light emitting layer, but any of a hole injection layer, an electron injection layer, or an electron transport layer is provided. There is also. As described above, various examples of combinations have already been reported, and any of the configurations may be used.

  In this embodiment, polyphenylene vinylene is formed by a vapor deposition method as a hole transport layer. The light-emitting layer is formed by vapor deposition of 30-40% PBD of 1,3,4-oxadiazole derivative in polyvinyl carbazole, and about 1% of coumarin 6 is used as a green emission center. It is added.

Note that the thickness of the organic layer 148 may be 10 to 400 nm, typically 60 to 150 nm, and the thickness of the cathode 151 may be 80 to 200 nm, typically 100 to 150 nm.
Further, when the thickness of the cathode 151 is 2000 nm, shrinkage of the light emitting element can be suppressed as viewed from the direction in which the display can be seen.

  Note that a portion where the pixel electrode 145, the organic layer 148, and the cathode 149 overlap corresponds to the light-emitting element 150.

  The material of the second substrate 153 is preferably an insulating material such as amorphous glass (borosilicate glass, quartz, or the like), crystallized glass, ceramic glass, glass, or polymer. Insulating substances such as organic resins (acrylic resins, styrene resins, polycarbonate resins or epoxy resins) and silicone resin polymers may also be used. Ceramics may be used. Further, if the sealing material is an insulator, a metal material such as a stainless alloy can be used.

  As a material of the sealing material, a sealing material such as an epoxy resin or an acrylate resin can be used. A thermosetting resin or a photocurable resin can also be used as the sealing material. However, it is desirable that the sealing material is a material that does not transmit moisture as much as possible.

Through the above steps, the light-emitting device of FIG. 8 is completed. A region surrounded by the first substrate 100, the second substrate 153, a sealant (not shown), the pixel electrode 145, the light emitting element 150, the third acid interlayer insulating film 147, and the like is filled with an inert gas 152. It is.
If it is after bonding, it may be opened to the atmosphere.

  The p-channel TFT 160 and the n-channel TFT 161 are TFTs included in the drive circuit, and form a complementary metal-oxide semiconductor (CMOS). The switching TFT 162 and the current control TFT 163 are TFTs included in the pixel portion, and the TFT of the driver circuit and the TFT of the pixel portion can be formed over the same substrate.

  As described above, the light-emitting device of this example includes the first concave portion 101a to the third concave portion 101c, and the first metal film 102a to the third concave portion 101c on the first concave portion 101a to the third concave portion 101c. A metal film 102c is formed. Therefore, part of the light generated from the organic layer 148 of the light emitting device of this embodiment is reflected by the first metal film 102a to the third metal film 102c, and the reflected light is emitted to the outside of the light emitting device of this embodiment. The An alloy containing Ag as a main component and containing 1% of Pd and Cu not only exhibits sufficient reflection characteristics as a metal film, but also has sufficient heat resistance and corrosion resistance for the TFT manufacturing process.

  Further, for a part of light emission that has caused light leakage to adjacent pixels, light having the light emission direction as shown in FIG. 8 is reflected by the convex portion 149a of the cathode of this embodiment, and the light emitting device of this embodiment The reflected light can be emitted to the outside. Therefore, when the light emitting device of this embodiment is used, the light extraction efficiency can be improved.

  If a technique for manufacturing TFTs at 200 ° C. to 250 ° C. is developed in the future, a material containing Al as a main component, for example, an Al—Ti alloy or the like can be used for the metal film.

  In this embodiment, a method for manufacturing a light-emitting device, which is different from that in Embodiment 1, will be described with reference to FIGS.

  Since other configurations have already been described in the first embodiment, the first embodiment is referred to for the detailed configuration, and the description thereof is omitted here.

  First, the same state as in FIG.

  Next, a third interlayer insulating film 246 is formed so as to overlap with the anode 245 as shown in FIG. The film thickness may be about 100 nm. The formation method and material of the first interlayer insulating film may be used.

  Next, a fourth interlayer insulating film 247 having an opening at a position corresponding to the anode 245 is formed. The fourth interlayer insulating film 247 has insulating properties, functions as a bank, and has a role of separating organic layers of adjacent pixels. In this embodiment, a fourth interlayer insulating film 247 is formed using a resist.

  In this embodiment, the thickness of the fourth interlayer insulating film 247 is set to about 1 μm, and the opening is formed to have a so-called reverse taper shape that becomes wider as the anode 245 becomes closer. This is formed by depositing a negative resist, covering a portion where an opening is to be formed with a mask, irradiating with UV light and exposing, and removing the exposed portion with a developer. The negative resist preferably contains a light-absorbing agent.

  In this embodiment, a resist film is used as the fourth interlayer insulating film. However, depending on the case, photosensitive polyimide, photosensitive acrylic, or the like can be used.

  Next, an organic layer 248 is formed on part of the third interlayer insulating film 246 and on the anode 245 by vapor deposition using a metal mask. An end portion of the organic layer is formed on the third interlayer insulating film.

  Note that a known material can be used for the organic layer 248. In this embodiment, the organic layer has a two-layer structure consisting of a hole transporting layer and a light emitting layer, but any of a hole injection layer, an electron injection layer, or an electron transport layer is provided. There is also. As described above, various examples of combinations have already been reported, and any of the configurations may be used.

  In this embodiment, polyphenylene vinylene is formed by a vapor deposition method as a hole transport layer. The light-emitting layer is formed by vapor deposition of 30-40% PBD of 1,3,4-oxadiazole derivative in polyvinyl carbazole, and about 1% of coumarin 6 is used as a green emission center. It is added.

Note that the thickness of the organic layer 248 may be 10 to 400 nm, typically 60 to 150 nm, and the thickness of the cathode 151 may be 80 to 200 nm, typically 100 to 150 nm.
Further, when the thickness of the cathode 251 is 2000 nm, shrinkage of the light-emitting element can be suppressed as viewed from the display direction.

  Next, a cathode 249 is formed on the organic layer 248. In this embodiment, MgAg is used as the cathode 249. Therefore, a fourth insulating film 247 having an upper surface and a slope is formed on the third interlayer insulating film 246 and in the lateral direction of the organic layer 248 and the cathode 249. If MgAg is a thin film and a semi-transmissive film, a buffer layer may be provided on MgAg. Note that an indium tin oxide (ITO) film or a transparent conductive film in which 2 to 20% zinc oxide (ZnO) is mixed with indium oxide may be used as the buffer layer.

  Further, a fifth interlayer insulating film 250 is formed by ion plating. By using the ion plating method, a cathode is also formed on the slope of the fourth interlayer insulating film 247. Examples of the material of the fifth interlayer insulating film 250 include DLC and SiNO. A fifth interlayer insulating film 250 is in contact with the end of the cathode 249, the upper surface and slope of the fourth interlayer insulating film 247, a part of the third interlayer insulating film 246, and the end of the organic layer 248. By forming, a recess is formed.

Next, a metal film 251 is formed on the fifth interlayer insulating film 250 by an evaporation method.
In this embodiment, Al is used as the material of the metal film 251. Of the fifth interlayer insulating film 250, the end of the cathode 249, the end of the organic layer 248, the slope of the fourth interlayer insulating film 246, and the third interlayer insulating film formed on part of the third interlayer insulating film. The metal film enters the recess formed by the interlayer insulating film 250. Therefore, the surface of the metal film 251 in contact with the fifth interlayer insulating film 250 has the convex portion 251a.

  At this time, it is desirable that heat treatment is performed on the anode 245 prior to the formation of the organic layer 248 and the cathode 251 to completely remove moisture. The subsequent steps are performed in an inert gas (nitrogen or noble gas) atmosphere. Keep the moisture concentration in the atmosphere as low as possible. Specifically, the water concentration is desirably 1 ppm or less.

  In this embodiment, an MgAg electrode is used as the cathode of the light emitting element, but other known materials may be used.

  Note that a portion where the anode 245, the organic layer 248, and the cathode 249 overlap corresponds to the light-emitting element 252.

  As a material of the second substrate 253, an insulating material such as amorphous glass (borosilicate glass, quartz, or the like), crystallized glass, ceramic glass, glass, or polymer is preferable. Insulating substances such as organic resins (acrylic resins, styrene resins, polycarbonate resins or epoxy resins) and silicone resin polymers may also be used. Ceramics may be used. Further, if the sealing material is an insulator, a metal material such as a stainless alloy can be used.

  As a material of the sealing material, a sealing material such as an epoxy resin or an acrylate resin can be used. A thermosetting resin or a photocurable resin can also be used as the sealing material. However, it is desirable that the sealing material is a material that does not transmit moisture as much as possible.

  Through the above steps, the light emitting device of FIG. 13 is completed. A region surrounded by the first substrate 200, the second substrate 253, a sealing material (not shown), the anode 245, the metal film 251, the fifth interlayer insulating film 250, and the like is filled with an inert gas 254. If it is after bonding, it may be opened to the atmosphere.

  The p-channel TFT 260 and the n-channel TFT 261 are TFTs included in the drive circuit, and form a complementary metal-oxide semiconductor (CMOS). The switching TFT 262 and the current control TFT 263 are TFTs included in the pixel portion, and the TFT of the driver circuit and the TFT of the pixel portion can be formed over the same substrate.

As described above, the light-emitting device of this example includes the first recess 201a to the third recess 201c, and the first metal film 202a to the third recess 201c on the first recess 201a to the third recess 201c. A metal film 202c is formed. Therefore, part of light generated from the organic layer 248 of the light emitting device of this embodiment is reflected by the first metal film 202a to the third metal film 202c, and reflected light is emitted to the outside of the light emitting device of this embodiment. The In addition, it is possible to reflect a part of light emission that has leaked light to an adjacent pixel by the convex portion 251a on the surface of the cathode and to emit reflected light to the outside of the light emitting device of this embodiment.
Furthermore, by forming the metal film 250 above the cathode 249 through the fifth interlayer insulating film 250, the light emitted upward can be reflected and the light extracted downward. Therefore, when the light emitting device of this embodiment is used, the light extraction efficiency can be improved.

In this example, an external input terminal of the light-emitting device manufactured in Example 1 and an FPC attaching step will be described.
FIG. 14 is a cross-sectional view of the pixel portion, the drive circuit, and the external input terminal. Reference numeral 169 denotes a sealing material. The external input terminal is formed on the first substrate 100 side, and in the same layer as the gate wiring through the second interlayer insulating film 146 by the wiring 170 in order to reduce interlayer capacitance and wiring resistance and prevent defects due to disconnection. It connects with the wiring 171 formed. A transparent conductive film 172 formed by patterning the transparent conductive film in Example 1 is provided on the wiring 170. The transparent conductive film 172 has a role of preventing the wiring 170 from being oxidized.

  Further, an FPC 175 including a base film 173 and a wiring 174 is bonded to the external input terminal with an anisotropic conductive resin 176. Further, the mechanical strength is increased by the reinforcing plate 177.

  In addition to the pixel portion, the fourth metal film 102d and the fifth metal film 102e may be provided below the external input terminal and the driver circuit. By providing the fourth metal film 102d and the fifth metal film 102e below the external input terminal and the drive circuit, the guided light in the substrate can be reflected, and the light extraction efficiency can be improved.

  In this example, a method for manufacturing a recess by a sandblasting method will be described. Other methods for manufacturing the light-emitting device are the same as those in Example 1, and a detailed description thereof is omitted.

  A resist is formed on a glass substrate other than a portion where a recess is to be formed. Put it in a sandblasting machine and spray sand onto the glass substrate with high pressure. Next, when the resist is removed, the glass is scraped off to complete a substrate on which concave portions are formed. At this time, a known sandblasting device may be used.

  Next, the light emitting devices of FIGS. 8 and 13 are manufactured according to the manufacturing method of Example 1 and Example 2, respectively, using the substrate made of glass formed with the recesses manufactured by the manufacturing method of this example. Can do.

In Example 3, the method for manufacturing the concave portion by the sandblasting method was mentioned, but in this example, the method for manufacturing the concave portion by etching the glass will be described in detail.
Other methods for manufacturing the light-emitting device are the same as those in Example 1, and a detailed description thereof is omitted.

  First, as shown in FIG. 15A, a resist 502 is formed on a glass substrate 500a by a spin coating method. Next, the resist 502 is exposed through the opening of the photomask 503 using the photomask 503 (FIG. 15A: resist application / exposure).

  Next, as shown in FIG. 15B, development is performed to remove the exposed portion of the resist. In the unexposed portion, the resist 502a and the resist 502b remain on the sealing substrate 500a made of glass (development in FIG. 15B).

Next, as shown in FIG. 16A, when etching is performed, a recess 501 is formed in the sealing substrate 500b made of glass. As the etchant, hydrofluoric acid or a solution containing hydrofluoric acid as a main component is used. In the case of wet etching, isotropic etching is performed, so that the shape after etching has a partially curved shape as shown in FIG. Further, dry etching may be used.
In this case, the cross-sectional shape is rectangular. (FIG. 16 (A) Etching)

Next, when the resist 502a and the resist 502b are peeled and washed, a substrate 500b made of glass in which a recess 501 as shown in FIG. 16B is formed is obtained.
The substrate 500b and the concave portion 501 made of glass correspond to the first substrate 100 and the first concave portion 101a to the third concave portion 101c in FIG. About the depth of the recessed part 501, it can adjust with the time of an etching (FIG. 16 (B) peeling and washing | cleaning).
.

  The light-emitting devices of FIGS. 8 and 13 can be manufactured in accordance with the manufacturing method of Example 1 and Example 2, respectively, using the substrate 500b made of glass formed with the recess 501 manufactured by the manufacturing method of this example. it can.

  In Example 5, the method of forming the recesses by the glass etching method was described, but in this example, the method of manufacturing the glass by using a mold is described. The other device manufacturing methods are the same as those in the first embodiment, and a detailed description thereof is omitted.

  A glass substrate having a recess is formed by a mold. A convex mold is prepared so that a concave portion is formed on the glass substrate, and a first substrate in which the concave portion is formed is manufactured using the mold.

  Next, using the first substrate on which the concave portion formed by the manufacturing method of this example is formed, the light-emitting devices of FIGS. 8 and 13 can be manufactured according to the manufacturing method of Example 1 and Example 2, respectively. it can.

  Although the 2nd board | substrate of the light-emitting device of this invention is a sheet form, the example of the light-emitting device by which the desiccant was sealed by the recessed part in the 2nd board | substrate which has a recessed part is described.

  As shown in FIG. 17, the present invention can also be applied to a light emitting device in which the second substrate 453 has a recess 401 above the light emitting element 451 and the desiccant 402 is sealed in the recess 401. The film 403 has a role of confining the desiccant 402 in the recess 401. The second substrate 453 is bonded to the first substrate 400 with the sealant 404 interposed therebetween.

  The present invention can also be applied to a passive light emitting device. An example in which the present invention is applied to a passive light-emitting device is shown in FIG. Reference numeral 800 denotes a first substrate, 801a denotes a recess, 802a denotes a metal film, 803 denotes a first insulating film, 804 denotes a second insulating film, 805 denotes a sealing material, 806 denotes an inert gas, and 807 denotes an anode (pixel electrode). , 808 is an organic layer, 809 is a cathode, 810 is a third insulating film, 811 is a fourth insulating film, 812 is a second substrate, 814 is a recess, 815 is a desiccant, and 816 is a film. The direction of light emission from the organic layer 808 is indicated by an arrow.

  While maintaining the rotation axis of a dicer having a triangular blade in cross section in the peripheral portion in parallel to the first substrate, and keeping the rotation surface of the dicer perpendicular to the first substrate, rotating the dicer, By cutting the surface of the first substrate with a blade, a V-shaped dent such as 801a can be formed. Further, if the time for rotating the dicer is lengthened, a U-shaped recess as shown in FIG. 12C can be formed.

  In the case of using the light-emitting device of this embodiment, part of the light emitted from the organic layer 808 is reflected by the metal film 802a, and the reflected light 813 can be extracted to the outside.

  Since the light-emitting device of the present invention is a light-emitting type, it has excellent visibility in a bright place as compared with a liquid crystal display, and has a wide viewing angle. Therefore, it can be used as a display unit of various electric appliances. For example, in order to appreciate TV broadcasting or the like on a large screen, the light emitting device of the present invention may be used in a display portion of a display having a diagonal of 30 inches or more (typically 40 inches or more).

  The display includes all information display devices such as a personal computer display device, a TV broadcast receiving display device, and an advertisement display device. In addition, the light-emitting device of the present invention can be used for display portions of various electric appliances.

  Such an electric appliance of the present invention includes a video camera, a digital camera, a goggle type display device (head mounted display), a navigation system, a sound reproduction device (car audio, audio component, etc.), a notebook type personal computer, a game machine, In-vehicle rear-view confirmation monitor, videophone, portable information terminal (mobile computer, mobile phone, portable game machine, electronic book, etc.), image playback device equipped with a recording medium (specifically, a digital video disc (DVD), etc.) A device provided with a display capable of reproducing a recording medium and displaying the image). Specific examples of these electric appliances are shown in FIGS.

  FIG. 19A illustrates a display, which includes a housing 901, a support base 902, a display portion 903, and the like. The light emitting device of the present invention can be used in the display portion 903. Note that since the light-emitting device of the present invention is a self-luminous type, a backlight is not necessary, and a display portion thinner than a liquid crystal display can be obtained.

  FIG. 19B shows a video camera, which includes a main body 911, a display portion 912, an audio input portion 913, operation switches 914, a battery 915, an image receiving portion 916, and the like. The light emitting device of the present invention can be used in the display portion 912.

  FIG. 19C shows a part (right side) of the head mounted display, which includes a main body 921, a signal cable 922, a head fixing band 923, a display portion 924, an optical system 925, a display device 926, and the like. The light-emitting device of the present invention can be used in the display device 926.

FIG. 19D shows an image playback device (specifically a DVD playback device) provided with a recording medium.
A main body 931, a recording medium (DVD or the like) 932, an operation switch 933, a display unit (a) 934, a display unit (b) 935, and the like. The display portion (a) 934 mainly displays image information, and the display portion (b) 935 mainly displays character information. The light emitting device of the present invention is displayed on the display portion (a) 934 and the display portion (b) 935. Can be used. Note that an image reproducing device provided with a recording medium includes a home game machine and the like.

  FIG. 19E illustrates a goggle type light emitting device (head mounted display), which includes a main body 941, a display portion 942, and an arm portion 943. The light emitting device of the present invention can be used in the display portion 942.

  FIG. 19F illustrates a personal computer, which includes a main body 951, a housing 952, a display portion 953, a keyboard 954, and the like. The light emitting device of the present invention can be used in the display portion 953.

  If the emission luminance of the material of the organic layer 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 material of the organic layer is very high, the light emitting device of the present invention is preferable for displaying moving images.

FIG. 20A illustrates a mobile phone, which includes a display panel 1001, an operation panel 1002, a connection portion 1003, a display portion 1004, an audio output portion 1005, an operation switch 1006, a power switch 1007, an audio input portion 1008, and an antenna 1009. Including.
The light emitting device of the present invention can be used in the display portion 1004. Note that the display portion 1004 can reduce power consumption of the mobile phone by displaying white characters on a black background.

  FIG. 20B illustrates a sound reproduction device, specifically a car audio, which includes a main body 1011, a display portion 1012, an operation switch 1013, and an operation switch 1014. The light emitting device of the present invention can be used in the display portion 1012. Moreover, although the vehicle-mounted audio is shown in the present embodiment, it may be used for a portable or household sound reproducing device. Note that the display unit 1014 can reduce power consumption by displaying white characters on a black background. This is particularly effective in a portable sound reproducing apparatus.

  FIG. 20C illustrates a digital camera, which includes a main body 1021, a display portion (A) 1022, an eyepiece portion 1023, operation switches 1024, a display portion (B) 1025, and a battery 1026. The light-emitting device of the present invention can be used in the display portion (A) 1022 and the display portion (B) 1025. In addition, when the display portion (B) 1025 is mainly used as an operation panel, power consumption can be suppressed by displaying white characters on a black background.

  FIG. 21A shows a vehicle rearward confirmation monitor, which includes a main body 3201, a display portion 3202, a connection portion 3203 with a car, a relay cable 3204, a camera 3205, a mirror 3206, and the like. The light emitting device of the present invention can be applied to the display portion 3202. In the present application, the mirror 3206 includes the display unit 3202, but the mirror and the display unit may be separated.

  FIG. 21B illustrates a videophone, which includes a main body 3301, a display portion 3302, an image receiving portion 3303, a keyboard 3304, operation switches 3305, a receiver 3306, and the like. The light emitting device of the present invention can be applied to the display portion 3303.

  FIG. 21C illustrates a car navigation system including a main body 3401, a display portion 3402, operation switches 3403, and the like. The light emitting device of the present invention can be applied to the display portion 3402. The display unit 3402 displays a picture such as a road.

  FIG. 21D illustrates an electronic notebook, which includes a main body 3501, a display portion 3502, an operation switch 3503, an electronic pen 3504, and the like. The light emitting device of the present invention can be applied to the display portion 3502.

  In the portable electric device shown in this embodiment, as a method for reducing power consumption, a sensor unit that senses external brightness is provided, and when used in a dark place, For example, there is a method of adding a function such as reducing brightness.

  As described above, the applicable range of the light-emitting device of the present invention is so wide that the light-emitting device can be used for electric appliances in various fields. Moreover, you may apply any structure shown in Example 1- Example 8 to the electric appliance of a present Example.

FIG. 5 shows a manufacturing process of a light-emitting device of the present invention. FIG. 5 shows a manufacturing process of a light-emitting device of the present invention. FIG. 5 shows a manufacturing process of a light-emitting device of the present invention. FIG. 5 shows a manufacturing process of a light-emitting device of the present invention. FIG. 5 shows a manufacturing process of a light-emitting device of the present invention. FIG. 5 shows a manufacturing process of a light-emitting device of the present invention. FIG. 5 shows a manufacturing process of a light-emitting device of the present invention. Sectional view of light-emitting device of the present invention Enlarged view of cathode surface of light emitting device of the present invention Top view of the light emitting device of the present invention Top view of another light emitting device of the present invention The figure which shows the cross-sectional shape of a recessed part Sectional view of light-emitting device of the present invention FIG. 5 shows a manufacturing process of a light-emitting device of the present invention. FIG. 5 shows a manufacturing process of a light-emitting device of the present invention FIG. 5 shows a manufacturing process of a light-emitting device of the present invention. Sectional view of light-emitting device of the present invention Sectional view of the passive light emitting device of the present invention The figure which shows the electric appliance of this invention The figure which shows the electric appliance of this invention The figure which shows the electric appliance of this invention Cross section of light emitting device

Claims (7)

A pixel portion having a first TFT and a second TFT formed on a substrate;
A first recess, a second recess, and a third recess provided in the substrate in a region where the pixel portion is formed;
A first metal film having a recess shape formed along the shapes of the first recess, the second recess, and the third recess, respectively , a second metal film having a recess shape , And a third metal film having a concave shape ,
A base film formed by a coating method so as to fill the recesses of the first metal film, the recesses of the second metal film, and the recesses of the third metal film;
The first TFT and the second TFT formed on the base film;
An interlayer insulating film formed on the first TFT and the second TFT;
A first contact hole formed in the interlayer insulating film, formed in the region of the first TFT, and a second contact hole and a third contact hole formed in the region of the second TFT;
A light emitting element electrically connected to the first TFT through the first contact hole;
The light-emitting element has an anode, a cathode, and an organic layer sandwiched between the anode and the cathode,
The first concave portion, the second concave portion, and the third concave portion do not overlap with the light emitting element, and the first contact hole and the second contact hole are respectively interposed through the interlayer insulating film. And a light emitting device arranged to overlap with the third contact hole. In claim 1,
The depths of the first recess, the second recess, and the third recess are 25 to 200 μm,
The light emitting device, wherein the first metal film, the second metal film, and the third metal film are made of W, Ta, Ag, Ti, Al, Cu, or Pd alone or an alloy. A pixel portion having a first TFT and a second TFT formed on a substrate, and a drive circuit portion having a third TFT formed on the substrate;
A first recess, a second recess, and a third recess provided in the substrate in the region where the pixel portion is formed, and a fourth provided in the substrate in the region where the drive circuit portion is formed. A recess of
A first metal film having a recess shape formed along the shapes of the first recess, the second recess, the third recess, and the fourth recess, respectively, and having a recess shape. A second metal film, a third metal film having a concave shape, and a fourth metal film having a concave shape ;
A base film formed by a coating method so as to fill the recesses of the first metal film, the recesses of the second metal film , the recesses of the third metal film, and the recesses of the fourth metal film; ,
The first TFT, the second TFT, and the third TFT formed on the base film;
An interlayer insulating film formed on the first TFT, the second TFT, and the third TFT;
A first contact hole formed in the interlayer insulating film and formed in the region of the first TFT, a second contact hole and a third contact hole formed in the region of the second TFT, and the A fourth contact hole formed in the region of the third TFT;
A light emitting element electrically connected to the first TFT through the first contact hole;
The light-emitting element has an anode, a cathode, and an organic layer sandwiched between the anode and the cathode,
The first concave portion, the second concave portion, the third concave portion, and the fourth concave portion do not overlap with the light emitting element, and the first contact hole, respectively, through the interlayer insulating film, A light emitting device, wherein the light emitting device is disposed so as to overlap the second contact hole, the third contact hole, and the fourth contact hole. A pixel portion having a first TFT and a second TFT formed on a substrate; a drive circuit portion having a third TFT formed on the substrate; and an external input terminal portion.
A first recess, a second recess, and a third recess provided in the substrate in the region where the pixel portion is formed, and a fourth provided in the substrate in the region where the drive circuit portion is formed. And a fifth recess provided in the substrate in the region where the external input terminal portion is formed,
A first metal film having a recess shape formed along the shapes of the first recess, the second recess, the third recess, the fourth recess, and the fifth recess, respectively. A second metal film having a concave shape, a third metal film having a concave shape, a fourth metal film having a concave shape, and a fifth metal film having a concave shape,
So as to fill the recesses of the first metal film, the recesses of the second metal film, the recesses of the third metal film, the recesses of the fourth metal film, and the recesses of the fifth metal film. A base film formed by a coating method;
The first TFT, the second TFT, and the third TFT formed on the base film;
An interlayer insulating film formed on the first TFT, the second TFT, and the third TFT;
A first contact hole formed in the interlayer insulating film and formed in the region of the first TFT, a second contact hole and a third contact hole formed in the region of the second TFT, and the A fourth contact hole formed in the region of the third TFT, and a fifth contact hole formed in the region of the external input terminal portion;
Electrically connected to an external terminal using a wiring formed in the fifth contact hole;
A light emitting element electrically connected to the first TFT through the first contact hole;
The light-emitting element has an anode, a cathode, and an organic layer sandwiched between the anode and the cathode,
The first concave portion, the second concave portion, the third concave portion, the fourth concave portion, and the fifth concave portion do not overlap with the light emitting element and are respectively interposed through the interlayer insulating film. A light emitting device, wherein the light emitting device is disposed to overlap the first contact hole, the second contact hole, the third contact hole, the fourth contact hole, and the fifth contact hole. In claim 4,
A light-emitting device, wherein a transparent conductive film is provided in contact with a wiring formed in the fifth contact hole. In any one of Claims 1 thru | or 5,
A first insulating film formed on the interlayer insulating film;
A second insulating film formed on the first insulating film, and the organic layer,
The second insulating film has an opening so as to separate the adjacent organic layers,
The opening widens toward the organic layer such that the second insulating film and the organic layer are separated from each other on the first insulating film,
The cathode includes an upper surface of the second insulating film and a slope of the opening, a region where the second insulating film on the first insulating film is separated from the organic layer, and an upper surface of the organic layer . And is surrounded by a slope of the opening , a region where the second insulating film on the first insulating film is separated from the organic layer, and an end of the organic layer A light emitting device having a shape of a convex portion. In claim 6,
An end portion of the organic layer has a thickness.

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