JP2009069735A - Display, and manufacturing method for display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display and a manufacturing method for the display, capable of enhancing productivity. <P>SOLUTION: This display is provided with a transistor formed on a substrate 11, an insulating film 13 formed on the substrate 11, and an organic flattened film 14 formed on an upper face of the insulating film 13 and on an upper face of the transistor. The organic flattened film 14 is constituted of an organic insulating material capable of patterning the insulating film 13, using the organic flattened film 14 as a mask. A contact hole 13a is thereby formed in the insulating film 13, using the organic flattened film 14 formed with a contact hole 14a as a mask, and the number of the masks used for the patterning is reduced by this manner. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a display device and a method for manufacturing the display device.

  In recent years, a display device using an organic electroluminescence element (organic EL element) has attracted attention as a display device of an electronic apparatus. An organic EL element has a laminated structure in which an anode electrode, an organic EL layer, and a cathode electrode are laminated in this order on a substrate. When a voltage is applied between the anode electrode and the cathode electrode, holes are formed in the organic EL layer. Then, electrons are injected and electroluminescence occurs in the organic EL layer.

  A display device using such an organic EL element includes a display panel in which organic EL elements are two-dimensionally arranged. For example, one or a plurality of thin film transistors are provided per pixel, and the organic EL elements are caused to emit light by the thin film transistors.

For example, in the organic EL display device of Patent Document 1, two thin film transistors are provided for each pixel. In manufacturing such an organic EL display, a transistor array substrate in which a thin film transistor is patterned for each pixel is manufactured, and then an organic EL element is patterned on the surface of the transistor array substrate for each pixel.
JP-A-8-330600

  By the way, in the manufacturing method of the organic EL display device disclosed in Patent Document 1, for example, a predetermined mask is used in a formation process of a thin film transistor (gate insulating film, gate electrode, drain-source electrode, etc.), an interlayer insulating film, a transparent electrode, and the like. It is necessary to use and pattern. Further, when the wet method is used for forming the organic EL layer, it is necessary to perform patterning using a mask in the step of forming the partition walls that partition the organic EL layer.

  Thus, when the process of patterning using a mask increases, there exists a problem that the manufacturing process of an organic electroluminescent display apparatus will become long and productivity will worsen. Therefore, there is a demand for a display device and a method for manufacturing the display device that can reduce the number of masks used for patterning and improve productivity.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a display device and a method for manufacturing the display device that can improve productivity.
It is another object of the present invention to provide a display device and a display device manufacturing method that can reduce the number of masks used for patterning.

In order to achieve the above object, a display device according to the first aspect of the present invention provides:
A display device comprising a light emitting element and a drive circuit for driving the light emitting element,
A transistor of the drive circuit formed on a substrate;
An insulating film formed on the substrate;
An interlayer insulating film formed on the upper surface of the insulating film and the upper surface of the transistor;
With
The interlayer insulating film includes an organic insulating material capable of patterning the insulating film using the interlayer insulating film as a mask.

The interlayer insulating film includes, for example, a photosensitive organic insulating material.
The interlayer insulating film includes, for example, an organic insulating material capable of forming a contact hole in the insulating film using the interlayer insulating film as a mask.

  A capacitor electrode of the driving circuit, a gate electrode of the transistor, and a data line for applying a gradation signal to the driving circuit are formed on the substrate, and the capacitor electrode includes the gate electrode and the data line. It is preferable that it is comprised from the same material.

The light emitting layer of the light emitting element is formed by a wet method, for example.
The light emitting element is, for example, an organic electroluminescence element.

A manufacturing method of a display device according to the second aspect of the present invention is as follows.
A method of manufacturing a display device including a light emitting element and a drive circuit for driving the light emitting element,
Transistor formation for forming a gate electrode of a transistor of the driving circuit, an insulating film functioning as a gate insulating film, a source and drain electrodes of the transistor of the driving circuit, and a wiring connected to the driving circuit on a substrate Process,
An interlayer insulating film forming step of forming an interlayer insulating film on the upper surface of the insulating film and the upper surface of the transistor;
An interlayer insulating film patterning step of patterning the interlayer insulating film formed in the interlayer insulating film forming step using a mask;
An insulating film patterning step of patterning the insulating film using the interlayer insulating film patterned in the interlayer insulating film patterning step as a mask;
It is characterized by comprising.

In the interlayer insulating film forming step, for example, the interlayer insulating film is formed of a photosensitive organic insulating material.
In the insulating film patterning step, for example, contact holes are formed in the insulating film.

  In the transistor forming step, for example, a metal film is formed on the substrate, and the metal film is patterned using a patterning mask, whereby the gate electrode, the capacitor electrode of the driver circuit, and the driver circuit are stepped. And a gate electrode forming step of forming a data line to which the adjustment signal is applied.

A light emitting layer forming step of forming a light emitting layer of the light emitting element is further provided, and in the light emitting layer forming step, the light emitting layer is formed by, for example, a wet method.
After the insulating film patterning step, there is further provided a connection wiring forming step of forming a connection wiring for connecting the wiring and the transistor through a contact hole of the interlayer insulating film formed by the insulating film patterning step. Good.
An organic electroluminescence element is preferably used for the light emitting element.

  According to the present invention, productivity can be improved.

  Hereinafter, a display device and a method for manufacturing the display device of the present invention will be described with reference to the drawings. In the present embodiment, the present invention will be described using a display device including a plurality of display pixels each having an organic EL (Electro Luminescence) element as an example.

(First embodiment)
FIG. 1 is a diagram illustrating an example of a pixel array of the display device 1 in the present embodiment. As shown in FIG. 1, the display device 1 includes a display panel in which pixels (organic EL elements) 2 are two-dimensionally arranged. As shown in FIG. 1, the display panel has a pixel set of three colors of red (R), green (G), and blue (B), and this set is repeated in the row direction (left-right direction in FIG. 1). A plurality of pixels of the same color are arranged in the column direction (vertical direction in FIG. 1).

  The display device 1 also includes an anode line La, a data line Ld, and a select line Ls connected to the pixel (organic EL element) 2. The anode line La is formed so as to extend in the row direction. The data line Ld is formed so as to extend in the column direction. The select line Ls is formed to extend in the row direction.

  FIG. 2 is an equivalent circuit diagram illustrating an example of a circuit configuration of the pixel 2 of the display device 1. As shown in FIG. 2, the display device 1 has a circuit configuration including a pixel driving circuit Dc having a TFT (Thin Film Transistor) and the like, and an organic EL element OEL that emits light by a current controlled by the pixel driving circuit Dc. Have. That is, the display device 1 of this embodiment is an active drive type display device in which TFTs are arranged in each pixel to drive each organic EL element.

  As shown in FIG. 2, the pixel drive circuit Dc includes a transistor (selection transistor) Tr11, a transistor (light emission drive transistor) Tr12, a capacitor Cs, and an organic EL element OEL.

  The selection transistor Tr11 has a gate terminal connected to the select line Ls, a drain terminal connected to the data line Ld arranged in the column direction of the display panel, and a source terminal connected to the contact N11. The light emission driving transistor Tr12 has a gate terminal connected to the contact N11, a drain terminal connected to the supply voltage line La, and a source terminal connected to the contact N12. The capacitor Cs is connected to the gate terminal and the source terminal of the transistor Tr12. The capacitor Cs is an auxiliary capacitance additionally provided between the gate and the source of the transistor Tr12, or a capacitance component composed of these parasitic capacitance and auxiliary capacitance. The organic EL element has an anode terminal (anode electrode) connected to the contact N12 and a cathode terminal (cathode electrode) connected to a predetermined low potential power source (reference voltage Vss, for example, ground potential GND).

  As the transistors Tr11 and Tr12, n-channel thin film transistors (field effect transistors) are used, but p channel field effect transistors may be used. In this case, the source terminal and the drain terminal are illustrated. 2 is connected in reverse.

  The select line Ls is connected to a select driver (not shown), and a selection voltage (select signal) Ssel for setting a plurality of pixels (organic EL elements) arranged in the row direction of the display panel to a selected state at a predetermined timing. Is applied. The data line Ld is connected to a data driver (not shown), and a data voltage (grayscale signal) Vpix corresponding to display data is applied at a timing synchronized with the selection state of the organic EL element (pixel).

  In addition, the anode line (supply voltage line) La is connected directly or indirectly to a predetermined high potential power source, for example, and applies a light emission driving current corresponding to display data to a pixel electrode (for example, an anode electrode) of the organic EL element. Shed. Therefore, a predetermined high potential (supply voltage Vdd) having a potential higher than the reference voltage Vss applied to the counter electrode (cathode electrode) of the organic EL element is applied to the anode line La.

  That is, in each pixel, the supply voltage Vdd and the reference voltage Vss are applied to both ends (the drain terminal of the transistor Tr12 and the cathode terminal of the organic EL element) of the pair of the transistor Tr12 and the organic EL element connected in series. A forward bias is applied to the EL element so that the organic EL element can emit light, and the current value of the light emission drive current that flows according to the gradation signal Vpix is controlled by the pixel drive circuit.

  Next, display pixels of the display device 1 will be described. FIG. 3 is a plan layout diagram illustrating an example of the display pixel. 4A is a cross-sectional view taken along line AA shown in FIG. 3, and FIG. 4B is a cross-sectional view taken along line BB shown in FIG. Note that the display device 1 of the present embodiment is a so-called bottom emission type in which light is extracted from the substrate side.

  The board | substrate 11 is comprised from the material provided with translucency, for example, a glass substrate. On the substrate 11, gate electrodes Tr11g and Tr12g, a data line Ld, a transparent Cs electrode 12, and an insulating film 13 are formed.

  The gate electrodes Tr11g, Tr12g and the data line Ld have, for example, an aluminum-titanium (AlTi) / Cr two-layer structure, an AlNdTi / Cr two-layer structure, or a Cr single-layer structure. The gate electrodes Tr11g and Tr12g and the data line Ld are simultaneously formed by, for example, forming a gate metal layer on the substrate 11 and patterning the gate metal layer.

  The transparent Cs electrode 12 is made of a conductive material having translucency, for example, ITO (Indium Tin Oxide), ZnO or the like. The transparent Cs electrode 12 is connected to the gate electrode Tr12g.

  The insulating film 13 is made of an insulating material such as a silicon oxide film or a silicon nitride film. The insulating film 13 is formed on the substrate 11 so as to cover the gate electrodes Tr11g and Tr12g, the data line Ld, and the transparent Cs electrode 12. The insulating film 13 functions as a gate insulating film for the transistors Tr11 and Tr12 in the region where the gate electrodes Tr11g and Tr12g are formed, and also serves as an auxiliary capacitor between the transparent Cs electrode 12 and a pixel electrode 15 described later. Function as.

  A contact hole 13 a is formed on the data line Ld of the insulating film 13. The contact hole 13a is formed by patterning the insulating film 13 using an organic planarizing film 14 described later as a mask.

  On the substrate 11, transistors Tr11 and Tr12 are formed. The transistors Tr11 and Tr12 are n-channel amorphous silicon thin film transistors (TFTs). The transistor Tr11 includes a gate electrode Tr11g, a source electrode Tr11s, a drain electrode Tr11d, a semiconductor layer SMC, a protective film BL, and an ohmic contact layer OHM. Similar to the transistor Tr11, the transistor Tr12 also includes a gate electrode Tr12g, a source electrode Tr12s, a drain electrode Tr12d, a semiconductor layer, a protective film BL, and an ohmic contact layer.

  The gate electrodes Tr11g and Tr12g of the transistors Tr11 and Tr12 have, for example, an aluminum-titanium (AlTi) / Cr two-layer structure, an AlNdTi / Cr two-layer structure, or a Cr single-layer structure.

  The source electrodes Tr11s and Tr12s and the drain electrodes Tr11d and Tr12d each have, for example, an aluminum-titanium (AlTi) / Cr two-layer structure, an AlNdTi / Cr two-layer structure, or a Cr single-layer structure. The source electrodes Tr11s and Tr12s and the drain electrodes Tr11d and Tr12d are formed in regions corresponding to the gate electrodes Tr11g and Tr12g. The source electrodes Tr11s and Tr12s and the drain electrodes Tr11d and Tr12d are formed so as to extend to both ends of the semiconductor layer SMC. In the present embodiment, the drain electrode Tr11d is connected to the data line Ld via a connection wiring 16 described later.

  The semiconductor layer SMC is formed in a region corresponding to the gate electrodes Tr11g and Tr12g, similarly to the source electrodes Tr11s and Tr12s and the drain electrodes Tr11d and Tr12d. The semiconductor layer SMC is made of amorphous silicon or the like. The semiconductor layer SMC is formed with a source region and a drain region (not shown). When a predetermined voltage is applied to the gate electrodes Tr11g and Tr12g, the semiconductor layer SMC has a region facing the gate electrodes Tr11g and Tr12g. A channel is formed.

  The protective film BL is formed on the semiconductor layer SMC where the source and drain electrodes of the transistors Tr11 and Tr12 are opposed to each other. The protective film BL is for preventing etching damage during patterning of the semiconductor layer SMC, and is made of, for example, silicon oxide, silicon nitride, or the like.

  The ohmic contact layer OHM is formed between the source electrodes Tr11s and Tr12s, the drain electrodes Tr11d and Tr12d, and the semiconductor layer SMC, and has low resistance contact therebetween, and has amorphous silicon containing n-type impurities. .

  On the insulating film 13, an anode line La and a select line Ls are formed. The anode line La and the select line Ls are in the same layer as the source electrodes Tr11s and Tr12s and the drain electrodes Tr11d and Tr12d. For example, these are formed simultaneously. Therefore, the anode line La and the select line Ls are, for example, a two-layer structure of aluminum-titanium (AlTi) / Cr, AlNdTi / Cr, like the source electrodes Tr11s and Tr12s and the drain electrodes Tr11d and Tr12d. It has a two-layer structure or a single-layer structure of Cr.

  An organic planarization film 14 is formed on the transistor Tr11, the anode line La, and the select line Ls. The organic planarizing film 14 functions as an interlayer insulating film having a flat surface. Further, the organic planarization film 14 functions as a mask when forming the contact hole 13a of the insulating film 13, and thus is formed of an organic insulating material that can be used as a mask. Examples of the organic planarizing film layer 14 include polyacrylic resin, epoxy resin, phenolic resin, polyamide resin, polyimide resin, unsaturated polyester resin, polyphenylene ether resin, polyphenylene sulfide resin, and benzocyclo. There are butenes.

  Further, as will be described later, the contact hole 13a can be formed in the lower insulating film 13 without forming a new photoresist mask with the patterned organic planarizing film layer 14, so that the organic planarizing film layer 14 can be formed. 14 is preferably a photosensitive organic insulating material that can be patterned without using a photoresist mask.

  A contact hole 14 a communicating with the contact hole 13 a of the insulating film 13 is formed in the organic planarization film 14. Further, a contact hole 14b is formed on the source electrode Tr11s of the organic planarizing film 14.

  A pixel electrode (anode electrode) 15 is formed on the organic planarization film 14 formed in the pixel formation region (pixel region: Rpx). The pixel electrode 15 is made of a conductive material having translucency, for example, ITO (Indium Tin Oxide), ZnO, or the like. The pixel electrode 15 is subjected to a surface treatment so as to be lyophilic with respect to the organic compound-containing liquid applied to the pixel region.

  A connection wiring 16 is formed on the organic planarization film 14. The connection wiring 16 is also formed in the contact hole 13a of the insulating film 13, the contact hole 14a of the organic planarization film 14, and the contact hole 14b, and connects the data line Ld and the source electrode Tr11s. The connection wiring 16 is formed at the same time as the pixel electrode 15 by patterning a conductive layer formed on the organic planarization film 14, for example, and has a transparent conductive material such as ITO in the case of the bottom emission type. Further, the connection wiring 22 that connects the select line Ls and the gate electrode Tr11g via the contact holes 32 and 32, and the connection wiring 23 that connects the source electrode Tr11s and the gate electrode Tr12g via the contact holes 33 and 33, respectively. It is formed by patterning a conductive layer formed on the organic planarizing film 14 together with the connection wiring 16.

  A partition wall (bank) 17 is formed on the organic planarization film 14. The bank 17 is made of resin, for example, photosensitive polyimide. As shown in FIGS. 3 and 4, the bank 17 is formed in a stripe shape so that the cross-sectional shape is square and the planar shape is square, and extends in the column direction (vertical direction shown in FIG. 3).

  In addition, when forming an organic EL layer into a film using a wet system, it is preferable that the surface of the bank 17 is subjected to a liquid repellent treatment. When the solution containing an organic compound that becomes the organic EL layer contacts the bank 17, it has a property of sucking up to the side surface of the bank 17 by a meniscus action. However, by applying a liquid repellent treatment to the surface of the bank 17, In addition to being able to suppress sucking up and preventing these solutions from mixing into adjacent pixels, the organic EL layer formed in the pixel is formed relatively uniformly without significantly increasing the film thickness on the side surface. can do.

  An organic EL layer 18 is formed on the pixel electrode 15. The organic EL layer 18 includes, for example, a hole injection layer 18a and a light emitting layer 18b.

  The hole injection layer 18a is formed on the pixel electrode 15 serving as an anode electrode. The hole injection layer 18a supplies holes to the light emitting layer 18b. The hole injection layer 18a is made of an organic polymer material that can inject and transport holes. The hole injection layer 18a is preferably made of a material having a low injection barrier from the pixel electrode 15 and high hole mobility. In this embodiment, the organic compound-containing liquid containing an organic polymer-based hole injection / transport material is used. As described above, a PEDOT / PSS aqueous solution that is a dispersion in which polyethylenedioxythiophene (PEDOT) as a conductive polymer and polystyrene sulfonic acid (PSS) as a dopant are dispersed in an aqueous solvent is used. The hole injection layer 18a is formed by applying and evaporating this aqueous solution of PEDOT / PSS by a wet method.

  The light emitting layer 18b is formed on the hole injection layer 18a. The light emitting layer 18 b has a function of generating light by applying a predetermined voltage between the pixel electrode 15 and the counter electrode 19. The light emitting layer 18b is made of a known polymer light emitting material capable of emitting fluorescence or phosphorescence, for example, a light emitting material containing a conjugated double bond polymer such as polyparaphenylene vinylene or polyfluorene. These luminescent materials are appropriately solutions (dispersions) dissolved (or dispersed) in an aqueous solvent or an organic solvent such as tetralin, tetramethylbenzene, mesitylene, and xylene. The light emitting layer 18b is formed by applying this solution (dispersion) by a wet method and volatilizing the solvent.

  A counter electrode (cathode electrode) 19 is provided on the light emitting layer 18 b and the bank 17. The counter electrode 19 is made of a material having a light reflection characteristic, for example, a thin film having a low work function such as magnesium, calcium, barium, lithium, or indium having a thickness of 1 to 10 nm, and aluminum, chromium, or the like having a thickness of 100 nm or more. A high work function thin film made of silver, a palladium-silver alloy, or the like is used. In the present embodiment, the counter electrode 19 is composed of an electrode layer formed on the entire surface of the substrate 11 and is connected to GND.

  A protective layer (sealing layer) for protecting the counter electrode 19 and the like are formed on the counter electrode 19.

  In the display device 1 (organic EL element) configured as described above, light corresponding to the amount of current flowing through the light emitting layer 18b is generated by applying a predetermined voltage between the pixel electrode 15 and the counter electrode 19. . Then, the generated light is extracted from the pixel electrode 15 side directly or indirectly from the pixel electrode 15 side.

  Next, a method for manufacturing the display device 1 of the present embodiment will be described with reference to FIGS.

  First, a substrate 11 made of a glass substrate is prepared. Next, a metal film (gate metal layer) is formed on the substrate 11 by sputtering, vacuum deposition, or the like. Subsequently, a photoresist solution is applied and prebaked, and then exposed using a first patterning mask (not shown) to form a photoresist mask PR1. The photoresist mask PR1 may be a negative type or a positive type. Then, by patterning the metal film using the photoresist mask PR1, the gate electrodes Tr11g and Tr12g and the data line Ld are formed on the substrate 11 as shown in FIG.

  Next, a transparent electrode material such as ITO is formed on the gate electrodes Tr11g, Tr12g, and the data line Ld by sputtering or the like. Subsequently, a photoresist solution is applied and prebaked, and then exposed using a second patterning mask (not shown) to form a photoresist mask PR2. The photoresist mask PR2 may be negative or positive. Then, by patterning the transparent electrode material using the photoresist mask PR2, as shown in FIG. 5B, the transparent Cs electrode 12 is formed on the substrate 11 and the gate electrode Tr12g.

  Next, an insulating film 13 is formed on the entire surface of the substrate 11 by a CVD (Chemical Vapor Deposition) method or the like. Subsequently, a semiconductor layer 21 made of amorphous silicon or the like is formed on the insulating film 13, and a protective film layer made of silicon oxide or the like is further formed by a CVD method or the like. Next, a photoresist solution is applied and prebaked, and then exposed using a third patterning mask (not shown) to form a photoresist mask PR3. The photoresist mask PR3 may be a negative type or a positive type. Then, by patterning the protective film layer using the photoresist mask PR3, a protective film BL is formed as shown in FIG.

  Next, an impurity layer for forming an ohmic connection with the semiconductor layer SMC is formed on the semiconductor layer 21 and the protective film BL by a sputtering method, a vacuum evaporation method, or the like. Subsequently, a metal layer is formed on the impurity layer by sputtering, vacuum deposition, or the like. Next, a photoresist solution is applied and prebaked, and then exposed using a fourth patterning mask (not shown) to form a photoresist mask PR4. The photoresist mask PR4 may be a negative type or a positive type. Then, by patterning the metal layer using the photoresist mask PR4, source electrodes Tr11s and Tr12s, drain electrodes Tr11d and Tr12d, an anode line La, and a select line Ls are formed. Further, by patterning using the source electrodes Tr11s and Tr12s and the drain electrodes Tr11d and Tr12d as a mask, an ohmic contact layer OHM and a semiconductor layer SMC are formed as shown in FIG.

Next, a photosensitive organic insulating material is applied to the entire surface of the substrate 11 and then pre-baked. Subsequently, after aligning a fifth photo patterning mask having a shape corresponding to the contact holes 14a and 14b on the organic insulating material, the organic insulating material is exposed by an exposure apparatus. Thereafter, the organic flattening film 14 having the contact holes 14a and 14b is formed by developing and baking. At this time, together with the contact holes 14a and 14b, a contact hole 31 for connecting the pixel electrode 15 and the source electrode Tr12s, a contact hole 32 for connecting the select line Ls and the gate electrode Tr11g, and the source electrode Tr11s and the gate electrode A contact hole 33 for connecting Tr12g is formed in the organic planarization film. Next, plasma etching is performed in an oxygen and SF ₆ atmosphere using the organic flattening film 14 as a mask, and the insulating film 13 is patterned, whereby the insulating film exposed by the contact hole 14a is exposed as shown in FIG. 13 is etched to form a contact hole 13 a in the insulating film 13.

Here, since the organic planarizing film 14 is formed of an organic insulating material that serves as a mask when forming the contact hole 13a of the insulating film 13, it is not etched by plasma in an oxygen and SF ₆ atmosphere. Therefore, the contact hole 13a of the insulating film 13 can be formed using the organic planarizing film 14 as a mask. Therefore, it is not necessary to prepare a photo patterning mask for forming the contact hole 13a of the insulating film 13, and the number of masks used for patterning can be reduced. Therefore, the productivity of the display device 1 can be improved.

  Next, a transparent electrode material such as ITO is formed on the organic planarization film 14 and in the contact holes 13a, 14a, and 14b by sputtering or the like. Subsequently, a photoresist solution is applied and prebaked, and then exposed using a sixth patterning mask (not shown) to form a photoresist mask PR5. The photoresist mask PR5 may be negative or positive. Then, by patterning the transparent electrode material using the photoresist mask PR5, as shown in FIG. 6A, the pixel electrode 15, the connection wiring 16 that connects the data line Ld and the source electrode Tr11s, the contact hole 32, A connection wiring 22 that connects the select line Ls and the gate electrode Tr11g via 32 and a connection wiring 23 that connects the source electrode Tr11s and the gate electrode Tr12g via contact holes 33 and 33 are formed. Note that a capacitor Cs shown in FIG. 2 is a capacitor using the insulating film 13 and the organic planarizing film 14 between the pixel electrode 15 and the transparent Cs electrode 12 as dielectrics. The pixel electrode 15 is electrically connected to the source electrode Tr12s by being partially embedded in the contact hole 31 formed in the organic planarization film 14 by the fifth photo patterning mask.

  Next, for example, a photosensitive polyimide organic resin material is applied to the entire surface of the substrate 11. Subsequently, after aligning a seventh photo patterning mask for exposing the pixel electrode 15 on the organic resin material, the organic resin material is exposed by an exposure apparatus. Thereafter, development and baking are performed to form a bank 17 having an opening 17a exposing the pixel electrode 15, as shown in FIG. 6B. As a result, the pixel formation regions of the plurality of display pixels PIX of the same color arranged in the column direction of the display panel are defined by being surrounded by the bank 17, and the upper surface of the pixel electrode 15 is exposed in the region.

  Next, after cleaning the substrate 11, for example, by performing oxygen plasma treatment, UV ozone treatment, or the like, the surface of the pixel electrode 15 (pixel electrode) in each pixel region Rpx defined in the bank 17 is an organic EL layer described later. The hole injection material 18a used in the forming step 18 is made lyophilic.

  Next, a PEDOT / PSS aqueous solution in which a hole injection material (PEDOT as a conductive polymer and PSS as a dopant) is dispersed is applied onto the pixel electrode 15 by a wet method. After the application of the PEDOT / PSS aqueous solution, for example, the hole injection layer 18 a is formed on the pixel electrode 15 by performing drying at a temperature of 100 ° C. or higher on a hot plate. In this embodiment, since the pixel electrode 15 is lyophilic, the applied PEDOT ink spreads sufficiently. For this reason, the film thickness of the formed hole injection layer 18a can be made uniform.

  Subsequently, a solution obtained by dissolving red, green, and blue light emitting materials (polyfluorene-based) in an organic solvent such as tetralin, tetramethylbenzene, and mesitylene is formed on the hole injection layer 18a by a wet method. After the light emitting material is formed, the residual solvent is removed by drying with a hot plate in a nitrogen atmosphere or drying with a sheathed heater in a vacuum. Thereby, as shown in FIG.6 (c), the light emitting layer 18b is formed on the positive hole injection layer 18a.

  Here, since the pixel formation region Rpx is defined by the bank 17, the light emitting material is not mixed between the adjacent display pixels PIX (color pixels PXr, PXg, PXb), and the color mixture between the adjacent color pixels is not performed. Can be prevented.

  Next, the counter electrode 19 such as Ca, Ba or the like is formed on the entire surface of the substrate 11 on which the light emitting layer 18a is formed by vacuum deposition, sputtering, or the like. Then, the display device 1 is completed by forming a sealing layer and bonding a sealing lid and a sealing substrate.

  As described above, according to the present embodiment, since the contact hole 13a of the insulating film 13 is formed using the organic planarization film 14 as a mask, it is necessary to prepare a photo patterning mask for forming the contact hole 13a. Therefore, the number of masks used for patterning can be reduced. For this reason, the productivity of the display device 1 can be improved.

  In addition, according to the present embodiment, since a photosensitive organic insulating material is used for the organic planarizing film layer 14, a photomask having a shape corresponding to the contact holes 14a and 14b is formed using an exposure apparatus. Can do.

  Furthermore, according to this embodiment, since the surface of the pixel electrode 15 is made lyophilic with respect to the hole injection material 18a, the applied solution is sufficiently spread. For this reason, the film thickness of the formed hole injection layer 18a can be made uniform.

(Second Embodiment)
In the first embodiment, the present invention has been described by taking as an example the case where the transparent Cs electrode 12 is formed after the gate metal is patterned to form the gate electrodes Tr11g, Tr12g and the data line Ld. In the present embodiment, the present invention will be described taking as an example the case where the gate electrodes Tr11g, Tr12g, the data line Ld, and the Cs electrode 112 are formed by patterning the gate metal. In the present embodiment, the same members as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  FIG. 7 is a plan layout diagram illustrating an example of the display pixel of the present embodiment. 8A is a cross-sectional view taken along the line CC shown in FIG. 7, and FIG. 8B is a cross-sectional view taken along the line DD shown in FIG.

  As shown in FIGS. 7 and 8, gate electrodes Tr <b> 11 g and Tr <b> 12 g, a data line Ld, a Cs electrode 112, and an insulating film 13 are formed on the substrate 11.

  Unlike the first embodiment, the Cs electrode 112 is made of aluminum-neodymium-titanium (AlNdTi) or chromium (Cr). That is, unlike the material of the transparent Cs electrode 12 of the first embodiment, the Cs electrode 112 of the present embodiment is made of the same material as the gate electrodes Tr11g, Tr12g and the data line Ld. In the present embodiment, the shapes of the gate electrode Tr12g and the Cs electrode 112 are changed. Therefore, in this embodiment, the Cs electrode 112, the gate electrodes Tr11g and Tr12g, and the data line Ld can be formed at the same time.

  Next, a method for manufacturing the display device 1 of the present embodiment will be described with reference to FIG.

  First, a substrate 11 made of a glass substrate is prepared. Next, a metal film (gate metal layer) is formed on the substrate 11 by sputtering, vacuum deposition, or the like. Subsequently, patterning is performed using a mask to form a gate electrode Tr11g (and Tr12g), a data line Ld, and an annular Cs electrode 112 on the substrate 11, as shown in FIG. 9A.

  As described above, in the present embodiment, the gate metal layer is formed on the substrate 11 and opened in the pixel region Rpx instead of the first patterning mask in the first embodiment, and around the pixel region Rpx. A photoresist mask PR11 is formed using a patterning mask that forms an annular Cs electrode 112 so as to surround it. By patterning the gate metal layer using the photoresist mask PR11, the Cs electrode 112, the gate electrodes Tr11g and Tr12g, and the data line Ld were formed at the same time. Therefore, unlike the first embodiment, it is not necessary to prepare a mask for forming the Cs electrode 112, and the number of masks used for patterning can be reduced. Therefore, the productivity of the display device 1 can be improved.

  Next, an insulating film 13 is formed on the entire surface of the substrate 11 by a CVD method or the like. Subsequently, a semiconductor layer 21 made of amorphous silicon or the like is formed on the insulating film 13, and a protective film layer made of silicon oxide or the like is further formed by a CVD method or the like. Next, by patterning using a mask, as shown in FIG. 9B, a protective film BL is formed.

  Subsequently, the source electrodes Tr11s and Tr12s, the drain electrodes Tr11d and Tr12d, the anode line La, the select line Ls, the ohmic contact layer OHM, the semiconductor layer SMC, and the organic planarization film are processed in the same procedure as the manufacturing method of the first embodiment. 14, contact holes 14 a and 14 b, contact holes 13 a, pixel electrodes 15, connection wirings 16, banks 17, hole injection layers 18 a, light emitting layers 18 b, counter electrodes 19, and the like are formed (FIGS. 5D to 6 ( c)), the display device 1 is completed.

  As described above, according to the present embodiment, it is not necessary to prepare a mask for forming the Cs electrode 112, the number of masks used for patterning can be reduced, and the time required for alignment of the patterning mask can be reduced. The cost for manufacturing the patterning mask can be reduced. Therefore, the productivity of the display device 1 can be improved.

  In addition, this invention is not restricted to said embodiment, A various deformation | transformation and application are possible. Hereinafter, other embodiments applicable to the present invention will be described.

  In the above embodiment, the present invention has been described by taking as an example the case where the organic planarizing film 14 is formed of a photosensitive organic insulating material. However, the organic planarizing film 14 is used when forming the contact hole 13 a of the insulating film 13. As long as it is formed from an organic insulating material capable of functioning as a mask, for example, it may not be a photosensitive material.

  In the above-described embodiment, the present invention has been described by taking the case where the surface of the pixel electrode 15 is lyophilic with respect to the solution of the hole injection material 18a to be used as an example.

  In the above embodiment, the present invention has been described by taking the case where the organic EL layer 18 is formed of the hole injection layer 18a and the light emitting layer 18b as an example. However, for example, between the hole injection layer 18a and the light emitting layer 18b, In addition, an interlayer layer having a function of blocking electrons moving in the light emitting layer 18b may be formed. In this case, there is an effect of increasing the recombination probability between electrons and holes in the light emitting layer 18b. This interlayer layer is preferably made of a material having a high hole mobility and an electron blocking function.

  Further, an electron transport layer may be provided on the light emitting layer 18b. In this case, it is possible to increase the efficiency of electron injection into the light emitting layer 18b and to have a hole blocking function. The electron transport layer is preferably made of an alkaline earth metal such as Mg, Ca, Ba, an oxide thereof, or an alloy with a metal.

  In the above-described embodiment, the present invention has been described by taking the case of using a wet-type bottom emission organic EL element as an example. However, for example, the organic EL layer 18 may be formed by an evaporation method. Further, a top emission type organic EL element may be used.

  In the above embodiment, the present invention has been described by taking the case where the pixel driving circuit Dc has two transistors (TFTs) as an example. However, for example, the pixel driving circuit Dc may have three TFTs. Moreover, it may have four or more TFTs.

  In the above embodiment, the present invention has been described by taking the case where the light emitting element is an organic EL element as an example. Absent.

It is a figure which shows an example of the pixel array of the display apparatus of the 1st Embodiment of this invention. It is an equivalent circuit diagram showing an example of a pixel circuit configuration of the display device. It is a plane layout figure which shows an example of a display pixel. (A) is the sectional view on the AA line shown in FIG. 3, (b) is the sectional view on the BB line shown in FIG. It is a figure for demonstrating the manufacturing method of a display apparatus. It is a figure for demonstrating the manufacturing method of a display apparatus. It is a plane layout figure which shows an example of the display pixel of the 2nd Embodiment of this invention. (A) is CC sectional view taken on the line shown in FIG. 7, (b) is DD sectional view taken on the line shown in FIG. It is a figure for demonstrating the manufacturing method of the display apparatus of 2nd Embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Display apparatus, 2 ... Pixel (organic EL element), 11 ... Substrate, 12 ... Transparent Cs electrode, 13 ... Insulating film 13, 13a ... Contact hole, 14 ... Organic flattening film, 14a, 14b ... contact hole, 15 ... pixel electrode, 16 ... connection wiring, 17 ... bank, 18 ... organic EL layer, 18a ... hole injection Layer 18b... Luminescent layer 19 counter electrode Ls select line La ... anode line Ld data line Tr11 Tr12 transistor Tr11g Tr12g. Gate electrode, Tr11s, Tr12s ... Source electrode, Tr11d, Tr12d ... Drain electrode, OHM ... Ohmic contact layer, SMC ... Semiconductor layer

Claims (12)

A display device comprising a light emitting element and a drive circuit for driving the light emitting element,
A transistor of the drive circuit formed on a substrate;
An insulating film formed on the substrate;
An interlayer insulating film formed on the upper surface of the insulating film and the upper surface of the transistor;
With
The display device, wherein the interlayer insulating film includes an organic insulating material capable of patterning the insulating film using the interlayer insulating film as a mask.   The display device according to claim 1, wherein the interlayer insulating film includes a photosensitive organic insulating material.   The display device according to claim 1, wherein the interlayer insulating film includes an organic insulating material capable of forming a contact hole in the insulating film using the interlayer insulating film as a mask. A capacitor electrode of the driving circuit, a gate electrode of the transistor, and a data line for applying a gradation signal to the driving circuit are formed on the substrate.
4. The display device according to claim 1, wherein the capacitor electrode is made of the same material as the gate electrode and the data line. 5.   The display device according to claim 1, wherein the light emitting layer of the light emitting element is formed by a wet method.   The display device according to claim 1, wherein the light emitting element is an organic electroluminescence element. A method of manufacturing a display device including a light emitting element and a drive circuit for driving the light emitting element,
Transistor formation for forming a gate electrode of the transistor of the driving circuit, an insulating film functioning as a gate insulating film, a source / drain electrode of the transistor of the driving circuit, and a wiring connected to the driving circuit on a substrate Process,
An interlayer insulating film forming step of forming an interlayer insulating film on the upper surface of the insulating film and the upper surface of the transistor;
An interlayer insulating film patterning step of patterning the interlayer insulating film formed in the interlayer insulating film forming step using a mask;
An insulating film patterning step of patterning the insulating film using the interlayer insulating film patterned in the interlayer insulating film patterning step as a mask;
A method for manufacturing a display device, comprising:   8. The method for manufacturing a display device according to claim 7, wherein in the interlayer insulating film forming step, an interlayer insulating film is formed of a photosensitive organic insulating material.   9. The method of manufacturing a display device according to claim 7, wherein a contact hole is formed in the insulating film in the insulating film patterning step.   In the transistor formation step, a metal film is formed on the substrate, and the metal film is patterned using a patterning mask, whereby a gradation signal is applied to the gate electrode, the capacitor electrode of the driver circuit, and the driver circuit. 10. The method of manufacturing a display device according to claim 7, further comprising a gate electrode forming step of forming a data line to which the voltage is applied. A light emitting layer forming step of forming a light emitting layer of the light emitting element;
The method for manufacturing a display device according to claim 7, wherein the light emitting layer is formed by a wet method in the light emitting layer forming step.   A connection wiring forming step of forming a connection wiring for connecting the wiring and the transistor through a contact hole of the interlayer insulating film formed by the insulating film patterning step after the insulating film patterning step; The method for manufacturing a display device according to claim 7, wherein:

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