JP2006195317A - Display device, its manufacturing method and electronic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display device which can avoid the reflecting in by the reflection of an external light entering from the side of a substrate without influencing light-emitting elements, drive elements, etc., when a bottom emission-type display device is adopted, and with which the increase in the number of manufacturing steps is suppressed, and to prevent its manufacturing method, and electronic equipment. <P>SOLUTION: The invented device is a display device which performs display by emitting light from luminous layers 54 through the substrate 10, and the display device is equipped with a wiring part 28 provided on the substrate 10; a first electrode 42 provided by being electrically connected to the wiring part 28; a luminous layer 54 provided on the first electrodes 42; a second electrode 56 provided on the luminous layer 54 by facing the first electrode 42; and a light-absorbing layer 26 provided downward of the wiring part 28 so as to be overlapped in planar manner, with at least a part of the wiring part 28. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a display device, a display device manufacturing method, and an electronic apparatus.

  In recent years, various electronic devices have been reduced in size and weight due to rapid progress in semiconductor technology. Along with this, there has been a rapid increase in demand for an electronic display device adapted to a new environment, that is, a thin display device that is thin and light, and has low drive voltage and low power consumption characteristics. As one of such thin display devices, an EL display device (also known as an LED display device) using an organic electroluminescence (EL) element has attracted attention. An organic EL element using electroluminescence has excellent characteristics such as high visibility due to self-emission and excellent impact resistance. The organic EL device has an active matrix type and a passive matrix type as driving methods. An active matrix organic EL device is a display device in which a thin film transistor, which is a switching element, is arranged in each pixel and the organic EL element corresponding to each pixel is driven independently.

The schematic configuration of the active matrix organic EL device will be briefly described below. The organic EL device employs a bottom emission type in which emitted light is emitted from the substrate side.
In an organic EL device, an insulating film made of silicon oxide is formed on a transparent substrate such as glass. On the insulating film, a thin film transistor (hereinafter referred to as TFT) composed of a polycrystalline silicon film, a gate insulating film, a gate electrode, an interlayer insulating film, and a source / drain electrode is formed. A protective film is formed on the entire surface of the transparent substrate including the TFT. An anode made of a transparent conductive film electrically connected to the drain electrode through a contact hole is formed on the protective film. An organic bank is formed on the protective film including the anode so as to partition the anode. A light emitting layer is formed in the partitioned organic bank, and a common electrode is formed on the light emitting layer. With such a structure, emitted light emitted from the light emitting layer is emitted from the substrate side.

  However, since the above-described conventional organic EL device employs a bottom emission structure, light generated in the light emitting layer passes through the transparent substrate on which the TFT below is formed and is emitted to the viewer side. The Accordingly, since the TFT is formed on the viewer side with respect to the light emitting layer that emits the emitted light, the external natural light incident on the display region is reflected by the TFT and the metal wiring that drives the TFT. Thereby, reflection appears in the display area, and the observer feels dazzling. Further, even when the TFT is off, that is, even when the light emitting layer of a certain pixel does not emit light, there is a problem that black cannot be displayed due to the presence of reflected light, and the contrast is lowered.

Therefore, in order to prevent reflection of external light on the TFT and the metal wiring that drives the TFT, an organic EL device in which a pattern made of a material that realizes low reflectance is formed in a region that does not overlap the display region has been proposed. (For example, refer to Patent Document 1).
Specifically, in the pattern, after depositing a metal oxide film made of an opaque insulating material on an insulating substrate such as glass, a metal film such as Cr having a high reflectance is deposited thereon. Subsequently, by patterning the metal film and the metal oxide film by a photolithography process, a low reflectance is formed in the non-display region on the insulating substrate. That is, a pattern made of a material that realizes low reflectance is formed on the lower side of the TFT and the metal wiring that drives the TFT.
As a result, by absorbing external natural light incident from the substrate side, it is possible to avoid reflection of natural light to the outside, avoiding glare to the user, and reflected light is generated even when the thin film transistor is in an off state. It can exist and embody black.
JP 2003-249370 A

However, in the invention disclosed in Patent Document 1, in order to pattern a pattern made of a material that realizes low reflectance into a predetermined shape, a photolithography processing step and an etching processing step in addition to a conventional manufacturing process of an organic EL device. Need more. Thereby, the manufacturing process of the organic EL device increased, and problems such as an increase in manufacturing cost and an increase in manufacturing time occurred.
Further, when the pattern having the low reflectance is formed in the non-display area, a step (unevenness) may be formed at the boundary between the non-display area and the display area. As a result, a step is also generated in the TFT (driving element) formed above the pattern having a low reflectivity, and in some cases, good electrical characteristics cannot be obtained due to disconnection or the like in the TFT. In addition, the step may cause a step in the light emitting element, and there is a problem that uneven light emission occurs during display.
Accordingly, the present invention has been made in view of the above problems, and when a bottom emission type display device is adopted, reflection by external light incident from the substrate side without affecting the light emitting element, the driving element, etc. It is an object of the present invention to provide a display device, a display device manufacturing method, and an electronic apparatus that can prevent the above-described process from occurring and suppress an increase in the number of manufacturing steps of the display device.

  In order to solve the above-described problems, the present invention provides a display device that performs display by emitting light from a light emitting layer through a substrate, and a wiring portion provided on the substrate, and an electrical connection to the wiring portion A first electrode connected to the first electrode; a light-emitting layer provided on the first electrode; a second electrode provided on the light-emitting layer so as to face the first electrode; and the wiring And a light absorption layer provided so as to overlap with at least a part of the wiring portion in a plane.

The light emitting device of the present invention employs a bottom emission structure that emits light emitted from the light emitting layer from the substrate side. According to the present invention, the light absorption layer is provided below the wiring portion so that at least a part of the wiring portion overlaps. Therefore, the external light incident from the substrate side is absorbed by the light absorption layer provided below the wiring portion. As a result, the external light is blocked or attenuated by the light absorption layer, and therefore does not reach the wiring portion or reaches the attenuated state. Therefore, reflection of external light from the wiring part (non-display area) can be avoided or attenuated, and reflection due to reflection of external light can be avoided. Here, in the bottom emission structure, a region including the first electrode, the light emitting layer, and the second electrode is a display region, and a region where the wiring portion is formed is a non-display region.
Further, the display device of the present invention can adopt either a passive matrix type or an active matrix type as a driving method. When the active matrix type is employed, a TFT that is a switching element is formed on a substrate, and a source electrode and a drain electrode that are wiring portions are formed above the TFT. When the active matrix type is adopted, according to the present invention, since the light absorption layer is formed above the TFT and below the wiring layer, the light absorption layer does not cause a step below the TFT, and the flat region A TFT, a light emitting layer, and the like can be formed. Here, when an active matrix type organic EL device is employed, the “wiring portion” means a signal line, a power supply line, a scanning line, a first relay conductive layer, a second relay conductive layer, and a source for driving TFT, which will be described later. It means a wiring layer such as an electrode and a drain electrode.

In the display device of the present invention, it is also preferable that the light absorption layer absorbs wavelengths in almost all wavelength bands of light incident from the substrate side.
According to this configuration, almost all of the external light incident from the substrate side can be absorbed. Thereby, reflection of external light from the wiring part (non-display area) can be avoided or attenuated, and reflection due to reflection of external light can be avoided.

In the display device according to the aspect of the invention, it is also preferable that the light absorption layer is provided on the lower layer of the wiring portion so as to overlap with the same pattern as the wiring portion.
According to this configuration, the light absorption layer is provided in the same pattern in the lower layer of the wiring portion. That is, the entire wiring portion is covered with the light absorption layer. Therefore, the external light incident from the substrate side is once blocked or attenuated by the light absorption layer. Therefore, reflection of external light from the wiring portion (non-display area) can be avoided or attenuated, and reflection due to reflection of external light can be avoided.

  In the display device of the present invention, it is also preferable that the light absorption layer is formed of any material including a resin added with a black pigment or a black dye, or a metal oxide or a metal nitride.

In the display device of the present invention, it is also preferable that the metal oxide contains any one of chromium oxide, iron oxide, and nickel oxide.
According to this configuration, the resin added with the black pigment or the black dye, or the metal oxide (chromium oxide, iron oxide, or nickel oxide) or the metal nitride can absorb external light incident from the substrate side. . That is, the resin added with the black pigment or the black dye, or the metal oxide or the metal nitride absorbs the wavelengths of all the wavelength bands of the external light. Furthermore, a metal oxide or a metal nitride has a high absorbability with a thin film. Therefore, reflection of external light from the wiring portion (non-display area) can be avoided or attenuated, and reflection due to reflection of external light can be avoided.

In the display device of the present invention, it is also preferable that the light absorption layer is provided by stacking the metal oxide or the nitride and a metal.
According to this configuration, canceling interference occurs with external light incident from the substrate side. Therefore, reflection of external light from the wiring portion (non-display area) can be avoided or attenuated, and reflection due to reflection of external light can be avoided.

  The display device manufacturing method of the present invention includes a step of forming an element on a substrate, a step of forming an insulating layer on the substrate so as to cover the element, and a light absorption layer on the insulating layer. Patterning the insulating layer and the light absorbing layer in a batch to form a through hole reaching the element in the insulating layer and the light absorbing layer, and the light including the inside of the through hole. The method includes a step of forming a wiring material on the absorption layer, and a step of forming a wiring portion by patterning the light absorption layer and the wiring material together.

  According to this method, since the insulating layer and the light absorption layer are patterned at once, the manufacturing process can be simplified, and the cost can be reduced.

The display device manufacturing method of the present invention includes a step of forming an element on a substrate, a step of forming a light absorption layer on the substrate so as to cover the element, and patterning the light absorption layer, Forming a through hole reaching the element in the light absorption layer, removing the light absorption layer in the display region, forming the wiring material on the light absorption layer including the inside of the through hole, and
Forming a wiring portion by patterning the light absorption layer and the wiring material at once.

  According to this method, since the light absorbing layer has an insulating function and a light absorbing function, it is not necessary to form the insulating layer and the light absorbing layer by separate steps, and the insulating function and the light absorbing function can be obtained in one step. A light absorption layer can also be formed. Therefore, a light absorption layer made of a low reflection material can be formed without increasing the number of steps, and the cost can be reduced.

According to another aspect of the present invention, there is provided an electronic apparatus including the display device.
According to the present invention, it is possible to realize an electronic apparatus including an organic EL device with less reflection.

  Embodiments of the present invention will be described below with reference to the drawings. In each drawing used for the following description, the scale of each member is appropriately changed to make each member a recognizable size.

[First Embodiment]
Next, the active matrix type organic EL device 1 of the present embodiment will be described with reference to FIGS. FIG. 1 is a plan view schematically showing the configuration of the organic EL device 1.
As shown in FIG. 1, the organic EL device 1 according to the present embodiment includes a substrate 10 having optical transparency and electrical insulation, and an anode connected to a switching TFT (not shown) in a matrix on the substrate 10. A display area (not shown) arranged in a shape, a power line arranged around the display area and connected to each anode, and at least a pixel portion 3 having a substantially rectangular shape in plan view located on the anode area ( In FIG. 2, it is comprised with the dashed-dotted line frame). In the present embodiment, the pixel unit 3 includes an actual display area 4 (within the two-dot chain line in the figure) in the center and a dummy area 5 (one-dot chain line and two-dot chain line) arranged around the actual display area 4. Between the two areas).

  In the actual display area 4, display areas R, G, and B each having an anode are regularly arranged along A-A '. Further, scanning line drive circuits 80 and 80 are arranged on both sides of the actual display area 4 in FIG. The scanning line driving circuits 80 and 80 are provided on the lower layer side of the dummy region 5.

  Further, an inspection circuit 90 is disposed above the actual display area 4 in FIG. 1, and this inspection circuit 90 is disposed on the lower layer side of the dummy area 5. This inspection circuit 90 is a circuit for inspecting the operating state of the organic EL device 1 and includes, for example, inspection information output means (not shown) for outputting the inspection result to the outside, and is displayed during manufacture or at the time of shipment. It is configured to be able to inspect the quality and defects of the apparatus.

Next, a cross-sectional structure of the organic EL device 1 will be described with reference to FIG. FIG. 2 is a cross-sectional view taken along the line AA ′ of the organic EL device 1 shown in FIG.
Since the substrate 10 shown in FIG. 2 employs a bottom emission type in this embodiment, a transparent substrate or a translucent substrate is used. Examples of the transparent substrate or translucent substrate include glass, quartz, and resin (plastic and plastic film). In particular, an inexpensive soda glass substrate is preferably used.

  On the substrate 10, a circuit unit 11 including a driving TFT for driving the anode 42 is formed. In FIG. 2, the detailed description of the circuit unit 11 is omitted. On the circuit portion 11, an anode 42 connected to each driving TFT is formed, and the lyophilic control layer 46 and the organic bank layer 48 are formed by partitioning the anode 42. An organic functional layer 54 is formed on the anode 42 partitioned by the organic bank layer 48. An adhesive layer 171 and a sealing substrate 170 are laminated on the entire surface including the organic functional layer 54 and the organic bank layer 48 so as to cover them. The adhesive layer 171 and the sealing substrate 170 form a sealing structure.

Next, the wiring structure of the organic EL device 1 will be described using an equivalent circuit. FIG. 3 is an equivalent circuit diagram showing a wiring structure of the organic EL device of this embodiment.
As shown in FIG. 3, the organic EL display device 1 of the present embodiment includes a plurality of scanning lines 101, a plurality of signal lines 102 extending in a direction intersecting with the scanning lines 101, and the signal lines 102 in parallel. A plurality of power supply lines 103 extending in a grid pattern are respectively wired. An area partitioned by the scanning line 101 and the signal line 102 is configured as a pixel area.
The signal line 102 is connected to a data side driving circuit 100 including a shift register, a level shifter, a video line, and an analog switch. Further, a scanning side driving circuit 80 including a shift register and a level shifter is connected to the scanning line 101.

  In each pixel region, a switching TFT 112 to which a scanning signal is supplied to the gate electrode via the scanning line 101, a holding capacitor 113 for holding a pixel signal supplied from the signal line 102 via the switching TFT 112, A driving TFT 123 in which a pixel signal held by the holding capacitor 113 is supplied to the gate electrode, and an anode 42 into which a driving current flows from the power supply line 103 when electrically connected to the power supply line 103 via the driving TFT 123. A cathode 56, and an organic functional layer 54 sandwiched between the anode 42 and the cathode 56. The anode 42, the cathode 56, and the organic functional layer 54 constitute a light emitting element 58, and the organic EL device 1 includes a plurality of the light emitting elements 58 in a matrix to form a light emitting display area.

  According to this configuration, when the scanning line 101 is driven and the switching TFT 112 is turned on, the potential of the signal line 102 at that time is held in the holding capacitor 113, and the driving TFT 123 of the driving TFT 123 depends on the state of the holding capacitor 113. The on / off state is determined. Then, a current flows from the power supply line 103 to the anode 42 via the channel of the driving TFT 123, and further a current flows to the cathode 56 via the organic functional layer 54. The organic functional layer 54 emits light with a luminance corresponding to the amount of current flowing therethrough.

Next, the planar structure of the light absorption layer 26 in the pixel region of the organic EL device 1 will be described. FIG. 4 schematically shows the planar structure of the pixel region in the organic EL device 1.
As shown in FIG. 4, the power supply line 103 and the signal line 102 are formed to extend in the vertical direction in the drawing in parallel. The scanning line 101 is formed so as to intersect the power supply line 103 and the signal line 102.
The semiconductor layer 15 (source side) of the switching TFT 112 formed in the intersecting region is connected to the signal line 102 through the contact hole 21, and the semiconductor layer 15 (drain side) is connected to the first through the contact hole 13. The relay conductive layer 23 is connected. Further, the semiconductor layer 25 (source side) of the driving TFT 123 is connected to the power supply line 103 through the contact hole 29, and the semiconductor layer 25 (drain side) is connected to the second relay conductive layer 37 through the contact hole 31. Has been. Further, the anode 42 is connected to the second relay conductive layer 37 through the contact hole 33. The first relay conductive layer 23 functions as a gate electrode of the driving TFT 123 at a portion where the semiconductor layer 25 of the driving TFT 123 intersects, and a portion arranged so as to overlap with the power supply line 103 serves as one electrode of the storage capacitor. Function.

  As shown in FIG. 4, the light absorption layer 26 includes a signal line 102, a power supply line 103, a scanning line 101, a first relay conductive layer 23, a second relay conductive layer 37, and source and drain electrodes of the driving TFT 123 (illustrated). (Omitted) or the like below the wiring layer (wiring portion). Further, the light absorption layer 26 is formed substantially equal to the pattern shape of the signal line 102 and the like, and is formed substantially equal to the wiring width of the signal line 102 and the like. Then, the entire surface of the light absorption layer 26 as viewed in plan is arranged so as to overlap with the wiring of the signal line 102 and the like, and external light is blocked or attenuated by the light absorption layer 26 so that the signal line 102 and the like are formed. The structure prevents external light from reaching. In the present embodiment, the hatched portion in FIG. 4 indicates the light absorption layer 26 formed below the wiring layer such as the signal line 102. That is, the light absorption layer 26 is formed in a lattice shape so as to partition the light emitting region below the non-light emitting region excluding the light emitting region. Here, the “light emitting region” refers to a region where the anode 42 is mainly formed in FIG. As will be described later, in this embodiment, the contact holes 13, 21, 29, 31, and 33 shown in FIG. Further, if the light absorption layer 26 is formed so as to at least partly overlap with the wiring layer, it is possible to absorb light of external light.

Next, a cross-sectional structure of one pixel of the organic EL device shown in FIG. 1 will be described. FIG. 5 is a diagram showing a cross-sectional structure of the organic EL device 1 including the driving TFT 123.
As shown in FIG. 5, a base protective film 12 made of a silicon oxide film is formed on a substrate 10 made of a transparent material. An n-channel polycrystalline silicon film (semiconductor layer) 14 is formed on the base protective film 12 by patterning in an island shape. A channel region 16 is formed in the central portion of the polycrystalline silicon film (semiconductor layer) 14, and the low concentration source region 18 b and the high concentration source region extend from the channel region to the left side of the polycrystalline silicon film 14 in the drawing. 18a is formed, and a lightly doped drain region 20b and a heavily doped drain region 20a are formed along the right direction in the figure. In this embodiment, the driving TFT adopts an LDD structure having a concentration gradient in the source region and the drain region. A gate insulating film 22 is formed on the polycrystalline silicon film 14 and the base protective film 12 so as to cover the entire surface thereof. A gate electrode 24 is formed on the gate insulating film 22 so as to face the channel region 16 and is patterned into a predetermined shape. An interlayer insulating film 40 made of silicon oxide is formed on the gate insulating film 22 and the gate electrode 24 so as to cover the entire surface thereof.

  The light absorption layer 26 is formed in a region located below a source electrode 28 and a drain electrode 30 described later on the interlayer insulating film 40, absorbs external light incident from the substrate 10 side, and reflects it to the substrate 10 side. It has a function to prevent. The light absorption layer 26 is made of a metal oxide such as chromium oxide, iron oxide, or nickel oxide, for example. That is, the light absorption layer is made of a low reflectance material that absorbs wavelengths in almost all wavelength bands of external light incident from the substrate 10 side. The film thickness of the light absorption layer 26 is preferably in the range of 50 nm to 200 nm. More preferably, it is 100 nm. This is because when the film thickness of the light absorption layer 26 is less than 50 nm, stable characteristics cannot be obtained, and external light is not sufficiently absorbed. On the other hand, when the thickness of the light absorption layer 26 is larger than 200 nm, it is possible to absorb the incident external light, but the step of the wiring layer (wiring part) becomes large, and a plurality of wiring layers are formed. In some cases, the wiring layer on the upper layer side is easily broken by a step.

  Note that the light absorption layer 26 preferably has a stacked structure of a metal oxide layer formed of chromium oxide or the like and a metal layer formed of metal such as chromium, nickel, or iron. According to this, the light reflected by the metal layer interferes with the light reflected by the metal oxide film, and the reflectance can be reduced compared to the case of a single metal oxide layer. The thickness of the metal oxide layer of the light absorption layer 26 is preferably in the range of 50 nm to 100 nm. More preferably, it is 50 nm. The film thickness of the metal layer is preferably in the range of 50 nm to 200 nm. More preferably, it is 100 nm.

  A source electrode 28 and a drain electrode 30 are formed on the light absorption layer 26. The interlayer insulating film 40 and the light absorption layer 26 are formed with contact holes 32 that allow the high-concentration source region 18a and the source electrode 28 to communicate with each other. A part of the source electrode 28 is filled in the contact hole 32, and the high-concentration source region 18a and the source electrode 28 are electrically connected. Similarly, a contact hole 34 that connects the high-concentration source region 20 a and the drain electrode 30 is formed immediately below the drain electrode 30. A part of the drain electrode 28 is filled in the contact hole 34, and the high concentration drain region 20 a and the drain electrode 30 are electrically connected. The insulating layer 36 made of silicon nitride is formed so as to cover the entire surface of the interlayer insulating film 40 including the source electrode 28 and the drain electrode 30. On the insulating layer 36, an acrylic layer 38 (flattening film) for ensuring flatness on the actual display region 4 is formed. A contact hole 44 is formed in the insulating layer 36 and the acrylic layer 38 on the source electrode 28 to communicate the source electrode 28 with an anode 42 described later. The anode 42 is filled in the contact hole 44 and is electrically connected to the drain electrode 30 and is patterned on the insulating layer 36 in a predetermined shape. The anode 42 injects holes into the organic functional layer by an applied voltage, and is formed of a transparent conductive film such as ITO (Indium Tin Oxide).

  The lyophilic control layer 46 is made of silicon oxide and is formed so as to overlap the peripheral portion of the anode 42 from the acrylic layer 38. The organic bank layer 48 is formed on the acrylic layer 38 and the lyophilic control layer 46 so as to partition the cathode 42 in a plane. The organic bank 48 is made of an organic material such as acrylic or polyimide.

  An organic functional layer 54 is formed on the anode 42 in a region partitioned by the organic bank layer 48. The organic functional layer 54 has a multilayer structure sandwiched between the anode 42 and the cathode 56, and is composed of a hole transport / injection layer 50, an organic light emitting layer 52, and an electron transport layer in this order from the anode 42 side. Yes. Hereinafter, the organic functional layer 54 will be described.

  The hole transport / injection layer 50 constitutes a hole injection layer for injecting holes of the anode 42 into the organic light emitting layer 52, and has a film thickness of 30 nm. Various conductive polymer materials are suitably used as examples of the material for forming the hole injection layer. For example, polythiophene, polyaniline, polypyrrole, and the like can be employed. Specifically, 3,4-polyethylenedioxythiophene / polystyrene sulfonic acid (PEDOT / PSS) dispersion, that is, 3,4-polyethylenedioxythiophene is dispersed in polystyrene sulfonic acid as a dispersion medium. A dispersion in which water is dispersed in water is used.

  The organic light emitting layer 52 has a function of generating fluorescence by combining holes injected from the anode 42 through the hole transport / injection layer 50 and electrons injected from the cathode 56. As a material for forming the organic light emitting layer 52, a known light emitting material capable of emitting fluorescence or phosphorescence can be used. Specifically, polyfluorene derivative (PF), (poly) paraphenylene vinylene derivative (PPV), polyphenylene derivative (PP), polyparaphenylene derivative (PPP), polyvinyl carbazole (PVK), polythiophene derivative, polymethylphenylsilane A polysilane such as (PMPS) is preferably used. In addition, these polymer materials include polymer materials such as perylene dyes, coumarin dyes, rhodamine dyes, such as rubrene, perylene, 9,10-diphenylanthracene, tetraphenylbutadiene, Nile red, coumarin 6, A material such as quinacridone can be doped.

  The electron transport layer plays a role of injecting electrons into the organic light emitting layer 52, and includes an oxadiazole derivative, anthraquinodimethane and its derivative, benzoquinone and its derivative, naphthoquinone and its derivative, anthraquinone and its derivative, tetra Examples include cyanoanthraquinodimethane and derivatives thereof, fluorenone derivatives, diphenyldicyanoethylene and derivatives thereof, diphenoquinone derivatives, and metal complexes of 8-hydroxyquinoline and derivatives thereof. Specifically, like the material for forming the hole transport layer, 2- (4-biphenylyl) -5- (4-t-butylphenyl) -1,3,4-oxadiazole, benzoquinone, anthraquinone Tris (8-quinolinol) aluminum is preferred. Further, the electron transport layer 52 may be formed of various conductive materials such as various simple materials such as aluminum, magnesium, lithium, and calcium, and alloys containing these materials as main components.

The cathode 56 is formed on the entire surface of the organic functional layer 54 and the organic bank layer 48. The cathode 56 is formed of a metal material such as aluminum (Al), magnesium (Mg), gold (Au), silver (Ag), or calcium (Ca).
In the present embodiment, the light emitting element 58 is formed by the anode 42, the cathode 56 disposed opposite thereto, and the organic functional layer 54 sandwiched between the anode 42 and the cathode 56.

  According to the present embodiment, the light absorption layer 26 is provided below the wiring layer such as the source electrode 28 and the drain electrode 30 of the driving TFT 123 so as to overlap the wiring layer. Therefore, the external light incident from the substrate 10 side is absorbed by the light absorption layer 26 provided in the lower layer of the wiring layer. Accordingly, the external light is blocked or attenuated by the light absorption layer 26, and therefore does not reach the wiring layer or reaches the attenuated state. Therefore, reflection of external light from the wiring layer (non-display area) can be avoided or attenuated, and reflection due to reflection of external light can be avoided. In this embodiment, since the light absorption layer 26 is formed above the driving TFT 123 (excluding the wiring layer described above), the light absorption layer 26 does not cause a step below the driving TFT 123. The driving TFT 123 can be formed in the flat region. Accordingly, the light emitting element region is also flattened, and uneven light emission can be prevented.

  Next, a method for manufacturing the organic EL device 1 according to this embodiment will be described with reference to FIGS. 6 (a) to 6 (c) and FIGS. 7 (a) to 7 (c). FIGS. 6A to 6C and FIGS. 7A to 7C are cross-sectional views showing a manufacturing process of the organic EL device.

  First, as shown in FIG. 6A, after preparing a substrate 10 cleaned by ultrasonic cleaning or the like, a base protective film 12 made of silicon oxide is formed on the entire surface of the substrate 10 by plasma CVD. . Next, an amorphous silicon film (amorphous semiconductor film) is formed on the entire surface of the substrate 10 on which the base protective film 12 is formed by a plasma CVD method or the like under conditions where the substrate temperature is 150 to 450 ° C. . Next, the amorphous silicon film is irradiated with excimer laser light to perform laser annealing to convert it into a polycrystalline silicon film 14. Next, the polycrystalline silicon film 14 is patterned into an island shape by photolithography. Next, a gate insulating film 22 made of a silicon oxide film or the like is formed on the entire surface of the substrate 10 on which the polycrystalline silicon film 14 is formed. Next, a conductive material such as a metal such as aluminum or an alloy containing these as a main component is formed on the entire surface of the substrate 10 on which the gate insulating film 22 is formed by sputtering or the like, and then patterned by photolithography. Then, the gate electrode 24 is formed.

  Next, using the gate electrode 24 as a mask, low concentration impurity ions (phosphorus ions) are implanted at a predetermined dose to form a low concentration source region 18b and a low concentration drain region 20b in a self-aligned manner in the polycrystalline silicon film 14. To do. Here, a portion that is located immediately below the gate electrode 24 and into which impurity ions are not introduced becomes the channel region 16. Next, a resist mask (not shown) wider than the gate electrode 24 is formed, and high-concentration impurity ions (arsenic ions) are implanted into the polycrystalline silicon film 14 with a predetermined dose amount, so that the high-concentration source region 18a, A concentration drain region 20a is formed. Thereafter, the substrate 10 provided with the polycrystalline silicon film 14 is annealed to activate (diffuse) the impurities. Next, an interlayer insulating film 40 made of silicon oxide is formed on the entire surface of the gate electrode 24 and the gate insulating film 22 by a CVD method or the like.

  Next, as shown in FIG. 6B, the light absorption layer 26 is formed on the entire surface of the interlayer insulating film 40 by sputtering, vapor deposition or the like. The light absorption layer 26 is formed of a metal oxide such as chromium oxide, iron oxide, or nickel oxide. The film thickness of the light absorption layer 26 at this time is, for example, about 100 nm.

  Next, as shown in FIG. 6C, contact holes 32 and 34 are formed in the light absorption layer 26 and the interlayer insulating film 40. Specifically, openings corresponding to the contact holes 32 and 34 are formed in the resist formed on the entire surface of the interlayer insulating film 40 by photolithography, and dry etching is performed using the resist as a mask. At this time, the light absorption layer 26 and the interlayer insulating film 40 are collectively etched. As a result, contact holes 32 and 34 are formed in the light absorption layer 26 and the interlayer insulating film 40.

  Next, as shown in FIG. 7A, the contact holes 32 and 34 are made of conductive material such as aluminum, titanium, titanium nitride, tantalum, molybdenum, or an alloy mainly containing any of these metals by sputtering or the like. The conductive material is filled, and the conductive material is formed over the entire surface of the light absorption layer 26. Thereby, the conductive layer 27 is formed on the light absorption layer 26.

  Next, as shown in FIG. 7B, a resist is applied to the entire surface of the conductive layer 27. Then, the resist is patterned into a predetermined shape by a photolithography method, and the conductive layer 27 and the light absorption layer 26 formed under the conductive layer 27 are dry-etched using the patterned resist as a mask. That is, in this embodiment, the light absorption layer 26 and the conductive layer 27 are collectively etched. As a result, the source electrode 28 and the drain electrode 30 are formed, and the light absorption layer 26 is formed below each of the source electrode 28 and the drain electrode 30. Thereafter, the resist on the conductive layer 27 is removed by a light etching process.

  Next, as shown in FIG. 7C, an insulating film 36 made of a silicon nitride film is formed so as to cover the substrate 10 including the source electrode 28 and the drain electrode 30, and the acrylic layer 38 is formed on the insulating film 36. Form. Next, a contact hole 44 that penetrates the insulating film 36 and the acrylic layer 38 is formed on the drain electrode 30. Then, a transparent conductive film (ITO) is formed on the acrylic layer 38 including the contact hole 44, the drain electrode 30 and the anode 42 are electrically connected, and the transparent conductive film is patterned by a wet etching process to form the anode 42. Form.

  Next, a lyophilic control layer 46 is formed so as to cover the periphery of the anode 42, and an organic bank layer 48 is formed on the lyophilic control layer 46 and the acrylic layer 38. That is, the organic bank layer 48 is formed so as to partition the anode 42. Next, the organic functional layer 54 described above is formed on the anode 42 which is a recessed region partitioned by the organic bank layer 48 by, for example, an ink jet method. Thereafter, a cathode 56 is formed on the entire surface of the organic functional layer 54 and the organic bank layer 48.

  According to the manufacturing method of the organic EL device 1 of the present embodiment, the light absorption layer 26 and the conductive layer 27 are patterned at once, so that the manufacturing process can be simplified. Further, since the light absorption layer 26 is formed on the conductive layer 27 before the contact holes 32 and 34 are formed, the light absorption layer 26 is not formed in the contact holes 32 and 34, and the source electrode 28 and the high concentration are formed. The contact resistance with the source region 18a is not increased.

[Second Embodiment]
Next, the present embodiment will be described with reference to the drawings.
In the above embodiment, the light absorption layer is formed of metal oxide, metal nitride, or the like. On the other hand, the present embodiment is different in that the light absorption layer is formed of a resin layer. The basic configuration of the other organic EL devices is the same as that of the first embodiment, and common constituent elements are denoted by the same reference numerals and detailed description thereof is omitted.

FIGS. 8A to 8C, 9A, and 9B are cross-sectional views showing manufacturing steps of the driving TFT of the organic EL device of this embodiment.
First, as shown in FIG. 8A, a base protective film 12 is formed on a substrate 10, and a driving TFT is formed by the formation method described in the first embodiment.
Next, as shown in FIG. 8B, a light absorbing material obtained by dissolving a black pigment or black dye in an acrylic resin, a polyimide resin, or the like is gated by various coating methods such as a spin coating method, a dip coating method, and an ink jet method. Coating is performed on the entire surface of the electrode 24 and the gate insulating film 22. That is, a light absorbing material which is a low-reflectance material colored in black is applied to a region including the gate electrode 24. As a result, a light absorption layer 26 having low reflectivity and insulation is formed on the entire surface of the gate electrode 24 and the gate insulating film 22.

Here, as dyes, various dyes usually used for inkjet recording, such as direct dyes, acid dyes, food dyes, basic dyes, reactive dyes, disperse dyes, vat dyes, soluble vat dyes, and reactive disperse dyes. Can be used.
Moreover, as a pigment, an inorganic pigment and an organic pigment can be used without a special restriction | limiting.
As the inorganic pigment, in addition to titanium oxide and iron oxide, carbon black produced by a known method such as a contact method, a furnace method, or a thermal method can be used.
Organic pigments include azo pigments (including azo lakes, insoluble azo pigments, condensed azo pigments, chelate azo pigments), polycyclic pigments (for example, phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazines). Pigments, thioindigo pigments, isoindolinone pigments, quinofullerone pigments, etc.), dye chelates (for example, basic dye chelate, acid dye chelate, etc.) nitro pigments, nitroso pigments, aniline black, and the like.

  In the present embodiment, the light absorption layer 26 is formed of a resin containing a black pigment or dye, but is not limited to a black pigment or dye. Any pigment or dye of a color that can absorb light incident from the substrate side to some extent can be employed.

  Next, as shown in FIG. 8C, contact holes 32 and 34 are formed in the light absorption layer 26. Specifically, first, a resist is applied to the entire surface of the light absorption layer 26, and openings are formed in the resist on the source electrode 28 and the drain electrode 30 by photolithography. Then, dry etching is performed using this resist as a mask, and the light absorption layer 26 and the gate insulating film 22 under the light absorption layer 26 are patterned at once. As a result, contact holes 32 and 34 are formed in the gate insulating film 22 and the light absorption layer 26. At the same time, in the present embodiment, the organic EL device 1 adopts the bottom emission type, and therefore removes the light absorption layer 26 formed in the light emitting region.

  Next, as shown in FIG. 9A, the contact holes 32 and 34 are filled with a conductive material, and a conductive layer 27 made of a conductive material is formed on the light absorption layer 26. Next, as shown in FIG. 9B, the conductive layer 27 is patterned to form the source electrode 28 and the drain electrode 30. Other processes of the organic EL device 1 are the same as those of the organic EL device 1 described in the first embodiment.

  According to this embodiment, the same effects as those of the first embodiment can be obtained, and the light absorption layer 26 has an insulating function and a light absorption function. Therefore, the insulating layer and the light absorption layer are formed in separate steps. Thus, the light absorption layer 26 having both an insulating function and a light absorption function can be formed in one step. Therefore, the light absorption layer 26 made of a low reflection material can be formed without increasing the number of steps, and the cost can be reduced.

[Third Embodiment]
Next, the present embodiment will be described with reference to the drawings.
In the above embodiment, the light absorption layer is formed before the contact hole is formed in the interlayer insulating film. In contrast, the present embodiment is different in that the light absorption layer is formed after the contact hole is formed in the interlayer insulating film. The basic configuration of the other organic EL devices is the same as that of the first embodiment, and common constituent elements are denoted by the same reference numerals and detailed description thereof is omitted.

FIGS. 10A to 10C and FIGS. 11A and 11B are cross-sectional views showing the manufacturing process of the driving TFT of the organic EL device of this embodiment.
First, as shown in FIG. 10A, a base protective film 12 is formed on a substrate 10, and a driving TFT is formed by the formation method described in the first embodiment. Next, as shown in FIG. 10A, an interlayer insulating film 40 made of silicon oxide is formed on the entire surface of the gate electrode 24 and the gate insulating film 22 by CVD or the like.

  Next, as shown in FIG. 10B, contact holes 32 and 34 are formed in the gate insulating film 22 and the interlayer insulating film 40 located above the high concentration source region 18a and the high concentration drain region 20a. Specifically, a resist in which a pattern corresponding to the contact hole is formed is formed by photolithography, and the gate insulating film 22 and the interlayer insulating film 40 are collectively dry-etched using this resist as a mask. As a result, contact holes 32 and 34 are formed in the gate insulating film 22 and the interlayer insulating film 40.

  Next, as shown in FIG. 10C, the contact holes 32 and 34 are filled with a metal oxide containing chromium oxide, iron oxide, or nickel oxide as a main component by sputtering or the like. The light absorption layer 26 is formed on the insulating film 40. The film thickness of the light absorption layer to be formed is, for example, about 100 nm.

  Next, as shown in FIG. 11A, the main component is aluminum, titanium, titanium nitride, tantalum, molybdenum, or any of these metals on the light absorption layer 26 and the contact holes 32 and 34 by sputtering. A conductive material such as an alloy is formed.

  Next, as shown in FIG. 11B, the conductive layer 27 and the light absorption layer 26 are patterned into a predetermined shape. Specifically, the resist applied on the conductive layer 27 is patterned by photolithography, and the light absorbing layer 26 formed below the conductive layer 27 and the conductive layer 27 is dry-etched using the patterned resist as a mask. Pattern at once. As a result, as shown in FIG. 11B, the source electrode 28 and the drain electrode 30 are formed, and the light absorption layer 26 is formed below the source electrode 28 and the drain electrode 30. Since the other manufacturing processes of the organic EL device 1 are the same as those in the first embodiment, description thereof is omitted.

  According to the manufacturing method of the organic EL device 1 of the present embodiment, the same effect as the first embodiment can be obtained, and the light absorption layer 26 and the conductive layer 27 can be continuously formed by sputtering. Therefore, there is no increase in the number of processes. In addition, since the light absorption layer 26 and the conductive layer 27 can be patterned at once, the manufacturing process can be simplified. In this embodiment, since the light absorption layer 26 is formed above the driving TFT 123 (excluding the wiring layer described above), the light absorption layer 26 does not cause a step below the driving TFT 123. The driving TFT 123 can be formed in the flat region. Accordingly, the light emitting element region is also flattened, and uneven light emission can be prevented.

<Electronic equipment>
Next, an example of the electronic device of the present invention will be described.
FIG. 12 is a perspective view showing an example of a mobile phone including an organic EL device in which the light absorption layer 26 is formed in the lower layer of the above-described wiring. As shown in FIG. 12, the mobile phone 600 includes a first body 106 a and a second body 106 b that can be folded around a hinge 122. The first body 106a is provided with a liquid crystal display device 601, a plurality of operation buttons 127, an earpiece 124, and an antenna 126. The second body 106b is provided with a mouthpiece 128. According to the present embodiment, it is possible to realize a mobile phone including an organic EL device with less reflection.

  Note that the organic EL device of this embodiment can be applied to various electronic devices other than the mobile phone. For example, LCD projectors, multimedia-compatible personal computers (PCs) and engineering workstations (EWS), pagers, word processors, televisions, viewfinder type or monitor direct view type video tape recorders, electronic notebooks, electronic desk calculators, car navigation systems The present invention can be applied to electronic devices such as a device, a POS terminal, and a device provided with a touch panel.

In addition, this invention is not limited to the example mentioned above, Of course, a various change can be added in the range which does not deviate from the summary of this invention. Moreover, you may combine each example mentioned above in the range which does not deviate from the summary of this invention.
In the above embodiment, the organic EL device adopts an active matrix type as a driving method, but it is also possible to adopt a passive type.

It is the top view which showed schematic structure of the organic EL apparatus. It is sectional drawing along the A-A 'line | wire of the organic electroluminescent apparatus shown in FIG. FIG. 2 is an equivalent circuit diagram of a pixel region of the organic EL device shown in FIG. It is the top view which expanded and showed the pixel area | region of the organic electroluminescent apparatus shown in FIG. It is sectional drawing which expanded and showed the pixel area | region of the organic electroluminescent apparatus shown in FIG. It is sectional drawing which shows the manufacturing process of the organic electroluminescent apparatus of 1st Embodiment. It is sectional drawing which shows the manufacturing process of the organic electroluminescent apparatus of 1st Embodiment. It is sectional drawing which shows the manufacturing process of the organic electroluminescent apparatus of 2nd Embodiment. It is sectional drawing which shows the manufacturing process of the organic electroluminescent apparatus of 2nd Embodiment. It is sectional drawing which shows the manufacturing process of the organic electroluminescent apparatus of 3rd Embodiment. It is sectional drawing which shows the manufacturing process of the organic electroluminescent apparatus of 3rd Embodiment. It is a perspective view which shows schematic structure of the mobile telephone which is an example of an electronic device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Organic EL device (light-emitting device), 10 ... Board | substrate, 26 ... Light absorption layer, 27 ... Conductive layer, 28 ... Source electrode (wiring part), 30 ... Drain electrode (wiring part), 32, 34, 44 ... Contact Hole (through hole), 40 ... interlayer insulating film (insulating layer), 42 ... anode (first electrode), 54 ... organic functional layer (light emitting layer), 56 ... cathode (second electrode)

Claims (9)

A display device that performs display by emitting light from a light emitting layer through a substrate,
A wiring portion provided on the substrate;
A first electrode electrically connected to the wiring portion;
A light emitting layer provided on the first electrode;
A second electrode provided opposite to the first electrode on the light emitting layer;
A light absorbing layer provided below the wiring portion so as to overlap with at least a part of the wiring portion in a plane;
A display device comprising:   The display device according to claim 1, wherein the light absorption layer absorbs wavelengths in substantially all wavelength bands of light incident from the substrate side.   3. The display device according to claim 1, wherein the light absorption layer is provided in a lower layer of the wiring portion and in a position overlapping in a planar manner with substantially the same pattern as the wiring portion.   The said light absorption layer consists of any material containing the resin which added the black pigment or the black dye, or a metal oxide or a metal nitride, The said any one of Claim 1 thru | or 3 characterized by the above-mentioned. The display device described in 1.   The display device according to claim 4, wherein the metal oxide is any one of chromium oxide, iron oxide, and nickel oxide.   The display device according to claim 1, wherein the light absorption layer is provided by stacking the metal oxide or the metal nitride and a metal. Forming an element on a substrate;
Forming an insulating layer on the substrate so as to cover the element;
Forming a light absorption layer on the insulating layer;
Patterning the insulating layer and the light absorbing layer together to form a through hole reaching the element in the insulating layer and the light absorbing layer;
Forming a wiring material on the light absorption layer including the inside of the through hole;
Forming a wiring portion by patterning the light absorption layer and the wiring material in a lump;
A method for manufacturing a display device, comprising: Forming an element on a substrate;
Forming a light absorption layer on the substrate so as to cover the element;
Patterning the light absorption layer to form a through hole reaching the element in the light absorption layer, and removing the light absorption layer in the display region;
Forming the wiring material on the light absorption layer including the inside of the through hole;
Forming a wiring portion by patterning the light absorption layer and the wiring material at once;
A method for manufacturing a display device, comprising:   An electronic apparatus comprising the display device according to claim 1.

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