Light-emitting element, light-emitting device, photoelectric conversion device, electronic device

Abstract

To microfabricate a light-emitting element.SOLUTION: A light-emitting element including a light-emitting region and a contact region includes a wiring layer, an interlayer insulation layer, a reflective layer, an optical adjustment layer, a first electrode, a light-emitting layer, and a second electrode in the light emitting region, in this order from a substrate side; and includes the wiring layer, a conductor, the first electrode, the light-emitting layer, and the second electrode in the contact region, in this order from the substrate side. The conductor is electrically connected to both the first electrode and the wiring layer. The shortest distance between the first electrode and the substrate in the contact region is equal to or greater than the shortest distance between the reflective layer and the substrate in the light-emitting region.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a light-emitting element, a light-emitting device, a photoelectric conversion device, and an electronic device. [Background technology]

[0002] The characteristics of organic light-emitting elements include being self-luminous, having a fast response speed, not needing a backlight, and consuming little power, etc. Due to these characteristics, display devices using organic light-emitting elements are gradually replacing liquid crystal display devices as the main type of color display device.

[0003] In an organic light-emitting element, the anode electrode needs to be electrically connected to the lower wiring. In Patent Document 1, as shown in Fig. 14, a deep through-hole is provided in the lower layer including the reflective layer to form an electrical contact between the anode electrode and the lower wiring. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2013-73884 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, when connecting the anode electrode to the lower layer via a through hole as in Patent Document 1, it is necessary to lay the wall surface of the through hole flat against the substrate (reducing θ in FIG. 14). Also, when connecting the anode electrode directly to the lower layer wiring as in Patent Document 1, it is necessary to deepen the through hole. Therefore, it was necessary to increase the opening width of the through hole (S in FIG. 14). This is disadvantageous from the viewpoint of miniaturization (high definition) of organic light-emitting elements. In other words, it was not possible to miniaturize organic light-emitting elements in the past.

[0006] Therefore, an object of the present disclosure is to miniaturize light-emitting elements. [Means for solving the problem]

[0007] One aspect of the disclosure of the present technology is a light-emitting element having a light-emitting region and a contact region, the light-emitting element having, in the light-emitting region, a wiring layer, an interlayer insulating layer, a reflective layer, an optical adjustment layer, a first electrode, a light-emitting layer, and a second electrode, in this order, from a substrate side, and the light-emitting element having, in the contact region, the wiring layer, a conductor, the first electrode, the light-emitting layer, and the second electrode, in this order, from the substrate side, the conductor being electrically connected to both the first electrode and the wiring layer; In the contact region, the top surface of the first electrode has a recessed region; The light-emitting element is characterized in that the shortest distance between the first electrode and the substrate in the contact region is greater than or equal to the shortest distance between the reflective layer and the substrate in the light-emitting region, the reflective layer has an opening, and in a planar view of the substrate, the contact region is included in the opening.

[0008] One aspect of the disclosure of the present technology is a light-emitting element having a light-emitting region and a contact region, the light-emitting element having, in the light-emitting region, a wiring layer, an interlayer insulating layer, a reflective layer, an optical adjustment layer, a first electrode, a light-emitting layer, and a second electrode, in this order, from a substrate side, and the light-emitting element having, in the contact region, the wiring layer, a conductor, the first electrode, the light-emitting layer, and the second electrode, in this order, from the substrate side, the conductor being electrically connected to both the first electrode and the wiring layer; In the contact region, the top surface of the first electrode has a recessed region; The light-emitting element is characterized in that, in a plan view of the substrate, the area of ​​the conductor is smaller than the area of ​​the wiring layer. Effect of the Invention

[0009] According to the present invention, the light emitting device can be miniaturized. [Brief description of the drawings]

[0010] [Figure 1] FIG. 2 is a cross-sectional view of the organic light-emitting device according to the first and second embodiments. [Diagram 2] 1A to 1C are diagrams illustrating a process for forming an organic light-emitting element according to embodiment 1. [Diagram 3] 1A to 1C are diagrams illustrating a process for forming an organic light-emitting element according to embodiment 1. [Figure 4] 1A to 1C are diagrams illustrating a process for forming an organic light-emitting element according to embodiment 1. [Diagram 5] 1A to 1C are diagrams illustrating a process for forming an organic light-emitting element according to embodiment 1. [Figure 6] 1A to 1C are diagrams illustrating a process for forming an organic light-emitting element according to embodiment 2. [Figure 7] 1A to 1C are diagrams illustrating a process for forming an organic light-emitting element according to embodiment 2. [Figure 8] 1A to 1C are diagrams illustrating a process for forming an organic light-emitting element according to Modification 1. [Figure 9] 1A to 1C are diagrams illustrating a process for forming an organic light-emitting element according to Modification 1. [Figure 10] FIG. 4 is a cross-sectional view of an organic light-emitting element according to embodiment 3. [Figure 11] 10A to 10C are diagrams illustrating a process for forming an organic light-emitting element according to embodiment 3. [Figure 12] 10A to 10C are diagrams illustrating a process for forming an organic light-emitting element according to embodiment 3. [Figure 13] FIG. 4 is a cross-sectional view of an organic light-emitting element according to a comparative example. [Figure 14] 1 is a cross-sectional view of an organic light-emitting device according to the prior art; [Figure 15] FIG. 11 is a schematic diagram illustrating an example of a display device according to a fourth embodiment. [Figure 16] 13A to 13C are schematic diagrams illustrating an example of an imaging device and an electronic device according to a fourth embodiment. [Figure 17] FIG. 11 is a schematic diagram illustrating an example of a display device according to a fourth embodiment. [Figure 18] 11 is a schematic diagram showing an example of an automobile and an illumination device according to a fourth embodiment. FIG. [Figure 19] 11 is a schematic diagram showing a wearable device and an imaging device according to a fourth embodiment. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] A preferred embodiment of the present invention will be described in detail below with reference to the attached drawings. However, the components described in this embodiment are merely examples, and the technical scope of the present invention is determined by the claims, and is not limited to the individual embodiments described below. Furthermore, the present invention is not limited to the following embodiments, and various modifications (including organic combinations of the embodiments) are possible based on the spirit of the disclosure of this specification, and are not excluded from the scope of the disclosure of this specification. In other words, configurations that combine the embodiments described below and their modified examples are all included in the embodiments disclosed in this specification.

[0012] In the following description, the direction of the light-emitting layer (organic compound layer) relative to the substrate is referred to as the upward direction, and the opposite direction is referred to as the downward direction. In this embodiment, the light is emitted in the upward direction. In addition, the provision of a second layer on a first layer includes both cases where the first layer and the second layer are in contact with each other, and cases where one or more third layers are interposed between the first layer and the second layer. In addition, "depth" refers to the length in the upward direction (downward direction). "Width" refers to the length in the direction perpendicular to the upward direction (the direction parallel to the surface on which the substrate extends (the main surface of the substrate)).

[0013] <Embodiment 1> FIG. 1A is a cross-sectional view of an organic light-emitting element 1 (organic EL display device) which is a light-emitting element according to embodiment 1. In FIG. 1A, sub-pixels R, G, and B arranged on a substrate represent red, green, and blue sub-pixels, respectively. Three sub-pixels R, G, and B form one pixel in the organic light-emitting element 1. The sub-pixels R, G, and B are separated by a bank insulating film 111, which will be described later. Note that in this embodiment, the light-emitting element is an organic light-emitting element containing an organic light-emitting material in the light-emitting layer, but it may be an inorganic light-emitting element containing an inorganic light-emitting material in the light-emitting layer. In addition, a region of the organic light-emitting element 1 corresponding to each sub-pixel on the substrate can be regarded as one light-emitting element, and this embodiment can also be regarded as an embodiment relating to a light-emitting device having a plurality of light-emitting elements.

[0014] The organic light-emitting element 1 includes a substrate 10, an Al wiring 20, an anti-reflection film 21 on the Al wiring 20, a conductor The organic light-emitting element 1 has a first electrode 22 (W plug), a first electrode 23 (anode electrode), an interlayer insulating layer 30, a reflective layer 40, an organic compound layer (OLED) 50, a second electrode 60 (cathode electrode), and a protective layer 70. The organic light-emitting element 1 also has a first interference film 101, a second interference film 102, and a third interference film 103, each of which is an optical interference film (optical adjustment layer). The organic light-emitting element 1 has a bank insulating film 111 that separates sub-pixels (pixels).

[0015] The substrate 10 is formed of a material capable of supporting the first electrode 23, the organic compound layer 50, and the second electrode 60. The material of the substrate 1 is preferably glass, plastic, silicon, etc. On the substrate 10, a switching element such as a transistor (not shown), an Al wiring 20, an interlayer insulating layer 30, etc. are formed.

[0016] From the viewpoint of luminous efficiency, the first electrode 23 is preferably a thin film of a material having optical transparency. In this embodiment, the material of the first electrode 23 is ITO (indium tin oxide) (the first electrode 23 is composed of indium tin oxide). The material of the first electrode 23 may be a transparent conductive oxide such as IZO (indium zinc oxide), or a metal or alloy such as Al, Ag, or Pt. The first electrode 23 has a concave region (opening) in a contact region described later, and the concave region contacts (connects) with the conductor 22.

[0017] The organic compound layer 50 is disposed on the first electrode 23, and can be formed by a known technique such as a vapor deposition method or a spin coating method. The organic compound layer 50 is a layer including at least one light-emitting layer, and may be composed of a plurality of layers. Examples of the plurality of layers include a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer, a hole blocking layer, an electron transport layer, and an electron injection layer. In the organic compound layer 50, holes injected from the anode and electrons injected from the cathode are recombined in the light-emitting layer, so that light is emitted from the light-emitting layer. That is, in the organic compound layer 50, a region directly sandwiched between the first electrode 23 and the second electrode 60 (a region sandwiched without the bank insulating film 111) emits light. The light-emitting layer may be a single layer or a plurality of layers. Any of the light-emitting layers may have a red light-emitting material, a green light-emitting material, or a blue light-emitting material, and it is also possible to obtain white light by mixing the respective light-emitting colors. Any of the light-emitting layers may have light-emitting materials of complementary colors, such as a blue light-emitting material and a yellow light-emitting material.

[0018] The second electrode 60 is disposed on the organic compound layer 50 and has a translucent property. The second electrode 60 may be a semi-transmissive material having a property of transmitting a part of light that reaches its surface and reflecting the other part (i.e., semi-transmissive reflectivity). In this embodiment, the material constituting the second electrode 60 may be MgAg. However, the material constituting the second electrode 60 may be, for example, a transparent conductive oxide such as ITO or IZO, or a semi-transmissive material made of a metal material. Examples of the metal material are elemental metals such as aluminum, silver, and gold, alkali metals such as lithium and cesium, alkaline earth metals such as magnesium, calcium, and barium, and alloy materials containing these metal materials. The semi-transmissive material is preferably an alloy mainly composed of magnesium or silver. The second electrode 60 may be a laminated structure of the above materials as long as it has a preferable transmittance.

[0019] The reflective layer 40 reflects the light emitted in the organic compound layer 50 and transmitted through the first electrode 23. The light reflected by the reflective layer 40 is extracted from the second electrode 60 to the light irradiation side. The reflective layer 40 is preferably made of a metal material such as Al or Ag, or an alloy to which Si, Cu, Ni, Nd, Ti, or the like is added, and is more preferably made of Al as a main component, and is more preferably an Al alloy (aluminum alloy). Note that the main component here refers to an element that is contained in the largest amount by weight among the constituent elements. In addition, since a voltage may be applied to the reflective layer 40, the reflective layer 40 may be a reflective electrode. The reflective layer 40 has an opening to form a region for contacting (connecting) the first electrode 23 and the conductor 22. This opening may be cylindrical. Therefore, the opening width of the reflective layer 40 is defined as the width of the bottom surface of the opening. may be a diameter of

[0020] The Al wiring 20 is made of a metal containing Al as a main component, and is a lower wiring (wiring layer) connected to an external power source. The Al wiring 20 is connected to the conductor 22 with low contact resistance, and is thereby electrically connected to the first electrode 23. Here, when connecting the first electrode 23 to the Al wiring 20, it is also possible to electrically connect the Al wiring 20 to the reflective layer 40 and then connect the reflective layer 40 to the first electrode 23. That is, it is also possible to connect the first electrode 23 to the Al wiring 20 via the reflective layer 40. However, in this case, a barrier metal such as TiN, Mo, or Cr is required at the interface in order to reduce the resistance at the contact between the first electrode 23 and the reflective layer 40. If such a barrier metal is provided on the surface of the reflective layer 40, the reflectance of the reflective layer 40 decreases, and the luminance of the light-emitting element decreases. In that case, the size of the light-emitting element needs to be increased in order to maintain the luminance of the light-emitting element, which makes it difficult to miniaturize the light-emitting element.

[0021] Therefore, in this embodiment, the first electrode 23 and the Al wiring 20 are electrically connected via the conductor 22. The conductor 22 is connected to the first electrode 23 and the Al wiring 20, and has low contact resistance between the first electrode 23 and the Al wiring 20. On the other hand, the conductor 22 is not electrically connected to the reflective layer 40. The conductor 22 is made of a second metal different from the first metal constituting the reflective layer 40, and may be made of a metal containing W (tungsten), for example. When the material of the conductor 22 is W, the conductor 22 can achieve low resistance contact with both the Al wiring 20 and the first electrode 23. In other words, when the material of the conductor 22 is W, the first electrode 23 and the Al wiring 20 can be electrically connected with low resistance.

[0022] The conductor 22 has a plug shape formed by being embedded in a through hole provided in an insulating layer including the interlayer insulating layer 30. By forming the conductor 22 in a plug shape, the depth of the through hole can be increased without forming the side wall of the through hole lying significantly against the substrate 10. The angle that the side wall of the through hole surrounding the conductor 22 makes with the substrate 10 is larger than the angle that the concave region of the first electrode 23 makes with the substrate 10. The side wall of the through hole surrounding the conductor 22 may be approximately perpendicular to the substrate 10. In a plan view of the organic light emitting element 1 (substrate 10) (when the organic light emitting element 1 is viewed from above (stack direction)), the size (area) of the conductor 22 is smaller than the size (area) of the Al wiring 20. This prevents the volume of the conductor 22 itself from becoming large, so the presence of the conductor 22 does not hinder the miniaturization of the organic light emitting element 1.

[0023] In this embodiment, the material of the antireflection film 21 may be TiN. The materials of the interlayer insulating layer 30, the first interference film 101, the second interference film 102, the third interference film 103 and the bank insulating film 111 may be SiO.

[0024] In this embodiment, the region of the organic compound layer 50 that extends in the stacking direction from the region that emits light is called the "light-emitting region." Therefore, in FIG. 1A, the region surrounded by the dashed line may be the light-emitting region. In the light-emitting region, from the substrate side, the substrate 10, the Al wiring 20, the interlayer insulating layer 30, the reflective layer 40, the optical interference film (optical adjustment layer), the first electrode 23, the organic compound layer 50, the second electrode 60, and the protective layer 70 are stacked in this order. In the light-emitting region, it is sufficient that each layer is stacked in this order, and other configurations may exist between the layers.

[0025] Furthermore, in this embodiment, the region extending in the stacking direction from the recessed region of the conductor 22 and the first electrode 23 is called the "contact region." Therefore, in FIG. 1A, the region surrounded by the dashed line can be the contact region. In the contact region, the substrate 10, the Al wiring 20, the first electrode 23, the bank insulating film 111, the organic compound layer 50, the second electrode 60, and the protective layer 70 are stacked in this order from the substrate side. Note that in the contact region, it is sufficient that each layer is stacked in this order, and other configurations may exist between the layers. Also, the contact region is a region where the Al wiring 20 and the first electrode 23, the conductor 22 is included between the first electrode 23 and the light-emitting region, but the contact region does not include the reflective layer 40. Therefore, it can be said that the contact region and the light-emitting region can be distinguished by the presence or absence of the reflective layer 40. Furthermore, the concave region of the first electrode 23 in the contact region is surrounded by the reflective layer 40. In the contact region, the first electrode 23 is electrically connected to the Al wiring 20 through an opening (region surrounded by the reflective layer 40) provided in the reflective layer 40. Furthermore, in a plan view of the substrate 10, the contact region is included in the opening of the reflective layer 40.

[0026] Here, in the contact region, a bank insulating film 111 is disposed between the first electrode 23 and the organic compound layer 50. By disposing the bank insulating film 111 in this manner, it is possible to prevent the light emitting layer of the organic compound layer 50 from emitting light in the contact region.

[0027] Furthermore, the upper surface (surface in contact with the first electrode 23) of the conductor 22 in the contact region is closer to the substrate 10 than the first electrode 23 in the light-emitting region. That is, in this embodiment, even the position of the conductor 22 farthest from the substrate 10 is not farther from the substrate 10 than the position of the first electrode 23 closest to the substrate 10. With this configuration, the recessed region of the first electrode 23 can be made shallow, so that the recessed region of the first electrode 23 and the opening of the reflective layer 40 can be narrowed. This is therefore advantageous in terms of miniaturization of the organic light-emitting element 1.

[0028] In this embodiment, the position of the upper surface of the conductor 22 (the surface in contact with the first electrode 23) and the position of the lower surface of the reflective layer 40 (the surface in contact with the interlayer insulating layer 30) are at the same position in the height direction. This facilitates the formation of a contact for the first electrode 23. In this embodiment, the "height" refers to the shortest distance from the substrate 10. That is, in this embodiment, the shortest distance between the upper surface of the conductor 22 and the substrate 10 is the same as the shortest distance between the lower surface of the reflective layer 40 and the substrate 10. This can also be said to mean that the first electrode 23 in the contact region and the reflective layer 40 in the light-emitting region are at the same distance (closeness) from the substrate 10.

[0029] Note that, although FIG. 1A shows an example in which the optical interference film of the organic light-emitting element 1 has a three-layer structure consisting of a first interference film 101, a second interference film 102, and a third interference film 103, the number of layers is not particularly limited, and a single-layer structure may also be used.

[0030] (Formation process of organic light-emitting element) 2A to 5C are schematic cross-sectional views illustrating steps for forming the organic light-emitting element 1 of Fig. 1A. Hereinafter, a method for forming the organic light-emitting element 1 will be described in the order of steps.

[0031] (1) As shown in FIG. 2A, a member in which Al wiring 20 is formed on a substrate 10 and an interlayer insulating layer 30 is formed (prepared). Here, a reflective layer 40 is formed on the interlayer insulating layer 30 and the conductor 22 using Al. In this state, the reflective layer 40 is formed so as to contact the interlayer insulating layer 30 and the conductor 22 with the reflective layer 40. Therefore, when the formation of the organic light-emitting element 1 is completed, the upper surface of the conductor 22 and the lower surface of the reflective layer 40 are at the same height. In order to prevent halation when the reflective layer 40 is patterned, an anti-reflection film 41 is formed on the Al surface of the reflective layer 40.

[0032] (2) The reflective layer 40 is patterned and etched, thereby exposing the conductor 22 as shown in FIG. 2B.

[0033] (3) As shown in Fig. 2C, an interlayer insulating layer 31 is formed on the reflective layer 40. The patterning, etching, and film formation processes up to this point are the same as those for forming a normal stacked via. In addition, the interlayer insulating layer 31 is formed of the same material as the interlayer insulating layer 30.

[0034] (4) As shown in Fig. 3A, the interlayer insulating layer 31 is planarized by CMP (Chemical Mechanical Polishing), and then polished continuously down to the reflective layer 40. At this time, the reflective layer 40 is planarized and the anti-reflective film 41 is also removed at the same time. This improves the overall reflectance of the reflective layer 40 and its surroundings.

[0035] (5) The first interference film 101, the second interference film 102, and the third interference film 103 are formed and etched in the order shown in Figures 3B, 3C, and 3D. This forms interference films optimized for each of the R, G, and B colors. Note that since the interlayer insulating layer 31 and the interlayer insulating layer 30 are made of the same material, the following will be illustrated and described as if the interlayer insulating layer 31 is part of the interlayer insulating layer 30.

[0036] (6) As shown in FIG. 4A, openings 211, 212, and 213 are formed by etching on the upper part of the conductor 22 (stacked via). Even if the depths of the openings 211, 212, and 213 are different during etching, this does not cause a problem because the dry etching selectivity can be made large. Here, the openings 211, 212, and 213 are formed in an inverted truncated cone shape. At this time, the taper angle of each of the openings 211, 212, and 213 is set to θ1. The magnitude of the taper angle θ1 is important in forming the first electrode 23 with a sufficient thickness on the side wall of the openings 211, 212, and 213. Specifically, the smaller the taper angle θ1, the greater the thickness of the first electrode 23 formed on the side wall of the openings 211, 212, and 213.

[0037] In addition, the taper angle θ1 of the openings 211, 212, and 213 is preferably as small as possible because it affects current leakage between the anode and the cathode when the organic compound layer 50 and the second electrode 60 are formed. Specifically, the taper angle θ1 is preferably equal to or smaller than the taper angle θ2 (see FIG. 4D) of the bank insulating film 111 that suppresses leakage between subpixels (between pixels). The taper angle is an angle with respect to the surface on which the substrate 10 extends (a surface perpendicular to the stacking direction in the substrate 10; a main surface). In FIG. 1A, the taper angle θ1 can be said to be an angle of the surface of the interlayer insulating layer 30 that contacts the first electrode 23 in the contact region with respect to the surface on which the substrate 10 extends. Alternatively, the taper angle θ1 can be said to be an angle of the outer wall (surface that contacts the interlayer insulating layer 30) of the concave region of the first electrode 23 in the contact region with respect to the surface on which the substrate 10 extends. In FIG. 1A, the taper angle θ2 can be said to be the angle of the side surface of the bank insulating film 111 present at the edge of the sub-pixel (light-emitting region) with respect to the surface on which the substrate 10 extends.

[0038] (7) As shown in FIG. 4B, a first electrode 23 is formed on the top of the third interference film 103 and on the side walls of the openings 211, 212, and 213. It is known that when ITO, which is the material of the first electrode 23, comes into direct contact with Al, a reaction occurs at the interface, and the contact resistance increases. On the other hand, in this embodiment, the first electrode 23 physically contacts the conductor 22 made of W (tungsten) instead of the reflective layer 40 made of Al. Therefore, the contact between the first electrode 23 and the conductor 22 can be achieved with low resistance.

[0039] (8) After a bank insulating film 111 for separating pixels is formed as shown in FIG. 4C, the bank insulating film 111 is patterned and etched as shown in FIG. 4D.

[0040] (9) An organic compound layer 50 is formed as shown in Fig. 5A, and a second electrode 60 is deposited by evaporation as shown in Fig. 5B. Then, a protective layer 70 is formed as shown in Fig. 5C. In this way, an organic light-emitting element 1 as shown in Fig. 1A can be formed.

[0041] In this manner, in this embodiment, since the conductor 22 is formed on the upper portion of the Al wiring 20, it is possible to reduce the depth of the deepest position (opening; concave region) of the first electrode 23. Therefore, the width of the concave region of the first electrode 23 in the contact region and the width of the opening of the reflective layer 40 can be reduced. Therefore, even in a configuration in which the reflective layer 40 is not electrically connected to the lower wiring (the Al wiring 20), the organic light emitting element can be miniaturized.

[0042] <Embodiment 2> 1B is a cross-sectional view of an organic light-emitting element 2 according to embodiment 2. The configuration of the organic light-emitting element 2 is generally the same as that of the organic light-emitting element 1 shown in FIG. 1A. The organic light-emitting element 2 differs from the organic light-emitting element 1 according to embodiment 1 in that the height of the upper surface of the conductor 22 is at the same position as the upper surface of the reflective layer 40. Therefore, the lower surface of the reflective layer 40 is closer to the substrate 10 than the upper surface of the conductor 22 and the first electrode 23. Furthermore, the conductor 22 in the contact region is surrounded by the reflective layer 40.

[0043] 6A to 7D are schematic cross-sectional views illustrating steps for forming the organic light-emitting element 2 according to embodiment 2. The method for forming the organic light-emitting element 2 will be described below in the order of steps.

[0044] (1) As shown in Fig. 6A, a member is prepared (formed) in which a conductor 22 is formed on an Al wiring 20. In this state, the upper surface of the conductor 22 and the surface (upper surface) of the interlayer insulating layer 30 are flush with each other.

[0045] (2) As shown in FIG. 6B, the interlayer insulating layer 30 is etched to excavate a region 401 in which the reflective layer 40 is to be formed.

[0046] (3) As shown in Fig. 6C, a film of aluminum or an alloy thereof is formed to form the reflective layer 40. At this time, the thickness of the reflective layer 40 should be approximately two to three times the depth (step) of the region 401.

[0047] (4) As shown in Fig. 7A, the reflective layer 40 is polished by a damascene method to expose the conductor 22. In the state shown in Fig. 7A, the upper surface of the conductor 22 and the upper surface of the reflective layer 40 are at the same height.

[0048] (5) After that, the same steps as those of the first embodiment (see FIGS. 3B to 3D) are performed to form interference films having different thicknesses for the R, G, and B sub-pixels as shown in FIG. 7B.

[0049] (6) As shown in Fig. 7C, openings 211, 212, and 213 are formed above the conductor 22 (stacked via). At this time, the depth of the openings 211, 212, and 213 is shallower than the openings 211, 212, and 213 according to the first embodiment by the thickness of the reflective layer 40. As a result, even if the taper angle θ1 is the same as that of the first embodiment, the width of the openings 211, 212, and 213 can be made smaller (narrower) than that of the first embodiment.

[0050] (7) After that, the first electrode 23 and the bank insulating film 111 are formed by the same steps as in embodiment 1 (see Figs. 4B to 4D), and then patterning and etching are performed as shown in Fig. 7D. Thereafter, the organic compound layer 50, the second electrode 60, and the protective layer 70 are formed in the same manner as in embodiment 1, and the organic light-emitting element 2 according to embodiment 2 is completed.

[0051] In this manner, also in the second embodiment, since the conductor 22 is formed on the upper portion of the Al wiring 20, the depth of the deepest position of the first electrode 23 can be reduced. In the second embodiment, the first electrode 23 in the contact region is formed at a position farther from the substrate 10 than the reflective layer 40. This makes it possible to further reduce the recessed region of the first electrode 23 and the opening of the reflective layer 40 in the contact region. Therefore, even in a configuration in which the reflective layer 40 is not electrically connected to the lower wiring (Al wiring 20), the organic light-emitting element can be miniaturized.

[0052] (Variation 1) In the second embodiment, the reflective layer 40 of the organic light-emitting element 2 is formed by the damascene method (see Figs. 6B to 7A), but the reflective layer 40 can also be realized by a method other than the damascene method. In the damascene method, the conductor 22 is formed, and then the reflective layer 40 is formed and polished, but as described below, the conductor 22 may be formed after the reflective layer 40 is formed. That is, instead of the steps described using Figs. 6B to 7A, the following steps described using Figs. 8A to 9B may be performed.

[0053] (1) From the state shown in FIG. 6A, a reflective layer 40 is formed on the upper surface of the interlayer insulating layer 30, and after the reflective layer 40 is etched, an interlayer insulating layer 31 is formed as shown in FIG. 8A.

[0054] (2) As shown in FIG. 8B, the interlayer insulating layer 31 and the reflective layer 40 are polished by CMP.

[0055] (3) As shown in Fig. 8C, an opening 210 (through hole) is formed, and as shown in Fig. 9A, tungsten 222 is deposited so as to contact the reflective layer 40. Then, as shown in Fig. 9B, the tungsten 222 is polished by CMP to form the conductor 22. In this way, a member similar to the member shown in Fig. 7A can be formed.

[0056] <Embodiment 3> FIG. 10 is a cross-sectional view of an organic light-emitting element 3 of embodiment 3. In this embodiment, the conductor has a two-stage stack structure, and in the subpixel R, the conductor 22 in the first stage and the conductor 22r in the second stage are stacked. In the subpixel G, the conductor 22 in the first stage and the conductor 22g in the second stage are stacked, and in the subpixel B, the conductor 22 in the first stage and the conductor 22b in the second stage are stacked. In addition, the conductors in the two-stage stack structure have different lengths in the direction perpendicular to the main surface of the substrate 10 for each of the subpixels R, G, and B. For example, the length of the conductor in the subpixel R in the direction perpendicular to the main surface of the substrate 10 is longer than the length of the conductor in the subpixel G in the direction perpendicular to the main surface of the substrate 10. Here, the region corresponding to each subpixel in the organic light-emitting element 3 can be regarded as one light-emitting element, and embodiment 3 can also be regarded as an embodiment relating to a light-emitting device having a plurality of light-emitting elements. In this way, when this embodiment is regarded as an embodiment relating to a light-emitting device, it can be said that the length of the conductor in the two-stage stack structure is different for each light-emitting element of each subpixel.

[0057] In the third embodiment, the height of the upper surface of the conductors 22r, 22g, and 22b of each subpixel is higher than the upper surface of the reflective layer 40. In the following, the first electrodes 23 of the subpixels R, G, and B are referred to as first electrodes 23r, 23g, and 23b, respectively. Therefore, in the subpixel G, the shortest distance between the upper surface of the conductor 22r (the surface in contact with the first electrode 23r) and the substrate 10 is equal to or greater than the shortest distance between the optical adjustment layer (first interference film 101) and the substrate 10. This is similarly true for the subpixels G and B.

[0058] 11A to 12D are schematic cross-sectional views illustrating steps for forming the organic light-emitting element 3. The method for forming the organic light-emitting element 3 will be described below in the order of steps.

[0059] (1) In a procedure similar to the steps described in embodiment 1 with reference to FIGS. 3A to 3C, a first interference film 101 and a second interference film 102 are formed on the upper surface of the interlayer insulating layer 30, as shown in FIG. 3C.

[0060] (2) As shown in FIG. 11A, the first interference film 101 and the second interference film 102 are etched or otherwise processed so that the first interference film 101 and the second interference film 102 remain in subpixel R, and only the second interference film 102 remains in subpixel G.

[0061] 11B, in each subpixel, openings 231, 232, and 233 are formed above the conductor 22. At this time, the widths of the openings 231, 232, and 233 are set to be the same as the width of the conductor 22, and the openings 231, 232, and 233 are not tapered.

[0062] 11C, tungsten 222 (W) is filled into the openings 231, 232, and 233. At this time, the reflective layer 40 and the tungsten 222 in the subpixel B are in contact with each other via a barrier metal (not shown).

[0063] (5) When the tungsten 222 and the barrier metal (not shown) are etched back, as shown in FIG. 11D, conductors 22r, 22g, and 22b having different depths (lengths) depending on the subpixel are formed in the conductor 22 of each subpixel.

[0064] (6) As shown in FIG. 12A, a third interference film 103 is formed, thereby forming an interference film structure corresponding to each sub-pixel.

[0065] (7) As shown in Fig. 12B, openings 211, 212, and 213 connected to the first electrodes 23 of the respective subpixels are formed. At this time, the depths of the openings 211, 212, and 213 are the same as the thickness of the third interference film 103 and are smaller than the openings 211, 212, and 213 according to the first and second embodiments. This is advantageous for forming the first electrodes 23 by sputtering in a later process.

[0066] (8) The first electrodes 23r, 23g, and 23b are formed as shown in Fig. 12C, and then the bank insulating film 111 is formed as shown in Fig. 12D. Then, similarly to the first embodiment, the organic compound layer 50, the second electrode 60, and the protective layer 70 are formed, and the organic light-emitting element 2 according to the second embodiment is completed.

[0067] Since the surface steps of the first electrodes 23 (anode contact portions) of the subpixels are equal, the surfaces of the bank insulating films 111 and the first electrodes 23 can be made almost flat by appropriately selecting the thickness of the bank insulating film 111. This is advantageous in terms of preventing leakage between the anode and cathode in the contact region.

[0068] On the other hand, if the first electrodes 23r, 23g, and 23b are flat as shown in FIG. 13, the bank insulating film 111 will form a protrusion in the contact region, which may cause leakage between the anode and cathode.

[0069] Also, if the conductors 22r, 22g, and 22r are completely filled with W (tungsten), the bank insulating film is not necessary, but a gap called a "seam" usually remains. If the "seam" is exposed on the conductor surface, it can cause anode-cathode leakage. For this reason, in the third embodiment, the bank insulating film 111 covers the upper part of the conductors 22r, 22g, and 22r to prevent anode-cathode leakage.

[0070] In the third embodiment, the height of the upper surfaces of the conductors 22r, 22g, and 22b of each subpixel is higher than the upper surface of the reflective layer 40. This allows the recessed regions of the first electrode 23 to be made shallower than in the first and second embodiments. This allows the recessed regions of the first electrode 23 and the opening width (diameter) of the reflective layer 40 to be made narrower, thereby enabling further miniaturization of the organic light-emitting element.

[0071] <Embodiment 4> In the following, a fourth embodiment will be described in which the organic light-emitting element according to any one of the first to third embodiments is applied to various devices.

[0072] 15 is a schematic diagram showing an example of a display device according to this embodiment. The display device 1000 may have a touch panel 1003, a display panel 1005, a frame 1006, a circuit board 1007, and a battery 1008 between an upper cover 1001 and a lower cover 1009. Flexible printed circuits FPC1002 and 1004 are connected to the touch panel 1003 and the display panel 1005. Transistors are printed on the circuit board 1007. The battery 1008 may not be provided if the display device is not a portable device, and may be provided in a different position if the display device is a portable device.

[0073] The display device according to this embodiment may have color filters having red, green, and blue colors, the red, green, and blue colors being arranged in a delta arrangement.

[0074] The display device according to the present embodiment may be used as a display unit of a mobile terminal. In this case, the display device may have both a display function and an operation function. Examples of the mobile terminal include mobile phones such as smartphones, tablets, and head-mounted displays.

[0075] The display device according to the present embodiment may be used as a display unit of an imaging device having an optical unit with a plurality of lenses and an imaging element that receives light that has passed through the optical unit. The imaging device may have a display unit that displays information acquired by the imaging element. The display unit may be a display unit exposed to the outside of the imaging device, or may be a display unit disposed within a viewfinder. The imaging device may be a digital camera or a digital video camera.

[0076] 16A is a schematic diagram showing an example of an imaging device according to this embodiment. The imaging device 1100 may have a viewfinder 1101, a rear display 1102, an operation unit 1103, and a housing 1104. The viewfinder 1101 may have a display device according to this embodiment. In this case, the display device may display not only an image to be captured, but also environmental information, imaging instructions, and the like. The environmental information may include the intensity of external light, the direction of external light, the moving speed of the subject, the possibility that the subject will be blocked by an obstruction, and the like.

[0077] Since the timing suitable for imaging is short, it is better to display information as soon as possible. Therefore, it is preferable to use a display device using the organic light-emitting element according to any one of the first to third embodiments. This is because the organic light-emitting element has a fast response speed. Since a display speed is required, a display device using the organic light-emitting element can be used more preferably than a liquid crystal display device.

[0078] The imaging device 1100 has an optical section (not shown). The optical section has a plurality of lenses, which form an image on an imaging element housed in a housing 1104. The focus of the plurality of lenses can be adjusted by adjusting their relative positions. This operation can also be performed automatically. The imaging device may be called a photoelectric conversion device. The photoelectric conversion device can include an imaging method that does not capture images sequentially, but detects the difference from the previous image, cuts out an image from an image that is always recorded, and the like.

[0079] FIG. 16B is a schematic diagram showing an example of an electronic device according to this embodiment. The electronic device 1200 has a display unit 1201, an operation unit 1202, and a housing 1203. The housing 1203 may have a circuit, a printed circuit board having the circuit, a battery, and a communication unit. The operation unit 1202 may be a button or a touch panel type reaction unit. The operation unit may be a biometric recognition unit that recognizes a fingerprint and performs unlocking or the like. An electronic device having a communication unit can also be called a communication device. The electronic device may further have a camera function by including a lens and an image sensor. An image captured by the camera function is displayed on the display unit. Examples of the electronic device include a smartphone and a notebook computer.

[0080] 17A and 17B are schematic diagrams illustrating an example of a display device according to this embodiment. Reference numeral 17A denotes a display device such as a television monitor, a PC monitor, etc. A display device 1300 has a frame 1301 and a display unit 1302. The display unit 1302 may use the organic light-emitting element according to any one of the first to third embodiments.

[0081] It has a frame 1301 and a base 1303 that supports a display unit 1302. The base 1303 is not limited to the form shown in Fig. 17A. The lower side of the frame 1301 may also serve as the base.

[0082] The frame 1301 and the display unit 1302 may be curved. The radius of curvature may be 5000 mm or more and 6000 mm or less.

[0083] FIG. 17B is a schematic diagram showing another example of the display device according to the present embodiment. The display device 1310 in FIG. 17B is configured to be bendable, and is a so-called foldable display device. The display device 1310 has a first display unit 1311, a second display unit 1312, a housing 1313, and a bending point 1314. The first display unit 1311 and the second display unit 1312 may use the organic light-emitting element according to any one of the first to third embodiments. The first display unit 1311 and the second display unit 1312 may be a single display unit without a joint. The first display unit 1311 and the second display unit 1312 can be separated by the bending point. The first display unit 1311 and the second display unit 1312 may display different images, or the first and second display units may display a single image.

[0084] FIG. 18A is a schematic diagram showing an example of the lighting device according to the present embodiment. The lighting device 1400 may have a housing 1401, a light source 1402, a circuit board 1403, an optical film 1404, and a light diffusion section 1405. The light source may have an organic light-emitting element according to any one of the first to third embodiments. The optical filter may be a filter that improves the color rendering of the light source. The light diffusion section can effectively diffuse the light of the light source, such as for lighting up, and deliver the light over a wide range. The optical filter and the light diffusion section may be provided on the light emission side of the lighting. If necessary, a cover may be provided on the outermost part.

[0085] The lighting device is, for example, a device that illuminates a room. The lighting device may emit white light, neutral white light, or any other color from blue to red. It may have a dimming circuit that dims the light. The lighting device may have an organic light-emitting element according to any one of the first to third embodiments and a power supply circuit connected thereto. The power supply circuit is a circuit that converts AC voltage into DC voltage. Moreover, white is a color with a color temperature of 4200K, and neutral white is a color with a color temperature of 5000K. The lighting device may have a color filter.

[0086] The lighting device according to the present embodiment may also include a heat dissipation section that dissipates heat from within the device to the outside, and examples of the heat dissipation section include metals with high specific heat, liquid silicon, and the like.

[0087] 18B is a schematic diagram of an automobile, which is an example of a moving body according to this embodiment. The automobile has tail lamps, which are an example of a lamp. The automobile 1500 has tail lamps 1501, and may be configured to turn on the tail lamps 1501 when braking or the like is performed.

[0088] The tail lamp 1501 may have an organic light-emitting element according to any one of the first to third embodiments. The tail lamp 1501 may have a protective member for protecting the organic EL element. The protective member may be made of any material as long as it has a certain degree of strength and is transparent, but is preferably made of polycarbonate or the like. A furandicarboxylic acid derivative, an acrylonitrile derivative, or the like may be mixed with the polycarbonate.

[0089] The automobile 1500 may have a body 1503 and a window 1502 attached thereto. The window may be a transparent display as long as it is not a window for checking the front and rear of the vehicle. The transparent display may have the organic light-emitting element according to any one of the first to third embodiments. In this case, the constituent materials of the electrodes and the like of the organic light-emitting element are made of transparent members.

[0090] The moving body according to the present embodiment may be a ship, an aircraft, a drone, or the like. The moving body may have a body and a lighting device provided on the body. The lighting device may emit light to notify the position of the body. The lighting device has the organic light-emitting element according to any one of the first to third embodiments.

[0091] An application example of the above-mentioned display device will be described with reference to Fig. 19A and Fig. 19B. The display device can be applied to a system that can be worn as a wearable device such as smart glasses, HMD, and smart contacts. The image capturing and display device used in such an application example has an image capturing device capable of photoelectrically converting visible light, and a display device capable of emitting visible light.

[0092] 19A illustrates glasses 1600 (smart glasses) according to one application example. An imaging device 1602 such as a CMOS sensor or a SPAD is provided on the front side of a lens 1601 of the glasses 1600. In addition, the above-mentioned display device is provided on the back side of the lens 1601.

[0093] The glasses 1600 further include a control device 1603. The control device 1603 functions as a power source that supplies power to the image capture device 1602 and the display device according to this embodiment. The control device 1603 also controls the operations of the image capture device 1602 and the display device. The lens 1601 is formed with an optical system for focusing light on the image capture device 1602.

[0094] FIG. 19B illustrates glasses 1610 (smart glasses) according to one application example. The glasses 1610 have a control device 1612, and the control device 1612 is equipped with an imaging device equivalent to the imaging device 1602 and a display device. The lens 1611 is formed with an optical system for projecting light emitted from the imaging device in the control device 1612 and the display device, and an image is projected onto the lens 1611. The control device 1612 functions as a power source for supplying power to the imaging device and the display device, and controls the operation of the imaging device and the display device. The control device may have a line-of-sight detection unit that detects the line of sight of the wearer. Infrared light may be used for detecting the line of sight. The infrared light emission unit emits infrared light toward the eyeball of a user gazing at a display image. An imaging unit having a light receiving element detects the reflected light of the emitted infrared light from the eyeball, thereby obtaining an image of the eyeball. By having a reduction means for reducing light from the infrared light emission unit to the display unit in a planar view, deterioration of image quality is reduced.

[0095] The gaze of the user with respect to the displayed image is detected from an image of the eyeball obtained by capturing infrared light. Any known method can be applied to gaze detection using the image of the eyeball. As an example, a gaze detection method based on a Purkinje image formed by reflection of irradiated light on the cornea can be used.

[0096] More specifically, the gaze detection process is performed based on the pupil-corneal reflex method. Using the pupil-corneal reflex method, a gaze vector that indicates the direction (rotation angle) of the eyeball is calculated based on the pupil image and the Purkinje image included in the captured image of the eyeball, thereby detecting the user's gaze.

[0097] A display device according to one embodiment may have an imaging device having a light receiving element, and may control a display image on the display device based on information about a user's line of sight from the imaging device.

[0098] Specifically, the display device determines a first field of view area to which the user is gazing and a second field of view area other than the first field of view area based on the line-of-sight information. The first field of view area and the second field of view area may be determined by a control device of the display device, or may be determined by an external control device. In the display area of ​​the display device, the display resolution of the first viewing area may be controlled to be higher than the display resolution of the second viewing area, that is, the resolution of the second viewing area may be lower than the first viewing area.

[0099] The display area includes a first display area and a second display area different from the first display area, and a high priority area is determined from the first display area and the second display area based on line-of-sight information. The first field of view area and the second field of view area may be determined by a control device of the display device, or may be determined by an external control device and received. The resolution of the high priority area may be controlled to be higher than the resolution of areas other than the high priority area. In other words, the resolution of an area with a relatively low priority may be lowered.

[0100] AI may be used to determine the first field of view area and areas with high priority. The AI ​​may be a model configured to estimate the angle of the line of sight and the distance to an object in the line of sight from an image of the eyeball, using an image of the eyeball and the direction in which the eyeball in the image was actually looking as teacher data. The AI ​​program may be included in the display device, the imaging device, or an external device. If included in the external device, it is transmitted to the display device via communication.

[0101] When display control is performed based on visual recognition detection, the present invention is preferably applied to smart glasses that further include an imaging device for capturing images of the outside world. The smart glasses can display captured outside information in real time.

[0102] As described above, by using a device using the organic light-emitting element according to this embodiment, it is possible to achieve a display with good image quality and stability even over a long period of time. [Explanation of symbols]

[0103] 1: organic light-emitting element, 10: substrate, 20: aluminum wiring, 22: conductor, 23: first electrode, 30: interlayer insulating layer, 40: reflective layer, 50: organic compound layer, 60: second electrode, 101: first interference film, 102: second interference film, 103: Third interference film

Claims

1. A light emitting device having a light emitting region and a contact region, The light-emitting element has, in the light-emitting region, a wiring layer, an interlayer insulating layer, a reflective layer, an optical adjustment layer, a first electrode, a light-emitting layer, and a second electrode, in this order from the substrate side; the light-emitting element has, in the contact region, the wiring layer, a conductor, the first electrode, the light-emitting layer, and the second electrode, in this order from the substrate side; the conductor is electrically connected to both the first electrode and the wiring layer; In the contact region, the top surface of the first electrode has a recessed region; a shortest distance between the first electrode and the substrate in the contact region is equal to or greater than a shortest distance between the reflective layer and the substrate in the light-emitting region; the reflective layer has an opening; In a plan view of the substrate, the contact region is included in the opening. A light-emitting device characterized by:

2. A light emitting device having a light emitting region and a contact region, the light-emitting element has, in the light-emitting region, a wiring layer, an interlayer insulating layer, a reflective layer, an optical adjustment layer, a first electrode, a light-emitting layer, and a second electrode, in this order from the substrate side; the light-emitting element has, in the contact region, the wiring layer, a conductor, the first electrode, the light-emitting layer, and the second electrode, in this order from the substrate side; the conductor is electrically connected to both the first electrode and the wiring layer; In the contact region, the top surface of the first electrode has a recessed region; In a plan view of the substrate, the area of ​​the conductor is smaller than the area of ​​the wiring layer. A light-emitting device characterized by:

3. the reflective layer has an opening; In a plan view of the substrate, the contact region is included in the opening. The light-emitting device according to claim 2 .

4. The conductor has a plug shape. The light-emitting device according to claim 1 .

5. the reflective layer is made of a first metal; The conductor is made of a second metal different from the first metal. The light-emitting device according to claim 1 .

6. the first electrode and the conductor are in physical contact; the first electrode is made of indium tin oxide; The conductor is made of a metal including tungsten. The light-emitting device according to claim 1 .

7. The reflective layer is made of a metal including aluminum. The light-emitting device according to claim 1 .

8. The wiring layer is made of a metal including aluminum. The light-emitting device according to claim 1 .

9. In the contact region, an insulating layer is disposed between the first electrode and the light emitting layer. The light-emitting device according to claim 1 .

10. A surface of the conductor in the contact region that is in contact with the first electrode is closer to the substrate than the first electrode in the light emitting region. The light-emitting device according to claim 1 .

11. An insulating layer is disposed at an edge of the light emitting region, The angle of the outer wall of the recessed region of the first electrode in the contact region with respect to the main surface of the substrate is smaller than the angle of the side of the insulating layer disposed at the edge of the light emitting region with respect to the main surface of the substrate. The light-emitting device according to claim 1 .

12. A light emitting device having a plurality of sub-pixels arranged on a substrate, Each of the sub-pixels includes the light-emitting element according to claim 1 , the plurality of subpixels include a first subpixel and a second subpixel; The length of the conductor of the light-emitting element of the first sub-pixel in a direction perpendicular to the main surface of the substrate is different from the length of the conductor of the light-emitting element of the second sub-pixel in a direction perpendicular to the main surface of the substrate. A light emitting device characterized by:

13. The conductor is a laminate of a first conductor and a second conductor, The length of the second conductor of the light emitting element of the first subpixel in a direction perpendicular to the main surface of the substrate is different from the length of the second conductor of the light emitting element of the second subpixel in a direction perpendicular to the main surface of the substrate.

13. The light emitting device according to claim 12.

14. The shortest distance between the surface of the second conductor that is in contact with the first electrode and the substrate is equal to or greater than the shortest distance between the optical adjustment layer and the substrate.

14. The light emitting device according to claim 13.

15. An optical section having a plurality of lenses; an imaging element that receives light that has passed through the optical unit; a display unit that displays an image captured by the imaging element, The display unit has a light-emitting element according to any one of claims 1 to 11. A photoelectric conversion device comprising:

16. A display section having the light-emitting element according to any one of claims 1 to 11; A housing provided with the display unit; a communication unit provided in the housing and configured to communicate with an external device; 1. An electronic device comprising:

Images