Indication device

Abstract

Provided is a high-definition display device. The display device has a first light emission device, a second light emission device, a first sidewall insulation layer, a second sidewall insulation layer, an insulation layer, a first coloration layer, and a second coloration layer. The first light emission device has a first pixel electrode, a first EL layer, and a common electrode. The second light emission device has a second pixel electrode, a second EL layer, and a common electrode. The first EL layer and the second EL layer display white light. The first sidewall insulation layer contacts a side surface of the first pixel electrode, and the second sidewall insulation layer contacts a side surface of the second pixel electrode. The insulation layer covers a side surface and a part of the upper surface of the first EL layer, and a side surface and a part of the upper surface of the second EL layer. The first coloration layer overlaps with the first light emission device, and the second coloration layer overlaps with the second light emission device. The first coloration layer and the second coloration layer each have a function of transmitting light of a different color.

Description

Display device, display module, and electronic device

[0001] 1. Field of the Invention One embodiment of the present invention relates to a display device, a display module, and an electronic device. 2. Description of the Related Art One embodiment of the present invention relates to a manufacturing method of a display device.

[0002] Note that one embodiment of the present invention is not limited to the above technical field. Examples of the technical field of one embodiment of the present invention include a semiconductor device, a display device, a light-emitting device, a power storage device, a memory device, a lighting device, an input device (for example, a touch sensor), an input / output device (for example, a touch panel), a display module including any of these devices, an electronic device including the display module, a driving method thereof, or a manufacturing method thereof.

[0003] In recent years, display devices have been expected to be used in a variety of applications. For example, applications of large display devices include home television devices (also referred to as televisions or television receivers), digital signage, public information displays (PIDs), etc. Furthermore, development of mobile information terminals such as smartphones and tablet terminals equipped with touch panels is progressing.

[0004] There is also a demand for higher definition display devices. Devices requiring high-definition display devices, such as devices for virtual reality (VR), augmented reality (AR), substitutional reality (SR), and mixed reality (MR), are being actively developed.

[0005] As a display device, for example, a light-emitting device having a light-emitting device (also referred to as a light-emitting element) has been developed. A light-emitting device (also referred to as an EL device or an EL element) utilizing the electroluminescence (hereinafter referred to as EL) phenomenon has features such as being easily thin and lightweight, being capable of high-speed response to input signals, and being capable of being driven by a DC constant voltage power supply, and is therefore applied to a display device.

[0006] Patent Document 1 discloses a display device for VR that uses an organic EL device (also called an organic EL element).

[0007] International Publication No. 2018 / 087625

[0008] An object of one embodiment of the present invention is to provide a high-resolution display device.An object of one embodiment of the present invention is to provide a high-resolution display device.An object of one embodiment of the present invention is to provide a highly reliable display device.

[0009] An object of one embodiment of the present invention is to provide a method for manufacturing a high-resolution display device.An object of one embodiment of the present invention is to provide a method for manufacturing a high-resolution display device.An object of one embodiment of the present invention is to provide a method for manufacturing a highly reliable display device.An object of one embodiment of the present invention is to provide a method for manufacturing a display device with high yield.

[0010] Note that the description of these problems does not preclude the existence of other problems. One embodiment of the present invention does not necessarily solve all of these problems. Problems other than these can be extracted from the description in the specification, drawings, and claims.

[0011] One aspect of the present invention provides a first light-emitting device, a second light-emitting device, a first sidewall insulating layer, a second sidewall insulating layer, a first insulating layer, a first colored layer, and a second colored layer, wherein the first light-emitting device has a first pixel electrode, a first EL layer on the first pixel electrode, and a common electrode on the first EL layer, and the second light-emitting device has a second pixel electrode, a second EL layer on the second pixel electrode, and a common electrode on the second EL layer, and the first EL layer and the second EL layer each emit blue light. a first sidewall insulating layer contacting a side surface of the first pixel electrode; a second sidewall insulating layer contacting a side surface of the second pixel electrode; a first insulating layer covering a part of the upper surface and the side surface of the first EL layer and a part of the upper surface and the side surface of the second EL layer; a first colored layer overlapping a first light-emitting device; a second colored layer overlapping a second light-emitting device; and a display device having a function of transmitting light of different colors.

[0012] In the above, it is preferable that a material layer isolated from the first EL layer and the second EL layer is provided between the first light-emitting device and the second light-emitting device, and the material layer includes a first light-emitting material and a second light-emitting material.

[0013] In the above, the first sidewall insulating layer and the second sidewall insulating layer preferably each contain an inorganic insulating material.

[0014] In the above, the first insulating layer preferably has a tapered shape at the end.

[0015] In the above, the first insulating layer preferably contains an organic insulating material.

[0016] In the above, it is preferable to have a second insulating layer covering a portion of the top surface and the side surface of the first EL layer and a portion of the top surface and the side surface of the second EL layer, and to have a first insulating layer on the second insulating layer.

[0017] In the above, the second insulating layer preferably has a tapered shape at the end.

[0018] In the above, the second insulating layer preferably contains an inorganic insulating material.

[0019] Another embodiment of the present invention is a display module including the display device described above and at least one of a connector and an integrated circuit.

[0020] Another embodiment of the present invention is an electronic device including the above-described display module and at least one of a housing, a battery, a camera, a speaker, and a microphone.

[0021] According to one embodiment of the present invention, a high-definition display device can be provided. According to one embodiment of the present invention, a high-resolution display device can be provided. According to one embodiment of the present invention, a highly reliable display device can be provided.

[0022] According to one embodiment of the present invention, a method for manufacturing a high-resolution display device can be provided. According to one embodiment of the present invention, a method for manufacturing a high-resolution display device can be provided. According to one embodiment of the present invention, a method for manufacturing a highly reliable display device can be provided. According to one embodiment of the present invention, a method for manufacturing a display device with high yield can be provided.

[0023] Note that the description of these effects does not preclude the existence of other effects. One embodiment of the present invention does not necessarily have all of these effects. Effects other than these can be extracted from the description in the specification, drawings, and claims.

[0024] FIG. 1A is a top view showing an example of a display device. FIG. 1B is a cross-sectional view showing an example of a display device. FIG. 2 is a cross-sectional view showing an example of a display device. FIGS. 3A to 3D are cross-sectional views showing an example of a display device. FIGS. 4A and 4B are cross-sectional views showing an example of a display device. FIGS. 5A and 5B are cross-sectional views showing an example of a display device. FIGS. 6A and 6B are cross-sectional views showing an example of a display device. FIGS. 7A and 7B are cross-sectional views showing an example of a display device. FIGS. 8A and 8B are cross-sectional views showing an example of a display device. FIGS. 9A to 9C are cross-sectional views showing an example of a display device. FIG. 10 is a cross-sectional view showing an example of a display device. FIGS. 11A and 11B are cross-sectional views showing an example of a display device. FIGS. 12A and 12B are cross-sectional views showing an example of a display device. FIGS. 13A and 13B are cross-sectional views showing an example of a display device. FIGS. 14A to 14E are cross-sectional views showing an example of a manufacturing method of a display device. FIGS. 15A to 15D are cross-sectional views showing an example of a manufacturing method of a display device. FIGS. 16A to 16F are cross-sectional views showing an example of a manufacturing method of a display device. FIGS. 17A to 17G are diagrams showing an example of a pixel. FIGS. 18A to 18I are diagrams showing an example of a pixel. FIGS. 19A and 19B are perspective views showing an example of a display device. FIG. 20 is a cross-sectional view showing an example of a display device. FIG. 21 is a cross-sectional view showing an example of a display device. FIG. 22 is a cross-sectional view showing an example of a display device. FIG. 23 is a cross-sectional view showing an example of a display device. FIG. 24 is a cross-sectional view showing an example of a display device. FIG. 25 is a cross-sectional view showing an example of a display device. FIG. 26 is a perspective view showing an example of a display device. FIG. 27A is a cross-sectional view showing an example of a display device. FIGS. 27B and 27C are cross-sectional views showing an example of a transistor. FIGS. 28A to 28D are cross-sectional views showing an example of a display device. FIGS. 29A to 29F are diagrams showing an example of a configuration of a light-emitting device. FIGS. 30A to 30C are diagrams showing an example of a configuration of a light-emitting device. FIGS. 31A to 31D are diagrams showing an example of an electronic device. FIGS. 32A to 32F are diagrams showing an example of an electronic device. FIGS. 33A to 33G are diagrams showing an example of an electronic device.

[0025] Hereinafter, embodiments will be described in detail with reference to the drawings. However, the present invention is not limited to the following description, and it will be readily understood by those skilled in the art that various changes can be made in form and detail without departing from the spirit and scope of the present invention. Therefore, the present invention should not be interpreted as being limited to the description of the embodiments shown below.

[0026] In the configuration of the invention described below, the same parts or parts having similar functions are denoted by the same reference numerals in different drawings, and repeated explanations thereof will be omitted. Furthermore, when referring to similar functions, the same hatching pattern may be used and no particular reference numeral may be assigned.

[0027] Furthermore, for ease of understanding, the position, size, range, etc. of each component shown in the drawings may not represent the actual position, size, range, etc. Therefore, the disclosed invention is not necessarily limited to the position, size, range, etc. disclosed in the drawings.

[0028] It should be noted that the terms "film" and "layer" can be interchangeable depending on the circumstances. For example, the term "conductive layer" can be changed to the term "conductive film." Or, for example, the term "insulating film" can be changed to the term "insulating layer."

[0029] In this specification, etc., a device fabricated using a metal mask or an FMM (fine metal mask, high-resolution metal mask) may be referred to as a device with an MM (metal mask) structure. In addition, in this specification, etc., a device fabricated without using a metal mask or an FMM may be referred to as a device with an MML (metal maskless) structure.

[0030] In this specification and the like, holes or electrons may be referred to as "carriers." Specifically, a hole injection layer or an electron injection layer may be referred to as a "carrier injection layer," a hole transport layer or an electron transport layer may be referred to as a "carrier transport layer," and a hole block layer or an electron block layer may be referred to as a "carrier block layer." Note that the above-mentioned carrier injection layer, carrier transport layer, and carrier block layer may not be clearly distinguishable from each other depending on their cross-sectional shapes or characteristics. Furthermore, one layer may have two or three functions among the carrier injection layer, carrier transport layer, and carrier block layer.

[0031] In this specification and the like, a light-emitting device has an EL layer between a pair of electrodes. The EL layer has at least a light-emitting layer. Here, examples of layers (also referred to as functional layers) included in the EL layer include a light-emitting layer, a carrier injection layer (a hole injection layer and an electron injection layer), a carrier transport layer (a hole transport layer and an electron transport layer), and a carrier block layer (a hole block layer and an electron block layer). In this specification and the like, one of the pair of electrodes may be referred to as a pixel electrode, and the other may be referred to as a common electrode.

[0032] In this specification, the term "island-like" refers to a state in which two or more layers made of the same material and formed in the same process are physically separated. For example, an island-like light-emitting layer refers to a state in which the light-emitting layer is physically separated from the adjacent light-emitting layer.

[0033] In this specification and the like, the term "step discontinuity" refers to a phenomenon in which a layer, a film, or an electrode is divided due to the shape of the surface on which it is formed (for example, a step or the like).

[0034] In this specification and the like, a tapered shape refers to a shape in which at least a portion of the side surface of a structure is inclined with respect to the substrate surface or the surface on which the structure is to be formed. For example, it refers to a shape having a region in which the angle (also referred to as the taper angle) between the inclined side surface and the substrate surface or the surface on which the structure is to be formed is less than 90°. Note that the side surface of the structure, the surface on which the structure is to be formed, and the substrate surface do not necessarily need to be completely flat, and may be approximately planar with a slight curvature or approximately planar with a slight unevenness.

[0035] Embodiment 1 In this embodiment, a display device of one embodiment of the present invention will be described with reference to FIGS.

[0036] A display device according to one embodiment of the present invention includes a plurality of sub-pixels, each of which includes a light-emitting device having the same light-emitting material and a colored layer overlapping the light-emitting device. By providing a colored layer that transmits visible light of a different color depending on the sub-pixel, full-color display can be achieved.

[0037] When using light-emitting devices having the same light-emitting material, layers other than pixel electrodes (e.g., light-emitting layers) included in the light-emitting device can be common to multiple sub-pixels. This allows multiple sub-pixels to share a continuous film. However, some layers included in the light-emitting device have relatively high conductivity. When multiple sub-pixels share a highly conductive layer as a continuous film, leakage current may occur between the sub-pixels. In particular, as display devices become higher in definition or aperture ratio and the distance between sub-pixels becomes smaller, this leakage current can become significant and may cause a deterioration in the display quality of the display device.

[0038] Therefore, in a display device according to one embodiment of the present invention, the EL layer shared by a plurality of light-emitting devices has a locally thin portion, or each of the plurality of light-emitting devices has an island-shaped EL layer. By configuring the EL layer to have a thin portion (which can also be referred to as a thin portion) or by configuring the EL layer to be separated for each light-emitting device, crosstalk between adjacent subpixels can be suppressed. This allows the display device to achieve high color reproducibility and high contrast, thereby achieving both high resolution and high display quality. Note that in the display device according to one embodiment of the present invention, the EL layer may be formed in an island shape in some subpixels, and in the other subpixels, the EL layer may be a continuous layer. In this case, it is preferable that the continuous layer has a locally thin portion.

[0039] For example, an island-shaped EL layer can be formed by vacuum deposition using a metal mask. However, this method can cause deviations in the shape and position of the island-shaped EL layer from the design due to various factors, such as the accuracy of the metal mask, misalignment between the metal mask and the substrate, deflection of the metal mask, and spreading of the contours of the formed film due to vapor scattering, making it difficult to achieve high-definition and high-aperture display devices. Furthermore, during deposition, the contours of the layer can become blurred, resulting in thin edges. In other words, the thickness of the island-shaped EL layer formed using a metal mask can vary depending on the location. Furthermore, when manufacturing large, high-resolution, or high-definition display devices, there is a concern that the manufacturing yield will be low due to the low dimensional accuracy of the metal mask and deformation due to heat, etc.

[0040] Therefore, when manufacturing a display device according to one embodiment of the present invention, an island-shaped EL layer is formed without using a shadow mask (for example, a metal mask).

[0041] For example, the greater the difference in height between the upper surface of the insulating layer exposed between adjacent pixel electrodes and the upper surface of the pixel electrode (which can also be referred to as the step between adjacent pixel electrodes), the easier it is to form locally thin portions in the EL layer or even to divide the EL layer to form island-shaped EL layers for each light-emitting device. By utilizing the step between adjacent pixel electrodes, the EL layer can be partially thinned or divided in a self-aligned manner when forming the EL layer. In other words, crosstalk can be suppressed without increasing the number of processes, and a display device with high color reproducibility and contrast can be realized.

[0042] Furthermore, if the EL layer has a thin portion or is separated for each light-emitting device, there is a risk of the light-emitting device shorting out due to the common electrode coming into contact with the exposed portion of the pixel electrode.

[0043] Therefore, in a manufacturing method of a display device according to one embodiment of the present invention, a sidewall insulating layer (also referred to as a sidewall, a sidewall protective layer, an insulating layer, or the like) is provided in contact with a side surface of a pixel electrode, which can prevent the pixel electrode from being in contact with a common electrode, prevent a short circuit in the light-emitting device, and improve the reliability of the light-emitting device.

[0044] Furthermore, if the step between adjacent pixel electrodes is large, the step may cause a disconnection of the common electrode provided on the EL layer.

[0045] Therefore, in a method for manufacturing a display device according to one embodiment of the present invention, an insulating layer is provided so as to cover at least a part of the top surface and side surfaces of the island-shaped EL layer. Then, a common electrode is provided so as to cover the insulating layer and the EL layer. This can prevent the common electrode from being disconnected due to a step between adjacent pixel electrodes.

[0046] In addition, it is preferable that the end of the insulating layer has a tapered shape with a taper angle of less than 90° in a cross-sectional view. This can prevent a step in the common electrode provided on the insulating layer and suppress poor connection of the common electrode. Furthermore, it can suppress an increase in the electrical resistance of the common electrode due to a local thinning of the common electrode caused by the step at the end of the insulating layer.

[0047] In this manner, the island-shaped EL layer manufactured by the manufacturing method of the display device according to one embodiment of the present invention is formed not using a fine metal mask but by utilizing the steps between pixel electrodes, thereby realizing a high-definition display device or a display device with a high aperture ratio, which has been difficult to achieve until now.

[0048] Although it is difficult to reduce the distance between adjacent light-emitting regions (which can also be referred to as the shortest distance) to less than 10 μm using, for example, a formation method that uses a fine metal mask, the method for manufacturing a display device according to one embodiment of the present invention makes it possible to narrow the distance between adjacent light-emitting regions, adjacent EL layers, adjacent sidewall insulating layers, or adjacent pixel electrodes to, for example, less than 10 μm, 8 μm or less, 5 μm or less, 3 μm or less, 2 μm or less, 1.5 μm or less, 1 μm or less, or 0.5 μm or less in a process on a glass substrate. Furthermore, by using, for example, an exposure apparatus for LSIs, the distance between adjacent light-emitting regions, adjacent EL layers, adjacent sidewall insulating layers, or adjacent pixel electrodes can be narrowed to, for example, 500 nm or less, 200 nm or less, 100 nm or less, or even 50 nm or less in a process on a Si wafer. This allows the area of ​​a non-light-emitting region that may exist between two light-emitting devices to be significantly reduced, and the aperture ratio can approach 100%. For example, in a display device according to one embodiment of the present invention, the aperture ratio can be 40% or more, 50% or more, 60% or more, 70% or more, 80% or more, or even 90% or more, but less than 100%.

[0049] Increasing the aperture ratio of a display device can improve the reliability of the display device. Specifically, as the aperture ratio increases, the current density flowing through the light-emitting device can be reduced, thereby improving the lifespan of the display device.

[0050] The resolution of the display device of one embodiment of the present invention can be, for example, 1000 ppi or more, preferably 2000 ppi or more, preferably 3000 ppi or more, more preferably 5000 ppi or more, and still more preferably 6000 ppi or more, and can be 20000 ppi or less, or 30000 ppi or less.

[0051] In this embodiment, a cross-sectional structure of a display device according to one embodiment of the present invention will be mainly described, and a manufacturing method of the display device according to one embodiment of the present invention will be described in detail in Embodiment 2.

[0052] FIG. 1A shows a top view of a display device 100. The display device 100 has a display section in which a plurality of pixels 110 are arranged, and a connection section 140 outside the display section. A plurality of sub-pixels are arranged in a matrix in the display section. FIG. 1A shows two rows and six columns of sub-pixels, which together form two rows and two columns of pixels 110. The connection section 140 can also be called a cathode contact section.

[0053] The top surface shape of the sub-pixel shown in FIG. 1A corresponds to the top surface shape of the light-emitting region.

[0054] The top surface shape of the subpixel may be, for example, a triangle, a quadrangle (including a rectangle, a diamond, and a square), a polygon such as a pentagon, a polygon with rounded corners, an ellipse, or a circle.

[0055] Furthermore, the circuit layout constituting the subpixel is not limited to the range of the subpixel shown in Fig. 1A and may be arranged outside of it. That is, some or all of the transistors (not shown) included in the subpixel 11R shown in Fig. 1A may be located outside the range of the subpixel 11R. The transistors included in the subpixel 11R may be located within the range of the subpixel 11R, the range of the subpixel 11G, or the range of the subpixel 11B shown in Fig. 1A, or may be arranged across multiple of these ranges.

[0056] 1A shows the subpixels 11R, 11G, and 11B as having the same or approximately the same aperture ratio (which can also be referred to as the size or the size of the light-emitting region), but this is not a limitation of one embodiment of the present invention. The aperture ratios of the subpixels 11R, 11G, and 11B can be determined as appropriate. The aperture ratios of the subpixels 11R, 11G, and 11B may be different from one another, or two or more of them may be the same or approximately the same.

[0057] A stripe arrangement is applied to the pixel 110 shown in FIG. 1A. The pixel 110 shown in FIG. 1A is composed of three subpixels: subpixel 11R, subpixel 11G, and subpixel 11B. The subpixels 11R, 11G, and 11B emit light of different colors. Examples of the subpixels 11R, 11G, and 11B include subpixels of three colors: red (R), green (G), and blue (B), and subpixels of three colors: yellow (Y), cyan (C), and magenta (M). The number of types of subpixels is not limited to three, and may be four or more. Examples of the four subpixels include subpixels of four colors: R, G, B, and white (W), subpixels of four colors: R, G, B, and Y, and subpixels of R, G, B, and infrared light (IR).

[0058] In this specification and the like, the row direction may be referred to as the X direction, and the column direction may be referred to as the Y direction. The X direction and the Y direction intersect, for example, perpendicularly (see FIG. 1A ). FIG. 1A shows an example in which subpixels of different colors are arranged side by side in the X direction, and subpixels of the same color are arranged side by side in the Y direction.

[0059] 1A shows an example in which the connection unit 140 is located below the display unit when viewed from above, but this is not particularly limited. The connection unit 140 only needs to be located in at least one of the upper, right, left, and lower sides of the display unit when viewed from above, and may be located so as to surround all four sides of the display unit. The top surface shape of the connection unit 140 may be strip-shaped, L-shaped, U-shaped, frame-shaped, or the like. Furthermore, the connection unit 140 may be singular or plural.

[0060] Fig. 1B shows a cross-sectional view taken along dashed line X1-X2 in Fig. 1A. Fig. 2 shows a cross-sectional view taken along dashed line Y1-Y2 in Fig. 1A. Fig. 3A shows an enlarged view of region 150A shown in Fig. 1B. Figs. 3B to 3D show regions 150B to 150D, respectively, which are modifications of region 150A.

[0061] The sub-pixel 11R has a light-emitting device 130R and a colored layer 132R that transmits red light, so that light emitted from the light-emitting device 130R is extracted as red light to the outside of the display device via the colored layer 132R.

[0062] The sub-pixel 11G has a light-emitting device 130G and a colored layer 132G that transmits green light, so that light emitted from the light-emitting device 130G is extracted as green light to the outside of the display device via the colored layer 132G.

[0063] The subpixel 11B has a light-emitting device 130B and a colored layer 132B that transmits blue light, so that light emitted from the light-emitting device 130B is extracted as blue light to the outside of the display device via the colored layer 132B.

[0064] Here, examples of blue light include light whose emission spectrum has a peak wavelength of 400 nm or more and less than 480 nm, examples of green light include light whose emission spectrum has a peak wavelength of 480 nm or more and less than 580 nm, and examples of red light include light whose emission spectrum has a peak wavelength of 580 nm or more and less than 700 nm.

[0065] The colored layer is a colored layer that selectively transmits light in a specific wavelength range and absorbs light in other wavelength ranges. For example, a color filter that transmits light in the red wavelength range can be used for the colored layer 132R. For example, a color filter that transmits light in the green wavelength range can be used for the colored layer 132G. For example, a color filter that transmits light in the blue wavelength range can be used for the colored layer 132B. Examples of materials that can be used for the colored layers include metal materials, resin materials, and resin materials containing pigments or dyes.

[0066] As shown in FIG. 1B , in the display device 100, insulating layers (insulating layer 255a, insulating layer 255b, and insulating layer 255c) are provided on a layer 101 including a transistor (not shown). Light-emitting devices 130R, 130G, and 130B are provided on the insulating layer, and a protective layer 131 and an insulating layer 135 are provided to cover these light-emitting devices. Colored layers 132R, 132G, and 132B are provided on the insulating layer 135, and a substrate 120 is bonded to the colored layers 132R, 132G, and 132B by a resin layer 122. The colored layer 132R is provided at a position overlapping the light-emitting device 130R. The colored layer 132G is provided at a position overlapping the light-emitting device 130G. The colored layer 132B is provided at a position overlapping the light-emitting device 130B. In addition, an insulating layer 125 and an insulating layer 127 on the insulating layer 125 are provided in the region between adjacent light emitting devices.

[0067] 1B shows multiple cross sections of insulating layer 125 and insulating layer 127, but when display device 100 is viewed from above, insulating layer 125 and insulating layer 127 are each connected to one another. That is, display device 100 can be configured to have, for example, one insulating layer 125 and one insulating layer 127. Note that display device 100 may have multiple insulating layers 125 that are separated from one another, or may have multiple insulating layers 127 that are separated from one another.

[0068] The display device of one embodiment of the present invention may be any of a top-emission type that emits light in a direction opposite to a substrate on which a light-emitting device is formed, a bottom-emission type that emits light toward a substrate on which a light-emitting device is formed, and a dual-emission type that emits light to both sides. In this embodiment, a top-emission display device will be described as an example.

[0069] The layer 101 can have, for example, a stacked structure in which a plurality of transistors (not shown) are provided on a substrate and an insulating layer is provided to cover the transistors. The insulating layer over the transistors may have a single-layer structure or a stacked structure. FIG. 1B illustrates the insulating layers over the transistors, including an insulating layer 255a, an insulating layer 255b over the insulating layer 255a, and an insulating layer 255c over the insulating layer 255b. Note that the insulating layers over the transistors (insulating layers 255a to 255c) can also be considered as part of the layer 101.

[0070] As will be described later, it is preferable that the insulating layer 255c has a recess between two adjacent light-emitting devices. This results in a large step between adjacent pixel electrodes when forming the EL layer, making it easier to form the EL layer separately for each light-emitting device. Figure 1B shows an example in which a recess is provided in the insulating layer 255c. Furthermore, the insulating layer 255c may have an opening between two adjacent light-emitting devices, and in this case, a recess may be provided in the insulating layer 255b.

[0071] The insulating layers 255a, 255b, and 255c can each be suitably formed using various inorganic insulating films such as an oxide insulating film, a nitride insulating film, an oxynitride insulating film, or a nitride oxide insulating film. The insulating layers 255a and 255c are preferably formed using an oxide insulating film or an oxynitride insulating film such as a silicon oxide film, a silicon oxynitride film, or an aluminum oxide film. The insulating layer 255b is preferably formed using a nitride insulating film or a nitride oxide insulating film such as a silicon nitride film or a silicon nitride oxide film. More specifically, the insulating layers 255a and 255c are preferably formed using silicon oxide films, and the insulating layer 255b is preferably formed using a silicon nitride film. The insulating layer 255b preferably functions as an etching protective film.

[0072] In this specification and the like, an oxynitride refers to a material whose composition contains more oxygen than nitrogen, and a nitride oxide refers to a material whose composition contains more nitrogen than oxygen. For example, silicon oxynitride refers to a material whose composition contains more oxygen than nitrogen, and silicon nitride oxide refers to a material whose composition contains more nitrogen than oxygen.

[0073] A configuration example of the layer 101 will be described later in the fourth embodiment.

[0074] As the light-emitting device, for example, an OLED (organic light-emitting diode) or a QLED (quantum-dot light-emitting diode) is preferably used. Examples of the light-emitting material contained in the light-emitting device include a fluorescent material (fluorescent material), a phosphorescent material (phosphorescent material), a material that exhibits thermally activated delayed fluorescence (thermally activated delayed fluorescence (TADF) material), and an inorganic compound (quantum dot material, etc.). Furthermore, an LED such as a micro LED (light-emitting diode) can also be used as the light-emitting device.

[0075] The light emitting device can emit light of infrared, red, green, blue, cyan, magenta, yellow, white, etc. Furthermore, the color purity can be improved by providing the light emitting device with a microcavity structure.

[0076] Of the pair of electrodes of the light-emitting device, it is preferable that a conductive film that transmits visible light is used for the electrode from which light is extracted, and a conductive film that reflects visible light is used for the electrode from which light is not extracted.

[0077] Of the pair of electrodes that a light-emitting device has, one electrode functions as an anode and the other electrode functions as a cathode. In the following, an example in which the pixel electrode functions as the anode and the common electrode functions as the cathode will be described.

[0078] The light-emitting device 130R has a pixel electrode 111R on an insulating layer 255c, an island-shaped EL layer 113 on the pixel electrode 111R, and a common electrode 115 on the EL layer 113.

[0079] The light-emitting device 130G has a pixel electrode 111G on an insulating layer 255c, an island-shaped EL layer 113 on the pixel electrode 111G, and a common electrode 115 on the EL layer 113.

[0080] The light-emitting device 130B has a pixel electrode 111B on an insulating layer 255c, an island-shaped EL layer 113 on the pixel electrode 111B, and a common electrode 115 on the EL layer 113.

[0081] The light-emitting devices 130R, 130G, and 130B each independently include an island-shaped EL layer 113. These EL layers 113 are formed in the same process and have the same configuration. Therefore, it can be said that these EL layers 113 include the same light-emitting material.

[0082] The EL layer 113 can be configured to emit white light. For example, the EL layer 113 includes a first light-emitting material that emits blue light and a second light-emitting material that emits light with a wavelength longer than that of blue light.

[0083] In addition, by applying a microcavity structure, a light-emitting device having an EL layer configured to emit white light may emit light of a specific wavelength such as red, green, or blue intensified form.

[0084] For example, by applying a configuration that emits white light to the EL layer 113 and by applying a microcavity structure, red light can be emitted from the light-emitting device 130R, green light can be emitted from the light-emitting device 130G, and blue light can be emitted from the light-emitting device 130B.

[0085] The light-emitting device of the present embodiment may have a single structure (a structure having only one light-emitting unit) or a tandem structure (a structure having multiple light-emitting units). The light-emitting unit has at least one light-emitting layer.

[0086] The EL layer 113 includes at least a light-emitting layer. For example, the EL layer 113 may include a light-emitting layer that emits blue light and a light-emitting layer that emits light with a wavelength longer than that of blue light.

[0087] Furthermore, when a light-emitting device with a tandem structure is used, the EL layer 113 can have, for example, a structure including a light-emitting unit that emits blue light and a light-emitting unit that emits light with a wavelength longer than blue. It is preferable to provide a charge generation layer (also referred to as an intermediate layer) between the light-emitting units. By using a tandem structure, a light-emitting device capable of emitting light with high brightness can be realized.

[0088] The EL layer 113 may also have one or more of a hole injection layer, a hole transport layer, a hole blocking layer, a charge generating layer, an electron blocking layer, an electron transport layer, and an electron injection layer.

[0089] For example, the EL layer 113 may have, from the anode side, a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer, and an electron injection layer in this order. Alternatively, an electron blocking layer may be provided between the hole transport layer and the light-emitting layer. Alternatively, a hole blocking layer may be provided between the electron transport layer and the light-emitting layer.

[0090] Furthermore, for example, the EL layer 113 may have a first light-emitting unit, a charge generation layer on the first light-emitting unit, and a second light-emitting unit on the charge generation layer.

[0091] For more detailed information on the structure and materials of the light-emitting device, reference can be made to Embodiment 5.

[0092] In Figure 1B, the EL layers 113 of each light-emitting device are isolated from one another. By providing an island-like EL layer for each light-emitting device, leakage current between adjacent light-emitting devices can be suppressed. This prevents unintended light emission due to crosstalk, and realizes a display device with extremely high contrast. In particular, it can realize a display device with high current efficiency at low brightness.

[0093] Further, a material layer 113s, which is formed in the same process as the EL layer 113 and has the same structure as the EL layer 113, is located on the insulating layer 255c. The material layer 113s is separated from the EL layer 113 when the layers constituting the EL layer 113 are formed, and is provided independently on the insulating layer 255c.

[0094] The region where any one of the pixel electrodes 111R, 111G, and 111B overlaps with the EL layer 113 and the common electrode 115 can be called a light-emitting region, and is a region where EL light emission is obtained. The light-emitting region and the region where the material layer 113s is provided are each a region where PL (Photoluminescence) light emission is obtained. From these facts, it can be said that the light-emitting region and the region where the material layer 113s is provided can be distinguished by checking the EL light emission and the PL light emission.

[0095] Sidewall insulating layers 114 are provided so as to contact the side surfaces of the pixel electrodes 111R, 111G, and 111B, respectively. By providing the sidewall insulating layers 114, it is possible to prevent any of the pixel electrodes 111R, 111G, and 111B from contacting the common electrode 115. This makes it possible to prevent short circuits in the light-emitting device and improve the reliability of the light-emitting device.

[0096] The sidewall insulating layer 114 can be made of an inorganic insulating film such as an oxide insulating film, a nitride insulating film, an oxynitride insulating film, or a nitride oxide insulating film. Examples of oxide insulating films include a silicon oxide film, an aluminum oxide film, a gallium oxide film, a germanium oxide film, an yttrium oxide film, a zirconium oxide film, a lanthanum oxide film, a neodymium oxide film, a hafnium oxide film, and a tantalum oxide film. Examples of nitride insulating films include a silicon nitride film and an aluminum nitride film. Examples of oxynitride insulating films include a silicon oxynitride film and an aluminum oxynitride film. Examples of nitride oxide insulating films include a silicon nitride oxide film and an aluminum nitride oxide film.

[0097] The sidewall insulating layer 114 may have a single layer structure or a multilayer structure.

[0098] The method for forming the sidewall insulating layer 114 is not particularly limited. The sidewall insulating layer 114 can be formed by, for example, a sputtering method, a chemical vapor deposition (CVD) method, a plasma enhanced chemical vapor deposition (PECVD) method, or an atomic layer deposition (ALD) method. In particular, the sputtering method, the CVD method, or the PECVD method, each of which has a faster film formation rate than the ALD method, is preferable because it allows the sidewall insulating layer 114 to be formed with a thickness sufficient to ensure insulation with high productivity.

[0099] For example, a silicon oxide film, a silicon nitride film, a silicon oxynitride film, or a silicon nitride oxide film is preferably used as the sidewall insulating layer 114. This enables highly reliable display devices to be manufactured with high productivity.

[0100] Alternatively, an aluminum oxide film may be formed by ALD as the sidewall insulating layer 114. By using ALD, the sidewall insulating layer 114 can be formed with high coverage.

[0101] In FIG. 1B , an insulating layer (also referred to as a partition wall, bank, spacer, etc.) covering the upper edge of the pixel electrode 111R is not provided between the pixel electrode 111R and the EL layer 113. Furthermore, an insulating layer covering the upper edge of the pixel electrode 111G is not provided between the pixel electrode 111G and the EL layer 113. Similarly, an insulating layer covering the upper edge of the pixel electrode 111B is not provided between the pixel electrode 111B and the EL layer 113. This allows the distance between adjacent light-emitting regions to be extremely narrow. This allows a high-definition or high-resolution display device to be realized. Furthermore, a mask for forming the insulating layer is not required, thereby reducing the manufacturing cost of the display device.

[0102] Furthermore, by using a structure in which an insulating layer covering a part of the top surface of the pixel electrode (which can also be referred to as an edge of the top surface) is not provided between the pixel electrode and the EL layer, in other words, by using a structure in which an insulating layer is not provided between the pixel electrode and the EL layer, light from the EL layer can be efficiently extracted. Therefore, the display device of one embodiment of the present invention can have extremely low viewing angle dependence. By reducing the viewing angle dependence, the visibility of images in the display device can be improved. For example, in the display device of one embodiment of the present invention, the viewing angle (the maximum angle at which a certain contrast ratio is maintained when the screen is viewed from an oblique direction) can be set to a range of 100° to less than 180°, preferably 150° to 170°. Note that the above viewing angles can be applied to both the vertical and horizontal directions.

[0103] 1B, the EL layer 113 is formed so as to cover the entire upper surface of each of the pixel electrodes 111R, 111G, and 111B. This configuration allows the entire upper surface of the pixel electrodes to be used as a light-emitting region. Furthermore, compared to a configuration in which an insulating layer is provided to cover part of the upper surface of the pixel electrodes, it is easier to increase the aperture ratio.

[0104] The common electrode 115 is shared by the light-emitting devices 130R, 130G, and 130B. The common electrode 115 shared by the plurality of light-emitting devices is electrically connected to a conductive layer 123 provided in the connection portion 140 (see FIG. 2). The conductive layer 123 is preferably made of the same material and formed in the same process as the pixel electrodes 111R, 111G, and 111B.

[0105] 2, the conductive layer 123 is directly connected to the common electrode 115. For example, by using a mask for defining a film formation area (also called an area mask or a rough metal mask to distinguish it from a fine metal mask), the regions where the EL layer 113 and the common electrode 115 are formed can be changed.

[0106] 1B , an insulating layer 125 is provided so as to cover the region between adjacent light-emitting devices, specifically, the upper end and side surfaces of adjacent EL layers 113, parts of the side surfaces of adjacent sidewall insulating layers 114, and the upper surface of material layer 113s. In other words, the insulating layer 125 is provided in a non-light-emitting region, or has an opening in a portion overlapping with the light-emitting region.

[0107] 1B , one end of the insulating layer 125 is located on the upper surface of one of the adjacent EL layers 113, and the other end of the insulating layer 125 is located on the upper surface of the other of the adjacent EL layers 113. Here, it is preferable that the end of the insulating layer 125 overlaps with the EL layer 113 and the pixel electrode 111R (or the pixel electrode 111G or the pixel electrode 111B). In this case, the end of the insulating layer 125 is easily formed on a substantially flat surface of the EL layer 113.

[0108] The side surfaces of the EL layer 113 are covered with the insulating layer 125. The insulating layer 127 is provided to overlap with the side surfaces of the EL layer 113 with the insulating layer 125 interposed therebetween.

[0109] A part of the upper surface of the EL layer 113 is covered with an insulating layer 125. An insulating layer 127 is provided so as to overlap a part of the upper surface of the EL layer 113 with the insulating layer 125 interposed therebetween. Note that the upper surface of the EL layer 113 is not limited to only the upper surface of the flat portion overlapping the upper surface of the pixel electrode, but can also include the upper surface of a region located outside the upper surface of the pixel electrode (see region 103 in FIG. 7A ).

[0110] Since a portion of the upper surface and the side surfaces of the EL layer 113 are covered by at least one of the insulating layer 125 and the insulating layer 127, the common electrode 115 is prevented from contacting the pixel electrode 111R, the pixel electrode 111G, the pixel electrode 111B, and the side surfaces of the EL layer 113, thereby preventing short circuits in the light-emitting device.

[0111] The insulating layer 125 is preferably in contact with the upper end and side surfaces of the EL layer 113. The insulating layer 125 being in contact with the EL layer 113 can prevent the EL layer 113 from peeling off. The insulating layer 125 and the EL layer 113 are in close contact with each other, which has the effect of fixing or adhering the adjacent EL layers 113 and the like by the insulating layer 125.

[0112] Furthermore, as shown in FIG. 1B, the insulating layers 125 and 127 cover part of the top surface and both the side surfaces of the EL layer 113, which further prevents the EL layer 113 from peeling off.

[0113] The insulating layer 127 is provided over the insulating layer 125 so as to fill a recess formed in the insulating layer 125. The insulating layer 127 can overlap with part of the top surface and the side surfaces of the EL layer 113 with the insulating layer 125 interposed therebetween. The insulating layer 127 preferably covers at least part of the side surfaces of the insulating layer 125.

[0114] By providing the insulating layers 125 and 127, the gaps between adjacent island-shaped layers can be filled, which reduces the extreme unevenness of the surface on which a layer (e.g., a carrier injection layer, a common electrode, etc.) is formed on the island-shaped layers, thereby making the surface flatter, thereby improving the coverage of the carrier injection layer, the common electrode, etc.

[0115] The common electrode 115 is provided over the EL layer 113, the insulating layer 125, and the insulating layer 127. Before the insulating layer 125 and the insulating layer 127 are provided, a step is generated between a region where the pixel electrode and the island-shaped EL layer are provided (a region where the light-emitting device is located) and a region where the pixel electrode and the island-shaped EL layer are not provided (a region between the light-emitting devices). In the display device of one embodiment of the present invention, the insulating layer 125 and the insulating layer 127 can flatten the step, thereby improving the coverage of the common electrode 115. Therefore, poor connection due to a step in the common electrode 115 can be suppressed. Furthermore, the step can suppress an increase in the electrical resistance of the common electrode 115 due to a local thinning of the common electrode 115.

[0116] The upper surface of the insulating layer 127 preferably has a highly flat shape, but may have a convex portion, a convex curved surface, a concave curved surface, or a concave portion. For example, the upper surface of the insulating layer 127 preferably has a highly flat, smooth convex curved surface shape.

[0117] Next, examples of materials for the insulating layer 125 and the insulating layer 127 will be described.

[0118] The insulating layer 125 can be an insulating layer containing an inorganic material. For example, an inorganic insulating film such as an oxide insulating film, a nitride insulating film, an oxynitride insulating film, or a nitride oxide insulating film can be used for the insulating layer 125. The insulating layer 125 may have a single-layer structure or a stacked-layer structure. Examples of oxide insulating films include a silicon oxide film, an aluminum oxide film, a magnesium oxide film, an indium gallium zinc oxide film, a gallium oxide film, a germanium oxide film, an yttrium oxide film, a zirconium oxide film, a lanthanum oxide film, a neodymium oxide film, a hafnium oxide film, and a tantalum oxide film. Examples of nitride insulating films include a silicon nitride film and an aluminum nitride film. Examples of oxynitride insulating films include a silicon oxynitride film and an aluminum oxynitride film. Examples of nitride oxide insulating films include a silicon nitride oxide film and an aluminum nitride oxide film. In particular, aluminum oxide is preferable because it has a high etching selectivity with respect to the EL layer and functions to protect the EL layer in the formation of the insulating layer 127 described below. In particular, by using an inorganic insulating film such as an aluminum oxide film, a hafnium oxide film, or a silicon oxide film formed by an ALD method as the insulating layer 125, it is possible to form an insulating layer 125 that has few pinholes and has an excellent function of protecting the EL layer. The insulating layer 125 may also have a stacked structure of a film formed by an ALD method and a film formed by a sputtering method. For example, the insulating layer 125 may have a stacked structure of an aluminum oxide film formed by an ALD method and a silicon nitride film formed by a sputtering method.

[0119] The insulating layer 125 preferably functions as a barrier insulating layer against at least one of water and oxygen. The insulating layer 125 preferably has a function of suppressing diffusion of at least one of water and oxygen. The insulating layer 125 preferably has a function of capturing or fixing (also referred to as gettering) at least one of water and oxygen.

[0120] Note that in this specification and the like, a barrier insulating layer refers to an insulating layer having barrier properties. In addition, in this specification and the like, the barrier properties refer to a function of suppressing the diffusion of a corresponding substance (also referred to as low permeability) or a function of capturing or fixing (also referred to as gettering) a corresponding substance.

[0121] The insulating layer 125 has a function as a barrier insulating layer or a gettering function, which can suppress the intrusion of impurities (typically, at least one of water and oxygen) that can diffuse into each light-emitting device from the outside. With this configuration, a highly reliable light-emitting device and further a highly reliable display device can be provided.

[0122] The insulating layer 125 preferably has a low impurity concentration. This can prevent impurities from entering the EL layer from the insulating layer 125 and causing deterioration of the EL layer. Furthermore, a low impurity concentration in the insulating layer 125 can improve the barrier properties against at least one of water and oxygen. For example, it is desirable that the insulating layer 125 has a sufficiently low hydrogen concentration or a sufficiently low carbon concentration, or preferably both of them.

[0123] The insulating layer 127 provided on the insulating layer 125 has the function of flattening the extreme unevenness of the insulating layer 125 formed between adjacent light-emitting devices. In other words, the insulating layer 127 has the effect of improving the flatness of the surface on which the common electrode 115 is formed.

[0124] An insulating layer containing an organic material can be suitably used as the insulating layer 127. As the organic material, a photosensitive organic resin is preferably used, for example, a photosensitive resin composition containing an acrylic resin is preferably used. Note that in this specification and the like, the term "acrylic resin" does not refer only to polymethacrylic acid ester or methacrylic resin, but may refer to all acrylic polymers in a broad sense.

[0125] The insulating layer 127 may also be made of acrylic resin, polyimide resin, epoxy resin, imide resin, polyamide resin, polyimideamide resin, silicone resin, siloxane resin, benzocyclobutene-based resin, phenolic resin, or precursors of these resins. The insulating layer 127 may also be made of organic materials such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinylpyrrolidone, polyethylene glycol, polyglycerin, pullulan, water-soluble cellulose, or alcohol-soluble polyamide resin. The photosensitive resin may also be a photoresist. Either a positive-type material or a negative-type material may be used as the photosensitive organic resin.

[0126] The insulating layer 127 may be made of a material that absorbs visible light. By having the insulating layer 127 absorb light emitted from the light-emitting device, it is possible to suppress leakage of light from the light-emitting device to an adjacent light-emitting device through the insulating layer 127 (stray light). This can improve the display quality of the display device. Furthermore, since the display quality can be improved without using a polarizing plate in the display device, it is possible to reduce the weight and thickness of the display device.

[0127] Examples of materials that absorb visible light include materials containing pigments such as black, materials containing dyes, light-absorbing resin materials (e.g., polyimide), and resin materials that can be used for color filters (color filter materials). In particular, using a resin material in which two or more color filter materials are laminated or mixed is preferable because it can enhance the visible light blocking effect. In particular, mixing three or more color filter materials makes it possible to form a black or nearly black resin layer.

[0128] With the above-described effects, the display device of one embodiment of the present invention can improve the display quality, the reliability of the light-emitting device, and the manufacturing yield of the light-emitting device.

[0129] 1B and 3A, an island-shaped EL layer 113 is provided on the pixel electrode 111G, an island-shaped EL layer 113 is provided on the pixel electrode 111B, and a material layer 113s is provided on the insulating layer 255c. The EL layer 113 on the pixel electrode 111G, the EL layer 113 on the pixel electrode 111B, and the material layer 113s are isolated from each other.

[0130] In this way, by configuring the EL layer to be separated for each light-emitting device, it is possible to suppress the occurrence of crosstalk between adjacent sub-pixels.

[0131] Here, a description will be given of a configuration of the sidewall insulating layer 114 that is preferable for partially thinning the EL layer 113 in a self-aligned manner or for dividing the EL layer 113 when the EL layer 113 is formed.

[0132] The height T1 of the sidewall insulating layer 114 shown in FIG. 3A is preferably 0.5 times or more, more preferably 0.8 times or more, even more preferably 1 time or more, and even more preferably 1.5 times or more, the thickness of the EL layer 113.

[0133] It is preferable to use the thickness of the sidewall insulating layer 114 in the direction perpendicular to the substrate surface as the height T1 of the sidewall insulating layer 114. In addition, in Fig. 3A, the height T1 of the sidewall insulating layer 114 can also be said to be the sum of the thickness of the pixel electrode and the depth of the recess provided in the insulating layer 255c.

[0134] As the thickness of the EL layer 113, it is preferable to use the thickness T2 of the EL layer 113 in the region overlapping the upper surface of the pixel electrode as shown in FIG. 3A.

[0135] Furthermore, the angle formed between at least a part (e.g., a side surface) of the sidewall insulating layer 114 that is in contact with the EL layer 113 and the substrate surface is preferably perpendicular or approximately perpendicular. This angle can also be referred to as the angle formed between the part (e.g., a side surface) of the sidewall insulating layer 114 that is in contact with the EL layer 113 and the bottom surface. The angle is preferably 60° or more, more preferably 80° or more, and even more preferably 85° or more, and is preferably 140° or less, more preferably 110° or less, more preferably 100° or less, and even more preferably 95° or less.

[0136] In order to set the angle within the above-mentioned range, the angle formed between the side surface of the pixel electrode and the substrate surface is also preferably perpendicular or approximately perpendicular. The angle formed between the side surface of the pixel electrode and the substrate surface is preferably 60° or more, more preferably 80° or more, and even more preferably 85° or more, and is preferably 140° or less, more preferably 110° or less, more preferably 100° or less, and even more preferably 95° or less.

[0137] The region 150B shown in FIG. 3B and the region 150C shown in FIG. 3C are examples in which the EL layer 113 is provided so as to cover the pixel electrode 111G, the sidewall insulating layer 114, the insulating layer 255c, and the pixel electrode 111B.

[0138] A region 113t shown in FIG. 3B is a portion of the EL layer 113 that is thinner than other portions.

[0139] The thickness of the EL layer 113 in the region 113t does not refer to the thickness in the direction perpendicular to a reference plane such as the substrate surface, but refers to the thickness in the direction normal to the surface on which the EL layer 113 is formed. Therefore, if the surface on which the EL layer 113 is formed is uneven, the direction defining the thickness will differ depending on the location. For example, the thickness of the EL layer 113 in the region 113t can be said to be the thickness in the direction normal to the side surface of the sidewall insulating layer 114.

[0140] In this way, when the EL layer 113 is partially thinned, the electrical resistance of the thinned portion is higher than that of the other portions, so that the leakage current between adjacent light-emitting devices can be reduced. Therefore, even in a configuration in which the EL layer 113 between adjacent light-emitting devices is connected as shown in Figures 3B and 3C, the occurrence of crosstalk between adjacent sub-pixels can be suppressed.

[0141] Region 150C shown in FIG. 3C differs from the configuration of region 150B in that insulating layer 255c does not have a recess between two adjacent light emitting devices.

[0142] Moreover, a region 150D shown in FIG. 3D is an example in which the insulating layer 255c has two recesses, a shallow recess and a deep recess, between two adjacent light-emitting devices.

[0143] A recess may be formed in the insulating layer 255c when processing the conductive film that will become the pixel electrode. Furthermore, a recess may also be formed in the insulating layer 255c when processing the insulating film that will become the sidewall insulating layer 114. This results in shallow and deep recesses. In Figure 3D, the sidewall insulating layer 114 is in contact with the shallow recess, and the material layer 113s is in contact with the deep recess.

[0144] In addition, the distance T0 between the surface of the deep recess in the insulating layer 255c and the bottom surface of the sidewall insulating layer 114 shown in Figure 3D is also a parameter that affects whether the EL layer 113 is partially thinned or whether the EL layer 113 is divided.

[0145] For the same reasons as above, for example, the sum of the distance T0 and the height T1 of the sidewall insulating layer 114 is preferably 0.5 times or more the thickness of the EL layer 113, more preferably 0.8 times or more, even more preferably 1 time or more, and even more preferably 1.5 times or more.

[0146] In FIG. 3D, the sum of the distance T0 and the height T1 of the sidewall insulating layer 114 can also be said to be the sum of the thickness of the pixel electrode and the depth of the recess provided in the insulating layer 255c.

[0147] As described above, in the display device of one embodiment of the present invention, the sidewall insulating layer 114 is provided in contact with the side surface of the pixel electrode, which prevents the pixel electrode from being in contact with the common electrode 115 and thus prevents a short circuit in the light-emitting device. Furthermore, by setting the height and shape of the sidewall insulating layer 114 to a structure suitable for partially thinning the EL layer 113 or for dividing the EL layer 113, crosstalk between adjacent subpixels can be suppressed.

[0148] From the above, it can be said that the display device of one embodiment of the present invention is configured so that the EL layer 113 is intentionally disconnected.

[0149] Next, the structure of the insulating layer 127 and its vicinity will be described using Figures 4A and 4B. Figure 4A is an enlarged cross-sectional view of the insulating layer 127 between the light-emitting device 130R of the subpixel emitting red light and the light-emitting device 130G of the subpixel emitting green light, and a region including the periphery thereof. The following description will be given using the insulating layer 127 between two adjacent light-emitting devices, 130R and 130G, as an example, but the same applies to the insulating layer 127 between the light-emitting device 130G and 130B. Figure 4B is an enlarged view of the end of the insulating layer 127 on the EL layer 113 shown in Figure 4A and its vicinity. Note that the common electrode 115 and protective layer 131 are omitted from Figure 4B.

[0150] 4A , an EL layer 113 is provided covering the pixel electrode 111R and the sidewall insulating layer 114, and an EL layer 113 is provided covering the pixel electrode 111G and the sidewall insulating layer 114. An insulating layer 125 is provided in contact with a portion of the upper surface and the side surfaces of the EL layer 113. An insulating layer 127 is provided in contact with the upper surface of the insulating layer 125. The insulating layer 127 overlaps a portion of the upper surface and the side surfaces of the EL layer 113 via the insulating layer 125, and is in contact with at least a portion of the side surfaces of the insulating layer 125. A common electrode 115 is provided covering the EL layer 113, the insulating layer 125, and the insulating layer 127, and a protective layer 131 is provided on the common electrode 115.

[0151] Furthermore, the insulating layer 127 is formed in the region between the two island-shaped EL layers (for example, the region between the two EL layers 113 in FIG. 4A ). At this time, at least a portion of the insulating layer 127 is disposed in a position sandwiched between the side edge of one EL layer and the side edge of the other EL layer. By providing such an insulating layer 127, it is possible to prevent the formation of divided portions and locally thin portions in the common electrode 115 formed on the island-shaped EL layers and the insulating layer 127.

[0152] 4B , the insulating layer 127 preferably has a tapered shape at its end with a taper angle θ1 in a cross-sectional view of the display device. The taper angle θ1 is the angle between the side surface (or end) of the insulating layer 127 and the substrate surface. However, the taper angle θ1 is not limited to the substrate surface, and may be the angle between the top surface of the flat portion of the EL layer 113 or the top surface of the flat portion of the pixel electrode 111G and the side surface (or end) of the insulating layer 127.

[0153] The taper angle θ1 of the insulating layer 127 is less than 90°, preferably 60° or less, more preferably 45° or less, and even more preferably 20° or less. By forming the end of the insulating layer 127 in such a tapered shape, the common electrode 115 provided on the insulating layer 127 can be formed with good coverage, and the occurrence of step discontinuities or local thinning of the common electrode 115 can be suppressed. This improves the in-plane uniformity of the film thickness of the common electrode 115, thereby improving the display quality of the display device.

[0154] 4A, in a cross-sectional view of the display device, the upper surface of the insulating layer 127 preferably has a convex curved shape. The convex curved shape of the upper surface of the insulating layer 127 preferably bulges gently toward the center. Furthermore, the convex curved portion at the center of the upper surface of the insulating layer 127 preferably has a shape that is continuously connected to tapered portions at the edges. By forming the insulating layer 127 in this shape, the common electrode 115 can be formed with good coverage over the entire insulating layer 127.

[0155] 4B , the insulating layer 125 preferably has a tapered shape with a taper angle θ2 at an end (inclined portion) that overlaps with the insulating layer 127 in a cross-sectional view of the display device. The taper angle θ2 is the angle between the side surface of the end and the substrate surface. However, the taper angle θ2 is not limited to the substrate surface, and may be the angle between the top surface of the flat portion of the EL layer 113 or the top surface of the flat portion of the pixel electrode 111G and the side surface of the end.

[0156] The taper angle θ2 of the insulating layer 125 is less than 90°, preferably 60° or less, more preferably 45° or less, and even more preferably 20° or less.

[0157] 4B , the insulating layer 125 preferably has a tapered shape with a taper angle θ3 at an end (inclined portion) that does not overlap the insulating layer 127 in a cross-sectional view of the display device. The taper angle θ3 is the angle between the side surface of the end and the substrate surface. However, the taper angle θ3 is not limited to the substrate surface, and may be the angle between the top surface of the flat portion of the EL layer 113 or the top surface of the flat portion of the pixel electrode 111G and the side surface of the end.

[0158] The taper angle θ3 of the insulating layer 125 is less than 90°, preferably 60° or less, more preferably 45° or less, and even more preferably 20° or less. By forming the insulating layer 125 in such a tapered shape, the common electrode 115 provided on the insulating layer 125 can be formed with good coverage.

[0159] As will be described in detail in Embodiment 2, if the insulating film that will become the insulating layer 125 is etched in one step, the insulating layer 125 below the edge of the insulating layer 127 may disappear due to side etching, forming a cavity. Such a cavity may cause unevenness on the surface on which the common electrode 115 is formed, making the common electrode 115 more likely to break apart. Therefore, by performing the etching process in two steps and performing a heat treatment between the two etching processes, even if a cavity is formed in the first etching process, the heat treatment deforms the insulating layer 127, thereby filling the cavity. Furthermore, since the second etching process etches a thin film, the amount of side etching is reduced, making it less likely that a cavity will form. Even if a cavity does form, it can be made extremely small. Therefore, unevenness on the surface on which the common electrode 115 is formed can be suppressed, and step-off of the common electrode 115 can be suppressed. Performing the etching process twice in this manner may result in the taper angles θ2 and θ3 being different angles. Furthermore, the taper angles θ2 and θ3 may be the same angle. Furthermore, the taper angles θ2 and θ3 may each be smaller than the taper angle θ1.

[0160] Although the above example shows that the etching process of the insulating film that will become the insulating layer 125 is performed in two separate steps, this is not limitative. Depending on the film thickness of the insulating film that will become the insulating layer 125, the etching process conditions, etc., the etching process of the insulating film that will become the insulating layer 125 may be performed in one step.

[0161] 5A and 5B also show an example in which the insulating layer 127 covers the entire side surface of the insulating layer 125. Specifically, in FIG. 5B, the insulating layer 127 contacts and covers both of the two inclined surfaces. This is preferable because it further reduces the unevenness of the surface on which the common electrode 115 is formed. FIG. 5B also shows an example in which the end of the insulating layer 127 is located outside the end of the insulating layer 125. As shown in FIG. 4B, the end of the insulating layer 127 may be located inside the end of the insulating layer 125, or may be aligned or approximately aligned with the end of the insulating layer 125. Also, as shown in FIG. 5B, the insulating layer 127 may contact the EL layer 113.

[0162] In FIG. 5B as well, it is preferable that the taper angles θ1 to θ3 are each within the above ranges.

[0163] 6A and 6B show an example in which the insulating layer 127 has a concave curved shape (also referred to as a constricted portion, recess, dent, or depression) on the side surface. Depending on the material and forming conditions (heating temperature, heating time, heating atmosphere, etc.) of the insulating layer 127, the concave curved shape may be formed on the side surface of the insulating layer 127.

[0164] 6A shows an example in which the insulating layer 127 covers a part of the side surface of the insulating layer 125, and the remaining part of the side surface of the insulating layer 125 is exposed. FIG. 6B shows an example in which the insulating layer 127 contacts and covers the entire side surface of the insulating layer 125.

[0165] 4 to 6, it is preferable that one end of the insulating layer 127 overlaps the upper surface of the pixel electrode 111R, and the other end of the insulating layer 127 overlaps the upper surface of the pixel electrode 111G. This structure allows the end of the insulating layer 127 to be formed on a substantially flat region of the EL layer 113. This makes it relatively easy to form the tapered shapes of the insulating layer 127 and the insulating layer 125. Furthermore, it is possible to suppress film peeling between the EL layer 113 and the pixel electrode 111R or 111G. On the other hand, the smaller the overlapping portion between the upper surface of the pixel electrode and the insulating layer 127, the wider the light-emitting region of the light-emitting device and the higher the aperture ratio, which is preferable.

[0166] The insulating layer 127 does not have to overlap the upper surface of the pixel electrode. As shown in FIG. 7A , the insulating layer 127 does not overlap the upper surface of the pixel electrode, and in a plan view, one end of the insulating layer 127 may be positioned approximately in line with the side surface of the pixel electrode 111R, and the other end of the insulating layer 127 may be positioned approximately in line with the side surface of the pixel electrode 111G. As shown in FIG. 7B , the insulating layer 127 may not overlap the pixel electrode, but may be provided in a region sandwiched between the pixel electrodes 111R and 111G. In FIGS. 7A and 7B , part or all of the upper surface of the EL layer 113, in a region (region 103) located outside the upper surface of the pixel electrode, is covered by the insulating layer 125 and the insulating layer 127. Even with this configuration, the unevenness of the surface on which the common electrode 115 is formed can be reduced, and the coverage of the common electrode 115 can be improved, compared to a configuration without the insulating layer 125 and the insulating layer 127. The region 103 can be called a dummy region.

[0167] As shown in FIG. 8A, the upper surface of the insulating layer 127 may have a flat portion in a cross-sectional view of the display device.

[0168] 8B , the upper surface of the insulating layer 127 may have a concave curved shape in a cross-sectional view of the display device. In FIG. 8B , the upper surface of the insulating layer 127 has a shape that gently bulges toward the center, i.e., a convex curved surface, and a shape that is recessed in the center and its vicinity, i.e., a concave curved surface. Also, in FIG. 8B , the convex curved portion of the upper surface of the insulating layer 127 has a shape that is continuously connected to the tapered portions at the ends. Even when the insulating layer 127 has such a shape, the common electrode 115 can be formed with good coverage over the entire insulating layer 127.

[0169] 8B , one method for forming the insulating layer 127 with a concave curved surface in the center thereof is exposure using a multi-tone mask (typically, a half-tone mask or a gray-tone mask). The multi-tone mask is a mask capable of performing exposure at three exposure levels: an exposed portion, an intermediately exposed portion, and an unexposed portion, and is an exposure mask that transmits light with a variety of intensities. This makes it possible to form the insulating layer 127 with regions of multiple thicknesses (typically, two types) using only a single photomask (a single exposure and development process).

[0170] The method for forming the concave curved surface in the center of insulating layer 127 is not limited to the above. For example, two photomasks may be used to separately form an exposed portion and an intermediately exposed portion. Alternatively, the viscosity of the resin material used for insulating layer 127 may be adjusted. Specifically, the viscosity of the material used for insulating layer 127 may be set to 10 cP or less, preferably 1 cP or more and 5 cP or less.

[0171] 4 to 8 , the insulating layers 125 and 127 are provided, thereby enabling the common electrode 115 to be formed with good coverage. This prevents the common electrode 115 from being divided and from being locally thin. Therefore, between the light-emitting devices, poor connection between the common electrode 115 due to the divided portions and an increase in electrical resistance due to the locally thin portions can be suppressed. This allows the display device of one embodiment of the present invention to have improved display quality.

[0172] It is preferable to provide a protective layer 131 on the light-emitting device 130R, the light-emitting device 130G, and the light-emitting device 130B. By providing the protective layer 131, the reliability of the light-emitting device can be improved. The protective layer 131 may have a single-layer structure or a laminated structure of two or more layers.

[0173] There is no restriction on the conductivity of the protective layer 131. The protective layer 131 can be made of at least one of an insulating film, a semiconductor film, and a conductive film.

[0174] The protective layer 131 has an inorganic film, which prevents oxidation of the common electrode 115 and prevents impurities (water, oxygen, etc.) from entering the light-emitting device, thereby suppressing deterioration of the light-emitting device and improving the reliability of the display device.

[0175] For example, an inorganic insulating film such as an insulating oxide film, an insulating nitride film, an insulating oxynitride film, or an insulating nitride oxide film can be used for the protective layer 131. Specific examples of these inorganic insulating films are as given in the description of the sidewall insulating layer 114. In particular, the protective layer 131 preferably has an insulating nitride film or an insulating nitride oxide film, and more preferably has an insulating nitride film.

[0176] Alternatively, an inorganic film containing In—Sn oxide (also referred to as ITO), In—Zn oxide, Ga—Zn oxide, Al—Zn oxide, indium gallium zinc oxide (In—Ga—Zn oxide, also referred to as IGZO), or the like can be used for the protective layer 131. The inorganic film preferably has high resistance, specifically, preferably has higher resistance than the common electrode 115. The inorganic film may further contain nitrogen.

[0177] When light emitted from the light-emitting device is extracted through the protective layer 131, it is preferable that the protective layer 131 has high transparency to visible light. For example, ITO, IGZO, and aluminum oxide are preferable because they are inorganic materials that have high transparency to visible light.

[0178] For example, a stacked structure of an aluminum oxide film and a silicon nitride film on the aluminum oxide film, or a stacked structure of an aluminum oxide film and an IGZO film on the aluminum oxide film can be used as the protective layer 131. By using such a stacked structure, impurities (water, oxygen, etc.) can be prevented from entering the EL layer side.

[0179] The protective layer 131 may have a two-layer structure formed by using different film formation methods. Specifically, the first layer of the protective layer 131 may be formed by the ALD method, and the second layer of the protective layer 131 may be formed by the sputtering method.

[0180] The protective layer 131 may include an organic film. For example, the protective layer 131 may include both an organic film and an inorganic film.

[0181] An insulating layer 135 is preferably provided on the protective layer 131. A layer having a planarization function is preferably used for the insulating layer 135. By using an organic film for the insulating layer 135, the planarity of the surface of the insulating layer 135 can be improved, which is preferable.

[0182] Examples of organic materials that can be used for the protective layer 131 or the insulating layer 135 include acrylic resin, polyimide resin, epoxy resin, imide resin, polyamide resin, polyimideamide resin, silicone resin, siloxane resin, benzocyclobutene-based resin, phenol resin, precursors of these resins, etc. Alternatively, organic materials such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinylpyrrolidone, polyethylene glycol, polyglycerin, pullulan, water-soluble cellulose, or alcohol-soluble polyamide resin may be used for the protective layer 131 or the insulating layer 135.

[0183] A light-shielding layer may be provided on the surface of the substrate 120 facing the resin layer 122. Various optical members may be disposed on the outer side of the substrate 120 (the surface opposite to the resin layer 122). Examples of optical members include a polarizing plate, a retardation plate, a light diffusion layer (such as a diffusion film), an anti-reflection layer, and a light-collecting film. Furthermore, a surface protection layer such as an anti-static film that suppresses the adhesion of dust, a water-repellent film that makes it difficult for dirt to adhere, a hard coat film that suppresses the occurrence of scratches during use, or an impact absorbing layer may be disposed on the outer side of the substrate 120. For example, a glass layer or a silica layer (SiO ｘ The surface protection layer can be preferably formed of a material such as DLC (diamond-like carbon), aluminum oxide (AlO ｘ ), polyester-based materials, or polycarbonate-based materials may also be used. Note that it is preferable to use a material with high transmittance to visible light for the surface protection layer. It is also preferable to use a material with high hardness for the surface protection layer.

[0184] The substrate 120 can be made of glass, quartz, ceramics, sapphire, resin, metal, alloy, semiconductor, or the like. A material that transmits light is used for the substrate on the side from which light from the light-emitting device is extracted. Using a flexible material for the substrate 120 can increase the flexibility of the display device. Alternatively, a polarizing plate may be used as the substrate 120.

[0185] The substrate 120 may be made of polyester resin such as polyethylene terephthalate (PET) or polyethylene naphthalate (PEN), polyacrylonitrile resin, acrylic resin, polyimide resin, polymethyl methacrylate resin, polycarbonate (PC) resin, polyethersulfone (PES) resin, polyamide resin (nylon, aramid, etc.), polysiloxane resin, cycloolefin resin, polystyrene resin, polyamideimide resin, polyurethane resin, polyvinyl chloride resin, polyvinylidene chloride resin, polypropylene resin, polytetrafluoroethylene (PTFE) resin, ABS resin, cellulose nanofiber, etc. The substrate 120 may be made of glass having a thickness sufficient to provide flexibility.

[0186] When a circularly polarizing plate is superimposed on a display device, it is preferable that the display device has a substrate with high optical isotropy. A substrate with high optical isotropy has small birefringence (or a small amount of birefringence).

[0187] The absolute value of the retardation (phase difference) of a substrate having high optical isotropy is preferably 30 nm or less, more preferably 20 nm or less, and even more preferably 10 nm or less.

[0188] Examples of films with high optical isotropy include triacetyl cellulose (TAC, also called cellulose triacetate) films, cycloolefin polymer (COP) films, cycloolefin copolymer (COC) films, and acrylic films.

[0189] Furthermore, when a film is used as a substrate, the film may absorb water, causing deformation such as wrinkles in the display device. Therefore, it is preferable to use a film with low water absorption for the substrate. For example, it is preferable to use a film with a water absorption rate of 1% or less, more preferably 0.1% or less, and even more preferably 0.01% or less.

[0190] The resin layer 122 can be made of various curable adhesives, such as a photo-curable adhesive (e.g., an ultraviolet curable adhesive), a reactive curable adhesive, a thermosetting adhesive, or an anaerobic adhesive. Examples of such adhesives include epoxy resin, acrylic resin, silicone resin, phenolic resin, polyimide resin, imide resin, PVC (polyvinyl chloride) resin, PVB (polyvinyl butyral) resin, and EVA (ethylene vinyl acetate) resin. Materials with low moisture permeability, such as epoxy resin, are particularly preferred. Two-component resins may also be used. Adhesive sheets or the like may also be used.

[0191] The pixel electrodes 111R, 111G, and 111B may have different thicknesses. Alternatively, as will be described later, optical adjustment layers having different thicknesses may be provided on the pixel electrodes 111R, 111G, and 111B.

[0192] Figure 9A shows a variation of Figure 1B. Figures 9B and 9C are enlarged views of areas 150E and 150F shown in Figure 9A.

[0193] In FIG. 9A, an optical adjustment layer 116R is provided on a pixel electrode 111R, an optical adjustment layer 116G is provided on a pixel electrode 111G, and an optical adjustment layer 116B is provided on a pixel electrode 111B.

[0194] 9A shows an example in which the thickness of optical adjustment layer 116R is thicker than the thickness of optical adjustment layer 116G, which is thicker than the thickness of optical adjustment layer 116B. It is preferable to set the thickness of optical adjustment layer 116R so as to enhance red light, the thickness of optical adjustment layer 116G so as to enhance green light, and the thickness of optical adjustment layer 116B so as to enhance blue light. This allows for a microcavity structure to be realized, and the color purity of the light emitted by each light-emitting device to be improved.

[0195] The optical adjustment layer is preferably formed using a conductive material that is transparent to visible light, among conductive materials that can be used as electrodes of a light-emitting device.

[0196] 9A and 9B , an island-shaped EL layer 113 is provided on the pixel electrode 111R with an optical adjustment layer 116R interposed therebetween, an island-shaped EL layer 113 is provided on the pixel electrode 111G with an optical adjustment layer 116G interposed therebetween, and a material layer 113s is provided on the insulating layer 255c. The EL layer 113 on the pixel electrode 111R, the EL layer 113 on the pixel electrode 111G, and the material layer 113s are isolated from each other.

[0197] 9A and 9C , an island-shaped EL layer 113 is provided on the pixel electrode 111G via the optical adjustment layer 116G, and the island-shaped EL layer 113 is provided so as to cover the insulating layer 255c, the sidewall insulating layer 114 (on the pixel electrode 111B side), the pixel electrode 111B, and the optical adjustment layer 116B. The EL layer 113 on the pixel electrode 111G and the EL layer 113 covering the insulating layer 255c, the sidewall insulating layer 114 (on the pixel electrode 111B side), and the pixel electrode 111B are isolated from each other.

[0198] 9B and 9C , the height T3 of the sidewall insulating layer 114 covering the side surface of the pixel electrode 111R is greater than the height T4 of the sidewall insulating layer 114 covering the side surface of the pixel electrode 111G and the height T5 of the sidewall insulating layer 114 covering the side surface of the pixel electrode 111B, and the height T4 of the sidewall insulating layer 114 covering the side surface of the pixel electrode 111G is greater than the height T5 of the sidewall insulating layer 114 covering the side surface of the pixel electrode 111B.

[0199] 9C , depending on the value of height T5, the EL layer 113 may not be divided by the sidewall insulating layer 114 covering the side surface of the pixel electrode 111B, and one island-shaped EL layer 113 may have a portion located on the insulating layer 255c, a portion covering the sidewall insulating layer 114 (on the pixel electrode 111B side), and a portion covering the top surface of the pixel electrode 111B. However, in FIG. 9C , the EL layer 113 is divided by the sidewall insulating layer 114 covering the side surface of the pixel electrode 111G. In other words, since island-shaped EL layers are provided independently between adjacent light-emitting devices, crosstalk between adjacent subpixels can be suppressed.

[0200] Depending on the value of height T4, the EL layer 113 may not be divided even by the sidewall insulating layer 114 covering the side surface of the pixel electrode 111G. That is, one island-shaped EL layer 113 may cover the insulating layer 255c, the sidewall insulating layer 114 in contact with the pixel electrode 111G, the top surface of the pixel electrode 111G, the sidewall insulating layer 114 in contact with the pixel electrode 111B, and the top surface of the pixel electrode 111B. In this case, the portion of the EL layer 113 covering the sidewall insulating layer 114 is thinner than the other portions, so the electrical resistance of the thinned portion is higher than the other portions, thereby reducing the leakage current between adjacent light-emitting devices. Therefore, even in the configuration in which the EL layer 113 is connected between adjacent light-emitting devices as described above, crosstalk between adjacent subpixels can be suppressed.

[0201] In this manner, a structure in which the EL layer 113 is formed in an island shape in some light-emitting devices and the EL layer 113 is formed as a continuous layer in other light-emitting devices is also one embodiment of the present invention. For example, a display device of one embodiment of the present invention may have both the region 150A shown in FIG. 3A and the region 150B shown in FIG. 3B.

[0202] 1B and 9A show an example in which the colored layers 132R, 132G, and 132B are provided directly on the light-emitting device via the protective layer 131 and the insulating layer 135. This configuration improves the accuracy of alignment between the light-emitting device and the colored layers. Furthermore, by positioning the light-emitting device and the colored layers closer to each other, color mixing can be suppressed and viewing angle characteristics can be improved, which is preferable.

[0203] 10, 11A, 11B, 12A, and 12B show variations of FIG. 1B.

[0204] 10 , the substrate 120 provided with the colored layers 132R, 132G, and 132B may be bonded to the protective layer 131 with a resin layer 122. By providing the colored layers 132R, 132G, and 132B on the substrate 120, the temperature of the heat treatment in the process of forming the colored layers 132R, 132G, and 132B can be increased.

[0205] 11A and 11B, the display device may be provided with a lens 133. The lens 133 is preferably provided so as to overlap the light-emitting device. By providing the lens 133, light emitted by the light-emitting device can be extracted to the outside of the display device more efficiently than in the case where the lens 133 is not provided.

[0206] 11A shows an example in which colored layers 132R, 132G, and 132B are provided on a light-emitting device via a protective layer 131 and an insulating layer 135, an insulating layer 134 is provided on the colored layers 132R, 132G, and 132B, and a lens 133 is provided on the insulating layer 134. By forming the colored layers 132R, 132G, 132B, and the lens 133 directly on a substrate on which a light-emitting device is formed, the accuracy of alignment between the light-emitting device and the colored layers or the lens 133 can be improved.

[0207] The insulating layer 134 can be made of either or both of an inorganic insulating film and an organic insulating film. The insulating layer 134 may have a single-layer structure or a multi-layer structure. For example, the insulating layer 134 can be made of a material that can be used for the protective layer 131. The insulating layer 134 preferably has a planarizing function. Since light emitted from the light-emitting device is extracted through the insulating layer 134, the insulating layer 134 preferably has high transparency to visible light.

[0208] 11A, light emitted from the light-emitting device passes through the colored layer and then passes through the lens 133 to be extracted to the outside of the display device. By positioning the light-emitting device and the colored layer close to each other, color mixing can be suppressed and viewing angle characteristics can be improved, which is preferable. Alternatively, the lens 133 may be provided on the light-emitting device, and the colored layer may be provided on the lens 133.

[0209] 11B shows an example in which a substrate 120 provided with colored layers 132R, 132G, 132B, and lenses 133 is bonded to a protective layer 131 by a resin layer 122. By providing the colored layers 132R, 132G, 132B, and lenses 133 on the substrate 120, the temperature of the heat treatment in the formation process of these layers can be increased.

[0210] FIG. 11B shows an example in which colored layers 132R, 132G, and 132B are provided in contact with the substrate 120, an insulating layer 134 is provided in contact with the colored layers 132R, 132G, and 132B, and a lens 133 is provided in contact with the insulating layer 134.

[0211] 11B , light emitted from the light-emitting device passes through lens 133, then passes through the colored layer, and is extracted to the outside of the display device. Note that lens 133 may be provided in contact with substrate 120, insulating layer 134 may be provided in contact with lens 133, and colored layer may be provided in contact with insulating layer 134. In this case, light emitted from the light-emitting device passes through the colored layer, then passes through lens 133, and is extracted to the outside of the display device.

[0212] As shown in FIGS. 12A and 12B, one of the lens and the color layer may be provided on the insulating layer 135 and the other on the substrate 120.

[0213] Figure 12A shows an example in which a lens 133 is provided on a light-emitting device via a protective layer 131 and an insulating layer 135, and a substrate 120 on which colored layers 132R, 132G, and 132B are provided is bonded to the lens 133 and the insulating layer 135 by a resin layer 122.

[0214] Figure 12B shows an example in which colored layers 132R, 132G, and 132B are provided on a light-emitting device via a protective layer 131 and an insulating layer 135, and a substrate 120 provided with a lens 133 is bonded to the colored layers 132R, 132G, and 132B by a resin layer 122.

[0215] The lens 133 is preferably a lens having a convex surface and a flat surface on the surface opposite to the convex surface (also referred to as a plano-convex lens). The convex surface of the lens 133 may face either the substrate 120 side or the light-emitting device side, but from the viewpoint of ease of fabrication, when the lens 133 is provided on the light-emitting device side as in Figures 11A and 12A, it is preferably provided so that the convex surface faces the substrate 120 side. On the other hand, when the lens 133 is provided on the substrate 120 side as in Figures 11B and 12B, it is preferably provided so that the convex surface faces the light-emitting device side.

[0216] The lens 133 can be formed using at least one of an inorganic material and an organic material. For example, a material containing a resin can be used for the lens 133. Also, a material containing at least one of an oxide and a sulfide can be used for the lens 133. The lens 133 is preferably formed using a material having a refractive index higher than that of the resin layer 122. For example, a microlens array can be used as the lens 133. The lens 133 may be formed directly on the substrate or the light-emitting device, or a separately formed lens may be bonded thereto.

[0217] It is also preferable that the colored layers of different colors have overlapping portions. The overlapping portions can function as light-blocking layers, thereby further reducing the reflection of external light.

[0218] 13A is a schematic cross-sectional view of a display device exemplified below. The display device has subpixels 154R, 154G, and 154B.

[0219] Subpixel 154R, subpixel 154G, and subpixel 154B include light-emitting devices 137R, 137G, and 137B, respectively. Light-emitting devices 137R, 137G, and 137B differ from light-emitting devices 130R, 130G, and 130B in that light-emitting devices 137R, 137G, and 137B include EL layer 113B instead of EL layer 113. Furthermore, in the region between pixel electrode 111R and pixel electrode 111G, a material layer 113b is provided on insulating layer 255c. Similarly, in the region between pixel electrode 111G and pixel electrode 111B and the region between pixel electrode 111B and pixel electrode 111R, a material layer 113b is provided on insulating layer 255c. The material layer 113b is formed in the same process as the EL layer 113B, has the same structure, and corresponds to the material layer 113s shown in FIG. 1B and other figures. The EL layer 113B contains a light-emitting material that emits blue light, purple light, or ultraviolet light. Therefore, the light-emitting devices 137R, 137G, and 137B all emit blue light, purple light, or ultraviolet light.

[0220] Furthermore, the sub-pixel 154R has a color conversion layer 175R and a colored layer 132R on the optical path of the light emitted by the light emitting device 137R. The color conversion layer 175R has a function of absorbing the light emitted by the light emitting device 137R and emitting red light.

[0221] The subpixel 154G has a color conversion layer 175G and a colored layer 132G on the optical path of light emitted by the light emitting device 137G. The color conversion layer 175G has a function of absorbing the light emitted by the light emitting device 137G and emitting green light.

[0222] A light-emitting device 137B is provided in the subpixel 154B. When a light-emitting device that emits purple or ultraviolet light is used as the light-emitting device 137B, it is preferable to place one or both of a colored layer that transmits blue light and a color conversion layer that absorbs light emitted by the light-emitting device 137B and emits blue light on the optical path of the light-emitting device 137B.

[0223] The color conversion layers 175R and 175G may be made of, for example, a fluorescent material, a phosphorescent material, or a resin material in which quantum dots are dispersed.

[0224] The colored layers 132R and 132G each have the function of absorbing blue or purple light transmitted through the color conversion layer. This increases the color purity of the light emitted by each sub-pixel, thereby achieving a display device with high display quality. Note that a colored layer that transmits blue light may be provided in the sub-pixel 154B.

[0225] The display device shown in FIG. 13B has subpixels 155R, 155G, and 155B.

[0226] The subpixel 155R includes a light-emitting device 130R, a color conversion layer 175R, and a coloring layer 132R. As described above, the light-emitting device 130R is a light-emitting device that emits white light. The color conversion layer 175R has a function of absorbing light with a shorter wavelength than red light from the white light emitted by the light-emitting device 130R, thereby emitting red light. The coloring layer 132R has a function of transmitting red light and absorbing other visible light.

[0227] The subpixel 155G includes a light-emitting device 130G, a color conversion layer 175G, and a coloring layer 132G. As described above, the light-emitting device 130G is a light-emitting device that emits white light. The color conversion layer 175G has a function of absorbing light with a shorter wavelength than green light from the white light emitted by the light-emitting device 130G, thereby emitting green light. The coloring layer 132G has a function of transmitting green light and absorbing other visible light.

[0228] The subpixel 155B includes a light-emitting device 130B and a colored layer 132B. As described above, the light-emitting device 130B is a light-emitting device that emits white light. The colored layer 132B transmits blue light from the white light emitted by the light-emitting device 130B and absorbs other visible light.

[0229] In this way, by applying color conversion layers to the red and green sub-pixels, it is possible to reuse light emitted from the white light-emitting device that would otherwise be absorbed by the colored layer, thereby making it possible to improve the luminous efficiency compared to a configuration that does not use a color conversion layer.

[0230] 13A and 13B show an example in which a light-shielding layer 171 is provided on the insulating layer 135 in a portion overlapping with the insulating layer 127. The light-shielding layer 171 is preferably provided between adjacent light-emitting devices in a planar view. With such a configuration, the light-shielding layer 171 can block light mixed between adjacent color conversion layers, preventing the mixed light from escaping to the outside. The light-shielding layer 171 preferably includes a material that absorbs at least a portion of visible light. For example, the light-shielding layer 171 itself may be made of a material that absorbs visible light (e.g., a colored organic or inorganic material), or the light-shielding layer 171 may include a pigment that absorbs visible light. The light-shielding layer 171 can be, for example, a resin that contains carbon black as a pigment and functions as a black matrix, or a resin that can be used as a color filter that transmits red, blue, or green light and absorbs other light.

[0231] Note that the display device of one embodiment of the present invention may not have the light-blocking layer 171. In this case, as shown in FIG. 1B and the like, it is preferable that the display device have a structure in which the ends of adjacent colored layers overlap each other.

[0232] In the display device of one embodiment of the present invention, the EL layer is partially thinned or the EL layer is provided in an island shape for each light-emitting device, so that leakage current between subpixels can be suppressed, thereby preventing unintended light emission due to crosstalk and realizing a display device with extremely high contrast.

[0233] In addition, in a display device according to one embodiment of the present invention, a sidewall insulating layer is provided on a side surface of a pixel electrode, which can suppress short circuits in a light-emitting device and provide a highly reliable display device.

[0234] Furthermore, in a display device according to one embodiment of the present invention, an insulating layer is provided so as to cover at least a part of the top surface and side surfaces of the island-shaped EL layer. A common electrode is provided so as to cover the insulating layer and the EL layer. This can prevent the common electrode from being disconnected due to a step between adjacent pixel electrodes, thereby further increasing the manufacturing yield of light-emitting devices.

[0235] This embodiment mode can be combined with other embodiment modes as appropriate. In addition, in this specification, when a plurality of configuration examples are shown in one embodiment mode, the configuration examples can be combined as appropriate.

[0236] 14 to 16. Note that with regard to materials and formation methods of elements, descriptions of the same parts as those described in Embodiment 1 may be omitted. In addition, details of the structure of a light-emitting device will be described in Embodiment 5.

[0237] 14A to 14E, 15A to 15D, 16E, and 16F show cross-sectional views taken along dashed dotted lines X1-X2 and Y1-Y2 shown in FIG. 1A side by side.

[0238] Thin films (insulating films, semiconductor films, conductive films, etc.) constituting display devices can be formed using a sputtering method, a CVD method, a vacuum evaporation method, a pulsed laser deposition (PLD) method, an ALD method, etc. CVD methods include a PECVD method and a thermal CVD method. One type of thermal CVD method is a metal organic chemical vapor deposition (MOCVD) method.

[0239] Furthermore, thin films (insulating films, semiconductor films, conductive films, etc.) constituting the display device can be formed by a wet film formation method such as spin coating, dipping, spray coating, inkjet, dispensing, screen printing, offset printing, doctor knife, slit coating, roll coating, curtain coating, or knife coating.

[0240] In particular, vacuum processes such as vapor deposition and solution processes such as spin coating and inkjet printing can be used to fabricate light-emitting devices. Vapor deposition methods include physical vapor deposition (PVD) methods such as sputtering, ion plating, ion beam deposition, molecular beam deposition, and vacuum deposition, and chemical vapor deposition (CVD). In particular, functional layers included in the EL layer (hole injection layer, hole transport layer, hole blocking layer, light-emitting layer, electron blocking layer, electron transport layer, electron injection layer, charge generation layer, etc.) can be formed by vapor deposition (vacuum deposition, etc.), coating methods (dip coating, die coating, bar coating, spin coating, spray coating, etc.), printing methods (inkjet printing, screen (stencil printing), offset (lithographic printing), flexography (relief printing), gravure, microcontact printing, etc.), etc.

[0241] Furthermore, when processing the thin film that constitutes the display device, it can be processed using a photolithography method or the like. Alternatively, the thin film may be processed using a nanoimprint method, a sandblasting method, a lift-off method or the like. Furthermore, the island-shaped thin film may be directly formed by a film formation method using a shielding mask such as a metal mask.

[0242] There are two typical photolithography methods: one is to form a resist mask on the thin film to be processed, process the thin film by etching or the like, and then remove the resist mask; the other is to form a photosensitive thin film, and then process the thin film into the desired shape by exposure and development.

[0243] In photolithography, the light used for exposure can be, for example, i-line (wavelength 365 nm), g-line (wavelength 436 nm), h-line (wavelength 405 nm), or a mixture of these. Other light sources that can be used include ultraviolet light, KrF laser light, ArF laser light, etc. Exposure can also be performed by immersion exposure technology. Extreme ultraviolet (EUV) light or X-rays can also be used as the light used for exposure. An electron beam can also be used instead of the light used for exposure. Extreme ultraviolet light, X-rays, or an electron beam are preferred because they enable extremely fine processing. When exposure is performed by scanning a beam such as an electron beam, a photomask is not required.

[0244] For etching the thin film, dry etching, wet etching, sandblasting, or the like can be used.

[0245] First, an insulating layer 255a, an insulating layer 255b, and an insulating layer 255c are formed in this order over the layer 101. Then, the pixel electrodes 111R, 111G, and 111B and the conductive layer 123 are formed over the insulating layer 255c (FIG. 14A).

[0246] First, a conductive film to be a pixel electrode is formed on the insulating layer 255c, a resist mask is formed on the conductive film by photolithography, and unnecessary portions of the conductive film are removed by etching. The resist mask is then removed to form the pixel electrodes 111R, 111G, and 111B, and the conductive layer 123. The conductive film to be the pixel electrode can be formed by, for example, sputtering or vacuum evaporation. The conductive film can be processed by wet etching or dry etching. The conductive film is preferably processed by anisotropic etching.

[0247] When processing the conductive film, it is preferable to process the insulating layer 255c to form a recess in the insulating layer 255c. This allows the height of the sidewall insulating layer 114 to be formed later to be increased. This makes it easy to partially thin the EL layer 113 to be formed later or to divide the EL layer 113 into individual light-emitting devices. Note that other configurations according to one embodiment of the present invention include a configuration in which an opening is provided in the insulating layer 255c and a recess is provided in the insulating layer 255b, and a configuration in which openings are provided in the insulating layer 255b and the insulating layer 255c and a recess is provided in the insulating layer 255a. Furthermore, when the pixel electrode is sufficiently thick, the insulating layer 255c may not necessarily have a recess or an opening.

[0248] In other words, it is preferable that the thickness of the insulating layer 255c in the area that does not overlap with any of the pixel electrodes 111R, 111G, 111B, and the conductive layer 123 is thinner than the thickness of the insulating layer 255c in the area that overlaps with the pixel electrodes 111R, 111G, 111B, or the conductive layer 123.

[0249] Subsequently, an insulating film 114A is formed on the insulating layer 255c, the pixel electrodes 111R, 111G, 111B, and the conductive layer 123 (FIG. 14B).

[0250] The insulating film 114A is a film that will be processed later to become the sidewall insulating layer 114. Therefore, the configuration applicable to the sidewall insulating layer 114 described in the first embodiment can be applied to the insulating film 114A.

[0251] Next, the insulating film 114A is processed to form the sidewall insulating layer 114 ( FIG. 14C ). Processing the insulating film 114A exposes the upper surfaces of the insulating layer 255c, the pixel electrodes 111R, 111G, 111B, and the conductive layer 123. The sidewall insulating layer 114 is provided so as to contact the side surfaces of the pixel electrodes 111R, 111G, 111B, and the conductive layer 123.

[0252] For example, the sidewall insulating layer 114 can be formed by etching the upper surface of the insulating film 114A in a substantially uniform manner. Such uniform etching and planarization is also called an etch-back process. The sidewall insulating layer 114 can also be formed by photolithography.

[0253] The insulating film 114A can be processed by wet etching or dry etching, and is preferably processed by dry etching, and is preferably processed by anisotropic etching.

[0254] Note that when processing the insulating film 114A, the insulating layer 255c may also be processed to form a recess in the insulating layer 255c. Forming a recess in the insulating layer 255c makes it easier to partially thin the EL layer 113 to be formed later or to divide the EL layer 113 into individual light-emitting devices. Note that other configurations according to one embodiment of the present invention include a configuration in which an opening is provided in the insulating layer 255c and a recess is provided in the insulating layer 255b, and a configuration in which openings are provided in the insulating layer 255b and the insulating layer 255c and a recess is provided in the insulating layer 255a. Furthermore, when the pixel electrode is sufficiently thick, the insulating layer 255c may not necessarily have a recess or an opening.

[0255] In other words, in the insulating layer 255c shown in Figure 14C, the film thickness of the exposed region (the region that does not overlap with any of the sidewall insulating layer 114, pixel electrode 111R, pixel electrode 111G, pixel electrode 111B, and conductive layer 123) may be thinner than the film thickness of the region that overlaps with the sidewall insulating layer 114 (see Figure 3D).

[0256] The end of the sidewall insulating layer 114 may have a rounded shape. For example, when the sidewall insulating layer 114 is formed by using a dry etching method to etch the upper part of the insulating film 114A by anisotropic etching, the end of the sidewall insulating layer 114 becomes rounded as shown in Figures 14C, 1B, 3A to 3D, etc. Making the end of the sidewall insulating layer 114 rounded is preferable because it improves the coverage of a film to be formed later.

[0257] Next, the EL layer 113 is formed on the pixel electrode 111R, the pixel electrode 111G, and the pixel electrode 111B ( FIG. 14D ). The EL layer 113 includes a light-emitting material that emits blue light and a light-emitting material that emits light with a wavelength longer than blue. FIG. 14D shows an example in which an island-shaped EL layer 113 is provided for each light-emitting device. That is, an island-shaped EL layer 113 is provided on each of the pixel electrodes 111R, 111G, and 111B.

[0258] A material layer 113s is provided on the insulating layer 255c in the region between the pixel electrodes 111R and 111G. Similarly, a material layer 113s is provided on the insulating layer 255c in the region between the pixel electrodes 111G and 111B and in the region between the pixel electrodes 111B and 111R. The material layer 113s is formed in the same process as the EL layer 113 and has the same configuration.

[0259] 14D , in the cross-sectional view taken along the dashed dotted line Y1-Y2, the EL layer 113 is not formed on the conductive layer 123. For example, by using an area mask, the EL layer 113 can be formed only in a desired region.

[0260] The EL layer 113 can be formed by, for example, a vapor deposition method, specifically a vacuum deposition method. Alternatively, the EL layer 113 may be formed by a transfer method, a printing method, an inkjet method, a coating method, or the like.

[0261] Subsequently, an insulating film 125A, which will later become the insulating layer 125, is formed so as to cover the EL layer 113, the sidewall insulating layer 114, and the material layer 113s (FIG. 14E).

[0262] As will be described later, the insulating film 127a is formed in contact with the upper surface of the insulating film 125A. Therefore, it is preferable that the upper surface of the insulating film 125A has high adhesion to the resin composition (e.g., a photosensitive resin composition containing an acrylic resin) used for the insulating film 127a. To improve this adhesion, it is preferable to perform a surface treatment to hydrophobize (or increase the hydrophobicity of) the upper surface of the insulating film 125A. For example, it is preferable to perform the treatment using a silylating agent such as hexamethyldisilazane (HMDS). By hydrophobizing the upper surface of the insulating film 125A in this way, the insulating film 127a can be formed with good adhesion.

[0263] Subsequently, an insulating film 127a is formed on the insulating film 125A (FIG. 15A).

[0264] The insulating films 125A and 127a are preferably formed by a formation method that causes less damage to the EL layer 113. In particular, since the insulating film 125A is formed in contact with the surface of the EL layer 113, it is preferably formed by a formation method that causes less damage to the EL layer 113 than the insulating film 127a.

[0265] The insulating films 125A and 127a are formed at a temperature lower than the heat resistance temperature of the EL layer 113. By increasing the substrate temperature during film formation, the insulating film 125A can have a low impurity concentration and a high barrier property against at least one of water and oxygen, even if it is thin.

[0266] The substrate temperature when forming the insulating film 125A and the insulating film 127a is preferably 60°C or higher, 80°C or higher, 100°C or higher, or 120°C or higher, and 200°C or lower, 180°C or lower, 160°C or lower, 150°C or lower, or 140°C or lower, respectively.

[0267] As described above, in the display device of one embodiment of the present invention, a material with high heat resistance is used for the light-emitting device. Therefore, the substrate temperatures during the formation of the insulating film 125A and the insulating film 127a can be set to 100° C. or higher, 120° C. or higher, or 140° C. or higher, respectively. For example, the higher the deposition temperature of an inorganic insulating film, the denser the film can be and the higher the barrier property it can have. Therefore, by depositing the insulating film 125A at such a temperature, damage to the EL layer 113 during the deposition can be further reduced, and the reliability of the light-emitting device can be improved.

[0268] As the insulating film 125A, it is preferable to form an insulating film having a thickness of 3 nm or more, 5 nm or more, or 10 nm or more, and 200 nm or less, 150 nm or less, 100 nm or less, or 50 nm or less, within the above substrate temperature range.

[0269] The insulating film 125A is preferably formed by, for example, an ALD method. The ALD method is preferable because it can reduce film formation damage and form a film with high coverage. The insulating film 125A is preferably formed as an aluminum oxide film by, for example, an ALD method.

[0270] Alternatively, the insulating film 125A may be formed by a sputtering method, a CVD method, or a PECVD method, which have a faster film formation rate than an ALD method. This enables a highly reliable display device to be manufactured with high productivity.

[0271] The insulating film 127a is preferably formed by the wet deposition method described above. For example, the insulating film 127a is preferably formed by spin coating using a photosensitive resin, more specifically, using a photosensitive resin composition containing an acrylic resin.

[0272] After the insulating film 127a is formed, heat treatment (also referred to as pre-baking) is preferably performed. The heat treatment is performed at a temperature lower than the heat resistance temperature of the EL layer 113. The substrate temperature during the heat treatment is preferably 50° C. to 200° C., more preferably 60° C. to 150° C., and still more preferably 70° C. to 120° C. This allows the solvent contained in the insulating film 127a to be removed.

[0273] Next, visible light or ultraviolet light is irradiated onto a portion of the insulating film 127a to expose that portion (FIG. 15B). Here, when a positive-type photosensitive resin composition containing an acrylic resin is used for the insulating film 127a, visible light or ultraviolet light is irradiated using a mask 136 onto areas where the insulating layer 127 will not be formed in a later step. The insulating layer 127 is formed in the area sandwiched between any two of the pixel electrodes 111R, 111G, and 111B, and in the area surrounding the conductive layer 123. Therefore, as shown in FIG. 15B, light 139 is irradiated onto the portions of the insulating film 127a overlapping with the pixel electrodes 111R, 111G, 111B, and 123.

[0274] The width of the insulating layer 127 to be formed later can be controlled by the region to be exposed to light. In this embodiment, the insulating layer 127 is processed so as to have a portion overlapping with the upper surface of the pixel electrode (FIG. 4A). As shown in FIG. 7A or 7B, the insulating layer 127 does not necessarily have to have a portion overlapping with the upper surface of the pixel electrode.

[0275] The light used for exposure preferably contains i-line (wavelength 365 nm), and may contain at least one of g-line (wavelength 436 nm) and h-line (wavelength 405 nm).

[0276] 15B shows an example in which a positive photosensitive resin is used for the insulating film 127a and visible light or ultraviolet light is irradiated onto the region where the insulating layer 127 is not to be formed, but the present invention is not limited to this. For example, a negative photosensitive resin may be used for the insulating film 127a. In this case, the mask is changed and visible light or ultraviolet light is irradiated onto the region where the insulating layer 127 is to be formed.

[0277] 15C , development is performed to remove the exposed areas of the insulating film 127a, thereby forming an insulating layer 127b. The insulating layer 127b is formed in an area sandwiched between any two of the pixel electrodes 111R, 111G, and 111B, and in an area surrounding the conductive layer 123. When an acrylic resin is used for the insulating film 127a, it is preferable to use an alkaline solution as the developer, such as a tetramethylammonium hydroxide aqueous solution (TMAH).

[0278] After the development, a step of removing the residue (so-called scum) remaining after the development may be carried out. For example, the residue can be removed by ashing using oxygen plasma. A step of removing the residue may also be carried out after each of the development steps described below.

[0279] In order to adjust the height of the surface of the insulating layer 127b, etching may be performed. The insulating layer 127b may be processed by ashing using oxygen plasma, for example.

[0280] After development and before post-baking, exposure may be performed to irradiate the insulating layer 127b with visible light or ultraviolet light. The energy density of the exposure is 0 mJ / cm. ２ Larger, 800 mJ / cm ２ It is preferable that the dose is 0 mJ / cm or less. ２ Greater than 500 mJ / cm ２ By performing such exposure after development, the transparency of the insulating layer 127b can be improved in some cases, and the insulating layer 127b can be deformed into a tapered shape at a low temperature in some cases.

[0281] On the other hand, by not exposing the insulating layer 127b to light, it may be easier to change the shape of the insulating layer 127b or to deform the insulating layer 127 into a tapered shape in a later step. Therefore, it may be preferable not to expose the insulating layer 127b to light after development.

[0282] Subsequently, after the insulating layer 127b is formed, heat treatment (also referred to as post-baking) is performed. As shown in FIG. 15D , the heat treatment can transform the insulating layer 127b into the insulating layer 127 having tapered side surfaces. The heat treatment is performed at a temperature lower than the upper temperature limit of the EL layer 113. The heat treatment can be performed at a substrate temperature of 50° C. to 200° C., preferably 60° C. to 150° C., and more preferably 70° C. to 130° C. The heating atmosphere may be an air atmosphere or an inert gas atmosphere. The heating atmosphere may be an atmospheric pressure atmosphere or a reduced-pressure atmosphere. A reduced-pressure atmosphere is preferable because drying can be performed at a lower temperature. The substrate temperature in this heat treatment step is preferably higher than that in the heat treatment (pre-baking) performed after the formation of the insulating film 127a. This can improve adhesion between the insulating layer 127 and the insulating layer 125 and also improve the corrosion resistance of the insulating layer 127.

[0283] 6A and 6B, depending on the material of the insulating layer 127 and the temperature, time, and atmosphere of the post-baking, a concave curved shape may be formed on the side surface of the insulating layer 127. For example, the higher the temperature or the longer the post-baking time, the more likely the shape of the insulating layer 127 is to change, and a concave curved shape may be formed in cross section. Furthermore, as described above, if the developed insulating layer 127b is not exposed to light, the shape of the insulating layer 127 may be more likely to change during post-baking.

[0284] 15D , an etching process is performed using the insulating layer 127 as a mask to remove a portion of the insulating film 125A, thereby forming an opening in the insulating film 125A (i.e., the insulating layer 125 is formed), and the upper surfaces of the EL layer 113 and the conductive layer 123 are exposed.

[0285] The etching process can be performed by dry etching or wet etching.

[0286] When dry etching is used, it is preferable to use a chlorine-based gas. ２ , BCl ３ , SiCl４ , CCl ４ The above-mentioned chlorine-based gases may be appropriately added with oxygen gas, hydrogen gas, helium gas, argon gas, or the like, either alone or in combination. By using a dry etching method, a thin region of the insulating layer 125 can be formed with good in-plane uniformity.

[0287] Furthermore, when dry etching is used, by-products generated by the dry etching may be deposited on the upper surface and side surfaces of the insulating layer 127. As a result, components contained in the etching gas and components contained in the insulating film 125A may be contained in the insulating layer 127 after the display device is completed.

[0288] Furthermore, the etching treatment is preferably performed by a wet etching method. By using the wet etching method, damage to the EL layer 113 can be reduced compared to when using a dry etching method. For example, the wet etching method can be performed using an alkaline solution. For example, for wet etching of an aluminum oxide film, it is preferable to use an aqueous solution of tetramethylammonium hydroxide (TMAH), which is an alkaline solution. In this case, the wet etching can be performed by a paddle method.

[0289] As described above, by providing the insulating layers 125 and 127, it is possible to prevent poor connection between the light-emitting devices due to the divided portions of the common electrode 115 and an increase in electrical resistance due to a locally thin portion of the electrode. This can improve the display quality of the display device of one embodiment of the present invention. Furthermore, it is possible to further increase the manufacturing yield of the light-emitting devices.

[0290] After a portion of the EL layer 113 is exposed, heat treatment may be further performed. This heat treatment can remove water contained in the EL layer 113 and water adsorbed to the surface of the EL layer 113. Furthermore, this heat treatment may change the shape of the insulating layer 127. Specifically, the insulating layer 127 may expand to cover at least one of the end portion of the insulating layer 125 and the top surface of the EL layer 113. For example, the insulating layer 127 may have the shape shown in FIGS. 5A and 5B . For example, heat treatment can be performed in an inert gas atmosphere or a reduced-pressure atmosphere. The heat treatment can be performed at a substrate temperature of 50° C. to 200° C., preferably 60° C. to 150° C., and more preferably 70° C. to 120° C. A reduced-pressure atmosphere is preferable because dehydration can be performed at a lower temperature. However, the temperature range of the heat treatment is preferably set appropriately, taking into account the heat resistance temperature of the EL layer 113. In addition, when the heat resistance temperature of the EL layer 113 is taken into consideration, a temperature of 70° C. or more and 120° C. or less is particularly suitable within the above temperature range.

[0291] If the insulating layer 125 is etched all at once after the post-bake, side etching may cause the insulating layer 125 below the edge of the insulating layer 127 to disappear, forming a cavity. Such a cavity may cause unevenness on the surface on which the common electrode 115 is formed, making the common electrode 115 more likely to have a step. Therefore, it is preferable to perform the etching process of the insulating layer 125 separately, before and after the post-bake.

[0292] A method of performing the etching process of the insulating layer 125 separately before and after post-baking will be described below with reference to FIGS. 16A to 16D.

[0293] First, Fig. 16A shows an enlarged view of the EL layer 113 shown in Fig. 15C and the end portion of the insulating layer 127b and its vicinity. That is, Fig. 16A shows the insulating layer 127b formed by development.

[0294] 16B, an etching process is performed using insulating layer 127b as a mask to remove a portion of insulating film 125A and reduce the thickness of that portion. As a result, insulating layer 125B is formed below insulating layer 127b. Note that, hereinafter, the etching process using insulating layer 127b as a mask may be referred to as a first etching process.

[0295] The first etching process can be performed by dry etching or wet etching.

[0296] As shown in FIG. 16B, by performing etching using insulating layer 127b with tapered side surfaces as a mask, insulating layer 125B having a tapered upper surface can be formed relatively easily.

[0297] 16B , in the first etching process, the thin portions of insulating layer 125B (portions that do not overlap insulating layer 127b) are not completely removed, and the etching process is stopped at this stage. In this way, by leaving insulating layer 125B on EL layer 113, it is possible to prevent damage to EL layer 113 in subsequent processing steps.

[0298] 16B shows an example in which the shape of insulating layer 127b is unchanged from that of FIG. 16A, but the present invention is not limited to this. For example, the end of insulating layer 127b may droop and come into contact with the upper surface of insulating layer 125B. As described above, if insulating layer 127b is not exposed to light after development, the shape of insulating layer 127b may be easily changed.

[0299] 16C, post-baking can transform the insulating layer 127b into an insulating layer 127 having tapered side surfaces. As described above, the shape of the insulating layer 127b may have already changed to have tapered side surfaces by the time the first etching process is completed.

[0300] By leaving the thin portions of the insulating layer 125B in this state without completely removing them in the first etching process, it is possible to prevent the EL layer 113 from being damaged and deteriorated by post-baking, thereby improving the reliability of the light-emitting device.

[0301] 16D , an etching process is performed using the insulating layer 127 as a mask to remove a portion (a portion with a thin film thickness) of the insulating layer 125B. As a result, an opening is formed in the insulating layer 125B (i.e., the insulating layer 125 is formed), exposing the upper surfaces of the EL layer 113 and the conductive layer 123. Note that, hereinafter, the etching process using the insulating layer 127 as a mask may be referred to as a second etching process.

[0302] 16D shows an example in which a part of the end of the insulating layer 125 (specifically, the tapered portion formed by the first etching process) is covered with the insulating layer 127, and the tapered portion formed by the second etching process is exposed, which corresponds to the structure shown in FIGS. 4A and 4B.

[0303] As described above, when etching is performed before and after post-baking, the first etching process may side-etch the insulating film 125A (i.e., form the insulating layer 125B), potentially creating a cavity under the edge of the insulating layer 127b. However, by performing post-baking after that, the insulating layer 127b can be transformed into the insulating layer 127 having tapered sides. This allows the insulating layer 127 to fill the aforementioned cavity. The second etching process then etches only the thin portions of the insulating layer 125B (i.e., the portions that do not overlap with the insulating layer 127), minimizing the amount of side etching and reducing the likelihood of cavity formation. Even if a cavity does form, it can be minimized. This allows the surface on which the common electrode 115 is formed to be more flat.

[0304] Although the above example shows the case where the insulating layer 125 is formed by etching the insulating film 125A in two separate steps, the present invention is not limited to this example. Depending on the film thickness of the insulating film 125A or the etching conditions, the insulating layer 125 may be formed by etching the insulating film 125A only once.

[0305] 5A, 6B, and 7B, the insulating layer 127 may cover the entire end of the insulating layer 125. For example, the end of the insulating layer 127 may droop and cover the end of the insulating layer 125. Furthermore, for example, the end of the insulating layer 127 may come into contact with the upper surface of the EL layer 113. As described above, if the insulating layer 127b is not exposed to light after development, the shape of the insulating layer 127 may be easily deformed.

[0306] The second etching treatment is preferably performed by a wet etching method. By using the wet etching method, damage to the EL layer 113 can be reduced compared to when using a dry etching method. The wet etching method can be performed using an alkaline solution or the like.

[0307] Subsequently, the common electrode 115 is formed on the EL layer 113, the conductive layer 123, and the insulating layer 127 (FIG. 16E).

[0308] The common electrode 115 can be formed by, for example, sputtering or vacuum deposition. Alternatively, a film formed by deposition and a film formed by sputtering may be stacked.

[0309] Thereafter, a protective layer 131 is formed on the common electrode 115 ( FIG. 16F ). When applying a configuration having colored layers on an insulating layer 135 as shown in FIG. 1B , etc., the insulating layer 135 is formed on the protective layer 131, and colored layers 132R, 132G, and 132B are provided on the insulating layer 135. Then, a substrate 120 is bonded to the colored layers 132R, 132G, and 132B using a resin layer 122, thereby fabricating a display device ( FIG. 1B ). When applying a configuration having colored layers on the substrate 120 side as shown in FIG. 10 , etc., the colored layers 132R, 132G, and 132B are provided on the substrate 120 in advance, and the protective layer 131 and the colored layers formed on the substrate 120 are bonded to each other using a resin layer 122, thereby fabricating a display device.

[0310] The protective layer 131 and the insulating layer 135 may be formed by vacuum deposition, sputtering, CVD, ALD, or the like.

[0311] As described above, in the manufacturing method of the display device of this embodiment, the island-shaped EL layer 113 is formed without using a fine metal mask, and therefore, the island-shaped EL layer 113 can be formed with a uniform thickness. This makes it possible to realize a high-definition display device or a display device with a high aperture ratio. Furthermore, even if the definition or aperture ratio is high and the distance between subpixels is extremely short, the EL layers 113 in adjacent subpixels can be prevented from contacting each other. Therefore, it is possible to prevent leakage current from occurring between subpixels. This makes it possible to prevent unintended light emission due to crosstalk, and realize a display device with extremely high contrast.

[0312] Furthermore, in the manufacturing method of the display device of this embodiment mode, sub-pixels of three colors can be formed separately by forming only one type of EL layer. Therefore, the number of manufacturing steps is reduced, and the display device can be manufactured with high yield.

[0313] Furthermore, by providing the insulating layer 127 having a tapered end between adjacent island-shaped EL layers 113, it is possible to suppress the occurrence of a step in the common electrode 115 during the formation of the common electrode 115 and to prevent the formation of a locally thin portion in the common electrode 115. This can suppress the occurrence of a connection failure due to the disconnected portion in the common electrode 115 and an increase in electrical resistance due to the locally thin portion in the common electrode 115. Therefore, the display device of one embodiment of the present invention can achieve both high definition and high display quality.

[0314] This embodiment mode can be combined with other embodiment modes as appropriate.

[0315] Embodiment 3 In this embodiment, a display device of one embodiment of the present invention will be described with reference to FIGS.

[0316] [Pixel Layout] In this embodiment, pixel layouts different from that shown in FIG. 1A will be mainly described. There are no particular limitations on the arrangement of sub-pixels, and various methods can be applied. Examples of sub-pixel arrangements include a stripe arrangement, an S-stripe arrangement, a matrix arrangement, a delta arrangement, a Bayer arrangement, and a pentile arrangement.

[0317] The top shape of the sub-pixels shown in the drawings in this embodiment mode corresponds to the top shape of the light-emitting region.

[0318] The top surface shape of the subpixel may be, for example, a triangle, a quadrangle (including a rectangle, a diamond, and a square), a polygon such as a pentagon, a polygon with rounded corners, an ellipse, or a circle.

[0319] Furthermore, the circuit layout constituting the sub-pixel is not limited to the range of the sub-pixel shown in the figure, and the circuit components may be arranged outside of it.

[0320] An S-stripe arrangement is applied to the pixel 110 shown in Fig. 17A. The pixel 110 shown in Fig. 17A is composed of three subpixels: a subpixel 110a, a subpixel 110b, and a subpixel 110c.

[0321] The pixel 110 shown in Figure 17B includes a subpixel 110a having a generally trapezoidal top surface shape with rounded corners, a subpixel 110b having a generally triangular top surface shape with rounded corners, and a subpixel 110c having a generally rectangular or hexagonal top surface shape with rounded corners. Furthermore, the subpixel 110b has a larger light-emitting area than the subpixel 110a. In this manner, the shape and size of each subpixel can be determined independently. For example, the more reliable the light-emitting device, the smaller the size of the subpixel can be.

[0322] The Pentile arrangement is applied to the pixels 124a and 124b shown in Fig. 17C. Fig. 17C shows an example in which the pixel 124a having the subpixels 110a and 110b and the pixel 124b having the subpixels 110b and 110c are arranged alternately.

[0323] 17D to 17F, a delta arrangement is applied to the pixels 124a and 124b. The pixel 124a has two subpixels (subpixel 110a and subpixel 110b) in the upper row (first row) and one subpixel (subpixel 110c) in the lower row (second row). The pixel 124b has one subpixel (subpixel 110c) in the upper row (first row) and two subpixels (subpixel 110a and subpixel 110b) in the lower row (second row).

[0324] Figure 17D is an example in which each sub-pixel has an approximately rectangular top surface shape with rounded corners, Figure 17E is an example in which each sub-pixel has a circular top surface shape, and Figure 17F is an example in which each sub-pixel has an approximately hexagonal top surface shape with rounded corners.

[0325] In Figure 17F, each subpixel is arranged inside a closely packed hexagonal region. Each subpixel is arranged so that it is surrounded by six other subpixels when focusing on one subpixel. Furthermore, subpixels that emit light of the same color are arranged so that they are not adjacent to each other. For example, when focusing on subpixel 110a, three subpixels 110b and three subpixels 110c are arranged alternately so as to surround it.

[0326] 17G shows an example in which subpixels of each color are arranged in a zigzag pattern. Specifically, when viewed from above, the positions of the upper sides of two subpixels aligned in the column direction (for example, subpixels 110a and 110b, or subpixels 110b and 110c) are misaligned.

[0327] 17A to 17G, it is preferable that the subpixel 110a be the subpixel R that emits red light, the subpixel 110b be the subpixel G that emits green light, and the subpixel 110c be the subpixel B that emits blue light. Note that the configuration of the subpixels is not limited to this, and the colors that the subpixels emit and their order of arrangement can be determined appropriately. For example, the subpixel 110b may be the subpixel R that emits red light, and the subpixel 110a may be the subpixel G that emits green light.

[0328] In photolithography, the finer the pattern to be processed, the more the influence of light diffraction cannot be ignored. This reduces the fidelity when transferring a photomask pattern by exposure, making it difficult to process the resist mask into a desired shape. Therefore, even if the photomask pattern is rectangular, a pattern with rounded corners is likely to be formed. Therefore, the top surface shape of the pixel electrode may be a polygon with rounded corners, an ellipse, a circle, or the like. In a display device according to one embodiment of the present invention, the top surface shape of the EL layer and further the light-emitting device may be a polygon with rounded corners, an ellipse, a circle, or the like, influenced by the top surface shape of the pixel electrode.

[0329] In order to make the top surface shape of the pixel electrode into a desired shape, a technique for correcting the mask pattern in advance (OPC (Optical Proximity Correction) technique) may be used so that the design pattern and the transfer pattern coincide with each other. Specifically, the OPC technique adds a correction pattern to the corners of figures on the mask pattern.

[0330] As shown in Figures 18A to 18I, a pixel can be configured to have four types of sub-pixels.

[0331] A stripe arrangement is applied to the pixel 110 shown in FIGS. 18A to 18C.

[0332] Figure 18A shows an example in which each subpixel has a rectangular top surface shape, Figure 18B shows an example in which each subpixel has a top surface shape that is a combination of two semicircles and a rectangle, and Figure 18C shows an example in which each subpixel has an elliptical top surface shape.

[0333] A matrix arrangement is applied to the pixels 110 shown in FIGS. 18D to 18F.

[0334] Figure 18D is an example in which each sub-pixel has a square top surface shape, Figure 18E is an example in which each sub-pixel has an approximately square top surface shape with rounded corners, and Figure 18F is an example in which each sub-pixel has a circular top surface shape.

[0335] 18G and 18H show an example in which one pixel 110 is configured in two rows and three columns.

[0336] 18G has three subpixels (subpixels 110a, 110b, and 110c) in the top row (first row) and one subpixel (subpixel 110d) in the bottom row (second row). In other words, pixel 110 has subpixel 110a in the left column (first column), subpixel 110b in the center column (second column), subpixel 110c in the right column (third column), and subpixels 110d across these three columns.

[0337] The pixel 110 shown in FIG. 18H has three subpixels (subpixels 110a, 110b, and 110c) in the top row (first row) and three subpixels 110d in the bottom row (second row). In other words, the pixel 110 has subpixels 110a and 110d in the left column (first column), subpixels 110b and 110d in the center column (second column), and subpixels 110c and 110d in the right column (third column). By aligning the subpixels in the top and bottom rows as shown in FIG. 18H, it is possible to efficiently remove dust and other impurities that may occur during the manufacturing process. Therefore, a display device with high display quality can be provided.

[0338] FIG. 18I shows an example in which one pixel 110 is configured in three rows and two columns.

[0339] 18I has subpixel 110a in the top row (first row), subpixel 110b in the middle row (second row), subpixel 110c spanning from the first to second rows, and one subpixel (subpixel 110d) in the bottom row (third row). In other words, pixel 110 has subpixels 110a and 110b in the left column (first column), subpixel 110c in the right column (second column), and subpixel 110d spanning these two columns.

[0340] The pixel 110 shown in FIGS. 18A to 18I is composed of four subpixels: a subpixel 110a, a subpixel 110b, a subpixel 110c, and a subpixel 110d.

[0341] The subpixels 110a, 110b, 110c, and 110d may each have a light-emitting device that emits light of a different color, such as four subpixels of R, G, B, and white (W), four subpixels of R, G, B, and Y, or four subpixels of R, G, B, and infrared (IR).

[0342] 18A to 18I , it is preferable that, for example, the subpixel 110a be the subpixel R that emits red light, the subpixel 110b be the subpixel G that emits green light, the subpixel 110c be the subpixel B that emits blue light, and the subpixel 110d be any one of the subpixels W that emit white light, Y that emit yellow light, and IR that emit near-infrared light. With such a configuration, the pixel 110 shown in FIGS. 18G and 18H has a stripe layout of R, G, and B, thereby improving display quality. Furthermore, the pixel 110 shown in FIG. 18I has a so-called S-stripe layout of R, G, and B, thereby improving display quality.

[0343] As described above, in the display device of one embodiment of the present invention, various layouts can be applied to pixels each including a subpixel having a light-emitting device.

[0344] This embodiment mode can be combined with other embodiment modes as appropriate.

[0345] Embodiment 4 In this embodiment, a display device of one embodiment of the present invention will be described with reference to FIGS.

[0346] The display device of the present embodiment can be a high-definition display device, and can therefore be used, for example, as a display unit for a wristwatch-type or bracelet-type information terminal (wearable device), as well as a display unit for a wearable device that can be worn on the head, such as a head-mounted display (HMD) for VR, or a glasses-type AR device.

[0347] The display device of this embodiment can be a high-resolution display device or a large-sized display device. Therefore, the display device of this embodiment can be used in electronic devices having relatively large screens, such as television devices, desktop or notebook personal computers, computer monitors, digital signage, and large game machines such as pachinko machines, as well as in display units of digital cameras, digital video cameras, digital photo frames, mobile phones, portable game machines, personal digital assistants, and sound reproduction devices.

[0348] 19A shows a perspective view of a display module 280. The display module 280 includes a display device 100A and an FPC 290. Note that the display device included in the display module 280 is not limited to the display device 100A, and may be any of the display devices 100B to 100F described below.

[0349] The display module 280 has a substrate 291 and a substrate 292. The display module 280 has a display portion 281. The display portion 281 is a region that displays an image in the display module 280, and is a region where light from each pixel provided in a pixel portion 284 (described later) can be viewed.

[0350] 19B is a perspective view schematically illustrating the configuration on the substrate 291 side. A circuit portion 282, a pixel circuit portion 283 on the circuit portion 282, and a pixel portion 284 on the pixel circuit portion 283 are stacked on the substrate 291. A terminal portion 285 for connecting to the FPC 290 is provided in a portion of the substrate 291 that does not overlap with the pixel portion 284. The terminal portion 285 and the circuit portion 282 are electrically connected by a wiring portion 286 composed of a plurality of wirings.

[0351] The pixel section 284 has a plurality of periodically arranged pixels 284a. An enlarged view of one pixel 284a is shown on the right side of Fig. 19B. The various configurations described in the previous embodiments can be applied to the pixel 284a. Fig. 19B shows an example in which the pixel 284a has the same configuration as the pixel 110 shown in Fig. 1A.

[0352] The pixel circuit section 283 has a plurality of pixel circuits 283a arranged periodically.

[0353] One pixel circuit 283a is a circuit that controls the driving of multiple elements included in one pixel 284a. One pixel circuit 283a can be configured to have three circuits that control the light emission of one light-emitting device. For example, the pixel circuit 283a can be configured to have at least one selection transistor, one current control transistor (drive transistor), and a capacitor for each light-emitting device. In this case, a gate signal is input to the gate of the selection transistor, and a source signal is input to the source. This realizes an active matrix display device.

[0354] The circuit portion 282 includes a circuit for driving each pixel circuit 283a of the pixel circuit portion 283. For example, it is preferable that the circuit portion 282 includes one or both of a gate line driver circuit and a source line driver circuit. In addition, the circuit portion 282 may include at least one of an arithmetic circuit, a memory circuit, a power supply circuit, and the like.

[0355] The FPC 290 functions as wiring for supplying a video signal, a power supply potential, or the like from the outside to the circuit portion 282. An IC may be mounted on the FPC 290.

[0356] The display module 280 can be configured such that one or both of the pixel circuit unit 283 and the circuit unit 282 are provided overlapping the pixel unit 284, thereby enabling the aperture ratio (effective display area ratio) of the display unit 281 to be extremely high. For example, the aperture ratio of the display unit 281 can be set to 40% or more and less than 100%, preferably 50% or more and 95% or less, and more preferably 60% or more and 95% or less. Furthermore, the pixels 284a can be arranged at an extremely high density, enabling the resolution of the display unit 281 to be extremely high. For example, it is preferable that the pixels 284a be arranged in the display unit 281 at a resolution of 2000 ppi or more, preferably 3000 ppi or more, more preferably 5000 ppi or more, and even more preferably 6000 ppi or more, and 20000 ppi or less, or 30000 ppi or less.

[0357] Because such a display module 280 has extremely high resolution, it can be suitably used in VR devices such as HMDs or eyeglass-type AR devices. For example, even in a configuration in which the display unit of the display module 280 is viewed through lenses, the display module 280 has an extremely high-resolution display unit 281, so even if the display unit is enlarged with lenses, the pixels are not visible, allowing for a highly immersive display. Furthermore, the display module 280 is not limited to this, and can be suitably used in electronic devices with relatively small display units. For example, it can be suitably used in the display unit of a wearable electronic device such as a wristwatch.

[0358] Display Device 100A The display device 100A shown in FIG. 20 includes a substrate 301, a light-emitting device 130R, a light-emitting device 130G, a light-emitting device 130B, a colored layer 132R, a colored layer 132G, a colored layer 132B, a capacitor 240, and a transistor 310.

[0359] 19B includes a light-emitting device 130R and a colored layer 132R, a sub-pixel 11G includes a light-emitting device 130G and a colored layer 132G, and a sub-pixel 11B includes a light-emitting device 130B and a colored layer 132B. In the sub-pixel 11R, light emitted from the light-emitting device 130R is extracted as red light (R) to the outside of the display device 100A via the colored layer 132R. Similarly, in the sub-pixel 11G, light emitted from the light-emitting device 130G is extracted as green light (G) to the outside of the display device 100A via the colored layer 132G. In the sub-pixel 11B, light emitted from the light-emitting device 130B is extracted as blue light (B) to the outside of the display device 100A via the colored layer 132B.

[0360] 19A and 19B. The layered structure from the substrate 301 to the insulating layer 255c corresponds to the layer 101 in the first embodiment.

[0361] The transistor 310 has a channel formation region in a substrate 301. The substrate 301 can be, for example, a semiconductor substrate such as a single crystal silicon substrate. The transistor 310 includes a part of the substrate 301, a conductive layer 311, a low-resistance region 312, an insulating layer 313, and an insulating layer 314. The conductive layer 311 functions as a gate electrode. The insulating layer 313 is located between the substrate 301 and the conductive layer 311 and functions as a gate insulating layer. The low-resistance region 312 is a region in which the substrate 301 is doped with impurities and functions as one of a source and a drain. The insulating layer 314 is provided to cover a side surface of the conductive layer 311 and functions as an insulating layer.

[0362] An element isolation layer 315 is provided between two adjacent transistors 310 so as to be embedded in the substrate 301 .

[0363] In addition, an insulating layer 261 is provided to cover the transistor 310 , and a capacitor 240 is provided over the insulating layer 261 .

[0364] The capacitor 240 has a conductive layer 241, a conductive layer 245, and an insulating layer 243 located therebetween. The conductive layer 241 functions as one electrode of the capacitor 240, the conductive layer 245 functions as the other electrode of the capacitor 240, and the insulating layer 243 functions as a dielectric of the capacitor 240.

[0365] The conductive layer 241 is provided over the insulating layer 261 and is buried in the insulating layer 254. The conductive layer 241 is electrically connected to one of the source and the drain of the transistor 310 by a plug 271 buried in the insulating layer 261. The insulating layer 243 is provided to cover the conductive layer 241. The conductive layer 245 is provided in a region overlapping with the conductive layer 241 with the insulating layer 243 interposed therebetween.

[0366] Note that at least one of the conductive layers included in the layer 101 preferably includes a conductive layer surrounding the outside of the display portion 281 (or the pixel portion 284). The conductive layer can also be called a guard ring. By providing the conductive layer, it is possible to prevent elements such as transistors and light-emitting devices from being damaged by a high voltage applied to the elements due to charging caused by electrostatic discharge (ESD) or a process using plasma.

[0367] An insulating layer 255a is provided to cover the capacitor 240, an insulating layer 255b is provided on the insulating layer 255a, and an insulating layer 255c is provided on the insulating layer 255b. The light-emitting device 130R, the light-emitting device 130G, and the light-emitting device 130B are provided on the insulating layer 255c. Figure 20 shows an example in which the light-emitting device 130R, the light-emitting device 130G, and the light-emitting device 130B have the same stacked structure as the stacked structure shown in Figure 1B.

[0368] The pixel electrode 111R, the pixel electrode 111G, and the pixel electrode 111B are electrically connected to one of the source and drain of the transistor 310 via a plug 256 embedded in the insulating layer 243, the insulating layer 255a, the insulating layer 255b, and the insulating layer 255c, a conductive layer 241 embedded in the insulating layer 254, and a plug 271 embedded in the insulating layer 261. The height of the surface of the insulating layer 255c that contacts the pixel electrode and the height of the surface of the plug 256 that contacts the pixel electrode are the same or approximately the same. Various conductive materials can be used for the plug.

[0369] Furthermore, a protective layer 131 is provided on the light-emitting device 130R, the light-emitting device 130G, and the light-emitting device 130B. An insulating layer 135 is provided on the protective layer 131, and a colored layer 132R is provided on the insulating layer 135 at a position overlapping the light-emitting device 130R, a colored layer 132G is provided at a position overlapping the light-emitting device 130G, and a colored layer 132B is provided at a position overlapping the light-emitting device 130B. A substrate 120 is bonded to the colored layers 132R, 132G, and 132B by a resin layer 122. For details of the components from the light-emitting devices to the substrate 120, refer to Embodiment 1. The substrate 120 corresponds to the substrate 292 in FIG. 19A .

[0370] 21 has a configuration in which a transistor 310A and a transistor 310B, each having a channel formed in a semiconductor substrate, are stacked. Note that in the following description of the display device, descriptions of parts that are the same as those of the display device described above may be omitted.

[0371] The display device 100B has a configuration in which a substrate 301B on which a transistor 310B, a capacitor 240, and a light-emitting device are provided and a substrate 301A on which a transistor 310A is provided are bonded together.

[0372] Here, it is preferable to provide an insulating layer 345 on the lower surface of the substrate 301B (the surface on the substrate 301A side). It is also preferable to provide an insulating layer 346 on the insulating layer 261 provided on the substrate 301A. The insulating layers 345 and 346 are insulating layers that function as protective layers and can suppress the diffusion of impurities into the substrates 301B and 301A. The insulating layers 345 and 346 can be made of an inorganic insulating film that can be used for the protective layer 131.

[0373] The substrate 301B is provided with a plug 343 that penetrates the substrate 301B and an insulating layer 345. Here, it is preferable to provide an insulating layer 344 to cover the side surface of the plug 343. The insulating layer 344 is an insulating layer that functions as a protective layer and can suppress the diffusion of impurities from the plug 343 to the substrate 301B. As the insulating layer 344, an inorganic insulating film that can be used for the protective layer 131 can be used.

[0374] Furthermore, a conductive layer 342 is provided on the back surface of the substrate 301B (the surface opposite to the substrate 120 side), below the insulating layer 345. The conductive layer 342 is preferably provided so as to be embedded in the insulating layer 335. Furthermore, the lower surfaces of the conductive layer 342 and the insulating layer 335 (the surface on the substrate 301A side) are preferably flattened. Here, the conductive layer 342 is electrically connected to the plug 343.

[0375] On the other hand, in the substrate 301A, a conductive layer 341 is provided on an insulating layer 346. The conductive layer 341 is preferably provided so as to be embedded in the insulating layer 336. Furthermore, the upper surfaces of the conductive layer 341 and the insulating layer 336 are preferably flattened.

[0376] The substrate 301A and the substrate 301B are electrically connected by bonding the conductive layer 341 and the conductive layer 342. Here, by improving the flatness of the surface formed by the conductive layer 342 and the insulating layer 335 and the surface formed by the conductive layer 341 and the insulating layer 336, the conductive layer 341 and the conductive layer 342 can be favorably bonded to each other.

[0377] It is preferable to use the same conductive material for the conductive layers 341 and 342. For example, a metal film containing an element selected from Al, Cr, Cu, Ta, Ti, Mo, and W, or a metal nitride film containing the above elements (titanium nitride film, molybdenum nitride film, tungsten nitride film), etc., can be used. In particular, it is preferable to use copper for the conductive layers 341 and 342. This allows the use of Cu-Cu (copper-copper) direct bonding technology (technology that achieves electrical conductivity by connecting Cu (copper) pads together).

[0378] Display Device 100C A display device 100C shown in FIG. 22 has a configuration in which a conductive layer 341 and a conductive layer 342 are joined via a bump 347.

[0379] 22 , by providing a bump 347 between the conductive layer 341 and the conductive layer 342, the conductive layer 341 and the conductive layer 342 can be electrically connected. The bump 347 can be formed using a conductive material containing, for example, gold (Au), nickel (Ni), indium (In), tin (Sn), or the like. Alternatively, for example, solder may be used as the bump 347. An adhesive layer 348 may be provided between the insulating layer 345 and the insulating layer 346. Furthermore, when the bump 347 is provided, the insulating layer 335 and the insulating layer 336 shown in FIG. 21 may not be provided.

[0380] [Display Device 100D] A display device 100D shown in FIG. 23 differs from the display device 100A mainly in the configuration of the transistors.

[0381] The transistor 320 is a transistor (OS transistor) in which a metal oxide (also referred to as an oxide semiconductor) is used for a semiconductor layer in which a channel is formed.

[0382] The transistor 320 includes a semiconductor layer 321 , an insulating layer 323 , a conductive layer 324 , a pair of conductive layers 325 , an insulating layer 326 , and a conductive layer 327 .

[0383] 19A and 19B. The stacked structure from the substrate 331 to the insulating layer 255c corresponds to the layer 101 in Embodiment 1. The substrate 331 can be an insulating substrate or a semiconductor substrate.

[0384] An insulating layer 332 is provided over a substrate 331. The insulating layer 332 functions as a barrier layer that prevents impurities such as water or hydrogen from diffusing from the substrate 331 to the transistor 320 and prevents oxygen from being released from the semiconductor layer 321 toward the insulating layer 332. The insulating layer 332 can be, for example, a film through which hydrogen or oxygen is less likely to diffuse than a silicon oxide film, such as an aluminum oxide film, a hafnium oxide film, or a silicon nitride film.

[0385] A conductive layer 327 is provided over the insulating layer 332, and an insulating layer 326 is provided to cover the conductive layer 327. The conductive layer 327 functions as a first gate electrode of the transistor 320, and part of the insulating layer 326 functions as a first gate insulating layer. An oxide insulating film such as a silicon oxide film is preferably used for at least a portion of the insulating layer 326 that is in contact with the semiconductor layer 321. The top surface of the insulating layer 326 is preferably planarized.

[0386] The semiconductor layer 321 is provided over the insulating layer 326. The semiconductor layer 321 preferably includes a metal oxide (also referred to as an oxide semiconductor) film having semiconductor properties. A pair of conductive layers 325 is provided over and in contact with the semiconductor layer 321 and functions as a source electrode and a drain electrode.

[0387] An insulating layer 328 is provided to cover top surfaces and side surfaces of the pair of conductive layers 325 and side surfaces of the semiconductor layer 321, and an insulating layer 264 is provided over the insulating layer 328. The insulating layer 328 functions as a barrier layer that prevents impurities such as water or hydrogen from diffusing from the insulating layer 264 or the like into the semiconductor layer 321 and prevents oxygen from being released from the semiconductor layer 321. The insulating layer 328 can be an insulating film similar to the insulating layer 332.

[0388] Openings reaching the semiconductor layer 321 are provided in the insulating layer 328 and the insulating layer 264. Inside the openings, an insulating layer 323 and a conductive layer 324 are buried, which are in contact with side surfaces of the insulating layer 264, the insulating layer 328, and the conductive layer 325 and an upper surface of the semiconductor layer 321. The conductive layer 324 functions as a second gate electrode, and the insulating layer 323 functions as a second gate insulating layer.

[0389] The top surfaces of the conductive layer 324, the insulating layer 323, and the insulating layer 264 are planarized so that their heights are the same or approximately the same, and insulating layers 329 and 265 are provided to cover them.

[0390] The insulating layer 264 and the insulating layer 265 function as interlayer insulating layers. The insulating layer 329 functions as a barrier layer that prevents impurities such as water or hydrogen from diffusing from the insulating layer 265 or the like to the transistor 320. The insulating layer 329 can be formed using an insulating film similar to the insulating layer 328 and the insulating layer 332.

[0391] A plug 274 electrically connected to one of the pair of conductive layers 325 is provided to be embedded in the insulating layer 265, the insulating layer 329, and the insulating layer 264. Here, the plug 274 preferably includes a conductive layer 274a covering the side surfaces of the openings of the insulating layer 265, the insulating layer 329, the insulating layer 264, and the insulating layer 328 and part of the top surface of the conductive layer 325, and a conductive layer 274b in contact with the top surface of the conductive layer 274a. In this case, the conductive layer 274a is preferably made of a conductive material through which hydrogen and oxygen do not easily diffuse.

[0392] [Display Device 100E] A display device 100E illustrated in FIG. 24 has a stacked structure of a transistor 320A and a transistor 320B each including an oxide semiconductor in a semiconductor layer in which a channel is formed.

[0393] The transistor 320A, the transistor 320B, and the surrounding configurations thereof can be referred to the display device 100D.

[0394] Although two transistors including an oxide semiconductor are stacked here, the present invention is not limited to this structure, and for example, three or more transistors may be stacked.

[0395] [Display Device 100F] A display device 100F shown in FIG. 25 has a stacked structure of a transistor 310 in which a channel is formed in a substrate 301 and a transistor 320 in which a channel is formed and a semiconductor layer containing metal oxide.

[0396] An insulating layer 261 is provided to cover the transistor 310, and a conductive layer 251 is provided over the insulating layer 261. An insulating layer 262 is provided to cover the conductive layer 251, and a conductive layer 252 is provided over the insulating layer 262. The conductive layers 251 and 252 each function as wirings. An insulating layer 263 and an insulating layer 332 are provided to cover the conductive layer 252, and the transistor 320 is provided over the insulating layer 332. An insulating layer 265 is provided to cover the transistor 320, and a capacitor 240 is provided over the insulating layer 265. The capacitor 240 and the transistor 320 are electrically connected by a plug 274.

[0397] The transistor 320 can be used as a transistor that forms a pixel circuit. The transistor 310 can be used as a transistor that forms a pixel circuit or a driver circuit (gate line driver circuit, source line driver circuit) that drives the pixel circuit. The transistors 310 and 320 can be used as transistors that form various circuits such as an arithmetic circuit or a memory circuit.

[0398] By using this configuration, not only pixel circuits but also driving circuits etc. can be formed directly below the light-emitting device, making it possible to make the display device smaller than when driving circuits are provided around the periphery of the display area.

[0399] [Display Device 100G] FIG. 26 shows a perspective view of the display device 100G, and FIG. 27A shows a cross-sectional view of the display device 100G.

[0400] The display device 100G has a configuration in which a substrate 152 and a substrate 151 are bonded together. In Fig. 26, the substrate 152 is clearly indicated by a dashed line.

[0401] The display device 100G includes a display unit 162, a connection unit 140, a circuit 164, wiring 165, and the like. Fig. 26 shows an example in which an IC 173 and an FPC 172 are mounted on the display device 100G. Therefore, the configuration shown in Fig. 26 can also be said to be a display module including the display device 100G, an IC (integrated circuit), and an FPC.

[0402] The connection portion 140 is provided on the outside of the display portion 162. The connection portion 140 can be provided along one side or multiple sides of the display portion 162. The number of connection portions 140 may be single or multiple. Fig. 26 shows an example in which the connection portion 140 is provided so as to surround the four sides of the display portion 162. The connection portion 140 electrically connects the common electrode of the light-emitting device and the conductive layer, and can supply a potential to the common electrode.

[0403] The circuit 164 can be, for example, a scanning line driver circuit.

[0404] The wiring 165 has a function of supplying signals and power to the display portion 162 and the circuit 164. The signals and power are input to the wiring 165 from the outside via the FPC 172 or input to the wiring 165 from the IC 173.

[0405] 26 shows an example in which an IC 173 is provided on a substrate 151 by a chip-on-glass (COG) method, a chip-on-film (COF) method, or the like. For example, an IC including a scanning line driver circuit or a signal line driver circuit can be used as the IC 173. The display device 100G and the display module may not include an IC. Alternatively, the IC may be mounted on an FPC by a COF method or the like.

[0406] Figure 27A shows an example of a cross section of the display device 100G when a portion of the area including the FPC 172, a portion of the circuit 164, a portion of the display unit 162, a portion of the connection portion 140, and a portion of the area including the end portion are cut away.

[0407] The display device 100G shown in Figure 27A has, between the substrate 151 and the substrate 152, a transistor 201, a transistor 205, a light-emitting device 130R, a light-emitting device 130G, a light-emitting device 130B, a colored layer 132R that transmits red light, a colored layer 132G that transmits green light, a colored layer 132B that transmits blue light, and the like.

[0408] The light-emitting devices 130R, 130G, and 130B each have the same structure as the stacked structure shown in Fig. 1B except for the configuration of the pixel electrodes. For details of the light-emitting devices, refer to Embodiment 1.

[0409] The light-emitting device 130R has a conductive layer 112R, a conductive layer 126R on the conductive layer 112R, and a conductive layer 129R on the conductive layer 126R. All of the conductive layers 112R, 126R, and 129R may be referred to as pixel electrodes, or some of them may be referred to as pixel electrodes.

[0410] Light emitting device 130G includes conductive layer 112G, conductive layer 126G on conductive layer 112G, and conductive layer 129G on conductive layer 126G.

[0411] Light emitting device 130B includes conductive layer 112B, conductive layer 126B on conductive layer 112B, and conductive layer 129B on conductive layer 126B.

[0412] The conductive layer 112R is connected to the conductive layer 222b of the transistor 205 through an opening provided in the insulating layer 214. It is preferable that the end of the conductive layer 112R, the end of the conductive layer 126R, and the end of the conductive layer 129R are aligned or approximately aligned. This allows the height of the sidewall insulating layer 114 to be equal to or greater than the sum of the thicknesses of the three conductive layers, which makes it easy to thin a part of the EL layer or to divide the EL layer by the sidewall insulating layer 114. For example, conductive layers functioning as reflective electrodes can be used for the conductive layer 112R and the conductive layer 126R, and a conductive layer functioning as a transparent electrode can be used for the conductive layer 129R.

[0413] The conductive layers 112G, 126G, 129G, 112B, 126B, and 129B are similar to the conductive layers 112R, 126R, and 129R, and therefore will not be described in detail.

[0414] Recesses are formed in the conductive layers 112R, 112G, and 112B so as to cover the openings provided in the insulating layer 214. A layer 128 is buried in the recesses.

[0415] The layer 128 has a function of planarizing the recesses of the conductive layer 112R, the conductive layer 112G, and the conductive layer 112B. The conductive layers 126R, 126G, and 126B, which are electrically connected to the conductive layers 112R, 112G, and 112B, respectively, are provided on the conductive layers 112R, 112G, 112B, and the layer 128. Therefore, the regions overlapping with the recesses of the conductive layers 112R, 112G, and 112B can also be used as light-emitting regions, thereby increasing the aperture ratio of the pixel.

[0416] The layer 128 may be an insulating layer or a conductive layer. Various inorganic insulating materials, organic insulating materials, and conductive materials can be used as appropriate for the layer 128. In particular, the layer 128 is preferably formed using an insulating material, and is particularly preferably formed using an organic insulating material.

[0417] An insulating layer containing an organic material can be suitably used for the layer 128. Examples of the organic material that can be used for the layer 128 include the organic materials that can be used for the protective layer 131 or the insulating layer 135.

[0418] Parts of the top surfaces and side surfaces of adjacent EL layers 113, parts of the side surfaces of the sidewall insulating layers 114, the top surfaces of the material layers 113s, and parts of the top surfaces and side surfaces of the conductive layers 123 are covered with insulating layers 125 and 127. A common electrode 115 is provided on the EL layers 113, the insulating layers 125, and the insulating layers 127 so as to cover them. This makes it possible to prevent the common electrode 115 from being disconnected due to steps between adjacent pixel electrodes, thereby further improving the manufacturing yield of light-emitting devices. The common electrode 115 is a continuous film provided in common to multiple light-emitting devices.

[0419] A protective layer 131 is provided on the light-emitting devices 130R, 130G, and 130B. The protective layer 131 and the substrate 152 are bonded via an adhesive layer 142. The substrate 152 is provided with a light-shielding layer 117, a colored layer 132R, a colored layer 132G, and a colored layer 132B. A solid sealing structure, a hollow sealing structure, or the like can be applied to seal the light-emitting devices. In FIG. 27A , the space between the substrates 152 and 151 is filled with the adhesive layer 142, thereby applying a solid sealing structure. Alternatively, the space may be filled with an inert gas (such as nitrogen or argon), thereby applying a hollow sealing structure. In this case, the adhesive layer 142 may be provided so as not to overlap the light-emitting devices. Alternatively, the space may be filled with a resin different from the frame-shaped adhesive layer 142.

[0420] The protective layer 131 is preferably provided in at least the display portion 162 and is provided so as to cover the entire display portion 162. The protective layer 131 is preferably provided so as to cover not only the display portion 162 but also the connection portion 140 and the circuit 164. The protective layer 131 is preferably provided up to the edge of the display device 100G. On the other hand, in the connection portion 204, the FPC 172 and the conductive layer 166 are electrically connected to each other, so that a portion where the protective layer 131 is not provided is generated.

[0421] A connection portion 204 is provided in a region of the substrate 151 where the substrate 152 does not overlap. In the connection portion 204, the wiring 165 is electrically connected to the FPC 172 via a conductive layer 166 and a connection layer 242. The conductive layer 166 has an example of a stacked structure including a conductive film obtained by processing the same conductive film as the conductive layers 112R, 112G, and 112B, a conductive film obtained by processing the same conductive film as the conductive layers 126R, 126G, and 126B, and a conductive film obtained by processing the same conductive film as the conductive layers 129R, 129G, and 129B. The conductive layer 166 is exposed on the top surface of the connection portion 204. This allows the connection portion 204 and the FPC 172 to be electrically connected via the connection layer 242.

[0422] For example, after the protective layer 131 is formed over the entire surface of the display device 100G, a mask is used to remove the region of the protective layer 131 that overlaps with the conductive layer 166, thereby exposing the conductive layer 166.

[0423] Alternatively, a laminated structure of at least one organic layer and a conductive layer may be provided on the conductive layer 166, and the protective layer 131 may be provided on the laminated structure. A peeling initiation point (a portion that triggers peeling) may then be formed on the laminated structure using a laser or a sharp blade (e.g., a needle or cutter), selectively removing the laminated structure and the protective layer 131 thereon to expose the conductive layer 166. For example, the protective layer 131 can be selectively removed by pressing an adhesive roller against the substrate 151 and moving the roller relative to the substrate while rotating. Alternatively, adhesive tape may be attached to the substrate 151 and peeled off. Because of poor adhesion between the organic layer and the conductive layer, or between the organic layers themselves, separation occurs at the interface between the organic layer and the conductive layer or within the organic layer. This allows selective removal of the region of the protective layer 131 that overlaps with the conductive layer 166. If an organic layer or the like remains on the conductive layer 166, it can be removed using an organic solvent or the like.

[0424] As the organic layer, for example, at least one organic layer (a layer functioning as a light-emitting layer, a carrier blocking layer, a carrier transport layer, or a carrier injection layer) used in the EL layer 113 can be used. The organic layer may be formed simultaneously with the formation of the EL layer 113, or may be provided separately. The conductive layer can be formed in the same process and using the same material as the common electrode 115. For example, it is preferable to form an ITO film as the common electrode 115 and the conductive layer. Note that when a stacked structure is used for the common electrode 115, at least one layer of the layers constituting the common electrode 115 is provided as the conductive layer.

[0425] Furthermore, the top surface of the conductive layer 166 may be covered with a mask so that the protective layer 131 is not formed on the conductive layer 166. As the mask, for example, a metal mask (area metal mask) or an adhesive or adhesive tape or film may be used. By forming the protective layer 131 with the mask in place and then removing the mask, the conductive layer 166 can be kept exposed even after the protective layer 131 is formed.

[0426] Using this method, a region where the protective layer 131 is not provided can be formed in the connection portion 204, and in this region, the conductive layer 166 and the FPC 172 can be electrically connected via the connection layer 242.

[0427] In the connection portion 140, a conductive layer 123 is provided on the insulating layer 214. The conductive layer 123 has a stacked structure including a conductive film obtained by processing the same conductive film as the conductive layers 112R, 112G, and 112B, a conductive film obtained by processing the same conductive film as the conductive layers 126R, 126G, and 126B, and a conductive film obtained by processing the same conductive film as the conductive layers 129R, 129G, and 129B. The side surfaces of the conductive layer 123 are covered with a sidewall insulating layer 114. The sidewall insulating layer 114 functions as a sidewall of the conductive layer 123. The top surface and side surfaces of the sidewall insulating layer 114 and a portion of the top surface and side surfaces of the conductive layer 123 are covered with an insulating layer 125 and an insulating layer 127. A common electrode 115 is provided on and covers the conductive layer 123, the insulating layer 125, and the insulating layer 127. The common electrode 115 is provided in contact with a portion of the upper surface of the conductive layer 123 (a portion not covered by the insulating layer 125 and the insulating layer 127). In other words, the conductive layer 123 and the common electrode 115 are electrically connected at the connection portion 140.

[0428] The display device 100G is a top-emission type. Light emitted by the light-emitting device is emitted toward the substrate 152. The substrate 152 is preferably made of a material that is highly transparent to visible light. The pixel electrodes contain a material that reflects visible light, and the counter electrode (common electrode 115) contains a material that transmits visible light.

[0429] The laminated structure from the substrate 151 to the insulating layer 214 corresponds to the layer 101 in the first embodiment.

[0430] The transistor 201 and the transistor 205 are both formed over a substrate 151. These transistors can be manufactured using the same material and through the same process.

[0431] An insulating layer 211, an insulating layer 213, an insulating layer 215, and an insulating layer 214 are provided over the substrate 151 in this order. A part of the insulating layer 211 functions as a gate insulating layer for each transistor. A part of the insulating layer 213 functions as a gate insulating layer for each transistor. The insulating layer 215 is provided to cover the transistor. The insulating layer 214 is provided to cover the transistor and functions as a planarization layer. Note that the number of gate insulating layers and the number of insulating layers covering the transistors are not limited, and each may be a single layer or two or more layers.

[0432] At least one insulating layer covering the transistor is preferably made of a material that is resistant to the diffusion of impurities such as water and hydrogen. This allows the insulating layer to function as a barrier layer. With this structure, it is possible to effectively prevent impurities from diffusing into the transistor from the outside, thereby improving the reliability of the display device.

[0433] It is preferable to use an inorganic insulating film for each of the insulating layers 211, 213, and 215. Examples of the inorganic insulating film that can be used include a silicon nitride film, a silicon oxynitride film, a silicon oxide film, a silicon nitride oxide film, an aluminum oxide film, and an aluminum nitride film. Alternatively, a hafnium oxide film, an yttrium oxide film, a zirconium oxide film, a gallium oxide film, a tantalum oxide film, a magnesium oxide film, a lanthanum oxide film, a cerium oxide film, and a neodymium oxide film may also be used. Two or more of the above insulating films may be stacked.

[0434] An organic insulating layer is suitable for the insulating layer 214, which functions as a planarizing layer. Materials that can be used for the organic insulating layer include acrylic resin, polyimide resin, epoxy resin, polyamide resin, polyimideamide resin, siloxane resin, benzocyclobutene-based resin, phenolic resin, and precursors of these resins. Alternatively, the insulating layer 214 may have a laminated structure of an organic insulating layer and an inorganic insulating layer. The outermost layer of the insulating layer 214 preferably functions as an etching protection layer. This prevents recesses from being formed in the insulating layer 214 during processing of the conductive layer 112R, conductive layer 126R, conductive layer 129R, or the like. Alternatively, recesses may be formed in the insulating layer 214 during processing of the conductive layer 112R, conductive layer 126R, conductive layer 129R, or the like.

[0435] The transistor 201 and the transistor 205 each include a conductive layer 221 that functions as a gate electrode, an insulating layer 211 that functions as a gate insulating layer, conductive layers 222a and 222b that function as a source electrode and a drain electrode, a semiconductor layer 231, an insulating layer 213 that functions as a gate insulating layer, and a conductive layer 223 that functions as a gate electrode. Here, the same hatching pattern is applied to multiple layers obtained by processing the same conductive film. The insulating layer 211 is located between the conductive layer 221 and the semiconductor layer 231. The insulating layer 213 is located between the conductive layer 223 and the semiconductor layer 231.

[0436] The structure of the transistor included in the display device of this embodiment is not particularly limited. For example, a planar transistor, a staggered transistor, an inverted staggered transistor, or the like can be used. Furthermore, either a top-gate transistor or a bottom-gate transistor structure may be used. Alternatively, gate electrodes may be provided above and below a semiconductor layer in which a channel is formed.

[0437] The transistor 201 and the transistor 205 have a structure in which a semiconductor layer in which a channel is formed is sandwiched between two gate electrodes. The two gate electrodes may be connected and supplied with the same signal to drive the transistor. Alternatively, the threshold voltage of the transistor may be controlled by applying a potential for controlling the threshold voltage to one of the two gate electrodes and a potential for driving to the other.

[0438] The crystallinity of a semiconductor material used for a transistor is not particularly limited, and any of an amorphous semiconductor, a single crystal semiconductor, and a semiconductor having crystallinity other than a single crystal (a microcrystalline semiconductor, a polycrystalline semiconductor, or a semiconductor having a crystalline region in part) may be used. The use of a single crystal semiconductor or a crystalline semiconductor is preferable because it can suppress deterioration of transistor characteristics.

[0439] The semiconductor layer of the transistor preferably includes a metal oxide (also referred to as an oxide semiconductor). That is, the display device of this embodiment preferably includes a transistor using a metal oxide for a channel formation region (hereinafter referred to as an OS transistor).

[0440] Examples of crystalline oxide semiconductors include c-axis-aligned crystalline (CAAC)-OS and nanocrystalline (nc)-OS.

[0441] Alternatively, a transistor using silicon for a channel formation region (Si transistor) may be used. Examples of silicon include single crystal silicon, polycrystalline silicon, and amorphous silicon. In particular, a transistor having low temperature polysilicon (LTPS) in a semiconductor layer (hereinafter also referred to as an LTPS transistor) is preferably used. An LTPS transistor has high field-effect mobility and favorable frequency characteristics.

[0442] By using Si transistors such as LTPS transistors, circuits that need to be driven at high frequencies (such as source driver circuits) can be built on the same substrate as the display unit, which simplifies the external circuits mounted on the display device and reduces component and mounting costs.

[0443] An OS transistor has significantly higher field-effect mobility than a transistor using amorphous silicon. Furthermore, an OS transistor has significantly lower source-drain leakage current in an off state (hereinafter also referred to as off-state current), and can retain charge accumulated in a capacitor connected in series with the transistor for a long period of time. Furthermore, the use of an OS transistor can reduce the power consumption of a display device.

[0444] Furthermore, to increase the light emission luminance of a light-emitting device included in a pixel circuit, it is necessary to increase the amount of current flowing through the light-emitting device. To achieve this, it is necessary to increase the source-drain voltage of a driving transistor included in the pixel circuit. Since an OS transistor has a higher source-drain breakdown voltage than a Si transistor, a high voltage can be applied between the source and drain of the OS transistor. Therefore, by using an OS transistor as the driving transistor included in a pixel circuit, it is possible to increase the amount of current flowing through the light-emitting device and increase the light emission luminance of the light-emitting device.

[0445] Furthermore, when a transistor operates in the saturation region, an OS transistor can reduce the change in source-drain current with respect to a change in gate-source voltage compared to a Si transistor. Therefore, by using an OS transistor as a driving transistor included in a pixel circuit, the current flowing between the source and drain can be precisely controlled by changing the gate-source voltage, thereby controlling the amount of current flowing through the light-emitting device. This allows for a larger gradation in the pixel circuit.

[0446] Furthermore, in terms of the saturation characteristics of the current that flows when a transistor operates in the saturation region, an OS transistor can pass a more stable current (saturation current) than a Si transistor, even when the source-drain voltage gradually increases. Therefore, by using an OS transistor as a driving transistor, a stable current can be passed through a light-emitting device, even when the current-voltage characteristics of an EL device vary. In other words, when an OS transistor operates in the saturation region, the source-drain current of the OS transistor remains almost unchanged even when the source-drain voltage increases, thereby stabilizing the light-emitting luminance of the light-emitting device.

[0447] As described above, by using an OS transistor for a driving transistor included in a pixel circuit, it is possible to achieve "suppression of black floating," "increase in light emission luminance," "multiple gradations," "suppression of variations in light-emitting devices," and the like.

[0448] The semiconductor layer preferably contains, for example, indium, M (wherein M is one or more elements selected from gallium, aluminum, silicon, boron, yttrium, tin, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, and magnesium), and zinc. In particular, M is preferably one or more elements selected from aluminum, gallium, yttrium, and tin.

[0449] In particular, it is preferable to use an oxide containing indium (In), gallium (Ga), and zinc (Zn) (also referred to as IGZO) as the semiconductor layer. Alternatively, it is preferable to use an oxide containing indium, tin, and zinc. Alternatively, it is preferable to use an oxide containing indium, gallium, tin, and zinc. Alternatively, it is preferable to use an oxide containing indium (In), aluminum (Al), and zinc (Zn) (also referred to as IAZO). Alternatively, it is preferable to use an oxide containing indium (In), aluminum (Al), gallium (Ga), and zinc (Zn) (also referred to as IAGZO).

[0450] When the semiconductor layer is an In-M-Zn oxide, the atomic ratio of In in the In-M-Zn oxide is preferably equal to or greater than the atomic ratio of M. The atomic ratio of metal elements in such an In-M-Zn oxide may be In:M:Zn=1:1:1 or a composition thereabout, In:M:Zn=1:1:1 or a composition thereabout, In:M:Zn=1:1:1.2 or a composition thereabout, In:M:Zn=1:3:2 or a composition thereabout, In:M:Zn=1:3:4 or a composition thereabout, In:M:Zn=2:1:3 or a composition thereabout, In:M:Zn=3:1:2 or a composition thereabout, In:M:Zn=4:2: Examples of suitable compositions include a composition of In:M:Zn = 4:2:4.1 or a composition of In:M:Zn = 5:1:3 or a composition of In:M:Zn = 5:1:6 or a composition of In:M:Zn = 5:1:7 or a composition of In:M:Zn = 5:1:8 or a composition of In:M:Zn = 6:1:6 or a composition of In:M:Zn = 5:2:5 or a composition of In:M:Zn = 5:2:5. Note that the term "composition of a similar ratio" includes a range of ±30% of the desired atomic ratio.

[0451] For example, when describing a composition having an atomic ratio of In:Ga:Zn = 4:2:3 or thereabout, this includes a case where, when In is taken as 4, Ga is 1 to 3 and Zn is 2 to 4. Furthermore, when describing a composition having an atomic ratio of In:Ga:Zn = 5:1:6 or thereabout, this includes a case where, when In is taken as 5, Ga is more than 0.1 and 2 or less and Zn is 5 to 7. Furthermore, when describing a composition having an atomic ratio of In:Ga:Zn = 1:1:1 or thereabout, this includes a case where, when In is taken as 1, Ga is more than 0.1 and 2 or less and Zn is more than 0.1 and 2 or less.

[0452] The transistors included in the circuit 164 may have the same structure as or different from the transistors included in the display portion 162. The transistors included in the circuit 164 may all have the same structure or may have two or more types. Similarly, the transistors included in the display portion 162 may all have the same structure or may have two or more types.

[0453] All the transistors included in the display portion 162 may be OS transistors, all the transistors included in the display portion 162 may be Si transistors, or some of the transistors included in the display portion 162 may be OS transistors and the rest may be Si transistors.

[0454] For example, by using both an LTPS transistor and an OS transistor in the display portion 162, a display device with low power consumption and high driving capability can be realized. A structure in which an LTPS transistor and an OS transistor are combined may be referred to as LTPO. As a more preferable example, an OS transistor is preferably used as a transistor that functions as a switch for controlling conduction / non-conduction between wirings, and an LTPS transistor is preferably used as a transistor for controlling current.

[0455] For example, one of the transistors included in the display portion 162 functions as a transistor for controlling a current flowing through a light-emitting device and can also be called a driving transistor. One of the source and drain of the driving transistor is electrically connected to a pixel electrode of the light-emitting device. The driving transistor is preferably an LTPS transistor. This can increase the current flowing through the light-emitting device in the pixel circuit.

[0456] On the other hand, another transistor included in the display portion 162 functions as a switch for controlling pixel selection / non-selection and can also be called a selection transistor. The gate of the selection transistor is electrically connected to a gate line, and one of the source and drain is electrically connected to a source line (signal line). An OS transistor is preferably used as the selection transistor. This allows the gradation of a pixel to be maintained even when the frame frequency is significantly reduced (for example, 1 fps or less). Therefore, power consumption can be reduced by stopping the driver when displaying a still image.

[0457] As described above, the display device of one embodiment of the present invention can have a high aperture ratio, high definition, high display quality, and low power consumption.

[0458] A display device according to one embodiment of the present invention includes an OS transistor and a light-emitting device with a metal maskless (MML) structure. This structure significantly reduces leakage current that may flow through the transistor and leakage current that may flow between adjacent light-emitting devices (also referred to as lateral leakage current or side leakage current). Furthermore, when an image is displayed on the display device, the viewer can observe one or more of image clarity, image sharpness, high saturation, and a high contrast ratio. By significantly reducing leakage current that may flow through the transistor and lateral leakage current between light-emitting devices, light leakage that may occur during black display (so-called floating black) can be minimized.

[0459] 27B and 27C show other examples of transistor configurations.

[0460] The transistor 209 and the transistor 210 each include a conductive layer 221 functioning as a gate electrode, an insulating layer 211 functioning as a gate insulating layer, a semiconductor layer 231 including a channel formation region 231i and a pair of low-resistance regions 231n, a conductive layer 222a connected to one of the pair of low-resistance regions 231n, a conductive layer 222b connected to the other of the pair of low-resistance regions 231n, an insulating layer 225 functioning as a gate insulating layer, a conductive layer 223 functioning as a gate electrode, and an insulating layer 215 covering the conductive layer 223. The insulating layer 211 is located between the conductive layer 221 and the channel formation region 231i. The insulating layer 225 is located at least between the conductive layer 223 and the channel formation region 231i. Furthermore, an insulating layer 218 covering the transistor may be provided.

[0461] 27B shows an example in which the insulating layer 225 covers the top surface and side surfaces of the semiconductor layer 231. The conductive layer 222a and the conductive layer 222b are connected to the low-resistance region 231n through openings provided in the insulating layer 225 and the insulating layer 215, respectively. One of the conductive layer 222a and the conductive layer 222b functions as a source electrode, and the other functions as a drain electrode.

[0462] 27C , the insulating layer 225 overlaps with the channel formation region 231i of the semiconductor layer 231 but does not overlap with the low-resistance region 231n. For example, the insulating layer 225 is processed using the conductive layer 223 as a mask, thereby manufacturing the structure shown in FIG. 27C . In FIG. 27C , the insulating layer 215 is provided to cover the insulating layer 225 and the conductive layer 223, and the conductive layer 222a and the conductive layer 222b are connected to the low-resistance region 231n through openings in the insulating layer 215.

[0463] It is preferable to provide a light-shielding layer 117 on the surface of the substrate 152 facing the substrate 151. The light-shielding layer 117 can be provided between adjacent light-emitting devices, in the connection section 140, the circuit 164, etc. Various optical members can be disposed on the outside of the substrate 152.

[0464] The substrate 151 and the substrate 152 can be made of the same material as can be used for the substrate 120 shown in FIG. 1B and the like.

[0465] The adhesive layer 142 may be made of a material that can be used for the resin layer 122 shown in FIG. 1B and the like.

[0466] The connection layer 242 may be an anisotropic conductive film (ACF), an anisotropic conductive paste (ACP), or the like.

[0467] [Display Device 100H] The display device 100H shown in FIG. 28A differs from the display device 100G mainly in that it is a bottom-emission display device.

[0468] Light emitted from the light-emitting device is emitted toward the substrate 151. A material that is highly transparent to visible light is preferably used for the substrate 151. On the other hand, the light-transmitting property of the material used for the substrate 152 does not matter.

[0469] 28A shows an example in which the light-shielding layer 117 is provided over the substrate 151, the insulating layer 153 is provided over the light-shielding layer 117, and the transistor 201, the transistor 205, and the like are provided over the insulating layer 153. In addition, a coloring layer 132R, a coloring layer 132G, and a coloring layer 132B (not shown) are provided over the insulating layer 215.

[0470] Light emitting device 130R includes conductive layer 112R and conductive layer 126R on conductive layer 112R.

[0471] Light emitting device 130G includes conductive layer 112G and conductive layer 126G on conductive layer 112G.

[0472] Light emitting device 130B includes conductive layer 112B and conductive layer 126B on conductive layer 112B (neither shown).

[0473] The conductive layers 112R, 112G, 126R, and 126G are preferably made of a material that is highly transparent to visible light. The common electrode 115 is preferably made of a material that reflects visible light.

[0474] 27A, 28A, etc. show examples in which the layer 128 has a flat portion on the upper surface thereof, but there are no particular limitations on the shape of the layer 128. Figures 28B to 28D show modified examples of the layer 128.

[0475] As shown in FIGS. 28B and 28D, the upper surface of layer 128 can be configured to have a recessed shape in the center and its vicinity in cross section, that is, a shape having a concave curved surface.

[0476] As shown in FIG. 28C, the upper surface of layer 128 may be configured to have a shape in which the center and its vicinity bulge in cross section, that is, a shape having a convex curve.

[0477] The upper surface of layer 128 may have one or both of a convex curved surface and a concave curved surface. The number of convex curved surfaces and the number of concave curved surfaces that the upper surface of layer 128 has are not limited, and may be one or more.

[0478] Furthermore, the height of the upper surface of layer 128 and the height of the upper surface of conductive layer 112R may be the same or approximately the same, or may be different from each other. For example, the height of the upper surface of layer 128 may be lower or higher than the height of the upper surface of conductive layer 112R. The same applies to conductive layer 112G and conductive layer 112B.

[0479] 28B can also be considered an example in which layer 128 is contained within a recess formed in conductive layer 112R. On the other hand, as shown in FIG. 28D, layer 128 may be present outside the recess formed in conductive layer 112R, that is, the width of the upper surface of layer 128 may be wider than the recess. The same applies to conductive layers 112G and 112B.

[0480] This embodiment mode can be combined with other embodiment modes as appropriate.

[0481] Embodiment 5 In this embodiment, a light-emitting device that can be used for a display device according to one embodiment of the present invention will be described.

[0482] 29A, the light-emitting device has an EL layer 763 between a pair of electrodes (a lower electrode 761 and an upper electrode 762). The EL layer 763 can be composed of multiple layers, such as a layer 780, a light-emitting layer 771, and a layer 790.

[0483] The light-emitting layer 771 contains at least a light-emitting substance (also referred to as a light-emitting material).

[0484] When the lower electrode 761 is an anode and the upper electrode 762 is a cathode, the layer 780 includes one or more of a layer containing a substance with high hole-injecting properties (hole-injecting layer), a layer containing a substance with high hole-transporting properties (hole-transporting layer), and a layer containing a substance with high electron-blocking properties (electron-blocking layer). The layer 790 includes one or more of a layer containing a substance with high electron-injecting properties (electron-injecting layer), a layer containing a substance with high electron-transporting properties (electron-transporting layer), and a layer containing a substance with high hole-blocking properties (hole-blocking layer). When the lower electrode 761 is a cathode and the upper electrode 762 is an anode, the layers 780 and 790 have the opposite structures to those described above.

[0485] A structure including the layer 780, the light-emitting layer 771, and the layer 790 provided between a pair of electrodes can function as a single light-emitting unit, and the structure of FIG. 29A is referred to as a single structure in this specification.

[0486] 29B shows a modified example of the EL layer 763 included in the light-emitting device shown in Fig. 29A. Specifically, the light-emitting device shown in Fig. 29B has a layer 781 on a lower electrode 761, a layer 782 on the layer 781, a light-emitting layer 771 on the layer 782, a layer 791 on the light-emitting layer 771, a layer 792 on the layer 791, and an upper electrode 762 on the layer 792.

[0487] When the lower electrode 761 is an anode and the upper electrode 762 is a cathode, for example, the layer 781 can be a hole injection layer, the layer 782 can be a hole transport layer, the layer 791 can be an electron transport layer, and the layer 792 can be an electron injection layer. When the lower electrode 761 is a cathode and the upper electrode 762 is an anode, the layer 781 can be an electron injection layer, the layer 782 can be an electron transport layer, the layer 791 can be a hole transport layer, and the layer 792 can be a hole injection layer. Such a layer structure allows carriers to be efficiently injected into the light-emitting layer 771, and the efficiency of carrier recombination in the light-emitting layer 771 can be increased.

[0488] 29C and 29D, a variation of the single structure is a configuration in which multiple light-emitting layers (light-emitting layer 771, light-emitting layer 772, and light-emitting layer 773) are provided between layer 780 and layer 790. While an example having three light-emitting layers is shown in FIGS. 29C and 29D, the number of light-emitting layers in a single-structure light-emitting device may be two, or may be four or more. Furthermore, a light-emitting device with a single structure may have a buffer layer between the two light-emitting layers.

[0489] 29E and 29F, a configuration in which a plurality of light-emitting units (light-emitting unit 763a and light-emitting unit 763b) are connected in series via a charge generation layer 785 (also referred to as an intermediate layer) is referred to as a tandem structure in this specification. Note that the tandem structure may also be referred to as a stack structure. By using a tandem structure, a light-emitting device capable of emitting light with high brightness can be obtained. Furthermore, compared to a single structure, the tandem structure can reduce the current required to obtain the same brightness, thereby improving reliability.

[0490] 29D and 29F are examples of display devices having a layer 764 overlapping with the light-emitting device. Fig. 29D is an example in which the layer 764 overlaps with the light-emitting device shown in Fig. 29C, and Fig. 29F is an example in which the layer 764 overlaps with the light-emitting device shown in Fig. 29E. In Fig. 29D and 29F, a conductive film that transmits visible light is used for the upper electrode 762 in order to extract light to the upper electrode 762 side.

[0491] The layer 764 can be a color conversion layer, a color filter (coloring layer), or both.

[0492] 29C and 29D , light-emitting layers 771, 772, and 773 can be made of light-emitting materials that emit light of different colors. When the light emitted by light-emitting layers 771, 772, and 773 is of complementary colors, the light-emitting layers as a whole emit white light. For example, a light-emitting device with a single structure preferably has a light-emitting layer containing a light-emitting material that emits blue light and a light-emitting layer containing a light-emitting material that emits visible light with a wavelength longer than blue.

[0493] 29D, a color filter is preferably provided as layer 764. When white light passes through the color filter, light of a desired color can be obtained.

[0494] For example, when a light-emitting device with a single structure has three light-emitting layers, it preferably has a light-emitting layer containing a light-emitting material that emits red (R) light, a light-emitting layer containing a light-emitting material that emits green (G) light, and a light-emitting layer containing a light-emitting material that emits blue (B) light. The stacking order of the light-emitting layers may be R, G, B from the anode side, or R, B, G from the anode side, etc. In this case, a buffer layer may be provided between R and G or B.

[0495] Furthermore, for example, when a light-emitting device with a single structure has two light-emitting layers, a structure having one light-emitting layer containing a light-emitting substance that emits blue (B) light and another light-emitting layer containing a light-emitting substance that emits yellow (Y) light is preferred. This structure is sometimes referred to as a BY single structure.

[0496] A light-emitting device that emits white light preferably contains two or more types of light-emitting materials. To obtain white light emission, light-emitting materials may be selected such that the respective emissions of the two or more light-emitting materials have a complementary color relationship. For example, by making the emission color of the first light-emitting layer and the emission color of the second light-emitting layer complementary to each other, a light-emitting device that emits white light as a whole can be obtained. The same applies to a light-emitting device having three or more light-emitting layers.

[0497] 29C and 29D, the layer 780 and the layer 790 may each independently have a laminated structure made up of two or more layers, as shown in FIG. 29B.

[0498] 29E and 29F, the light-emitting layer 771 and the light-emitting layer 772 can be made of light-emitting materials that emit light of different colors. When the light emitted by the light-emitting layer 771 and the light emitted by the light-emitting layer 772 are complementary colors, white light can be obtained overall. A color filter is preferably provided as the layer 764 shown in FIG. 29F. When white light passes through the color filter, light of a desired color can be obtained.

[0499] 29E and 29F show an example in which the light-emitting unit 763a has one light-emitting layer 771 and the light-emitting unit 763b has one light-emitting layer 772, but this is not limiting. Each of the light-emitting unit 763a and the light-emitting unit 763b may have two or more light-emitting layers.

[0500] 29E and 29F illustrate light-emitting devices having two light-emitting units, but the present invention is not limited to this. The light-emitting device may have three or more light-emitting units. Note that a configuration having two light-emitting units may be referred to as a two-tiered tandem structure, and a configuration having three light-emitting units may be referred to as a three-tiered tandem structure.

[0501] 29E and 29F, the light-emitting unit 763a includes a layer 780a, a light-emitting layer 771, and a layer 790a, and the light-emitting unit 763b includes a layer 780b, a light-emitting layer 772, and a layer 790b.

[0502] When the lower electrode 761 is an anode and the upper electrode 762 is a cathode, the layers 780a and 780b each have one or more of a hole injection layer, a hole transport layer, and an electron blocking layer. The layers 790a and 790b each have one or more of an electron injection layer, an electron transport layer, and a hole blocking layer. When the lower electrode 761 is a cathode and the upper electrode 762 is an anode, the layers 780a and 790a have the opposite structures to those described above, and the layers 780b and 790b also have the opposite structures to those described above.

[0503] When the lower electrode 761 is an anode and the upper electrode 762 is a cathode, for example, the layer 780a may have a hole injection layer, a hole transport layer on the hole injection layer, and an electron blocking layer on the hole transport layer. The layer 790a may have an electron transport layer and a hole blocking layer between the light-emitting layer 771 and the electron transport layer. The layer 780b may have a hole transport layer and an electron blocking layer on the hole transport layer. The layer 790b may have an electron transport layer, an electron injection layer on the electron transport layer, and a hole blocking layer between the light-emitting layer 772 and the electron transport layer. When the lower electrode 761 is a cathode and the upper electrode 762 is an anode, for example, the layer 780a may have an electron injection layer, an electron transport layer on the electron injection layer, and an electron blocking layer on the electron transport layer. Layer 790a has a hole transport layer and may further have an electron blocking layer between light-emitting layer 771 and the hole transport layer. Layer 780b has an electron transport layer and may further have a hole blocking layer on the electron transport layer. Layer 790b has a hole transport layer and a hole injection layer on the hole transport layer and may further have an electron blocking layer between light-emitting layer 772 and the hole transport layer.

[0504] When a light-emitting device having a tandem structure is fabricated, two light-emitting units are stacked via a charge generation layer 785. The charge generation layer 785 has at least a charge generation region. The charge generation layer 785 has a function of injecting electrons into one of the two light-emitting units and injecting holes into the other when a voltage is applied between a pair of electrodes.

[0505] An example of a light emitting device with a tandem structure is shown in FIGS. 30A to 30C.

[0506] 30A shows a configuration having three light-emitting units. In FIG. 30A , a plurality of light-emitting units (light-emitting unit 763a, light-emitting unit 763b, and light-emitting unit 763c) are connected in series via charge generation layers 785. Furthermore, light-emitting unit 763a includes layer 780a, light-emitting layer 771, and layer 790a. Light-emitting unit 763b includes layer 780b, light-emitting layer 772, and layer 790b. Light-emitting unit 763c includes layer 780c, light-emitting layer 773, and layer 790c. Note that layer 780c can have a structure applicable to layers 780a and 780b, and layer 790c can have a structure applicable to layers 790a and 790b.

[0507] 30A , light-emitting materials that emit light of different colors can be used for some or all of the light-emitting layers 771, 772, and 773. Examples of combinations of the light-emitting colors of the light-emitting layers 771, 772, and 773 include a configuration in which two of them are blue (B) and the remaining one is yellow (Y), and a configuration in which one of them is red (R), the other is green (G), and the remaining one is blue (B).

[0508] 30B shows a tandem light-emitting device in which light-emitting units each having a plurality of light-emitting layers are stacked. In FIG. 30B, two light-emitting units (light-emitting unit 763a and light-emitting unit 763b) are connected in series via charge generation layer 785. Light-emitting unit 763a includes layer 780a, light-emitting layers 771a, 771b, and 771c, and layer 790a. Light-emitting unit 763b includes layer 780b, light-emitting layers 772a, 772b, and 772c, and layer 790b.

[0509] In FIG. 30B , light-emitting layers 771a, 771b, and 771c are selected from light-emitting materials that have complementary colors, enabling light-emitting unit 763a to emit white light (W). Light-emitting layers 772a, 772b, and 772c are also selected from light-emitting materials that have complementary colors, enabling light-emitting unit 763b to emit white light (W). In other words, the structure shown in FIG. 30B can be considered a two-tiered W / W tandem structure. The stacking order of the light-emitting materials that have complementary colors is not particularly limited. The implementer can select the optimal stacking order as appropriate. Although not shown, a three-tiered W / W / W tandem structure or a four-tiered or more tandem structure may also be used. Note that "a / b" means that a light-emitting unit having a light-emitting material that emits light of a is provided on a light-emitting unit having a light-emitting material that emits light of b, via a charge-generating layer, and a and b represent colors.

[0510] In addition, when a light-emitting device with a tandem structure is used, there are a B\Y or Y\B two-stage tandem structure having a light-emitting unit that emits yellow (Y) light and a light-emitting unit that emits blue (B) light, a R·G\B or B\R·G two-stage tandem structure having a light-emitting unit that emits red (R) and green (G) light and a light-emitting unit that emits blue (B) light, a light-emitting unit that emits yellow (Y) light and a light-emitting unit that emits blue (B) light, and a light-emitting unit that emits blue (B) light. Examples of such a tandem structure include a B\Y\B three-stage tandem structure having, in this order, a light-emitting unit that emits blue (B) light, a light-emitting unit that emits yellow-green (YG) light, and a light-emitting unit that emits blue (B) light, and a B\G\B three-stage tandem structure having, in this order, a light-emitting unit that emits blue (B) light, a light-emitting unit that emits green (G) light, and a light-emitting unit that emits blue (B) light. Note that "a·b" means that one light-emitting unit has a light-emitting substance that emits light of a and a light-emitting substance that emits light of b.

[0511] Furthermore, as shown in FIG. 30C, a light-emitting unit having one light-emitting layer and a light-emitting unit having multiple light-emitting layers may be combined.

[0512] 30C , a plurality of light-emitting units (light-emitting unit 763a, light-emitting unit 763b, and light-emitting unit 763c) are connected in series via charge generation layers 785. Light-emitting unit 763a includes layer 780a, light-emitting layer 771, and layer 790a. Light-emitting unit 763b includes layer 780b, light-emitting layer 772a, light-emitting layer 772b, light-emitting layer 772c, and layer 790b. Light-emitting unit 763c includes layer 780c, light-emitting layer 773, and layer 790c.

[0513] For example, in the configuration shown in Figure 30C, a three-stage tandem structure of B\R·G·YG\B can be applied, in which light-emitting unit 763a is a light-emitting unit that emits blue (B) light, light-emitting unit 763b is a light-emitting unit that emits red (R), green (G), and yellow-green (YG) light, and light-emitting unit 763c is a light-emitting unit that emits blue (B) light.

[0514] For example, the number of layers of the light-emitting units and the order of the colors can be, from the anode side, a two-layer structure of B and Y, a two-layer structure of B and light-emitting unit X, a three-layer structure of B, Y, and B, and the number of layers of the light-emitting layers in light-emitting unit X and the order of the colors can be, from the anode side, a two-layer structure of R and Y, a two-layer structure of R and G, a two-layer structure of G and R, a three-layer structure of G, R, and G, or a three-layer structure of R, G, and R. Furthermore, another layer can be provided between the two light-emitting layers.

[0515] Next, materials that can be used in light-emitting devices will be described.

[0516] Of the lower electrode 761 and the upper electrode 762, a conductive film that transmits visible light is used for the electrode from which light is extracted. A conductive film that reflects visible light is preferably used for the electrode from which light is not extracted. When the display device has a light-emitting device that emits infrared light, a conductive film that transmits visible light and infrared light is preferably used for the electrode from which light is extracted, and a conductive film that reflects visible light and infrared light is preferably used for the electrode from which light is not extracted.

[0517] A conductive film that transmits visible light may also be used for the electrode on the side from which light is not extracted. In this case, the electrode is preferably disposed between the reflective layer and the EL layer 763. That is, light emitted from the EL layer 763 may be reflected by the reflective layer and extracted from the display device.

[0518] Materials for forming the pair of electrodes of a light-emitting device can include metals, alloys, electrically conductive compounds, and mixtures thereof. Specific examples of such materials include metals such as aluminum, titanium, chromium, manganese, iron, cobalt, nickel, copper, gallium, zinc, indium, tin, molybdenum, tantalum, tungsten, palladium, gold, platinum, silver, yttrium, and neodymium, as well as alloys containing these metals in combination. Examples of such materials include indium tin oxide (In-Sn oxide, also referred to as ITO), In-Si-Sn oxide (also referred to as ITSO), indium zinc oxide (In-Zn oxide), and In-W-Zn oxide. Examples of such materials include aluminum alloys, such as aluminum-nickel-lanthanum alloys (Al-Ni-La), and silver-palladium-copper alloys (Ag-Pd-Cu, also referred to as APC). Other examples of the material include elements belonging to Group 1 or 2 of the periodic table (e.g., lithium, cesium, calcium, and strontium) that are not exemplified above, rare earth metals such as europium and ytterbium, alloys containing appropriate combinations of these, and graphene.

[0519] The light-emitting device preferably has a micro-optical resonator (microcavity) structure. Therefore, one of a pair of electrodes of the light-emitting device preferably has a transmissive and reflective electrode for visible light, and the other preferably has a reflective electrode for visible light. By having the light-emitting device have a microcavity structure, the light emitted from the light-emitting layer can be resonated between the two electrodes, thereby intensifying the light emitted from the light-emitting device.

[0520] The semi-transmitting / semi-reflective electrode can have a laminated structure of a conductive layer that can be used as a reflective electrode and a conductive layer that can be used as an electrode that is transparent to visible light (transparent electrode).

[0521] The light transmittance of the transparent electrode is 40% or more. For example, it is preferable to use an electrode having a visible light (light with a wavelength of 400 nm or more and less than 750 nm) transmittance of 40% or more for the transparent electrode of a light-emitting device. The visible light reflectance of the semi-transmissive / semi-reflective electrode is 10% or more and 95% or less, preferably 30% or more and 80% or less. The visible light reflectance of the reflective electrode is 40% or more and 100% or less, preferably 70% or more and 100% or less. The resistivity of these electrodes is 1×10 −２ Preferably, it is Ωcm or less.

[0522] The light-emitting device has at least a light-emitting layer. The light-emitting device may further have, as a layer other than the light-emitting layer, a layer containing a substance with high hole-injection properties, a substance with high hole-transport properties, a hole-blocking material, a substance with high electron-transport properties, an electron-blocking material, a substance with high electron-injection properties, or a bipolar substance (a substance with high electron-transport properties and high hole-transport properties). For example, the light-emitting device may have, in addition to the light-emitting layer, one or more layers selected from a hole-injection layer, a hole-transport layer, a hole-blocking layer, a charge-generating layer, an electron-blocking layer, an electron-transport layer, and an electron-injection layer.

[0523] The light-emitting device may contain either a low-molecular-weight compound or a high-molecular-weight compound, and may also contain an inorganic compound. The layers constituting the light-emitting device may be formed by a method such as vapor deposition (including vacuum vapor deposition), transfer, printing, ink-jet printing, or coating.

[0524] The light-emitting layer contains one or more light-emitting materials. As the light-emitting material, a material that emits light of blue, purple, blue-purple, green, yellow-green, yellow, orange, red, or the like is appropriately used. Furthermore, a material that emits near-infrared light can also be used as the light-emitting material.

[0525] Examples of the light-emitting material include fluorescent materials, phosphorescent materials, TADF materials, and quantum dot materials.

[0526] Examples of fluorescent materials include pyrene derivatives, anthracene derivatives, triphenylene derivatives, fluorene derivatives, carbazole derivatives, dibenzothiophene derivatives, dibenzofuran derivatives, dibenzoquinoxaline derivatives, quinoxaline derivatives, pyridine derivatives, pyrimidine derivatives, phenanthrene derivatives, and naphthalene derivatives.

[0527] Examples of phosphorescent materials include organometallic complexes (particularly iridium complexes) having a 4H-triazole skeleton, a 1H-triazole skeleton, an imidazole skeleton, a pyrimidine skeleton, a pyrazine skeleton, or a pyridine skeleton; organometallic complexes (particularly iridium complexes) having a phenylpyridine derivative having an electron-withdrawing group as a ligand; platinum complexes; and rare earth metal complexes.

[0528] The light-emitting layer may contain one or more organic compounds (host material, assist material, etc.) in addition to the light-emitting substance (guest material). As the one or more organic compounds, one or both of a substance with high hole-transporting properties (hole-transporting material) and a substance with high electron-transporting properties (electron-transporting material) can be used. As the hole-transporting material, a material with high hole-transporting properties that can be used for the hole-transporting layer, which will be described later, can be used. As the electron-transporting material, a material with high electron-transporting properties that can be used for the electron-transporting layer, which will be described later, can be used. Furthermore, as the one or more organic compounds, a bipolar material or a TADF material may be used.

[0529] The light-emitting layer preferably includes, for example, a phosphorescent material and a hole-transporting material and an electron-transporting material that are a combination that easily forms an exciplex. This configuration allows for efficient emission using Exciplex-Triple Energy Transfer (ExTET), which is energy transfer from the exciplex to the light-emitting material (phosphorescent material). By selecting a combination that forms an exciplex that emits light that overlaps with the wavelength of the lowest-energy absorption band of the light-emitting material, the energy transfer becomes smooth, allowing for efficient emission. This configuration allows for high efficiency, low-voltage operation, and long life of the light-emitting device to be achieved simultaneously.

[0530] The hole injection layer is a layer that injects holes from the anode into the hole transport layer and contains a material with high hole injection properties, such as an aromatic amine compound and a composite material containing a hole transport material and an acceptor material (electron acceptor material).

[0531] As the hole transporting material, a material having high hole transporting properties that can be used for the hole transport layer, which will be described later, can be used.

[0532] As the acceptor material, for example, an oxide of a metal belonging to Groups 4 to 8 of the periodic table can be used. Specific examples include molybdenum oxide, vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, tungsten oxide, manganese oxide, and rhenium oxide. Among these, molybdenum oxide is particularly preferred because it is stable in the air, has low hygroscopicity, and is easy to handle. Alternatively, an organic acceptor material containing fluorine can be used. Alternatively, an organic acceptor material such as a quinodimethane derivative, a chloranil derivative, or a hexaazatriphenylene derivative can be used.

[0533] For example, as a material with high hole injection properties, a material containing a hole transporting material and an oxide of a metal belonging to Groups 4 to 8 of the periodic table (typically, molybdenum oxide) may be used.

[0534] The hole transport layer is a layer that transports holes injected from the anode by the hole injection layer to the light emitting layer. The hole transport layer is a layer that contains a hole transport material. The hole transport material is a material having a concentration of 1×10 −６ cm ２ A substance having a hole mobility of 1 / Vs or more is preferred. Note that other substances can also be used as long as they have a higher hole transporting property than electron transporting property. As the hole transporting material, a material having a high hole transporting property, such as a π-electron-rich heteroaromatic compound (e.g., a carbazole derivative, a thiophene derivative, a furan derivative, etc.) or an aromatic amine (a compound having an aromatic amine skeleton), is preferred.

[0535] The electron blocking layer is provided in contact with the light-emitting layer. The electron blocking layer is a layer containing a material that has hole transport properties and can block electrons. The electron blocking layer can be made of a material that has electron blocking properties among the hole transport materials described above.

[0536] The electron blocking layer has hole transport properties and can therefore also be called a hole transport layer. Furthermore, a layer of the hole transport layer that has electron blocking properties can also be called an electron blocking layer.

[0537] The electron transport layer is a layer that transports electrons injected from the cathode by the electron injection layer to the light emitting layer. The electron transport layer is a layer that contains an electron transporting material. The electron transporting material is a material having a molecular weight of 1×10 −６ cm ２ A substance having an electron mobility of 1 / Vs or more is preferred. Note that other substances can also be used as long as they have a higher electron transporting property than holes. Examples of electron-transporting materials that can be used include metal complexes having a quinoline skeleton, metal complexes having a benzoquinoline skeleton, metal complexes having an oxazole skeleton, and metal complexes having a thiazole skeleton, as well as oxadiazole derivatives, triazole derivatives, imidazole derivatives, oxazole derivatives, thiazole derivatives, phenanthroline derivatives, quinoline derivatives having a quinoline ligand, benzoquinoline derivatives, quinoxaline derivatives, dibenzoquinoxaline derivatives, pyridine derivatives, bipyridine derivatives, pyrimidine derivatives, and other π-electron-deficient heteroaromatic compounds including nitrogen-containing heteroaromatic compounds.

[0538] The hole-blocking layer is provided in contact with the light-emitting layer. The hole-blocking layer is a layer containing a material that has electron transport properties and can block holes. The hole-blocking layer can be made of a material that has hole-blocking properties and is selected from the above electron-transporting materials.

[0539] The hole blocking layer has electron transport properties and can therefore also be called an electron transport layer. Furthermore, a layer of the electron transport layer that has hole blocking properties can also be called a hole blocking layer.

[0540] The electron injection layer is a layer that injects electrons from the cathode to the electron transport layer and contains a material with high electron injection properties. Examples of the material with high electron injection properties include alkali metals, alkaline earth metals, and compounds thereof. Examples of the material with high electron injection properties include a composite material containing an electron transport material and a donor material (electron donor material).

[0541] Furthermore, it is preferable that the LUMO level of a material with high electron injection properties has a small difference from the work function value of the material used for the cathode (specifically, 0.5 eV or less).

[0542] The electron injection layer may contain, for example, lithium, cesium, ytterbium, lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF ｘ , where X is an arbitrary number), 8-(quinolinolato)lithium (abbreviation: Liq), 2-(2-pyridyl)phenolatolithium (abbreviation: LiPP), 2-(2-pyridyl)-3-pyridinolatolithium (abbreviation: LiPPy), 4-phenyl-2-(2-pyridyl)phenolatolithium (abbreviation: LiPPP), lithium oxide (LiO ｘ ), alkali metals such as cesium carbonate, alkaline earth metals, or compounds thereof can be used. The electron injection layer may have a stacked structure of two or more layers. For example, the stacked structure may include a structure in which lithium fluoride is used in the first layer and ytterbium is provided in the second layer.

[0543] The electron injection layer may contain an electron transporting material. For example, a compound having an unshared electron pair and an electron-deficient heteroaromatic ring can be used as the electron transporting material. Specifically, a compound having at least one of a pyridine ring, a diazine ring (pyrimidine ring, pyrazine ring, pyridazine ring), and a triazine ring can be used.

[0544] The lowest unoccupied molecular orbital (LUMO) level of an organic compound having an unshared electron pair is preferably −3.6 eV or more and −2.3 eV or less. Generally, the highest occupied molecular orbital (HOMO) level and the LUMO level of an organic compound can be estimated by CV (cyclic voltammetry), photoelectron spectroscopy, optical absorption spectroscopy, inverse photoelectron spectroscopy, or the like.

[0545] For example, 4,7-diphenyl-1,10-phenanthroline (abbreviation: BPhen), 2,9-di(naphthalen-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBPhen), diquinoxalino[2,3-a:2',3'-c]phenazine (abbreviation: HATNA), 2,4,6-tris[3'-(pyridin-3-yl)biphenyl-3-yl]-1,3,5-triazine (abbreviation: TmPPPyTz), etc. can be used as the organic compound having an unshared electron pair. Note that NBPhen has a higher glass transition point (Tg) and is superior in heat resistance compared to BPhen.

[0546] As described above, the charge generation layer has at least a charge generation region. The charge generation region preferably contains an acceptor material, for example, a hole transport material and an acceptor material applicable to the hole injection layer.

[0547] The charge generation layer preferably includes a layer containing a material with high electron injection properties. This layer may also be called an electron injection buffer layer. The electron injection buffer layer is preferably provided between the charge generation region and the electron transport layer. By providing the electron injection buffer layer, the injection barrier between the charge generation region and the electron transport layer can be alleviated, so that electrons generated in the charge generation region can be easily injected into the electron transport layer.

[0548] The electron injection buffer layer preferably contains an alkali metal or an alkaline earth metal, and may contain, for example, an alkali metal compound or an alkaline earth metal compound. Specifically, the electron injection buffer layer preferably contains an inorganic compound containing an alkali metal and oxygen, or an inorganic compound containing an alkaline earth metal and oxygen, and may contain an inorganic compound containing lithium and oxygen (lithium oxide (Li ２ In addition, the electron injection buffer layer can be suitably made of the materials applicable to the electron injection layer described above.

[0549] The charge generation layer preferably has a layer containing a material with high electron transport properties. This layer can also be called an electron relay layer. The electron relay layer is preferably provided between the charge generation region and the electron injection buffer layer. When the charge generation layer does not have an electron injection buffer layer, the electron relay layer is preferably provided between the charge generation region and the electron transport layer. The electron relay layer has the function of preventing interaction between the charge generation region and the electron injection buffer layer (or the electron transport layer) and smoothly transferring electrons.

[0550] As the electron relay layer, it is preferable to use a phthalocyanine-based material such as copper (II) phthalocyanine (abbreviated as CuPc) or a metal complex having a metal-oxygen bond and an aromatic ligand.

[0551] It should be noted that the charge generation region, electron injection buffer layer, and electron relay layer may not be clearly distinguishable from one another due to their cross-sectional shapes or characteristics.

[0552] The charge generation layer may contain a donor material instead of an acceptor material. For example, the charge generation layer may contain a layer containing an electron transport material and a donor material that can be used for the electron injection layer.

[0553] When light-emitting units are stacked, an increase in driving voltage can be suppressed by providing a charge generating layer between two light-emitting units.

[0554] This embodiment mode can be combined with other embodiment modes as appropriate.

[0555] Embodiment 6 In this embodiment, electronic devices of one embodiment of the present invention will be described with reference to FIGS.

[0556] The electronic devices of this embodiment include the display device of one embodiment of the present invention in their display portions. The display device of one embodiment of the present invention can easily achieve high definition and high resolution. Therefore, the display device of one embodiment of the present invention can be used in the display portions of various electronic devices.

[0557] Examples of electronic devices include electronic devices with relatively large screens such as television sets, desktop or notebook personal computers, computer monitors, digital signage, large game machines such as pachinko machines, as well as digital cameras, digital video cameras, digital photo frames, mobile phones, portable game machines, personal digital assistants, and sound playback devices.

[0558] In particular, the display device of one embodiment of the present invention can be suitably used in electronic devices having a relatively small display area because it can increase the resolution. Examples of such electronic devices include wristwatch-type and bracelet-type information terminals (wearable devices), and head-mounted wearable devices such as VR devices such as head-mounted displays, AR glasses-type devices, and MR devices.

[0559] The display device of one embodiment of the present invention preferably has an extremely high resolution, such as HD (1280 × 720 pixels), FHD (1920 × 1080 pixels), WQHD (2560 × 1440 pixels), WQXGA (2560 × 1600 pixels), 4K (3840 × 2160 pixels), or 8K (7680 × 4320 pixels). A resolution of 4K, 8K, or higher is particularly preferable. Furthermore, the pixel density (resolution) of the display device of one embodiment of the present invention is preferably 100 ppi or higher, more preferably 300 ppi or higher, more preferably 500 ppi or higher, more preferably 1000 ppi or higher, more preferably 2000 ppi or higher, more preferably 3000 ppi or higher, more preferably 5000 ppi or higher, and even more preferably 7000 ppi or higher. By using a display device having either or both of high resolution and high definition, it is possible to further enhance the sense of realism and depth. Furthermore, the screen ratio (aspect ratio) of the display device of one embodiment of the present invention is not particularly limited. For example, the display device can support various screen ratios such as 1:1 (square), 4:3, 16:9, and 16:10.

[0560] The electronic device of this embodiment may have a sensor (including the function of detecting, detecting, or measuring force, displacement, position, velocity, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical substance, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor, or infrared rays).

[0561] The electronic device of the present embodiment can have various functions, such as a function of displaying various information (still images, videos, text images, etc.) on a display unit, a touch panel function, a function of displaying a calendar, date, time, etc., a function of executing various software (programs), a wireless communication function, a function of reading out programs or data recorded on a recording medium, etc.

[0562] 31A to 31D , examples of wearable devices that can be worn on the head will be described. These wearable devices have at least one of the following functions: a function to display AR content, a function to display VR content, a function to display SR content, and a function to display MR content. By having an electronic device have the function to display at least one of AR, VR, SR, MR, etc. content, it is possible to enhance the sense of immersion for the user.

[0563] The electronic device 700A shown in Figure 31A and the electronic device 700B shown in Figure 31B each have a pair of display panels 751, a pair of housings 721, a communication unit (not shown), a pair of mounting units 723, a control unit (not shown), an imaging unit (not shown), a pair of optical members 753, a frame 757, and a pair of nose pads 758.

[0564] The display device of one embodiment of the present invention can be applied to the display panel 751. Therefore, the electronic device can provide an extremely high-definition display.

[0565] The electronic device 700A and the electronic device 700B can each project an image displayed on the display panel 751 onto a display area 756 of the optical member 753. Because the optical member 753 is translucent, the user can see the image displayed in the display area superimposed on a transmitted image visually recognized through the optical member 753. Therefore, the electronic device 700A and the electronic device 700B are each electronic devices capable of AR display.

[0566] Electronic device 700A and electronic device 700B may be provided with a camera capable of capturing an image in front of them as an imaging unit. Furthermore, electronic device 700A and electronic device 700B may each be provided with an acceleration sensor such as a gyro sensor, thereby detecting the orientation of the user's head and displaying an image corresponding to that orientation in display area 756.

[0567] The communication unit has a wireless communication device, and can supply a video signal, etc. Instead of or in addition to the wireless communication device, a connector to which a cable through which a video signal and a power supply potential are supplied may be provided.

[0568] Furthermore, the electronic device 700A and the electronic device 700B are provided with batteries, which can be charged wirelessly and / or by wire.

[0569] The housing 721 may be provided with a touch sensor module. The touch sensor module has a function of detecting a touch on the outer surface of the housing 721. The touch sensor module can detect a tap operation, a slide operation, or the like by the user and perform various processes. For example, a tap operation can perform a process such as pausing or resuming a video, and a slide operation can perform a process such as fast-forwarding or fast-rewinding. Furthermore, providing a touch sensor module on each of the two housings 721 can broaden the range of operations.

[0570] Various touch sensors can be used as the touch sensor module. For example, various types of touch sensors can be used, such as a capacitance type, a resistive film type, an infrared type, an electromagnetic induction type, a surface acoustic wave type, and an optical type. In particular, it is preferable to use a capacitance type or an optical type sensor in the touch sensor module.

[0571] When an optical touch sensor is used, a photoelectric conversion device (also called a photoelectric conversion element) can be used as the light receiving device (also called a light receiving element). The active layer of the photoelectric conversion device can be made of either an inorganic semiconductor or an organic semiconductor, or both.

[0572] The electronic device 800A shown in Figure 31C and the electronic device 800B shown in Figure 31D each have a pair of display units 820, a housing 821, a communication unit 822, a pair of mounting units 823, a control unit 824, a pair of imaging units 825, and a pair of lenses 832.

[0573] The display device of one embodiment of the present invention can be applied to the display portion 820. Therefore, an electronic device capable of displaying images with extremely high definition can be provided. This allows a user to feel a high sense of immersion.

[0574] The display unit 820 is provided inside the housing 821 at a position that can be viewed through the lens 832. In addition, by displaying different images on the pair of display units 820, it is possible to perform three-dimensional display using parallax.

[0575] The electronic device 800A and the electronic device 800B can be said to be electronic devices for VR. A user wearing the electronic device 800A or the electronic device 800B can view an image displayed on the display unit 820 through the lens 832.

[0576] It is preferable that electronic device 800A and electronic device 800B each have a mechanism that can adjust the left and right positions of lens 832 and display unit 820 so that they are optimally positioned according to the position of the user's eyes. It is also preferable that electronic device 800A and electronic device 800B each have a mechanism that can adjust the focus by changing the distance between lens 832 and display unit 820.

[0577] The mounting unit 823 allows the user to mount the electronic device 800A or the electronic device 800B on the head. Note that in Fig. 31C and other figures, the mounting unit 823 is shaped like the temples of glasses, but is not limited to this. The mounting unit 823 may be shaped like a helmet or a band, for example, as long as it can be worn by the user.

[0578] The imaging unit 825 has a function of acquiring external information. Data acquired by the imaging unit 825 can be output to the display unit 820. An image sensor can be used for the imaging unit 825. Furthermore, multiple cameras may be provided to support multiple angles of view, such as telephoto and wide-angle.

[0579] Although an example including the imaging unit 825 is shown here, a distance measuring sensor (hereinafter also referred to as a detection unit) capable of measuring the distance to an object may be provided. That is, the imaging unit 825 is one aspect of the detection unit. As the detection unit, for example, an image sensor or a range image sensor such as a LIDAR (Light Detection and Ranging) can be used. By using an image obtained by the camera and an image obtained by the range image sensor, more information can be obtained, enabling more accurate gesture operations.

[0580] The electronic device 800A may have a vibration mechanism that functions as a bone conduction earphone. For example, a configuration having such a vibration mechanism can be applied to one or more of the display unit 820, the housing 821, and the wearing unit 823. This allows a user to enjoy video and audio simply by wearing the electronic device 800A, without the need for separate audio equipment such as headphones, earphones, or speakers.

[0581] The electronic device 800A and the electronic device 800B may each have an input terminal to which a cable can be connected for supplying a video signal from a video output device or the like and power for charging a battery provided in the electronic device.

[0582] The electronic device of one embodiment of the present invention may have a function of wireless communication with an earphone 750. The earphone 750 includes a communication unit (not shown) and has a wireless communication function. The earphone 750 can receive information (e.g., audio data) from the electronic device through the wireless communication function. For example, an electronic device 700A shown in FIG. 31A has a function of transmitting information to the earphone 750 through the wireless communication function. Furthermore, for example, an electronic device 800A shown in FIG. 31C has a function of transmitting information to the earphone 750 through the wireless communication function.

[0583] The electronic device may also have an earphone unit. Electronic device 700B shown in Fig. 31B has earphone unit 727. For example, earphone unit 727 and the control unit may be configured to be connected to each other by wire. Part of the wiring connecting earphone unit 727 and the control unit may be disposed inside housing 721 or attachment unit 723.

[0584] Similarly, electronic device 800B shown in Fig. 31D has earphone unit 827. For example, earphone unit 827 and control unit 824 can be configured to be connected to each other by wire. Part of the wiring connecting earphone unit 827 and control unit 824 may be disposed inside housing 821 or wearing unit 823. Furthermore, earphone unit 827 and wearing unit 823 may have magnets. This allows earphone unit 827 to be fixed to wearing unit 823 by magnetic force, which is preferable as it makes storage easier.

[0585] The electronic device may have an audio output terminal to which earphones or headphones can be connected. The electronic device may also have one or both of an audio input terminal and an audio input mechanism. For example, a sound collection device such as a microphone can be used as the audio input mechanism. By having the audio input mechanism, the electronic device may be endowed with the functionality of a so-called headset.

[0586] As described above, as electronic devices according to one embodiment of the present invention, both glasses-type devices (such as the electronic device 700A and the electronic device 700B) and goggle-type devices (such as the electronic device 800A and the electronic device 800B) are suitable.

[0587] Furthermore, the electronic device of one embodiment of the present invention can transmit information to the earphone by wire or wirelessly.

[0588] The electronic device 6500 shown in FIG. 32A is a portable information terminal that can be used as a smartphone.

[0589] The electronic device 6500 includes a housing 6501, a display portion 6502, a power button 6503, a button 6504, a speaker 6505, a microphone 6506, a camera 6507, a light source 6508, and the like. The display portion 6502 has a touch panel function.

[0590] The display device of one embodiment of the present invention can be applied to the display portion 6502 .

[0591] FIG. 32B is a schematic cross-sectional view including the end of the housing 6501 on the microphone 6506 side.

[0592] A light-transmitting protective member 6510 is provided on the display surface side of the housing 6501, and a display panel 6511, optical members 6512, a touch sensor panel 6513, a printed circuit board 6517, a battery 6518, etc. are arranged in the space surrounded by the housing 6501 and the protective member 6510.

[0593] A display panel 6511, an optical member 6512, and a touch sensor panel 6513 are fixed to the protective member 6510 by adhesive layers (not shown).

[0594] In a region outside the display portion 6502, a part of the display panel 6511 is folded back, and an FPC 6515 is connected to the folded back part. An IC 6516 is mounted on the FPC 6515. The FPC 6515 is connected to a terminal provided on a printed circuit board 6517.

[0595] The flexible display device of one embodiment of the present invention can be applied to the display panel 6511. Therefore, an extremely lightweight electronic device can be realized. Furthermore, since the display panel 6511 is extremely thin, the thickness of the electronic device can be reduced and a large-capacity battery 6518 can be mounted thereon. Furthermore, by folding back a part of the display panel 6511 and arranging a connection portion with the FPC 6515 on the back side of the display portion 6502, an electronic device with a narrow frame can be realized.

[0596] 32C shows an example of a television set. A television set 7100 has a display portion 7000 built into a housing 7101. Here, the housing 7101 is supported by a stand 7103.

[0597] The display device of one embodiment of the present invention can be applied to the display portion 7000 .

[0598] 32C can be operated using operation switches provided on the housing 7101 and a separate remote control 7111. Alternatively, the display portion 7000 may be provided with a touch sensor, and the television set 7100 may be operated by touching the display portion 7000 with a finger or the like. The remote control 7111 may have a display portion that displays information output from the remote control 7111. Using operation keys or a touch panel provided on the remote control 7111, the channel and volume can be controlled, and an image displayed on the display portion 7000 can be controlled.

[0599] The television device 7100 is configured to include a receiver, a modem, and the like. The receiver can receive general television broadcasts. In addition, by connecting to a wired or wireless communication network via the modem, it is possible to perform one-way (from a sender to a receiver) or two-way (between a sender and a receiver, or between receivers, etc.) information communication.

[0600] 32D shows an example of a laptop personal computer 7200. The laptop personal computer 7200 includes a housing 7211, a keyboard 7212, a pointing device 7213, and an external connection port 7214. The housing 7211 includes a display portion 7000.

[0601] The display device of one embodiment of the present invention can be applied to the display portion 7000 .

[0602] 32E and 32F show an example of digital signage.

[0603] 32E includes a housing 7301, a display portion 7000, and a speaker 7303. The digital signage 7300 may further include an LED lamp, operation keys (including a power switch or an operation switch), a connection terminal, various sensors, a microphone, and the like.

[0604] 32F shows a digital signage 7400 attached to a cylindrical pillar 7401. The digital signage 7400 has a display unit 7000 provided along the curved surface of the pillar 7401.

[0605] 32E and 32F, the display device of one embodiment of the present invention can be applied to the display portion 7000.

[0606] The larger the display unit 7000, the more information can be provided at one time. Also, the larger the display unit 7000, the more easily it will attract people's attention, which can increase the advertising effectiveness of, for example, advertisements.

[0607] Applying a touch panel to the display unit 7000 is preferable because it not only displays images or videos on the display unit 7000 but also allows the user to intuitively operate it. Furthermore, when used to provide information such as route information or traffic information, the intuitive operation can improve usability.

[0608] 32E and 32F , the digital signage 7300 or the digital signage 7400 is preferably capable of wirelessly linking with an information terminal 7311 or an information terminal 7411 such as a smartphone carried by a user. For example, advertising information displayed on the display unit 7000 can be displayed on the screen of the information terminal 7311 or the information terminal 7411. By operating the information terminal 7311 or the information terminal 7411, the display on the display unit 7000 can be switched.

[0609] Furthermore, the digital signage 7300 or the digital signage 7400 can be made to run a game using the screen of the information terminal 7311 or the information terminal 7411 as an operation means (controller), thereby allowing an unspecified number of users to simultaneously participate in and enjoy the game.

[0610] The electronic device shown in Figures 33A to 33G has a housing 9000, a display unit 9001, a speaker 9003, operation keys 9005 (including a power switch or an operation switch), a connection terminal 9006, a sensor 9007 (including a function to sense, detect, or measure force, displacement, position, speed, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical substance, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor, or infrared rays), a microphone 9008, etc.

[0611] 33A to 33G, the display device of one embodiment of the present invention can be applied to the display portion 9001.

[0612] The electronic devices shown in Figures 33A to 33G have various functions. For example, they may have a function to display various information (still images, videos, text images, etc.) on a display unit, a touch panel function, a function to display a calendar, date, or time, a function to control processing using various software (programs), a wireless communication function, a function to read and process programs or data recorded on a recording medium, etc. Note that the functions of the electronic devices are not limited to these, and they may have various other functions. The electronic devices may have multiple display units. Furthermore, the electronic devices may have a function to include a camera or the like to capture still images or videos and store them on a recording medium (external or built-in to the camera), a function to display the captured images on a display unit, etc.

[0613] The electronic devices shown in Figures 33A to 33G will be described in detail below.

[0614] FIG. 33A is a perspective view showing a mobile information terminal 9101. The mobile information terminal 9101 can be used as, for example, a smartphone. Note that the mobile information terminal 9101 may be provided with a speaker 9003, a connection terminal 9006, a sensor 9007, and the like. The mobile information terminal 9101 can display text and image information on multiple surfaces. FIG. 33A shows an example in which three icons 9050 are displayed. Information 9051, indicated by a dashed rectangle, can also be displayed on another surface of the display unit 9001. Examples of the information 9051 include notification of an incoming email, SNS, or phone call, the title of the email or SNS message, the sender's name, the date and time, the remaining battery level, and radio wave intensity. Alternatively, an icon 9050 or the like may be displayed in the position where the information 9051 is displayed.

[0615] 33B is a perspective view showing the mobile information terminal 9102. The mobile information terminal 9102 has a function of displaying information on three or more surfaces of the display unit 9001. Here, an example is shown in which information 9052, information 9053, and information 9054 are displayed on different surfaces. For example, a user can check information 9053 displayed in a position that can be observed from above the mobile information terminal 9102 while the mobile information terminal 9102 is stored in a breast pocket of clothes. The user can check the display without taking the mobile information terminal 9102 out of the pocket and determine, for example, whether to answer a call.

[0616] 33C is a perspective view showing a tablet terminal 9103. The tablet terminal 9103 is capable of executing various applications such as mobile phone calls, e-mail, text browsing and creation, music playback, internet communication, and computer games, for example. The tablet terminal 9103 has a display unit 9001, a camera 9002, a microphone 9008, and a speaker 9003 on the front side of a housing 9000, operation keys 9005 as operation buttons on the side of the housing 9000, and a connection terminal 9006 on the bottom.

[0617] FIG. 33D is a perspective view showing a wristwatch-type mobile information terminal 9200. The mobile information terminal 9200 can be used as, for example, a smart watch (registered trademark). The display surface of the display unit 9001 is curved, and display can be performed along the curved display surface. The mobile information terminal 9200 can also perform hands-free calling by communicating with, for example, a wirelessly capable headset. The mobile information terminal 9200 can also perform data transmission and charging with another information terminal through a connection terminal 9006. Note that charging may be performed by wireless power supply.

[0618] 33E to 33G are perspective views showing a foldable mobile information terminal 9201. Also, FIG. 33E is a perspective view of the mobile information terminal 9201 in an unfolded state, FIG. 33G is a perspective view of the mobile information terminal 9201 in a folded state, and FIG. 33F is a perspective view of a state in the process of changing from one of FIGS. 33E and 33G to the other. The mobile information terminal 9201 has excellent portability in a folded state, and excellent display visibility due to a seamless, wide display area in an unfolded state. A display portion 9001 of the mobile information terminal 9201 is supported by three housings 9000 connected by hinges 9055. For example, the display portion 9001 can be bent with a curvature radius of 0.1 mm or more and 150 mm or less.

[0619] This embodiment mode can be combined with other embodiment modes as appropriate.

[0620] 11B: subpixel, 11G: subpixel, 11R: subpixel, 100A: display device, 100B: display device, 100C: display device, 100D: display device, 100E: display device, 100F: display device, 100G: display device, 100H: display device, 100: display device, 101: layer, 103: region, 110a: subpixel, 110b: subpixel, 110c: subpixel, 110d: subpixel, 110: pixel, 111B: pixel electrode, 111G: pixel electrode, 111R: pixel electrode, 112B: conductive layer, 112G: conductive layer, 112R: conductive layer, 113b: material layer, 113s: material layer, 113t : region, 113B: EL layer, 113: EL layer, 114A: insulating film, 114: sidewall insulating layer, 115: common electrode, 116B: optical adjustment layer, 116G: optical adjustment layer, 116R: optical adjustment layer, 117: light-shielding layer, 120: substrate, 122: resin layer, 123: conductive layer, 124a: pixel, 124b: pixel, 125A: insulating film, 125B: insulating layer, 125: insulating layer, 126B: conductive layer, 126G: conductive layer, 126R: conductive layer, 127a: insulating film, 127b: insulating layer, 127: insulating layer, 128: layer, 129B: conductive layer, 129G: conductive layer, 129R: conductive layer, 130B: light-emitting device device, 130G: light-emitting device, 130R: light-emitting device, 131: protective layer, 132B: colored layer, 132G: colored layer, 132R: colored layer, 133: lens, 134: insulating layer, 135: insulating layer, 136: mask, 137B: light-emitting device, 137G: light-emitting device, 137R: light-emitting device, 139: light, 140: connecting portion, 142: adhesive layer, 150A: region, 150B: region, 150C: region, 150D: region, 150E: region, 150F: region, 151: substrate, 152: substrate, 153: insulating layer, 154B: sub-pixel, 154G: sub-pixel, 154R: sub-pixel , 155B: sub-pixel, 155G: sub-pixel, 155R: sub-pixel, 162: display section, 164: circuit, 165: wiring, 166: conductive layer, 171: light-shielding layer, 172: FPC, 173: IC, 175G: color conversion layer, 175R: color conversion layer, 201: transistor, 204: connection section, 205: transistor, 209: transistor, 210: transistor, 211: insulating layer, 213: insulating layer, 214: insulating layer, 215: insulating layer, 218: insulating layer, 221: conductive layer, 222a: conductive layer, 222b: conductive layer, 223: conductive layer, 225: insulating layer, 231i: channel formation region,231n: low resistance region, 231: semiconductor layer, 240: capacitor, 241: conductive layer, 242: connection layer, 243: insulating layer, 245: conductive layer, 251: conductive layer, 252: conductive layer, 254: insulating layer, 255a: insulating layer, 255b: insulating layer, 255c: insulating layer, 256: plug, 261: insulating layer, 262: insulating layer, 263: insulating layer, 264: insulating layer, 265: insulating layer, 271: plug, 274a: conductive layer, 274b: conductive layer, 274: plug, 280: display module, 281: display unit, 282: circuit unit, 283a: pixel circuit, 283: pixel circuit unit, 284a: pixel, 284: pixel portion, 285: terminal portion, 286: wiring portion, 290: FPC, 291: substrate, 292: substrate, 301A: substrate, 301B: substrate, 301: substrate, 310A: transistor, 310B: transistor, 310: transistor, 311: conductive layer, 312: low resistance region, 313: insulating layer, 314: insulating layer, 315: element isolation layer, 320A: transistor, 320B: transistor, 320: transistor, 321: semiconductor layer, 323: insulating layer, 324: conductive layer, 325: conductive layer, 326: insulating layer, 327: conductive layer, 328: insulating layer, 329: insulating layer, 3 31: substrate, 332: insulating layer, 335: insulating layer, 336: insulating layer, 341: conductive layer, 342: conductive layer, 343: plug, 344: insulating layer, 345: insulating layer, 346: insulating layer, 347: bump, 348: adhesive layer, 700A: electronic device, 700B: electronic device, 721: housing, 723: wearing part, 727: earphone part, 750: earphone, 751: display panel, 753: optical member, 756: display area, 757: frame, 758: nose pad, 761: lower electrode, 762: upper electrode, 763a: light-emitting unit, 763b: light-emitting unit, 763c: light-emitting unit 763: EL layer, 764: layer, 771a: light-emitting layer, 771b: light-emitting layer, 771c: light-emitting layer, 771: light-emitting layer, 772a: light-emitting layer, 772b: light-emitting layer, 772c: light-emitting layer, 772: light-emitting layer, 773: light-emitting layer, 780a: layer, 780b: layer, 780c: layer, 780: layer, 781: layer, 782: layer, 785: charge generation layer, 790a: layer, 790b: layer, 790c: layer, 790: layer, 791: layer, 792: layer, 800A: electronic device, 800B: electronic device, 820: display unit, 821: housing, 822: communication unit, 823: attachment unit, 824: control unit, 825: imaging unit,827: Earphone unit, 832: Lens, 6500: Electronic device, 6501: Housing, 6502: Display unit, 6503: Power button, 6504: Button, 6505: Speaker, 6506: Microphone, 6507: Camera, 6508: Light source, 6510: Protective member, 6511: Display panel, 6512: Optical member, 6513: Touch sensor panel, 6515: FPC, 6516: IC, 6517: Printed circuit board, 6518: Battery, 7000: Display unit, 7100: Television device, 7101: Housing, 7103: Stand, 7111: Remote control device, 7200: Notebook personal computer, 7211: Housing, 7212: Keyboard, 7213: Pointer device, 7214: external connection port, 7300: digital signage, 7301: housing, 7303: speaker, 7311: information terminal, 7400: digital signage, 7401: pillar, 7411: information terminal, 9000: housing, 9001: display unit, 9002: camera, 9003: speaker, 9005: operation keys, 9006: connection terminal, 9007: sensor, 9008: microphone, 9050: icon, 9051: information, 9052: information, 9053: information, 9054: information, 9055: hinge, 9101: mobile information terminal, 9102: mobile information terminal, 9103: tablet terminal, 9200: mobile information terminal, 9201: mobile information terminal,

Claims

1. a first light-emitting device, a second light-emitting device, a first sidewall insulating layer, a second sidewall insulating layer, a first insulating layer, a first colored layer, and a second colored layer; the first light-emitting device has a first pixel electrode, a first EL layer on the first pixel electrode, and a common electrode on the first EL layer; the second light-emitting device has a second pixel electrode, a second EL layer on the second pixel electrode, and the common electrode on the second EL layer; the first EL layer and the second EL layer each include a first light-emitting material that emits blue light and a second light-emitting material that emits light with a wavelength longer than blue; the first sidewall insulating layer has a region in contact with a side surface of the first pixel electrode, the second sidewall insulating layer has a region in contact with a side surface of the second pixel electrode, the first insulating layer has a region in contact with an upper surface of the first EL layer, a region in contact with a side surface of the first EL layer, a region in contact with an upper surface of the second EL layer, a region in contact with a side surface of the second EL layer, a region in contact with a side surface of the first sidewall insulating layer, and a region in contact with a side surface of the second sidewall insulating layer; the first colored layer overlies the first light-emitting device; the second colored layer overlies the second light-emitting device; the first colored layer and the second colored layer have a function of transmitting light of different colors, respectively; Display device.

2. In claim 1, a material layer between the first light-emitting device and the second light-emitting device, the material layer being isolated from the first EL layer and the second EL layer; the material layer includes the first light-emitting material and the second light-emitting material; Display device.

3. In claim 2, the first sidewall insulating layer and the second sidewall insulating layer each include an inorganic insulating material; Display device.

4. In claim 3, the first insulating layer has a tapered shape at an end portion; Display device.

5. In claim 1, an upper end of the first pixel electrode and an upper end of the first sidewall insulating layer have a region where they are in contact with each other in a cross-sectional view; Display device.

6. In claim 1, an upper end of the second pixel electrode and an upper end of the second sidewall insulating layer have a region where they are in contact with each other in a cross-sectional view; Display device.