Indication device

Abstract

The present invention provides a high-definition display device. The display device comprises a first through a third light-emitting device, a first and second color conversion layer, a first through third colored layers, and an insulation layer. The first through third light-emitting devices comprise pixel electrodes, a light-emitting layer on the pixel electrodes, and a common electrode on the light-emitting layer. The pixel electrodes are provided in each light-emitting device, the first through third light-emitting devices all emit white light, and the common electrode is shared by the light-emitting devices. Light emitted by the first light-emitting device is converted to red light in the first color conversion layer and the first colored layer. Light emitted by the second light-emitting device is converted to green light in the second color conversion layer and the second colored layer. Light emitted by the third light-emitting device is converted to blue light in the third colored layer. The first through the third colored layer have mutually overlapping regions. The insulation layer is positioned between mutually adjacent light-emitting devices.

Description

[Technical Field]

[0001] One aspect of the present invention relates to a display device, a display module, and electronic equipment. Another aspect of the present invention relates to a method for manufacturing a display device.

[0002] One aspect of the present invention is not limited to the above-mentioned technical field. Examples of technical fields of one aspect of the present invention include semiconductor devices, display devices, light-emitting devices, energy storage devices, memory devices, lighting devices, input devices (e.g., touch sensors), input / output devices (e.g., touch panels), display modules having these devices, electronic devices having said display modules, methods for driving them, or methods for manufacturing them. [Background technology]

[0003] In recent years, display devices have been expected to have applications in a variety of uses. For example, large-scale display devices are used in home television systems (also called televisions or television receivers), digital signage, and PID (Public Information Display). Furthermore, development is progressing on mobile information terminals such as smartphones and tablet devices equipped with touch panels.

[0004] Furthermore, there is a demand for higher resolution display devices. Devices requiring high-resolution displays, such as those 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 (also called a light-emitting element) has been developed. Light-emitting devices that utilize the electroluminescence (EL) phenomenon (also called EL devices or EL elements) have features such as being easy to make thin and light, being able to respond quickly to input signals, and being able to be driven using a DC constant voltage power supply, and are being applied to display devices.

[0006] Patent Document 1 discloses a display device for VR using an organic EL device (also called an organic EL element). [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] International Publication No. 2018 / 087625 [Overview of the project] [Problems that the invention aims to solve]

[0008] One aspect of the present invention aims to provide a high-definition display device. One aspect of the present invention aims to provide a high-resolution display device. One aspect of the present invention aims to provide a highly reliable display device. One aspect of the present invention aims to provide a display device capable of displaying at high brightness. One aspect of the present invention aims to provide a display device with high color purity.

[0009] One aspect of the present invention aims to provide a method for manufacturing a high-definition display device. One aspect of the present invention aims to provide a method for manufacturing a high-resolution display device. One aspect of the present invention aims to provide a method for manufacturing a highly reliable display device. One aspect of the present invention aims to provide a method for manufacturing a display device capable of displaying at high brightness. One aspect of the present invention aims to provide a method for manufacturing a display device with high color purity. One aspect of the present invention aims to provide a method for manufacturing a display device with high yield.

[0010] Furthermore, the description of these problems does not preclude the existence of other problems. One aspect of the present invention does not necessarily have to solve all of these problems. It is possible to extract other problems from the description in the specification, drawings, and claims. [Means for solving the problem]

[0011] One aspect of the present invention is a display device comprising a first light-emitting device, a second light-emitting device, a third light-emitting device, a first color conversion layer, a second color conversion layer, a first color layer, and an insulating layer, wherein each of the first to third light-emitting devices comprises a first light-emitting material that emits blue light and a second light-emitting material that emits light with a longer wavelength than blue light, the first color conversion layer is provided overlapping with the first light-emitting device and has the function of converting a portion of the light emitted by the first light-emitting device into red light, the second color conversion layer is provided overlapping with the second light-emitting device and has the function of converting a portion of the light emitted by the second light-emitting device into green light, the first color layer is provided overlapping with the third light-emitting device and has the function of transmitting blue light from the light emitted by the third light-emitting device, and the insulating layer is located between adjacent first and second light-emitting devices.

[0012] Furthermore, it is preferable that the device has a second colored layer that overlaps with the first light-emitting device and the first color conversion layer, and a third colored layer that overlaps with the second light-emitting device and the second color conversion layer, wherein the second colored layer has the function of transmitting red light from the light converted by the first color conversion layer, and the third colored layer has the function of transmitting green light from the light converted by the second color conversion layer, and the first colored layer and the second colored layer have overlapping regions.

[0013] Furthermore, in the above, the first light-emitting device has a first pixel electrode, a first light-emitting layer on the first pixel electrode, and a common electrode on the first light-emitting layer; the second light-emitting device has a second pixel electrode, a second light-emitting layer on the second pixel electrode, and a common electrode on the second light-emitting layer; and the third light-emitting device has a third pixel electrode, a third light-emitting layer on the third pixel electrode, and a common electrode on the third light-emitting layer. Preferably, the first to third pixel electrodes are all made of the same material, and the first to third light-emitting layers each have a first light-emitting material and a second light-emitting material.

[0014] Furthermore, in the above, it is preferable that the common electrode has both transmittance and reflectivity to visible light.

[0015] Furthermore, one aspect of the present invention is a display device comprising a first light-emitting device, a second light-emitting device, a third light-emitting device, a light-receiving device, a first color conversion layer, a second color conversion layer, a first color layer, and an insulating layer, wherein each of the first to third light-emitting devices comprises a first light-emitting material that emits blue light and a second light-emitting material that emits light with a longer wavelength than blue, the first color conversion layer is provided overlapping with the first light-emitting device and has the function of converting a portion of the light emitted by the first light-emitting device into red light, the second color conversion layer is provided overlapping with the second light-emitting device and has the function of converting a portion of the light emitted by the second light-emitting device into green light, the first color layer is provided overlapping with the third light-emitting device and has the function of transmitting blue light from the light emitted by the third light-emitting device, and the insulating layer is located between adjacent first and second light-emitting devices.

[0016] Also, in the above, it has a second colored layer that overlaps with the first light-emitting device and the first color conversion layer, and a third colored layer that overlaps with the second light-emitting device and the second color conversion layer. The second colored layer has a function of transmitting red light among the light converted by the first color conversion layer, and the third colored layer has a function of transmitting green light among the light converted by the second color conversion layer. It is preferable that the first colored layer and the second colored layer have an overlapping region with each other.

[0017] Also, in the above, the first light-emitting device has a first pixel electrode, a first light-emitting layer on the first pixel electrode, and a common electrode on the first light-emitting layer. The second light-emitting device has a second pixel electrode, a second light-emitting layer on the second pixel electrode, and a common electrode on the second light-emitting layer. The third light-emitting device has a third pixel electrode, a third light-emitting layer on the third pixel electrode, and a common electrode on the third light-emitting layer. The light-receiving device has a fourth pixel electrode, an active layer on the fourth pixel electrode, and a common electrode on the active layer. The first to fourth pixel electrodes are all formed of the same material. The first to third light-emitting layers all have a first light-emitting material and a second light-emitting material. It is preferable that the active layer has a function as a photoelectric conversion layer.

[0018] Also, in the above, it is preferable that the common electrode has both transmissivity and reflectivity with respect to visible light.

[0019] In addition, one aspect of the present invention includes a first light-emitting device, a second light-emitting device, a third light-emitting device, a first color conversion layer, a second color conversion layer, a first coloring layer, a second coloring layer, and an insulating layer. The first to third light-emitting devices each have a light-emitting material that emits blue light. The first color conversion layer is provided to overlap with the first light-emitting device and has a function of converting a part of the light emitted by the first light-emitting device into red light. The second color conversion layer is provided to overlap with the second light-emitting device and has a function of converting a part of the light emitted by the second light-emitting device into green light. The first coloring layer is provided to overlap with the first color conversion layer and has a function of transmitting red light among the light converted by the first color conversion layer. The second coloring layer is provided to overlap with the second color conversion layer and has a function of transmitting green light among the light converted by the second color conversion layer. The first coloring layer and the second coloring layer have an overlapping region with each other. The insulating layer is a display device located between the adjacent first light-emitting device and second light-emitting device.

[0020] Also, in the above, it preferably has a third coloring layer that overlaps with the third light-emitting device. The third coloring layer has a function of transmitting blue light among the light emitted by the third light-emitting device. The second coloring layer and the third coloring layer preferably have an overlapping region with each other.

[0021] Also, in the above, the first light-emitting device has a first pixel electrode, a first light-emitting layer on the first pixel electrode, and a common electrode on the first light-emitting layer. The second light-emitting device has a second pixel electrode, a second light-emitting layer on the second pixel electrode, and a common electrode on the second light-emitting layer. The third light-emitting device has a third pixel electrode, a third light-emitting layer on the third pixel electrode, and a common electrode on the third light-emitting layer. It is preferable that the first to third pixel electrodes are all formed of the same material, and the first to third light-emitting layers all have a light-emitting material.

[0022] Also, in the above, the common electrode preferably has both transmissivity and reflectivity with respect to visible light.

[0023] Furthermore, in the above, it is preferable that a light-shielding layer is provided between adjacent first light-emitting devices and second light-emitting devices, between adjacent second light-emitting devices and third light-emitting devices, and between adjacent third light-emitting devices and first light-emitting devices, in a plan view.

[0024] Furthermore, in the above, it is preferable that the insulating layer has a convex curved shape on its upper surface.

[0025] Furthermore, one aspect of the present invention is a display module having the above-mentioned display device and at least one of a connector and an integrated circuit.

[0026] Furthermore, one aspect of the present invention is an electronic device having the above-mentioned display module and at least one of a housing, a battery, a camera, a speaker, and a microphone. [Effects of the Invention]

[0027] According to one aspect of the present invention, a high-definition display device can be provided. According to one aspect of the present invention, a high-resolution display device can be provided. According to one aspect of the present invention, a highly reliable display device can be provided. According to one aspect of the present invention, a display device capable of displaying at high brightness can be provided. According to one aspect of the present invention, a display device with high color purity can be provided.

[0028] According to one aspect of the present invention, a method for manufacturing a high-definition display device can be provided. According to one aspect of the present invention, a method for manufacturing a high-resolution display device can be provided. According to one aspect of the present invention, a method for manufacturing a highly reliable display device can be provided. According to one aspect of the present invention, a method for manufacturing a display device capable of high-brightness display can be provided. According to one aspect of the present invention, a method for manufacturing a display device with high color purity can be provided. According to one aspect of the present invention, a method for manufacturing a display device with high yield can be provided.

[0029] Furthermore, the description of these effects does not preclude the existence of other effects. One aspect of the present invention does not necessarily have to possess all of these effects. Other effects can be extracted from the description, drawings, and claims. [Brief explanation of the drawing]

[0030] Figure 1A is a top view showing an example of a display device. Figure 1B is a cross-sectional view showing an example of a display device. Figure 1C is a top view showing an example of layer 113W. Figures 2A and 2B are cross-sectional views showing an example of a display device. Figures 3A and 3B are cross-sectional views showing an example of a display device. Figures 4A and 4B are cross-sectional views showing an example of a display device. Figures 5A and 5B are cross-sectional views showing an example of a display device. Figures 6A and 6B are cross-sectional views showing an example of a display device. Figures 7A and 7F are cross-sectional views showing an example of a display device. Figures 7B to 7E are cross-sectional views showing an example of a pixel electrode. Figures 8A to 8C are cross-sectional views showing an example of a display device. Figures 9A to 9D are cross-sectional views showing an example of a display device. Figures 10A to 10C are cross-sectional views showing an example of a display device. Figures 11A and 11B are cross-sectional views showing an example of a display device. Figure 12A is a top view showing an example of a display device. Figure 12B is a cross-sectional view showing an example of a display device. Figures 13A to 13C are cross-sectional views showing an example of a method for manufacturing a display device. Figures 14A and 14B are cross-sectional views showing an example of a method for manufacturing a display device. Figures 15A and 15B are cross-sectional views showing an example of a method for manufacturing a display device. Figures 16A and 16B are cross-sectional views showing an example of a method for manufacturing a display device. Figures 17A to 17E are cross-sectional views showing an example of a method for manufacturing a display device. Figures 18A and 18B are cross-sectional views showing an example of a method for manufacturing a display device. Figures 19A to 19G show examples of pixels. Figures 20A to 20K show examples of pixels. Figures 21A and 21B are perspective views showing an example of a display device. Figures 22A and 22B are cross-sectional views showing an example of a display device. Figure 23 is a cross-sectional view showing an example of a display device. Figure 24 is a cross-sectional view showing an example of a display device. Figure 25 is a cross-sectional view showing an example of a display device. Figure 26 is a cross-sectional view showing an example of a display device. Figure 27 is a cross-sectional view showing an example of a display device. Figure 28 is a perspective view showing an example of a display device. Figure 29A is a cross-sectional view showing an example of a display device. Figures 29B and 29C are cross-sectional views showing an example of a transistor. Figures 30A to 30D are cross-sectional views showing an example of a display device. Figure 31 is a cross-sectional view showing an example of a display device. Figures 32A to 32F show examples of the configuration of a light-emitting device. Figures 33A to 33C show examples of the configuration of a light-emitting device. Figures 34A and 34B show examples of the configuration of a light receiving device. Figures 34C to 34E show examples of the configuration of a display device. Figures 35A to 35D show examples of electronic devices. Figures 36A to 36F show examples of electronic devices. Figures 37A to 37G show examples of electronic devices. [Modes for carrying out the invention]

[0031] The embodiments will be described in detail below with reference to the drawings. However, it will be readily apparent to those skilled in the art that the present invention is not limited to the following description, and that its form and details can be modified in various ways without departing from the spirit and scope of the present invention. Therefore, the present invention should not be interpreted as being limited to the contents of the embodiments shown below.

[0032] In the invention described below, the same reference numerals are used in common across different drawings for identical parts or parts having similar functions, and repeated explanations are omitted. Furthermore, when referring to similar functions, the same hatching pattern may be used, and reference numerals may not be assigned.

[0033] Furthermore, the position, size, and scope of each component shown in the drawings may not represent the actual position, size, and scope for the sake of ease of understanding. Therefore, the disclosed invention is not necessarily limited to the position, size, and scope disclosed in the drawings.

[0034] It should be noted that the terms "film" and "layer" can be interchanged depending on the context or situation. For example, the term "conductive layer" can be changed to "conductive film." Or, for example, the term "insulating film" can be changed to "insulating layer."

[0035] Furthermore, in this specification, devices fabricated using a metal mask or FMM (Fine Metal Mask, a high-resolution metal mask) may be referred to as MM (Metal Mask) structured devices. Also, in this specification, devices fabricated without using a metal mask or FMM may be referred to as MML (Metal Maskless) structured devices.

[0036] Furthermore, in this specification, a structure in which at least the light-emitting layers are created separately for light-emitting devices with different emission wavelengths may be referred to as an SBS (Side By Side) structure. Since the SBS structure allows for the optimization of materials and configuration for each light-emitting device, the degree of freedom in selecting materials and configurations is increased, making it easier to improve brightness and reliability.

[0037] Furthermore, in this specification, holes or electrons may be referred to as "carriers." Specifically, a hole injection layer or electron injection layer may be called a "carrier injection layer," a hole transport layer or electron transport layer may be called a "carrier transport layer," and a hole block layer or electron block layer may be called a "carrier block layer." Note that the above-mentioned carrier injection layer, carrier transport layer, and carrier block layer may not be clearly distinguishable by their cross-sectional shape or characteristics. Also, a single layer may combine the functions of two or three of the carrier injection layer, carrier transport layer, and carrier block layer.

[0038] Furthermore, in this specification, a light-emitting device has an EL layer between a pair of electrodes. The EL layer has at least a light-emitting layer. Examples of the layers (also called functional layers) that make up the EL layer include a light-emitting layer, a carrier injection layer (hole injection layer and electron injection layer), a carrier transport layer (hole transport layer and electron transport layer), and a carrier blocking layer (hole blocking layer and electron blocking layer).

[0039] Furthermore, in this specification, 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 to be formed). For example, it refers to a shape having a region in which the angle between the inclined side surface and the substrate surface (or the surface to be formed) (also called the taper angle) is less than 90°. Note that the side surface of the structure and the substrate surface (or the surface to be formed) do not necessarily have to be perfectly flat, and may be substantially planar with fine curvature, or substantially planar with fine irregularities.

[0040] (Embodiment 1) In this embodiment, a display device according to one aspect of the present invention will be described with reference to Figures 1 to 12.

[0041] A display device according to one aspect of the present invention comprises a first light-emitting device, a second light-emitting device, and a third light-emitting device, each having an EL layer of the same configuration; a first color conversion layer having a region overlapping with the first light-emitting device; a second color conversion layer having a region overlapping with the second light-emitting device; a first coloring layer having a region overlapping with the first light-emitting device and the first color conversion layer; a second coloring layer having a region overlapping with the second light-emitting device and the second color conversion layer; and a third coloring layer having a region overlapping with the third light-emitting device.

[0042] When using light-emitting devices with identical EL layers, layers other than the pixel electrodes (e.g., the light-emitting layer) can be shared among multiple subpixels. Therefore, multiple subpixels can share a continuous film. However, some layers within the light-emitting device are relatively highly conductive. When multiple subpixels share a highly conductive layer as a continuous film, leakage current can occur between subpixels. In particular, as display devices become higher resolution or have higher aperture ratios, reducing the distance between subpixels, this leakage current can become significant enough to cause a decrease in the display quality of the display device.

[0043] Therefore, in a display device according to one aspect of the present invention, at least a portion of the layers constituting the EL layer are formed in an island shape in each light-emitting device. By separating at least a portion of the layers constituting the EL layer for each light-emitting device, the occurrence of crosstalk between adjacent subpixels can be suppressed. This makes it possible to achieve both high resolution and high display quality in the display device.

[0044] In this specification, "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 and an adjacent light-emitting layer are physically separated.

[0045] For example, island-shaped light-emitting layers can be deposited using a vacuum deposition method with a metal mask. However, with this method, deviations from the design occur in the shape and position of the island-shaped light-emitting layers due to various factors such as the precision of the metal mask, misalignment between the metal mask and the substrate, deflection of the metal mask, and the spreading of the contour of the deposited film due to vapor scattering. This makes it difficult to achieve high resolution and high aperture ratio in display devices. In addition, the contour of the layer may become blurred during deposition, and the thickness at the edges may become thinner. In other words, the thickness of the island-shaped light-emitting layer may vary depending on the location. Furthermore, when manufacturing large, high-resolution, or high-definition display devices, there is a concern that the low dimensional accuracy of the metal mask and deformation due to heat, etc., may lead to low manufacturing yield.

[0046] Therefore, when manufacturing a display device according to one aspect of the present invention, the light-emitting layer is processed into a fine pattern by photolithography without using a shadow mask such as a metal mask. Specifically, after forming a pixel electrode for each sub-pixel, a light-emitting layer is deposited across multiple pixel electrodes. Subsequently, the light-emitting layer is processed using photolithography to form one island-shaped light-emitting layer for each pixel electrode. This divides the light-emitting layer for each sub-pixel, allowing for the formation of an island-shaped light-emitting layer for each sub-pixel.

[0047] For example, if a display device consists of three types of light-emitting devices—one that emits blue light, one that emits green light, and one that emits red light—three types of island-shaped light-emitting layers can be formed by repeating the process of depositing the light-emitting layer and processing it using photolithography three times.

[0048] In this context, the state of the interface between the pixel electrode and the EL layer is important for the characteristics of the light-emitting device. In the process of forming the island-shaped light-emitting layer described above, the pixel electrodes of the light-emitting devices of the second and subsequent colors formed may be damaged by the preceding process. As a result, the driving voltage of the light-emitting devices of the second and subsequent colors may increase. Furthermore, the damage to the pixel electrodes is greater in the third color formed than in the second, and the impact on the characteristics of the light-emitting device is greater.

[0049] Furthermore, for the deposition of the light-emitting layer and the processing of the light-emitting layer using photolithography, fewer steps are preferable because this allows for a reduction in manufacturing costs and an improvement in manufacturing yield.

[0050] Therefore, in one embodiment of the present invention, a light-emitting device having the same light-emitting layer (or the same light-emitting material) is used for three subpixels, and different color conversion layers are used for two of these subpixels. Specifically, a color conversion layer that converts to red light is used for one of the two subpixels, and a color conversion layer that converts to green light is used for the other. The remaining subpixel of the three does not use a color conversion layer. Here, in one embodiment of the present invention, it is preferable to use a light-emitting device that emits white or blue light. The light-emitting device is configured to have at least a light-emitting layer (or light-emitting material) that emits blue light, which has a shorter wavelength (i.e., higher energy) than red and green light. This makes it possible to convert the white or blue light emitted by the light-emitting device into red or green light, which has a longer wavelength (i.e., lower energy) than blue light, by the color conversion layer. The light-emitting layer in one embodiment of the present invention will be described in detail in Embodiment 5.

[0051] Furthermore, in a display device according to one aspect of the present invention, it is preferable to use different coloring layers for each of the three subpixels. Specifically, it is preferable to use a coloring layer that transmits red light for the subpixel having a color conversion layer that converts to red light, a coloring layer that transmits green light for the subpixel having a color conversion layer that converts to green light, and a coloring layer that transmits blue light for the subpixel without a color conversion layer. This makes it possible to realize subpixels that emit red light, green light, and blue light, respectively, and enable full-color display.

[0052] As described above, a light-emitting device according to one aspect of the present invention emits white or blue light. In subpixels that emit red light, the light is converted to red light by a color conversion layer before being output; in subpixels that emit green light, the light is converted to green light by a color conversion layer before being output; and in subpixels that emit blue light, the light is output in its original state (i.e., white or blue). Furthermore, the light output by each light-emitting device (after color conversion) is further processed by the aforementioned coloring layer to extract only light of a specific color. Specifically, in subpixels that emit red light, only the red light is extracted from the light output by the color conversion layer by the coloring layer (light other than red is excluded); in subpixels that emit green light, only the green light is extracted from the light output by the color conversion layer by the coloring layer (light other than green is excluded); and in subpixels that emit blue light, only the blue light is extracted from the white or blue light emitted by the light-emitting device by the coloring layer (light other than blue is excluded). As a result, in a display device according to one aspect of the present invention, the color purity of the light exhibited by each subpixel can be increased.

[0053] Furthermore, as mentioned above, in one embodiment of the present invention, a light-emitting device having the same light-emitting layer is used for each of the three subpixels. Therefore, by processing one light-emitting layer into an island shape just once, it is possible to create subpixels of three different colors. Consequently, damage to the pixel electrodes in each subpixel of a different color can be suppressed, and the deterioration of the characteristics of the light-emitting device can be suppressed.

[0054] Furthermore, in the method for manufacturing a display device according to one aspect of the present invention, the number of times the light-emitting layer is processed using photolithography can be reduced to one, thus enabling the production of display devices with a high yield.

[0055] When processing the above-mentioned light-emitting layer into an island shape, a structure in which the processing is performed using photolithography directly above the light-emitting layer is conceivable. In this structure, the light-emitting layer may be damaged (e.g., damage from processing), and its reliability may be significantly impaired. Therefore, when manufacturing a display device according to one aspect of the present invention, it is preferable to use a method in which a mask layer (also called a sacrificial layer, protective layer, etc.) is formed on a functional layer located above the light-emitting layer (for example, a carrier block layer, carrier transport layer, or carrier injection layer, more specifically a hole block layer, electron transport layer, or electron injection layer, etc.), and the light-emitting layer and the functional layer are processed into an island shape. By applying this method, a highly reliable display device can be provided. By having other layers such as a functional layer between the light-emitting layer and the mask layer, it is possible to suppress the exposure of the light-emitting layer to the outermost surface during the manufacturing process of the display device and reduce the damage the light-emitting layer receives.

[0056] Preferably, the EL layer has a first region which is the light-emitting region (also called the light-emitting area) and a second region outside the first region. The second region can also be called a dummy region or dummy area. The first region is located between the pixel electrode and the common electrode. The first region is covered by a mask layer during the manufacturing process of the display device, and the damage it receives is extremely reduced. Therefore, a light-emitting device with high luminous efficiency and a long lifespan can be realized. On the other hand, the second region includes the edge of the EL layer and its vicinity, and includes parts that may be damaged during the manufacturing process of the display device, such as by exposure to plasma. By not using the second region as the light-emitting region, variations in the characteristics of the light-emitting device can be suppressed.

[0057] Furthermore, when processing the light-emitting layer in an island shape, it is preferable to process the layers located below the light-emitting layer (for example, carrier injection layer, carrier transport layer, or carrier block layer, more specifically hole injection layer, hole transport layer, electron block layer, etc.) in the same pattern as the light-emitting layer to form an island shape. By processing the layers located below the light-emitting layer in the same pattern as the light-emitting layer to form an island shape, it is possible to reduce the leakage current (sometimes referred to as lateral leakage current, transverse leakage current, or lateral leakage current) that may occur between adjacent subpixels. For example, when a hole injection layer is used in common between adjacent subpixels, a transverse leakage current may occur due to the hole injection layer. In contrast, in a display device according to one aspect of the present invention, since the hole injection layer can be processed in the same pattern as the light-emitting layer to form an island shape, the transverse leakage current between adjacent subpixels is substantially eliminated or can be made extremely small.

[0058] For example, when processing using photolithography, the EL layer may suffer various types of damage due to heating during the preparation of the resist mask, and exposure to etching solution or etching gas when processing and removing the resist mask. Furthermore, when a mask layer is placed on the EL layer, the EL layer may also be affected by heating, etching solution, etching gas, etc., during the deposition, processing, and removal of the mask layer.

[0059] Furthermore, if the subsequent processes after the deposition of the EL layer are carried out at temperatures higher than the heat resistance temperature of the EL layer, the EL layer may degrade, potentially reducing the luminous efficiency and reliability of the light-emitting device.

[0060] Therefore, in one embodiment of the present invention, the heat resistance temperature of the compounds contained in the light-emitting device is preferably 100°C or more and 180°C or less, more preferably 120°C or more and 180°C or less, and even more preferably 140°C or more and 180°C or less.

[0061] Indicators of heat resistance temperature include, for example, the glass transition temperature (Tg), softening point, melting point, thermal decomposition temperature, and 5% weight loss temperature. For example, the glass transition temperature of the material in each layer constituting the EL layer can be used as an indicator of the heat resistance temperature of that layer. Also, if the layer is a mixed layer consisting of multiple materials, for example, the glass transition temperature of the most abundant material can be used. Alternatively, the lowest temperature among the glass transition temperatures of the multiple materials may be used.

[0062] In particular, it is preferable to increase the heat resistance temperature of the functional layer provided on the light-emitting layer. Furthermore, it is even more preferable to increase the heat resistance temperature of the functional layer provided in contact with the light-emitting layer. The high heat resistance of the functional layer makes it possible to effectively protect the light-emitting layer and reduce the damage it receives.

[0063] Furthermore, it is particularly preferable to increase the heat resistance temperature of the light-emitting layer. This helps to prevent damage to the light-emitting layer due to heating, which can reduce luminous efficiency and shorten the lifespan of the material.

[0064] By increasing the heat resistance temperature of light-emitting devices, their reliability can be improved. Furthermore, the temperature range in the manufacturing process of display devices can be broadened, leading to improved manufacturing yield and reliability.

[0065] In light-emitting devices that emit different colors, it is not necessary to fabricate all the layers constituting the EL layer separately; some layers can be formed in the same process. In a method for manufacturing a display device according to one aspect of the present invention, some of the layers constituting the EL layer are formed in island-like structures for each color, then at least a portion of the mask layer is removed, and the remaining layers constituting the EL layer (sometimes called common layers) and a common electrode (also called an upper electrode) are formed in common for each color (as a single film). For example, a carrier injection layer and a common electrode can be formed in common for each color.

[0066] On the other hand, the carrier injection layer is often a relatively conductive layer within the EL layer. Therefore, if the carrier injection layer comes into contact with the side surface of some of the island-shaped EL layers, or with the side surface of the pixel electrode, there is a risk of a short circuit in the light-emitting device. Furthermore, even when the carrier injection layer is provided in an island shape and a common electrode is formed common to each color, there is a risk of a short circuit in the light-emitting device if the common electrode comes into contact with the side surface of the EL layer, or with the side surface of the pixel electrode.

[0067] Therefore, a display device according to one aspect of the present invention has an insulating layer that covers at least the sides of the island-shaped light-emitting layer. Furthermore, it is preferable that the insulating layer covers a portion of the upper surface of the island-shaped light-emitting layer.

[0068] This prevents at least a portion of the island-shaped EL layer and the pixel electrodes from coming into contact with the carrier injection layer or common electrode. Therefore, it is possible to suppress short circuits in the light-emitting device and improve the reliability of the light-emitting device.

[0069] Furthermore, it is preferable that the edges of the insulating layer have a tapered shape with a taper angle of less than 90° in cross-sectional view. This prevents step breaks in the common layer and common electrode provided on the insulating layer, and suppresses connection defects between the common layer and common electrode. In addition, it is possible to suppress the local thinning of the common electrode due to the step at the edge of the insulating layer, which would increase the electrical resistance of the common electrode.

[0070] In this specification, "step breakage" refers to the phenomenon in which a layer, film, or electrode is divided due to the shape of the surface on which it is formed (for example, a step).

[0071] Thus, the island-shaped light-emitting layer produced by the method for manufacturing a display device according to one aspect of the present invention is not formed using a fine metal mask, but rather by processing after the light-emitting layer has been deposited on one surface. Therefore, it is possible to realize a high-definition display device or a display device with a high aperture ratio, which has been difficult to achieve until now. Furthermore, since the light-emitting layer can be made separately for each color, it is possible to realize a display device that is extremely vivid, has high contrast, and has high display quality. In addition, by providing a mask layer on the light-emitting layer, the damage that the light-emitting layer receives during the manufacturing process of the display device can be reduced, and the reliability of the light-emitting device can be improved.

[0072] Furthermore, while it is difficult to reduce the spacing between adjacent light-emitting devices to less than 10 μm using, for example, a formation method employing a fine metal mask, a method using photolithography according to one embodiment of the present invention allows for narrowing the spacing between adjacent light-emitting devices, adjacent EL layers, or adjacent pixel electrodes to less than 10 μm, 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. Moreover, by using, for example, an exposure apparatus for LSIs, the spacing between adjacent light-emitting devices, adjacent EL layers, or adjacent pixel electrodes in a process on a Si Wafer can be narrowed to, for example, 500 nm or less, 200 nm or less, 100 nm or less, and even 50 nm or less in a process on a Si Wafer. This significantly reduces the area of ​​the non-emitting region that may exist between two light-emitting devices, making it possible to bring the aperture ratio closer to 100%. For example, in a display device according to one aspect of the present invention, the aperture ratio can be 40% or more, 50% or more, 60% or more, 70% or more, 80% or more, and even 90% or more, while achieving less than 100%.

[0073] Furthermore, increasing the aperture ratio of a display device can improve its reliability. More specifically, using an organic EL device, if the lifespan of a display device with an aperture ratio of 10% is used as a baseline, the lifespan of a display device with an aperture ratio of 20% (i.e., twice the aperture ratio of the baseline) is approximately 3.25 times longer, and the lifespan of a display device with an aperture ratio of 40% (i.e., four times the aperture ratio of the baseline) is approximately 10.6 times longer. Thus, as the aperture ratio is increased, the current density flowing through the organic EL device can be reduced, making it possible to improve the lifespan of the display device. In one embodiment of the present invention, since the aperture ratio can be increased, the display quality of the display device can be improved. Moreover, as the aperture ratio of the display device is increased, the reliability (especially the lifespan) of the display device is significantly improved, which is a great effect.

[0074] Furthermore, the processing size of the light-emitting layer itself can be made significantly smaller compared to when using a fine metal mask. For example, when a metal mask is used to create different types of light-emitting layers, variations in thickness occur between the center and edges of the processed light-emitting layer, resulting in a smaller effective area usable as a light-emitting region relative to the total area of ​​the processed light-emitting layer. On the other hand, with the above manufacturing method, a film deposited to a uniform thickness is processed, allowing for the formation of island-shaped light-emitting layers with uniform thickness. Therefore, even if the processing size of the light-emitting layer is minute, almost the entire area can be used as a light-emitting region. As a result, it is possible to manufacture a display device that combines high resolution and a high aperture ratio. In addition, it is possible to achieve miniaturization and weight reduction of the display device.

[0075] Specifically, a display device according to one aspect of the present invention may have 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 may be 20000 ppi or less, or 30000 ppi or less.

[0076] In this embodiment, the cross-sectional structure of the display device according to one aspect of the present invention will be mainly described, and the method for manufacturing the display device according to one aspect of the present invention will be described in detail in Embodiment 2.

[0077] Figure 1A shows a top view of the display device 100. The display device 100 has a display unit on which a plurality of pixels 110 are arranged, and a connection unit 140 on the outside of the display unit. Multiple subpixels (subpixels 11R, 11G, and 11B) are arranged in a matrix on the display unit. Figure 1A shows subpixels in 2 rows and 6 columns, which together constitute a 2 row and 2 column pixel 110. The connection unit 140 can also be called the cathode contact unit.

[0078] The top surface shape of the subpixel shown in Figure 1A corresponds to the top surface shape of the light-emitting region.

[0079] Examples of the top surface shape of a sub-pixel include polygons such as triangles, quadrilaterals (including rectangles, rhombuses, and squares), pentagons, polygons with rounded corners, ellipses, or circles.

[0080] Furthermore, the circuit layout constituting the subpixel is not limited to the subpixel range shown in Figure 1A, but may be located outside of it. For example, the transistor (not shown) of subpixel 11R may be located within the range of subpixel 11G shown in Figure 1A, or some or all of it may be located outside the range of subpixel 11R.

[0081] In Figure 1A, the aperture ratios (sizes, also known as the size of the light-emitting area) of sub-pixels 11R, 11G, and 11B are shown to be equal or approximately equal, but the present invention is not limited to this. The aperture ratios of sub-pixels 11R, 11G, and 11B can be determined as appropriate. The aperture ratios of sub-pixels 11R, 11G, and 11B may be different, or two or more may be equal or approximately equal.

[0082] A stripe array is applied to pixel 110 shown in Figure 1A. Pixel 110 in Figure 1A is composed of three subpixels: subpixel 11R, subpixel 11G, and subpixel 11B. Subpixels 11R, 11G, and 11B each emit light of a different color. Examples of 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). Furthermore, the number of subpixel types is not limited to three; there may be four or more. Examples of 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 four colors: R, G, B, and infrared (IR).

[0083] In this specification, the row direction is sometimes referred to as the X direction, and the column direction as the Y direction. The X and Y directions intersect, for example, perpendicularly (see Figure 1A). Figure 1A shows an example where subpixels of different colors are arranged in the X direction, and subpixels of the same color are arranged in the Y direction.

[0084] Figure 1A shows an example in which the connecting portion 140 is located below the display portion in a plan view, but it is not particularly limited. The connecting portion 140 only needs to be provided at least one location on the top, right, left, or bottom of the display portion in a plan view, and may be provided so as to surround all four sides of the display portion. The top surface shape of the connecting portion 140 can be a strip, L-shape, U-shape, or frame shape, etc. Also, there may be one or more connecting portions 140.

[0085] Figure 1B shows a cross-sectional view between the dashed-dotted lines X1 and X2 in Figure 1A. Figure 1C shows a top view of layer 113W. Figures 2A and 2B show enlarged views of a portion of the cross-sectional view shown in Figure 1B. Figures 3 to 6 show modified examples of Figure 2. Figures 7A, 8A to 8C, 9C and 9D, 10A to 10C, and 11A and 11B show modified examples of Figure 1B. Figures 7B to 7E show cross-sectional views of modified pixel electrodes. Figure 7F shows a modified example of Figure 7A. Figures 9A and 9B show cross-sectional views between the dashed-dotted lines Y1 and Y2 in Figure 1A.

[0086] The sub-pixel 11R includes a light-emitting device 130a that emits white light and a color conversion layer 135R that converts the white light into red light. As a result, the light emitted from the light-emitting device 130a is extracted as red light to the outside of the display device via the color conversion layer 135R.

[0087] Preferably, the sub-pixel 11R further has a colored layer 132R that transmits red light. Some of the white light emitted by the light-emitting device 130a may be transmitted directly without being converted by the color conversion layer 135R. Also, the color-converted light may contain not only red light but also light of wavelengths other than red. By extracting the light transmitted through the color conversion layer 135R via the colored layer 132R, the aforementioned light other than red is absorbed by the colored layer 132R, thereby increasing the color purity of the light exhibited by the sub-pixel 11R.

[0088] The sub-pixel 11G includes a light-emitting device 130b that emits white light and a color conversion layer 135G that converts the white light into green light. The light-emitting device 130b can be made of the same material and configuration as the light-emitting device 130a. As a result, the light emitted from the light-emitting device 130b is extracted as green light to the outside of the display device via the color conversion layer 135G.

[0089] Preferably, the sub-pixel 11G further has a colored layer 132G that transmits green light. Some of the white light emitted by the light-emitting device 130b may be transmitted directly without being converted by the color conversion layer 135G. Also, the color-converted light may contain not only green light but also light of wavelengths other than green. By extracting the light transmitted through the color conversion layer 135G via the colored layer 132G, the aforementioned light other than green is absorbed by the colored layer 132G, thereby increasing the color purity of the light exhibited by the sub-pixel 11G.

[0090] The sub-pixel 11B includes a light-emitting device 130c that emits white light and a colored layer 132B that transmits blue light. The light-emitting device 130c can be made of the same material and has the same configuration as the light-emitting devices 130a and 130b. The light emitted from the light-emitting device 130c is extracted as blue light to the outside of the display device. Thus, the display device 100 according to one aspect of the present invention can realize sub-pixels 11R, 11G, and 11B that emit red light, green light, and blue light, respectively, with high color purity.

[0091] Here, blue light can be defined as light with a peak wavelength of emission spectrum between 400 nm and less than 480 nm. Green light can be defined as light with a peak wavelength of emission spectrum between 480 nm and less than 580 nm. Red light can be defined as light with a peak wavelength of emission spectrum between 580 nm and 700 nm.

[0092] In a display device 100 according to one aspect of the present invention, when comparing the three peak wavelengths of light extracted from sub-pixels 11R, 11G, and 11B, the peak wavelength of light extracted from sub-pixel 11B is the shortest, followed by the peak wavelength of light extracted from sub-pixel 11G, and then the peak wavelength of light extracted from sub-pixel 11R is the longest.

[0093] It is preferable to use either a phosphor or a quantum dot (QD) or both as the color conversion layer. In particular, quantum dots have a narrow peak width in their emission spectrum, allowing for emission with good color purity. This can improve the display quality of the display device.

[0094] The color conversion layer can be formed using methods such as droplet ejection (e.g., inkjet), coating, imprint, and various printing methods (screen printing, offset printing). Alternatively, a color conversion film such as a quantum dot film may be used.

[0095] When processing the film that will become the color conversion layer, it is preferable to use photolithography. Photolithography methods include a method in which a resist mask is formed on the thin film to be processed, the thin film is processed by etching or the like, and the resist mask is removed, and a method in which a photosensitive thin film is formed, and then exposed and developed to process the thin film into the desired shape. For example, an island-shaped color conversion layer can be formed by forming a thin film using a material in which quantum dots are mixed with photoresist, and then processing the thin film using photolithography.

[0096] There are no particular limitations on the materials that constitute quantum dots. Examples include Group 14 elements, Group 15 elements, Group 16 elements, compounds consisting of multiple Group 14 elements, compounds of elements belonging to Groups 4 through 14 and Group 16 elements, compounds of Group 2 elements and Group 16 elements, compounds of Group 13 elements and Group 15 elements, compounds of Group 13 elements and Group 17 elements, compounds of Group 14 elements and Group 15 elements, compounds of Group 11 elements and Group 17 elements, iron oxides, titanium oxides, chalcogenide spinels, and various semiconductor clusters.

[0097] Specifically, cadmium selenide, cadmium sulfide, cadmium telluride, zinc selenide, zinc oxide, zinc sulfide, zinc telluride, mercury sulfide, mercury selenide, mercury telluride, indium arsenide, indium phosphide, gallium arsenide, gallium phosphide, indium nitride, gallium nitride, indium antimonide, gallium antimonide, aluminum phosphide, aluminum arsenide, aluminum antimonide, lead selenide, lead telluride, lead sulfide, indium selenide, telluride Indium sulfide, indium sulfide, gallium selenide, arsenic sulfide, arsenic selenide, arsenic telluride, antimony sulfide, antimony selenide, antimony telluride, bismuth sulfide, bismuth selenide, bismuth telluride, silicon, silicon carbide, germanium, tin, selenium, tellurium, boron, carbon, phosphorus, boron nitride, boron phosphide, boron arsenide, aluminum nitride, aluminum sulfide, barium sulfide, barium selenide, barium telluride, calcium sulfide, selenide Calcium, calcium telluride, beryllium sulfide, beryllium selenide, beryllium telluride, magnesium sulfide, magnesium selenide, germanium sulfide, germanium selenide, germanium telluride, tin sulfide, tin selenide, tin telluride, lead oxide, copper fluoride, copper chloride, copper bromide, copper iodide, copper oxide, copper selenide, nickel oxide, cobalt oxide, cobalt sulfide, iron oxide, iron sulfide, manganese oxide, molybdenum sulfide, vanadium oxide, tungsten oxide, acid Examples include tantalum oxide, titanium oxide, zirconium oxide, silicon nitride, germanium nitride, aluminum oxide, barium titanate, compounds of selenium, zinc, and cadmium, compounds of indium, arsenic, and phosphorus, compounds of cadmium, selenium, and sulfur, compounds of cadmium, selenium, and tellurium, compounds of indium, gallium, and arsenic, compounds of indium, gallium, and selenium, compounds of indium, selenium, and sulfur, compounds of copper, indium, and sulfur, and combinations thereof. In addition, so-called alloy-type quantum dots, whose composition is expressed in any ratio, may also be used.

[0098] Quantum dot structures include core type, core-shell type, and core-multishell type. Furthermore, because quantum dots have a high proportion of surface atoms, they are highly reactive and prone to aggregation. Therefore, it is preferable that a protective agent or protective group is attached to the surface of the quantum dots. This attachment of a protective agent or protective group prevents aggregation and improves solubility in solvents. It also reduces reactivity and improves electrical stability.

[0099] As the size of a quantum dot decreases, its band gap increases; therefore, its size is adjusted appropriately to obtain light of a desired wavelength. As the crystal size decreases, the emission of quantum dots shifts towards the blue side, that is, towards higher energy. Therefore, by changing the size of the quantum dots, the emission wavelength can be adjusted across the ultraviolet, visible, and infrared spectral wavelength regions. The size (diameter) of the quantum dots is, for example, 0.5 nm to 20 nm, preferably 1 nm to 10 nm. The narrower the size distribution of the quantum dots, the narrower the emission spectrum becomes, and the better the color purity of the emission can be obtained. Furthermore, the shape of the quantum dots is not particularly limited and may be spherical, rod-shaped, disc-shaped, or other shapes. A quantum rod, which is a rod-shaped quantum dot, has the function of exhibiting directional light.

[0100] The colored layer is a colored layer that transmits light in a specific wavelength range. For the colored layer 132R, a color filter that transmits light in the red wavelength range can be used. For the colored layer 132G, a color filter that transmits light in the green wavelength range can be used. For the colored layer 132B, a color filter that transmits light in the blue wavelength range can be used. Materials that can be used for the colored layer include metal materials, resin materials, or resin materials containing pigments or dyes.

[0101] As shown in Figure 1B, the display device 100 has an insulating layer (insulating layer 255a, insulating layer 255b, and insulating layer 255c) on a layer 101 including a transistor (not shown), light-emitting devices 130a, 130b, and 130c are provided on the insulating layer, and a protective layer 131 is provided to cover these light-emitting devices. On the protective layer 131, a color conversion layer 135R and a coloring layer 132R are laminated so as to have an area overlapping with the light-emitting device 130a, a color conversion layer 135G and a coloring layer 132G are laminated so as to have an area overlapping with the light-emitting device 130b, and a coloring layer 132B is provided so as to have an area overlapping with the light-emitting device 130c. A substrate 120 is bonded to the coloring layers 132R, 132G, and 132B by a resin layer 122. Furthermore, an insulating layer 125 and an insulating layer 127 on the insulating layer 125 are provided in the region between adjacent light-emitting devices.

[0102] In Figure 1B, multiple cross-sections of the insulating layer 125 and insulating layer 127 are shown, but when the display device 100 is viewed from above, the insulating layer 125 and insulating layer 127 are connected as one unit each. In other words, the display device 100 can be configured to have, for example, one insulating layer 125 and one insulating layer 127. The display device 100 may also have multiple insulating layers 125 that are separated from each other, or multiple insulating layers 127 that are separated from each other.

[0103] A display device according to one aspect of the present invention may be a top-emission type that emits light in the direction opposite to the substrate on which the light-emitting device is formed, a bottom-emission type that emits light toward the substrate on which the light-emitting device is formed, or a dual-emission type that emits light on both sides.

[0104] Layer 101 can be a laminated structure in which, for example, multiple transistors (not shown) are provided on a substrate, and an insulating layer is provided to cover these transistors. The insulating layer on the transistor may be a single layer or a laminated structure. Figure 1B shows insulating layer 255a, insulating layer 255b on insulating layer 255a, and insulating layer 255c on insulating layer 255b, which are insulating layers on the transistor. These insulating layers may have recesses between adjacent light-emitting devices. Figure 1B and others show an example in which insulating layer 255c has a recess. Note that insulating layer 255c does not have to have a recess between adjacent light-emitting devices. The insulating layers on the transistor (insulating layers 255a to insulating layers 255c) can also be considered as part of layer 101.

[0105] Various inorganic insulating films such as oxide insulating films, nitride insulating films, oxidative nitride insulating films, and nitride oxide insulating films can be suitably used as insulating layers 255a, 255b, and 255c, respectively. For insulating layers 255a and 255c, it is preferable to use oxide insulating films or oxidative nitride insulating films such as silicon oxide films, silicon oxidative nitride films, and aluminum oxide films, respectively. For insulating layer 255b, it is preferable to use nitride insulating films or nitride oxide insulating films such as silicon nitride films and silicon nitride oxide films. More specifically, it is preferable to use silicon oxide films as insulating layers 255a and 255c, and silicon nitride films as insulating layer 255b. It is preferable that insulating layer 255b has the function of an etching protective film.

[0106] In this specification, the term "oxide-nitride" refers to a material in which the oxygen content is greater than the nitrogen content, and the term "nitride oxide" refers to a material in which the nitrogen content is greater than the oxygen content. For example, when "silicon oxynitride" is written, it refers to a material in which the oxygen content is greater than the nitrogen content, and when "silicon nitride oxide" is written, it refers to a material in which the nitrogen content is greater than the oxygen content.

[0107] An example of the configuration of layer 101 will be described later in Embodiment 4.

[0108] Light-emitting devices 130a, 130b, and 130c all emit white (W) light.

[0109] As the light-emitting device, it is preferable to use, for example, an OLED (Organic Light Emitting Diode) or a QLED (Quantum-dot Light Emitting Diode). Examples of light-emitting materials for the light-emitting device include fluorescent materials, phosphorescent materials, thermally activated delayed fluorescence (TADF) materials, and inorganic compounds (quantum dot materials, etc.). In addition, LEDs such as microLEDs (Light Emitting Diodes) can also be used as the light-emitting device.

[0110] The light-emitting device can emit light in the following colors: infrared, red, green, blue, cyan, magenta, yellow, or white. Furthermore, the color purity can be improved by adding a microcavity structure to the light-emitting device.

[0111] For details regarding the configuration and materials of the light-emitting device, refer to Embodiment 5.

[0112] In a light-emitting device, one electrode functions as the anode and the other as the cathode. In the following explanation, we may use the example where the pixel electrode functions as the anode and the common electrode functions as the cathode.

[0113] The light-emitting device 130a of the sub-pixel 11R includes a pixel electrode 111a on an insulating layer 255c, an island-shaped layer 113W on the pixel electrode 111a, a common layer 114 on the island-shaped layer 113W, and a common electrode 115 on the common layer 114. In the light-emitting device 130a, the layer 113W and the common layer 114 can be collectively called the EL layer.

[0114] The light-emitting device 130b of the sub-pixel 11G includes a pixel electrode 111b on an insulating layer 255c, an island-shaped layer 113W on the pixel electrode 111b, a common layer 114 on the island-shaped layer 113W, and a common electrode 115 on the common layer 114. In the light-emitting device 130b, the layer 113W and the common layer 114 can be collectively called the EL layer.

[0115] The light-emitting device 130c of the sub-pixel 11B includes a pixel electrode 111c on an insulating layer 255c, an island-shaped layer 113W on the pixel electrode 111c, a common layer 114 on the island-shaped layer 113W, and a common electrode 115 on the common layer 114. In the light-emitting device 130c, the layer 113W and the common layer 114 can be collectively called the EL layer.

[0116] In this specification, among the EL layers of a light-emitting device, the layers provided in an island-like manner for each light-emitting device are all referred to as layer 113W, and the layer that is common to multiple light-emitting devices is referred to as common layer 114. In this specification, the common layer 114 may be omitted, and layer 113W may be referred to as an island-like EL layer, an island-shaped EL layer, etc.

[0117] Adjacent layers 113W are spaced apart from each other. By providing the EL layer in an island-like configuration for each light-emitting device, leakage current between adjacent light-emitting devices can be suppressed. This prevents crosstalk caused by unintended light emission, enabling the realization of a display device with extremely high contrast. In particular, it enables the realization of a display device with high current efficiency at low brightness levels.

[0118] It is preferable that the ends of each of the pixel electrodes 111a, 111b, and 111c have a tapered shape. Specifically, it is preferable that the ends of each of the pixel electrodes 111a, 111b, and 111c have a tapered shape with a taper angle of less than 90°. When the ends of these pixel electrodes have a tapered shape, the layer 113W provided along the side surface of the pixel electrode also has a tapered shape. By making the side surface of the pixel electrode tapered, the coverage of the EL layer provided along the side surface of the pixel electrode can be improved.

[0119] Furthermore, while Figure 1B and other figures illustrate a configuration in which a portion of the shape of the recess provided in the insulating layer 255c has a taper angle equivalent to that of the tapered shape of the pixel electrodes 111a, 111b, and 111c, the configuration is not limited to this. For example, the tapered shapes of the pixel electrodes 111a, 111b, and 111c may be different from the tapered shape of the recess formed in the insulating layer 255c.

[0120] In Figure 1B, there is no insulating layer (also called a partition, bank, or spacer) covering the upper edge of the pixel electrode 111a between the pixel electrode 111a and layer 113W. Similarly, there is no insulating layer covering the upper edge of the pixel electrode 111b between the pixel electrode 111b and layer 113W. Likewise, there is no insulating layer covering the upper edge of the pixel electrode 111c between the pixel electrode 111c and layer 113W. As a result, the spacing between adjacent light-emitting devices can be made extremely narrow. Consequently, high-definition or high-resolution display devices can be realized. Furthermore, a mask for forming the insulating layer becomes unnecessary, reducing the manufacturing cost of the display device.

[0121] Furthermore, by not providing an insulating layer covering the edges of the pixel electrodes between the pixel electrodes and the EL layer, in other words, by not providing an insulating layer between the pixel electrodes and the EL layer, the light emitted from the EL layer can be efficiently extracted. Therefore, a display device according to one aspect of the present invention can have extremely low viewing angle dependence. By reducing viewing angle dependence, the visibility of images in the display device can be improved. For example, in a display device according to one aspect of the present invention, the viewing angle (the maximum angle at which a constant contrast ratio is maintained when viewing the screen from an oblique direction) can be set to a range of 100° or more and less than 180°, preferably 150° or more and 170° or less. The above viewing angle can be applied to both vertical and horizontal directions.

[0122] The light-emitting device of this embodiment may be 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.

[0123] Layer 113W has at least an emissive layer. For example, layer 113W may have an emissive material that emits blue light and an emissive material that emits visible light with a longer wavelength than blue. For example, layer 113W may have a configuration having an emissive material that emits blue light and an emissive material that emits yellow light, or a configuration having an emissive material that emits blue light, an emissive material that emits green light and an emissive material that emits red light, and so on.

[0124] Furthermore, when using a tandem light-emitting device, it is preferable that layer 113W has a structure having, for example, multiple light-emitting units that emit white light. It is preferable to provide a charge generation layer between each light-emitting unit. By applying a tandem structure, a light-emitting device capable of high-brightness light emission can be realized.

[0125] Furthermore, each layer 113W may have one or more of the following: a hole injection layer, a hole transport layer, a hole blocking layer, a charge generation layer, an electron blocking layer, an electron transport layer, and an electron injection layer.

[0126] For example, layer 113W may have a hole injection layer, a hole transport layer, an emissive layer, and an electron transport layer in this order. Alternatively, an electron blocking layer may be present between the hole transport layer and the emissive layer. Furthermore, a hole blocking layer may be present between the electron transport layer and the emissive layer. Additionally, an electron injection layer may be present on the electron transport layer.

[0127] Furthermore, for example, layer 113W may have an electron injection layer, an electron transport layer, an emissive layer, and a hole transport layer in this order. It may also have a hole blocking layer between the electron transport layer and the emissive layer. It may also have an electron blocking layer between the hole transport layer and the emissive layer. Furthermore, it may have a hole injection layer on the hole transport layer.

[0128] Thus, it is preferable that layer 113W has an emissive layer and a carrier transport layer (electron transport layer or hole transport layer) on the emissive layer. Alternatively, it is preferable that layer 113W has an emissive layer and a carrier block layer (hole block layer or electron block layer) on the emissive layer. Alternatively, it is preferable that layer 113W has an emissive layer, a carrier block layer on the emissive layer, and a carrier transport layer on the carrier block layer. Since the surface of layer 113W is exposed during the manufacturing process of the display device, by providing one or both of the carrier transport layer and the carrier block layer on the emissive layer, it is possible to suppress the exposure of the emissive layer to the outermost surface and reduce the damage to the emissive layer. This can improve the reliability of the light-emitting device.

[0129] The heat resistance temperature of the compounds contained in layer 113W is preferably 100°C to 180°C, preferably 120°C to 180°C, and more preferably 140°C to 180°C. For example, the glass transition temperature (Tg) of these compounds is preferably 100°C to 180°C, preferably 120°C to 180°C, and more preferably 140°C to 180°C, respectively.

[0130] In particular, it is preferable that the heat resistance temperature of the functional layer provided on the light-emitting layer is high. Furthermore, it is even more preferable that the heat resistance temperature of the functional layer provided in contact with the light-emitting layer is high. The high heat resistance of the functional layer makes it possible to effectively protect the light-emitting layer and reduce the damage it receives.

[0131] Furthermore, it is preferable that the heat resistance temperature of the light-emitting layer be high. This helps to prevent damage to the light-emitting layer due to heating, which can reduce luminous efficiency and shorten its lifespan.

[0132] The light-emitting layer comprises a light-emitting substance (also called a light-emitting material, light-emitting organic compound, guest material, etc.) and an organic compound (also called a host material, etc.). In the composition of the light-emitting layer, the organic compound is present in a larger proportion than the light-emitting substance, so the Tg of the organic compound can be used as an indicator of the heat resistance temperature of the light-emitting layer.

[0133] Furthermore, for example, layer 113W 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.

[0134] The second light-emitting unit preferably has a light-emitting layer and a carrier transport layer (electron transport layer or hole transport layer) on the light-emitting layer. Alternatively, the second light-emitting unit preferably has a light-emitting layer and a carrier block layer (hole block layer or electron block layer) on the light-emitting layer. Alternatively, the second light-emitting unit preferably has a light-emitting layer, a carrier block layer on the light-emitting layer, and a carrier transport layer on the carrier block layer. Since the surface of the second light-emitting unit is exposed during the manufacturing process of the display device, by providing one or both of the carrier transport layer and the carrier block layer on the light-emitting layer, it is possible to suppress the exposure of the light-emitting layer to the outermost surface and reduce the damage to the light-emitting layer. This can improve the reliability of the light-emitting device. If there are three or more light-emitting units, it is preferable that the light-emitting unit provided in the uppermost layer has a light-emitting layer and one or both of the carrier transport layer and the carrier block layer on the light-emitting layer.

[0135] The common layer 114 may have, for example, an electron injection layer or a hole injection layer. Alternatively, the common layer 114 may have an electron transport layer and an electron injection layer stacked together, or a hole transport layer and a hole injection layer stacked together. The common layer 114 is shared by light-emitting devices 130a, 130b, and 130c.

[0136] Figure 1B shows an example where the edge of layer 113W is located outside the edge of pixel electrode 111a. While the following explanation uses pixel electrode 111a and layer 113W as examples, the same applies to pixel electrode 111b and layer 113W, and pixel electrode 111c and layer 113W.

[0137] In Figure 1B, layer 113W is formed to cover the edge of the pixel electrode 111a. This configuration makes it possible to make the entire upper surface of the pixel electrode an emitting region, and it is easier to increase the aperture ratio compared to a configuration in which the edge of the island-shaped EL layer is located inside the edge of the pixel electrode.

[0138] Furthermore, by covering the sides of the pixel electrodes with the EL layer, contact between the pixel electrodes and the common electrode 115 can be suppressed, thereby preventing short circuits in the light-emitting device. In addition, the distance between the light-emitting region of the EL layer (i.e., the region overlapping with the pixel electrodes) and the edge of the EL layer can be increased. Since the edge of the EL layer may be damaged during processing, using a region away from the edge of the EL layer as the light-emitting region can sometimes improve the reliability of the light-emitting device.

[0139] The layer 113W preferably has a first region which is a light-emitting region and a second region (dummy region) outside the first region. The first region is located between the pixel electrode and the common electrode. The first region is covered by the mask layer during the manufacturing process of the display device, and the damage it receives is greatly reduced. Therefore, a light-emitting device with high luminous efficiency and a long lifespan can be realized. On the other hand, the second region includes the edge of the EL layer and its vicinity, and includes parts that may be damaged during the manufacturing process of the display device, such as by exposure to plasma. By not using the second region as a light-emitting region, variations in the characteristics of the light-emitting device can be suppressed.

[0140] The width L3 shown in Figures 1B and 1C corresponds to the width of the first region 113_1 (luminescent region) in layer 113W. The widths L1 and L2 shown in Figures 1B and 1C correspond to the width of the second region 113_2 (dummy region) in layer 113W. As shown in Figure 1C, the second region 113_2 is provided so as to surround the first region 113_1; therefore, in cross-sectional views such as Figure 1B, the width of the second region 113_2 can be confirmed at two locations, left and right. The width of the second region 113_2 can be either width L1 or width L2; for example, the shorter of widths L1 and L2 may be used. Widths L1 to L3 can be confirmed in cross-sectional observation images. In this embodiment, the explanation uses a cross-sectional view in the X direction as an example, but the widths of the luminescent region and the dummy region can also be confirmed in a cross-sectional view in the Y direction.

[0141] The enlarged view shown in Figure 2A shows the width L2 of the second region 113_2. The second region 113_2 is the portion in layer 113W where at least one of the mask layer 118a, insulating layer 125, and insulating layer 127 overlap. Also, as shown in region 103 in Figure 5B, the portion in layer 113W that is located outside the edge of the upper surface of the pixel electrode is a dummy region.

[0142] The width of the second region 113_2 is 1 nm or more, preferably 5 nm or more, 50 nm or more, or 100 nm or more. A wider dummy region is preferable because it allows for more uniform quality of the light-emitting region and suppresses variations in the characteristics of the light-emitting device. On the other hand, a narrower dummy region allows for a wider light-emitting region and increases the aperture ratio of the pixels. Therefore, the width of the second region 113_2 is preferably 50% or less of the width L3 of the first region 113_1, more preferably 40% or less, 30% or less, 20% or less, or 10% or less. Furthermore, in the case of small and high-resolution display devices such as those for wearable devices, the width of the second region 113_2 is preferably 500 nm or less, more preferably 300 nm or less, 200 nm or less, or 150 nm or less.

[0143] In the island-shaped EL layer, the first region (emission region) is the region where EL emission is obtained. Furthermore, in the island-shaped EL layer, both the first region (emission region) and the second region (dummy region) are regions where PL (photoluminescence) emission is obtained. Therefore, it can be said that the first region and the second region can be distinguished by confirming EL emission and PL emission.

[0144] Furthermore, the common electrode 115 is shared by light-emitting devices 130a, 130b, and 130c. The common electrode 115, which is shared by multiple light-emitting devices, is electrically connected to a conductive layer 123 provided at the connection portion 140 (see Figures 9A and 9B). It is preferable to use a conductive layer for the conductive layer 123 that is made of the same material and formed using the same process as the pixel electrodes 111a, 111b, and 111c.

[0145] In Figure 9A, a common layer 114 is provided on the conductive layer 123, and the conductive layer 123 and the common electrode 115 are electrically connected via the common layer 114. The common layer 114 does not need to be provided at the connection part 140. In Figure 9B, the conductive layer 123 and the common electrode 115 are directly connected. For example, by using a mask to define the film deposition area (also called an area mask or rough metal mask, to distinguish it from a fine metal mask), the areas to be film-deposited by the common layer 114 and the common electrode 115 can be changed.

[0146] Furthermore, in Figure 1B, mask layers 118a are located on the layer 113W of the light-emitting device 130a, on the layer 113W of the light-emitting device 130b, and on the layer 113W of the light-emitting device 130c, respectively. The mask layers are provided so as to surround the first region 113_1 (light-emitting region). In other words, the mask layers have openings in the portion that overlaps with the light-emitting region. The upper surface shape of the mask layers is consistent, roughly consistent, or similar to the second region 113_2 shown in Figure 1C. Mask layer 118a is a portion of the mask layer that was provided in contact with the upper surface of layer 113W when layer 113W was processed. Thus, in one embodiment of the present invention, a part of the mask layer used to protect the EL layer during its manufacture may remain.

[0147] In Figure 1B, one end of the mask layer 118a (the end opposite to the light-emitting region, the outer end) is aligned with or approximately aligned with the end of layer 113W, and the other end of the mask layer 118a (the end on the light-emitting region side, the inner end) is located on layer 113W. Here, it is preferable that the other end of the mask layer 118a overlaps with layer 113W and the pixel electrode 111a (or pixel electrode 111b, pixel electrode 111c). In this case, the other end of the mask layer 118a is more likely to be formed on the approximately flat surface of layer 113W. Furthermore, the mask layer 118a remains between, for example, the upper surface of the island-shaped EL layer (layer 113W) and the insulating layer 125. The mask layer will be described in detail in Embodiment 2.

[0148] Furthermore, if the edges are aligned or roughly aligned, and the top surface shapes match or roughly match, then in a plan view, at least a portion of the contours overlaps between the stacked layers. This includes, for example, cases where the upper and lower layers are processed with the same mask pattern, or partially with the same mask pattern. However, strictly speaking, the contours may not overlap, and the upper layer may be located inside the lower layer, or the upper layer may be located outside the lower layer; in this case as well, the edges are said to be roughly aligned, or the top surface shapes roughly match.

[0149] The sides of layer 113W are covered by insulating layer 125. Insulating layer 127 overlaps with the sides of layer 113W via insulating layer 125.

[0150] Furthermore, a portion of the upper surface of layer 113W is covered by the mask layer 118a. The insulating layers 125 and 127 overlap with a portion of the upper surface of layer 113W via the mask layer 118a. Note that the upper surface of layer 113W is not limited to the upper surface of the flat portion that overlaps with the upper surface of the pixel electrode, but can also include the upper surfaces of the inclined portion and the flat portion located outside the upper surface of the pixel electrode (see region 103 in Figure 5A).

[0151] By covering a portion of the top surface and sides of layer 113W with at least one of the insulating layer 125, insulating layer 127, and mask layer 118a, contact between the common layer 114 (or common electrode 115) and the pixel electrodes 111a, 111b, 111c, and the sides of layer 113W is suppressed, thereby preventing a short circuit in the light-emitting device. This improves the reliability of the light-emitting device.

[0152] In Figure 1B, the film thickness of all layers 113W is shown to be the same, but the present invention is not limited to this. The film thickness of each layer 113W may be different. For example, the film thickness of layer 113W in light-emitting device 130a may be set to a thickness corresponding to the optical path length that enhances red light, the film thickness of layer 113W in light-emitting device 130b may be set to a thickness corresponding to the optical path length that enhances green light, and the film thickness of layer 113W in light-emitting device 130c may be set to a thickness corresponding to the optical path length that enhances blue light.

[0153] Furthermore, for example, each pixel electrode (pixel electrode 111a, pixel electrode 111b, and pixel electrode 111c) is made of a material that is reflective to visible light, and the common electrode 115 is made of a material that is both transparent and reflective to visible light. Then, a top-emission type display device having a microcavity composed of the common electrode 115, common layer 114, layer 113W, and each pixel electrode can be realized.

[0154] In the above case, in the light-emitting device 130a, a portion of the white light emitted by layer 113W passes through the common electrode 115, which has both transmittance and reflectivity to visible light, while the remaining light is reflected by the common electrode 115. This reflected light undergoes multiple reflections within the microcavity described above, excluding light other than red, and the intensity of the red light is increased. This red light then passes through the common electrode 115. In other words, by applying the microcavity structure, the light-emitting device 130a can emit red light with higher color purity than when it is not applied. Similarly, the light-emitting device 130b can emit green light with higher color purity, and the light-emitting device 130c can emit blue light with higher color purity.

[0155] The above example shows the application of a microcavity structure to the light-emitting device of a top-emission type display device, but this is not the only example. For example, a bottom-emission type display device can also be realized by using a material that is reflective to visible light for the common electrode 115, and using materials that are both transparent and reflective to visible light for each pixel electrode.

[0156] The insulating layer 125 is preferably in contact with the side surface of layer 113W (see the dashed area at the edge of layer 113W and its vicinity shown in Figure 2A). By configuring the insulating layer 125 to be in contact with layer 113W, peeling of the layer 113W can be prevented. The close contact between the insulating layer 125 and layer 113W provides the effect of fixing or bonding adjacent layers 113W to each other. This can improve the reliability of the light-emitting device and increase the manufacturing yield of the light-emitting device.

[0157] Furthermore, as shown in Figure 1B, the insulating layers 125 and 127 cover both a portion of the top surface and the sides of layer 113W, thereby further preventing delamination of the EL layer and improving the reliability of the light-emitting device. Additionally, the manufacturing yield of the light-emitting device can be increased.

[0158] Figure 1B shows an example where the stacked structure of layer 113W, mask layer 118a, insulating layer 125, and insulating layer 127 is located on the edge of the pixel electrode 111a. Similarly, the stacked structure of layer 113W, mask layer 118a, insulating layer 125, and insulating layer 127 is located on the edge of the pixel electrode 111b, and the stacked structure of layer 113W, mask layer 118a, insulating layer 125, and insulating layer 127 is located on the edge of the pixel electrode 111c.

[0159] Figure 1B shows a configuration in which the edge of the pixel electrode 111a is covered by layer 113W, and the insulating layer 125 is in contact with the side surface of layer 113W. Similarly, the edge of the pixel electrode 111b is covered by layer 113W, and the insulating layer 125 is in contact with the side surface of layer 113W. In addition, the edge of the pixel electrode 111c is covered by layer 113W, and the insulating layer 125 is in contact with the side surface of layer 113W.

[0160] The insulating layer 127 is provided on the insulating layer 125 so as to fill the recesses formed in the insulating layer 125. The insulating layer 127 can be configured to overlap a portion of the upper surface and side surfaces of the layer 113W via the insulating layer 125. Preferably, the insulating layer 127 covers at least a portion of the side surfaces of the insulating layer 125.

[0161] By providing insulating layers 125 and 127, the gaps between adjacent island-shaped layers can be filled, thereby reducing extreme irregularities on the surface of layers formed on the island-shaped layers (e.g., carrier injection layers, common electrodes, etc.) and making them flatter. Consequently, the coverage of carrier injection layers, common electrodes, etc. can be improved.

[0162] The common layer 114 and common electrode 115 are provided on layer 113W, mask layer 118a, insulating layer 125, and insulating layer 127. Before the insulating layer 125 and insulating layer 127 are provided, a step difference exists between the region where the pixel electrode and island-shaped EL layer are provided (the region where the light-emitting device is located) and the region where the pixel electrode and island-shaped EL layer are not provided (the region between light-emitting devices). In one embodiment of the present invention, the presence of the insulating layer 125 and insulating layer 127 can flatten this step difference and improve the coverage of the common layer 114 and common electrode 115. Therefore, connection failures due to step breaks in the common layer 114 or common electrode 115 can be suppressed. In addition, it is possible to suppress the local thinning of the common electrode 115 due to the step difference, which would increase the electrical resistance of the common electrode 115.

[0163] The upper surface of the insulating layer 127 preferably has a shape that is more flat, but it may also have convex portions, convex curved surfaces, concave curved surfaces, or recesses. For example, the upper surface of the insulating layer 127 preferably has a flat, smooth convex curved surface shape.

[0164] Next, we will describe examples of materials for the insulating layer 125 and the insulating layer 127.

[0165] The insulating layer 125 can be an insulating layer having an inorganic material. For example, inorganic insulating films such as oxide insulating films, nitride insulating films, oxidative nitride insulating films, and nitride oxide insulating films can be used for the insulating layer 125. The insulating layer 125 may be a single layer or a laminated structure. Examples of oxide insulating films include silicon oxide film, aluminum oxide film, magnesium oxide film, indium gallium zinc oxide film, gallium oxide film, germanium oxide film, yttrium oxide film, zirconium oxide film, lanthanum oxide film, neodymium oxide film, hafnium oxide film, and tantalum oxide film. Examples of nitride insulating films include silicon nitride film and aluminum nitride film. Examples of oxidative nitride insulating films include silicon oxidative nitride film and aluminum oxidative nitride film. Examples of nitride oxide insulating films include silicon nitride oxide film and aluminum nitride oxide film. In particular, aluminum oxide is preferred because it has a high selectivity ratio with the EL layer during etching and has the function of protecting the EL layer during the formation of the insulating layer 127, which will be described later. In particular, by applying an inorganic insulating film such as an aluminum oxide film, a hafnium oxide film, or a silicon oxide film formed by atomic layer deposition (ALD) to the insulating layer 125, an insulating layer 125 with fewer pinholes and excellent protection for the EL layer can be formed. Alternatively, the insulating layer 125 may have a laminated structure of a film formed by ALD and a film formed by sputtering. For example, the insulating layer 125 may have a laminated structure of an aluminum oxide film formed by ALD and a silicon nitride film formed by sputtering.

[0166] Preferably, the insulating layer 125 functions as a barrier insulating layer against at least one of water and oxygen. Furthermore, preferably, the insulating layer 125 has the function of suppressing the diffusion of at least one of water and oxygen. Also, preferably, the insulating layer 125 has the function of capturing or fixing (also known as gettering) at least one of water and oxygen.

[0167] In this specification, the term "barrier insulating layer" refers to an insulating layer that has barrier properties. Furthermore, in this specification, "barrier properties" refers to the function of suppressing the diffusion of the corresponding substance (also known as low permeability), or the function of capturing or fixing the corresponding substance (also known as gettering).

[0168] The insulating layer 125 has the function of a barrier insulating layer or a gettering function, thereby suppressing the intrusion of impurities (typically at least one of water and oxygen) that could diffuse from the outside into each light-emitting device. This configuration makes it possible to provide a highly reliable light-emitting device, and furthermore, a highly reliable display device.

[0169] Furthermore, it is preferable that the insulating layer 125 has a low impurity concentration. This prevents impurities from mixing from the insulating layer 125 into the EL layer and degrading the EL layer. Also, by lowering the impurity concentration in the insulating layer 125, the barrier properties against at least one of water and oxygen can be improved. For example, it is desirable that the insulating layer 125 has a sufficiently low hydrogen concentration and a sufficiently low carbon concentration, preferably both.

[0170] Furthermore, the same material can be used for the insulating layer 125 and the mask layer 118a. In this case, the boundary between the mask layer 118a and the insulating layer 125 may become unclear and indistinguishable. Therefore, the mask layer 118a and the insulating layer 125 may be perceived as a single layer. In other words, one layer may be observed to be in contact with a part of the upper surface and side surface of layer 113W, and the insulating layer 127 may be observed to cover at least a part of the side surface of that single layer.

[0171] The insulating layer 127, provided on the insulating layer 125, has the function of flattening the extreme irregularities in the insulating layer 125 formed between adjacent light-emitting devices. In other words, the presence of the insulating layer 127 has the effect of improving the flatness of the surface forming the common electrode 115.

[0172] As the insulating layer 127, an insulating layer having an organic material can be suitably used. Preferably, a photosensitive organic resin is used as the organic material; for example, a photosensitive resin composition containing an acrylic resin is preferred. In this specification, the term "acrylic resin" does not refer only to polymethacrylate esters or methacrylic resins, but may refer to acrylic polymers in a broad sense.

[0173] Furthermore, as the insulating layer 127, acrylic resin, polyimide resin, epoxy resin, imide resin, polyamide resin, polyimidoamide resin, silicone resin, siloxane resin, benzocyclobutene resin, phenol resin, precursors of these resins, etc. may be used. Alternatively, as the insulating layer 127, 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. Additionally, a photoresist may be used as the photosensitive resin. Either a positive-type or negative-type material may be used as the photosensitive organic resin.

[0174] The insulating layer 127 may be made of a material that absorbs visible light. By absorbing the light emitted from the light-emitting device, the insulating layer 127 can suppress light leakage (stray light) from the light-emitting device to adjacent light-emitting devices through the insulating layer 127. This improves the display quality of the display device. Furthermore, since the display quality can be improved without using a polarizing plate in the display device, the display device can be made lighter and thinner.

[0175] 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 as color filters (color filter materials). In particular, it is preferable to use a resin material which is made by laminating or mixing two or more color filter materials, as this can enhance the visible light shielding effect. In particular, by mixing three or more color filter materials, it is possible to create a black or near-black resin layer.

[0176] Next, the structure of the insulating layer 127 and its vicinity will be described using Figures 2A and 2B. Figure 2A is a magnified cross-sectional view of the region including the insulating layer 127 and its surrounding area between the light-emitting device 130a of the subpixel that emits red light and the light-emitting device 130b of the subpixel that emits green light. In the following explanation, the insulating layer 127 between two adjacent light-emitting devices 130a and 130b will be used as an example, but the same applies to the insulating layer 127 between light-emitting devices 130b and 130c. Figure 2B is a magnified view of the edge of the insulating layer 127 on layer 113W and its vicinity, as shown in Figure 2A. Note that the common layer 114 and common electrode 115 are not shown in Figure 2B.

[0177] As shown in Figure 2A, layer 113W is provided covering pixel electrode 111a, and layer 113W is provided covering pixel electrode 111b. A mask layer 118a is provided in contact with a part of the upper surface of layer 113W. An insulating layer 125 is provided in contact with the upper and side surfaces of mask layer 118a, the side surfaces of layer 113W, and the upper surface of insulating layer 255c. In addition, insulating layer 125 covers a part of the upper surface of layer 113W. An insulating layer 127 is provided in contact with the upper surface of insulating layer 125. In addition, insulating layer 127 overlaps with a part of the upper surface and side surfaces of layer 113W via insulating layer 125 and is in contact with at least a part of the side surfaces of insulating layer 125. A common layer 114 is provided covering layer 113W, mask layer 118a, insulating layer 125, and insulating layer 127, and a common electrode 115 is provided on the common layer 114.

[0178] Furthermore, the insulating layer 127 is formed in the region between the two island-shaped EL layers (for example, in Figure 2A, the region between the two layers 113W). At this time, at least a portion of the insulating layer 127 is positioned 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 areas and locally thin areas in the common layer 114 and common electrode 115 formed on the island-shaped EL layers and the insulating layer 127.

[0179] As shown in Figure 2B, the insulating layer 127 preferably has a tapered shape with a taper angle θ1 at its end 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, it is not limited to the substrate surface; it may also be the angle between the upper surface of the flat portion of layer 113W, or the upper surface of the flat portion of the pixel electrode 111b, and the side surface (or end) of the insulating layer 127.

[0180] 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 making the end of the insulating layer 127 tapered in this way, the common layer 114 and common electrode 115 provided on the insulating layer 127 can be formed with good coverage, and the occurrence of stepped cuts or localized thinning in the common layer 114 or common electrode 115 can be suppressed. As a result, the in-plane uniformity of the film thickness of the common layer 114 and common electrode 115 can be improved, and the display quality of the display device can be improved.

[0181] Furthermore, as shown in Figure 2A, in a cross-sectional view of the display device, it is preferable that the upper surface of the insulating layer 127 has a convex curved shape. The convex curved shape of the upper surface of the insulating layer 127 is preferably a shape that bulges gently towards the center. It is also preferable that the convex curved portion in the center of the upper surface of the insulating layer 127 is smoothly connected to the tapered portion at the end. By making the insulating layer 127 such a shape, the common layer 114 and the common electrode 115 can be formed on the entire insulating layer 127 with good coverage.

[0182] As shown in Figure 2B, it is preferable that the edge of the insulating layer 127 is located outside the edge of the insulating layer 125. This reduces the surface irregularities forming the common layer 114 and the common electrode 115, thereby improving the coverage of the common layer 114 and the common electrode 115.

[0183] As shown in Figure 2B, the insulating layer 125 preferably has a tapered shape with a taper angle θ2 at its end in a cross-sectional view of the display device. The taper angle θ2 is the angle between the side surface of the insulating layer 125 and the substrate surface. However, it is not limited to the substrate surface; it may also be the angle between the upper surface of the flat portion of layer 113W, or the upper surface of the flat portion of the pixel electrode 111b, and the side surface of the insulating layer 125.

[0184] 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.

[0185] As shown in Figure 2B, the mask layer 118a preferably has a tapered shape with a taper angle θ3 at its end in a cross-sectional view of the display device. The taper angle θ3 is the angle between the side surface (or end) of the mask layer 118a and the substrate surface. However, it is not limited to the substrate surface; it may also be the angle between the upper surface of the flat portion of layer 113W, or the upper surface of the flat portion of the pixel electrode 111b, and the side surface of the mask layer 118a.

[0186] The taper angle θ3 of the mask layer 118a is less than 90°, preferably 60° or less, more preferably 45° or less, and even more preferably 20° or less. By giving the mask layer 118a such a tapered shape, the common layer 114 and the common electrode 115 provided on the mask layer 118a can be formed with good coverage.

[0187] It is preferable that the edges of the mask layer 118a are located outside the edges of the insulating layer 125. This reduces the surface irregularities forming the common layer 114 and the common electrode 115, thereby improving the coverage of the common layer 114 and the common electrode 115.

[0188] As will be detailed in Embodiment 2, if the etching process of the insulating layer 125 and the mask layer 118a is performed at the same time, side etching may cause the insulating layer 125 and the mask layer 118a below the edge of the insulating layer 127 to disappear, forming a cavity. This cavity can cause unevenness on the surface forming the common layer 114 and the common electrode 115, making it easier for the common layer 114 and the common electrode 115 to break down. Therefore, by performing the etching process in two stages and performing a heat treatment between the two etching processes, even if a cavity is formed in the first etching process, the insulating layer 127 can be deformed by the heat treatment and the cavity can be filled. In addition, since the second etching process involves etching a thin film, the amount of side etching is reduced, making it less likely for a cavity to form, and even if a cavity is formed, it can be made extremely small. Therefore, it is possible to suppress the occurrence of unevenness on the surface forming the common layer 114 and the common electrode 115, and to suppress the breaking down of the common layer 114 and the common electrode 115. Because the etching process is performed twice, the taper angles θ2 and θ3 may be different angles. Alternatively, taper angles θ2 and θ3 may be the same angle. Furthermore, taper angles θ2 and θ3 may each be smaller than taper angle θ1.

[0189] The insulating layer 127 may cover at least a portion of the side surface of the mask layer 118a. For example, Figure 2B shows an example where the insulating layer 127 in contact with and covers the inclined surface located at the edge of the mask layer 118a formed by the first etching process, while the inclined surface located at the edge of the mask layer 118a formed by the second etching process is exposed. These two inclined surfaces can sometimes be distinguished by their different taper angles. Alternatively, there may be little difference in the taper angles of the side surfaces formed by the two etching processes, making them indistinguishable.

[0190] Furthermore, Figures 3A and 3B show examples in which the insulating layer 127 covers the entire side surface of the mask layer 118a. Specifically, in Figure 3B, the insulating layer 127 covers both of the two inclined surfaces in contact with each other. This is preferable because it can further reduce the unevenness of the surfaces forming the common layer 114 and the common electrode 115. Figure 3B shows an example in which the edge of the insulating layer 127 is located outside the edge of the mask layer 118a. The edge of the insulating layer 127 may be located inside the edge of the mask layer 118a, as shown in Figure 2B, and may be aligned with or approximately aligned with the edge of the mask layer 118a. Also, as shown in Figure 3B, the insulating layer 127 may be in contact with layer 113W.

[0191] In Figure 3B, it is preferable that the taper angles θ1 to θ3 are within the above ranges.

[0192] Furthermore, Figures 4A and 4B show examples in which the insulating layer 127 has a concave curved shape (also called a constricted portion, recess, indentation, or depression) on its side surface. Depending on the material of the insulating layer 127 and the formation conditions (heating temperature, heating time, heating atmosphere, etc.), a concave curved shape may be formed on the side surface of the insulating layer 127.

[0193] Figure 4A shows an example where the insulating layer 127 covers a portion of the side surface of the mask layer 118a, leaving the rest of the side surface of the mask layer 118a exposed. Figure 4B shows an example where the insulating layer 127 is in contact with and covers the entire side surface of the mask layer 118a.

[0194] Furthermore, as shown in Figures 2 to 4, it is preferable that one end of the insulating layer 127 overlaps with the upper surface of the pixel electrode 111a, and the other end of the insulating layer 127 overlaps with the upper surface of the pixel electrode 111b. This structure allows the end of the insulating layer 127 to be formed on a generally flat region of layer 113W. Therefore, it becomes relatively easy to form the tapered shapes of the insulating layer 127, insulating layer 125, and mask layer 118a. In addition, peeling of the film between layer 113W and the pixel electrode 111a or pixel electrode 111b can be suppressed. On the other hand, the smaller the overlap between the upper surface of the pixel electrode and the insulating layer 127, the wider the light-emitting region of the light-emitting device becomes, and the higher the aperture ratio can be, which is preferable.

[0195] Note that the insulating layer 127 does not necessarily have to overlap with the upper surface of the pixel electrode. As shown in Figure 5A, the insulating layer 127 may not overlap with the upper surface of the pixel electrode, with one end of the insulating layer 127 overlapping with the side surface of the pixel electrode 111a and the other end of the insulating layer 127 overlapping with the side surface of the pixel electrode 111b. Also, as shown in Figure 5B, the insulating layer 127 may not overlap with the pixel electrode and may be provided in the region sandwiched between the pixel electrode 111a and the pixel electrode 111b. In Figures 5A and 5B, part or all of the upper surface of the inclined portion and flat portion (region 103) located outside the upper surface of the pixel electrode of the upper surface of layer 113W is covered by the mask layer 118a, the insulating layer 125, and the insulating layer 127. Even with this configuration, compared to a configuration without the mask layer 118a, insulating layer 125, and insulating layer 127, the surface irregularities forming the common layer 114 and common electrode 115 can be reduced, and the coverage of the common layer 114 and common electrode 115 can be improved. Region 103 can be called a dummy region.

[0196] Furthermore, as shown in Figure 6A, the upper surface of the insulating layer 127 may have a flat portion in a cross-sectional view of the display device.

[0197] Furthermore, as shown in Figure 6B, the upper surface of the insulating layer 127 may have a concave curved shape in a cross-sectional view of the display device. In Figure 6B, the upper surface of the insulating layer 127 has a shape that bulges gently towards the center, that is, a convex curved surface, and a shape that is concave in the center and its vicinity. Also in Figure 6B, the convex curved portion of the upper surface of the insulating layer 127 is smoothly connected to the tapered portion at the end. Even if the insulating layer 127 has such a shape, the common layer 114 and the common electrode 115 can be formed on the entire insulating layer 127 with good coverage.

[0198] One method for creating an insulating layer 127 with a concave curved surface in the center, as shown in Figure 6B, is exposure using a multi-gradation mask (typically a halftone mask or graytone mask). A multi-gradation mask is an exposure mask that allows exposure at three exposure levels: an exposed area, an intermediate exposed area, and an unexposed area, resulting in transmitted light of multiple intensities. This makes it possible to form an insulating layer 127 with multiple (typically two) thicknesses using only one photomask (a single exposure and development process).

[0199] The method for forming a concave curved surface in the central part of the insulating layer 127 is not limited to the above. For example, two photomasks may be used to create an exposed portion and an intermediate exposed portion separately. Alternatively, the viscosity of the resin material used for the insulating layer 127 may be adjusted. Specifically, the viscosity of the material used for the insulating layer 127 may be set to 10 cP or less, preferably 1 cP or more and 5 cP or less.

[0200] Although not shown in the figures, the concave curved surface in the center of the insulating layer 127 does not necessarily have to be continuous and may be interrupted between adjacent light-emitting devices. In this case, as shown in Figure 6B, a portion of the insulating layer 127 disappears in the center, and the surface of the insulating layer 125 is exposed. In this configuration, the shape should be such that the common layer 114 and the common electrode 115 can be covered.

[0201] As described above, in each configuration shown in Figures 2 to 6, by providing insulating layer 127, insulating layer 125, and mask layer 118a, the common layer 114 and common electrode 115 can be formed with good coverage. This prevents the formation of divided areas and locally thin film areas in the common layer 114 and common electrode 115. Therefore, it is possible to suppress connection failures caused by divided areas and increases in electrical resistance caused by locally thin film areas in the common layer 114 and common electrode 115 between each light-emitting device. As a result, the display device according to one embodiment of the present invention can improve display quality.

[0202] It is preferable to provide a protective layer 131 on the light-emitting devices 130a, 130b, and 130c. Providing the protective layer 131 can improve the reliability of the light-emitting devices. The protective layer 131 may be a single layer or a laminated structure of two or more layers.

[0203] The conductivity of the protective layer 131 is not required. At least one of the following can be used as the protective layer 131: an insulating film, a semiconductor film, or a conductive film.

[0204] The presence of an inorganic film in the protective layer 131 prevents oxidation of the common electrode 115 and suppresses the intrusion of impurities (such as moisture and oxygen) into the light-emitting device, thereby suppressing degradation of the light-emitting device and improving the reliability of the display device.

[0205] For the protective layer 131, an inorganic insulating film such as an oxide insulating film, a nitride insulating film, an oxidoxide-nitriding insulating film, or a nitride-oxide insulating film can be used. Specific examples of these inorganic insulating films are given in the description of the insulating layer 125. In particular, the protective layer 131 preferably has a nitride insulating film or a nitride-oxide insulating film, and more preferably has a nitride insulating film.

[0206] Furthermore, the protective layer 131 may also be an inorganic film containing In-Sn oxide (also known as ITO), In-Zn oxide, Ga-Zn oxide, Al-Zn oxide, or indium gallium zinc oxide (In-Ga-Zn oxide, also known as IGZO). The inorganic film is preferably highly resistive, and more specifically, it is preferably more resistive than the common electrode 115. The inorganic film may further contain nitrogen.

[0207] When the light emitted from a light-emitting device is extracted via a protective layer 131, it is preferable that the protective layer 131 has high transmittance to visible light. For example, ITO, IGZO, and aluminum oxide are preferred because they are inorganic materials with high transmittance to visible light.

[0208] As the protective layer 131, for example, a laminated structure of an aluminum oxide film and a silicon nitride film on the aluminum oxide film, or a laminated structure of an aluminum oxide film and an IGZO film on the aluminum oxide film can be used. By using such a laminated structure, it is possible to suppress the penetration of impurities (water, oxygen, etc.) into the EL layer.

[0209] Furthermore, the protective layer 131 may have an organic film. For example, the protective layer 131 may have both an organic film and an inorganic film. Examples of organic materials that can be used for the protective layer 131 include organic insulating materials that can be used for the insulating layer 127.

[0210] The protective layer 131 may have a two-layer structure formed using different film deposition methods. Specifically, the first layer of the protective layer 131 may be formed using the ALD method, and the second layer of the protective layer 131 may be formed using the sputtering method.

[0211] A light-shielding layer may be provided on the side of the substrate 120 facing the resin layer 122. Various optical components can be placed on the outside of the substrate 120 (the side opposite to the resin layer 122). Examples of optical components include polarizing plates, phase difference plates, light diffusion layers (such as diffusion films), anti-reflective layers, and light-collecting films. Furthermore, surface protection layers such as an antistatic film to suppress dust adhesion, a water-repellent film to prevent dirt from adhering, a hard coat film to suppress scratches during use, and an impact-absorbing layer may be placed on the outside of the substrate 120. For example, a glass layer or a silica layer (SiO2) may be used as the surface protection layer. x By providing a protective layer, surface contamination and scratching can be suppressed, which is preferable. Furthermore, as a surface protective layer, DLC (diamond-like carbon), aluminum oxide (AlO2) x ), polyester-based materials, or polycarbonate-based materials may be used. It is preferable to use a material with high transmittance to visible light for the surface protective layer. Furthermore, it is preferable to use a material with high hardness for the surface protective layer.

[0212] The substrate 120 can be made of glass, quartz, ceramics, sapphire, resin, metal, alloy, semiconductor, etc. The substrate on the side that extracts light from the light-emitting device should be made of a material that transmits the light. 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.

[0213] As the substrate 120, various materials can be used, including polyester resins such as polyethylene terephthalate (PET) and 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, polyamide-imide resin, polyurethane resin, polyvinyl chloride resin, polyvinylidene chloride resin, polypropylene resin, polytetrafluoroethylene (PTFE) resin, ABS resin, cellulose nanofiber, etc. Glass with a thickness sufficient to provide flexibility may also be used for the substrate 120.

[0214] Furthermore, when a circular polarizing plate is superimposed on a display device, it is preferable to use a substrate with high optical isotropy for the substrate of the display device. A substrate with high optical isotropy has low birefringence (or a small amount of birefringence).

[0215] For substrates with high optical isotropy, the absolute value of the retardation (phase difference) is preferably 30 nm or less, more preferably 20 nm or less, and even more preferably 10 nm or less.

[0216] Examples of films with high optical isotropy include triacetylcellulose (TAC, also known as cellulose triacetate) film, cycloolefin polymer (COP) film, cycloolefin copolymer (COC) film, and acrylic resin film.

[0217] Furthermore, when a film is used as the substrate, the film may absorb water, potentially causing wrinkles or other shape changes in the display device. Therefore, it is preferable to use a film with a low water absorption rate as the substrate. For example, it is preferable to use a film with a water absorption rate of 1% or less, more preferable to use a film with a water absorption rate of 0.1% or less, and even more preferable to use a film with a water absorption rate of 0.01% or less.

[0218] As the resin layer 122, various types of curing adhesives can be used, such as UV-curing adhesives, reaction-curing adhesives, thermosetting adhesives, and anaerobic adhesives. Examples of these adhesives include epoxy resins, acrylic resins, silicone resins, phenolic resins, polyimide resins, imide resins, PVC (polyvinyl chloride) resins, PVB (polyvinyl butyral) resins, and EVA (ethylene vinyl acetate) resins. Materials with low moisture permeability, such as epoxy resins, are particularly preferred. Two-component mixed resins may also be used. Adhesive sheets may also be used.

[0219] Figures 7A, 8A to 8C, 9C and 9D, 10A to 10C, and 11A and 11B show modified examples of Figure 1B.

[0220] Figure 7A shows an example in which the top and side surfaces of pixel electrodes 111a, 111b, and 111c are covered by conductive layers 116a, 116b, and 116c, respectively. Conductive layers 116a, 116b, and 116c can also be considered as part of the pixel electrodes.

[0221] In Figure 1B, the side surface of the pixel electrode 111a is in contact with layer 113W. If the pixel electrode 111a has a stacked structure, there will be multiple conductive layers in contact with layer 113W. This may result in areas where the adhesion between the pixel electrode 111a and layer 113W is low. The same applies between the pixel electrode 111b and layer 113W, and between the pixel electrode 111c and layer 113W.

[0222] Furthermore, if, after the formation of pixel electrodes 111a, 111b, and 111c, a portion of the film above pixel electrodes 111a, 111b, and 111c is removed by wet etching, galvanic corrosion may occur on the pixel electrodes if the etching solution comes into contact with them.

[0223] In Figure 7A, the top and side surfaces of pixel electrodes 111a, 111b, and 111c are covered by conductive layers 116a, 116b, and 116c, respectively. Therefore, when removing the film above conductive layers 116a, 116b, and 116c by wet etching, it is possible to suppress contact of the etching solution with the pixel electrodes 111a, 111b, and 111c, thereby suppressing deterioration of the pixel electrodes due to galvanic corrosion, etc. This broadens the range of material choices for pixel electrodes 111a, 111b, and 111c. Furthermore, because layer 113W is in contact with conductive layers 116a, 116b, and 116c, the adhesion between layer 113W and the conductive layers is uniform.

[0224] In the case of a top-emission type display device, it is preferable to use electrodes that are reflective to visible light (reflective electrodes) for the pixel electrodes 111a, 111b, and 111c, and electrodes that are transparent to visible light (transparent electrodes) for the conductive layers 116a, 116b, and 116c.

[0225] The pixel electrode 111 shown in Figure 7B has a two-layer structure, and the conductive layer 116 has a single-layer structure. For example, it is preferable to use a two-layer structure of a titanium film and an aluminum film on the titanium film as the pixel electrode 111, and to use an oxide conductive layer (for example, In-Si-Sn oxide (also called ITSO)) as the conductive layer 116. The pixel electrode 111 shown in Figure 7C has a three-layer structure, and the conductive layer 116 has a single-layer structure. For example, it is preferable to use a three-layer structure of a titanium film, an aluminum film, and a titanium film as the pixel electrode 111, and to use an oxide conductive layer (for example, ITSO) as the conductive layer 116. The aluminum film has high reflectivity and is suitable as a reflective electrode. On the other hand, if the aluminum film and the oxide conductive layer come into contact, there is a risk of galvanic corrosion occurring in the aluminum film. Therefore, it is preferable to provide a titanium film between the aluminum film and the oxide conductive layer.

[0226] The pixel electrode 111 shown in Figure 7D has a two-layer structure, and the conductive layer 116 has a two-layer structure. For example, it is preferable to use a two-layer structure of a titanium film and an aluminum film on the titanium film as the pixel electrode 111, and a two-layer structure of a titanium film and an oxide conductive layer (e.g., ITSO) as the conductive layer 116. The pixel electrode 111 shown in Figure 7E has a three-layer structure, and the conductive layer 116 has a two-layer structure. For example, it is preferable to use a three-layer structure of a titanium film, an aluminum film, and a titanium film as the pixel electrode 111, and a two-layer structure of a titanium film and an oxide conductive layer (e.g., ITSO) as the conductive layer 116.

[0227] The thicknesses of conductive layers 116a, 116b, and 116c may be different. For example, as shown in Figure 7F, it is preferable that the thickness of conductive layer 116a be greater than the thickness of conductive layer 116b. Specifically, it is preferable to set the thickness of conductive layer 116a to enhance red light, the thickness of conductive layer 116b to enhance green light, and the thickness of conductive layer 116c to enhance blue light. This makes it possible to realize a microcavity structure and improve the color purity in each light-emitting device.

[0228] Figure 1B shows an example in which the color conversion layer 135R and the coloring layer 132R are directly provided on the light-emitting device 130a via a protective layer 131. It also shows an example in which the color conversion layer 135G and the coloring layer 132G are directly provided on the light-emitting device 130b via a protective layer 131. Furthermore, it shows an example in which the coloring layer 132B is directly provided on the light-emitting device 130c via a protective layer 131. This configuration improves the accuracy of the alignment between the light-emitting device and the color conversion layer or coloring layer. Additionally, bringing the light-emitting device and the coloring layer closer together suppresses color mixing and improves viewing angle characteristics, which is preferable.

[0229] As shown in Figure 8A, a substrate 120 provided with a color conversion layer 135R and a colored layer 132R, a color conversion layer 135G and a colored layer 132G, and a colored layer 132B may be bonded to a protective layer 131 by a resin layer 122. By providing the substrate 120 with the color conversion layer 135R and colored layer 132R, the color conversion layer 135G and a colored layer 132G, and a colored layer 132B, the temperature of the heat treatment in the formation process of the color conversion layer 135R and colored layer 132R, the color conversion layer 135G and a colored layer 132G, and a colored layer 132B can be increased.

[0230] As shown in Figures 8B and 8C, a lens 133 may be provided in the display device. It is preferable to provide the lens 133 on top of the light-emitting device. By providing the lens 133, the light emitted by the light-emitting device can be extracted to the outside of the display device more efficiently than when the lens 133 is not provided.

[0231] Figure 8B shows an example in which a color conversion layer 135R and a colored layer 132R are provided on the light-emitting device 130a via a protective layer 131, a color conversion layer 135G and a colored layer 132G are provided on the light-emitting device 130b via a protective layer 131, a colored layer 132B is provided on the light-emitting device 130c via a protective layer 131, an insulating layer 134 is provided on the color conversion layer 135R and colored layer 132R, the color conversion layer 135G and colored layer 132G, and the colored layer 132B, and a lens 133 is provided on the insulating layer 134. By directly forming the color conversion layer 135R and colored layer 132R, the color conversion layer 135G and colored layer 132G, the colored layer 132B, and the lens 133 on the substrate on which the light-emitting device is formed, the accuracy of alignment between the light-emitting device and the color conversion layer, colored layer, or lens can be improved.

[0232] The insulating layer 134 can be an inorganic insulating film, an organic insulating film, or both. The insulating layer 134 may be a single-layer structure or a multi-layer structure. For example, the insulating layer 134 can be made from a material that can be used for the protective layer 131. Since the light emitted from the light-emitting device is extracted through the insulating layer 134, it is preferable that the insulating layer 134 has high transmittance to visible light.

[0233] In Figure 8B, the light emitted from the light-emitting device passes through the color conversion layer and the coloring layer, then through the lens 133, and is extracted to the outside of the display device. Bringing the light-emitting device and the coloring layer closer together is preferable because it can suppress color mixing and improve viewing angle characteristics. Alternatively, the lens 133 may be provided on the light-emitting device, and the color conversion layer and coloring layer may be provided on the lens 133.

[0234] Figure 8C shows an example in which a substrate 120, on which a colored layer 132R and a color conversion layer 135R, a colored layer 132G and a color conversion layer 135G, a colored layer 132B, and a lens 133 are provided, is bonded to a protective layer 131 by a resin layer 122. By providing the substrate 120 with the colored layer 132R and a color conversion layer 135R, a colored layer 132G and a color conversion layer 135G, a colored layer 132B, and a lens 133, the temperature of the heat treatment in the formation process can be increased.

[0235] Figure 8C shows an example in which a colored layer 132R, a colored layer 132G, and a colored layer 132B are provided in contact with the substrate 120, a color conversion layer 135R is provided in contact with the colored layer 132R, a color conversion layer 135G is provided in contact with the colored layer 132G, an insulating layer 134 is provided in contact with the color conversion layer 135R, the color conversion layer 135G, and the colored layer 132B, and a lens 133 is provided in contact with the insulating layer 134.

[0236] In Figure 8C, the light emitted from the light-emitting device 130a passes through the lens 133, is converted into red light by the color conversion layer 135R, and only the red light passes through the colored layer 132R and is extracted to the outside of the display device. Similarly, the light emitted from the light-emitting device 130b passes through the lens 133, is converted into green light by the color conversion layer 135G, and only the green light passes through the colored layer 132G and is extracted to the outside of the display device. Furthermore, the light emitted from the light-emitting device 130c passes through the lens 133, and only the blue light passes through the colored layer 132B and is extracted to the outside of the display device.

[0237] In addition, at the position overlapping with the light-emitting devices 130a and 130b, a lens 133 may be provided in contact with the substrate 120, an insulating layer 134 in contact with the lens 133, a colored layer in contact with the insulating layer 134, and a color conversion layer in contact with the colored layer. Furthermore, at the position overlapping with the light-emitting device 130c, a lens 133 may be provided in contact with the substrate 120, an insulating layer 134 in contact with the lens 133, and a colored layer in contact with the insulating layer 134. In this case, the light emitted from the light-emitting device 130a (light-emitting device 130b) is converted into red (green) light by the color conversion layer, and only the red (green) light of this light passes through the colored layer, passes through the lens 133, and is then taken out to the outside of the display device. Similarly, the light emitted from the light-emitting device 130c is converted into blue light only, which passes through the colored layer, passes through the lens 133, and is then taken out to the outside of the display device.

[0238] Figures 1B and 8B show examples where a layer with planarization functionality is used as the protective layer 131. However, as shown in Figures 8A and 8C, the protective layer 131 does not necessarily have to have planarization functionality. For example, by using an organic film for the protective layer 131, the upper surface of the protective layer 131 can be made flat. Also, the protective layer 131 shown in Figures 8A and 8C can be formed by using, for example, an inorganic film.

[0239] Figure 9C shows an example in which a lens 133 is provided on light-emitting devices 130a, 130b, and 130c, respectively, via a protective layer 131, and a substrate 120 on which a colored layer 132R and a color conversion layer 135R, a colored layer 132G and a color conversion layer 135G, and a colored layer 132B are provided, is bonded to the lens 133 and the protective layer 131 by a resin layer 122.

[0240] Unlike in Figure 9C, the lens 133 may be provided on the substrate 120, and the color conversion layer 135R and colored layer 132R, color conversion layer 135G and colored layer 132G, and colored layer 132B may be directly formed on the protective layer 131. In this way, one of the lens and colored layer may be provided on the protective layer 131, and the other on the substrate 120. Furthermore, comparing the color conversion layer 135R (color conversion layer 135G) and the colored layer 132R (colored layer 132G), the color conversion layer 135R (color conversion layer 135G) is positioned closer to the light-emitting device 130a (light-emitting device 130b). For example, the color conversion layer 135R (color conversion layer 135G) may be provided on the protective layer 131, and the colored layer 132R (colored layer 132G) may be provided on the substrate 120.

[0241] The lens 133 may have its convex surface facing either the substrate 120 or the light-emitting device. However, from the viewpoint of ease of manufacturing, if the lens 133 is provided on the light-emitting device side, it is preferable that the convex surface faces the substrate 120 side. On the other hand, if the lens 133 is provided on the substrate 120 side, it is preferable that the convex surface faces the light-emitting device side.

[0242] The lens 133 can be formed using at least one of an inorganic material and an organic material. For example, a material containing resin can be used for the lens. Alternatively, a material containing at least one of an oxide and a sulfide can be used for the lens. Preferably, the lens 133 is formed using a material with a refractive index greater than that of the resin layer 122. As the lens 133, for example, a microlens array can be used. The lens 133 may be formed directly on the substrate 120 or on the light-emitting device, or a separately formed lens may be bonded to it.

[0243] Figure 9D is an example in which the colored layers 132R, 132G, and 132B are provided on the substrate 120 side, unlike in Figure 1B. The substrate 120 and the protective layer 131 are bonded together by a resin layer 122 such that the light-emitting device 130a and the color conversion layer 135R overlap with the colored layer 132R, the light-emitting device 130b and the color conversion layer 135G overlap with the colored layer 132G, and the light-emitting device 130c overlaps with the colored layer 132B.

[0244] By providing a colored layer so as to overlap with the light-emitting device, ambient light reflection can be significantly reduced, which is preferable. Furthermore, if the light-emitting device has a microcavity structure, ambient light reflection can be further reduced. Thus, by applying one or both of the colored layer and / or microcavity structure, ambient light reflection can be sufficiently suppressed without using optical components such as circular polarizers in the display device. By not using circular polarizers in the display device, attenuation of light emission from the light-emitting device can be suppressed, and the light extraction efficiency of the light-emitting device can be increased. As a result, the power consumption of the display device can be reduced.

[0245] Furthermore, it is preferable to have regions where colored layers of different colors overlap each other. Regions where colored layers of different colors overlap each other can function as light-shielding layers. This further reduces external light reflection. Also, even if the light emitted by the color conversion layer 135R and the light emitted by the color conversion layer 135G mix between the colored layer 132R and the colored layer 132G, it is possible to prevent the mixed light from being emitted to the outside. Also, even if the light emitted by the color conversion layer 135G and the light emitted by the light-emitting device 130c mix between the colored layer 132G and the colored layer 132B, it is possible to prevent the mixed light from being emitted to the outside. Also, even if the light emitted by the color conversion layer 135R and the light emitted by the light-emitting device 130c mix between the colored layer 132R and the colored layer 132B, it is possible to prevent the mixed light from being emitted to the outside.

[0246] Figure 10A shows an example in which a light-shielding layer 117 is added to the substrate 120 compared to the configuration example shown in Figure 8A. Preferably, the light-shielding layer 117 is provided between adjacent light-emitting devices in a plan view. This configuration allows the light-shielding layer 117 to block the mixed light between adjacent color conversion layers, preventing the mixed light from emitting to the outside. Preferably, the light-shielding layer 117 contains a material that absorbs at least a portion of visible light. For example, the light-shielding layer 117 itself may be made of a material that absorbs visible light (e.g., a colored organic or inorganic material), or the light-shielding layer 117 may contain a pigment that absorbs visible light. As the light-shielding layer 117, for example, a resin containing carbon black as a pigment and functioning as a black matrix, or a resin that transmits red, blue, or green light and can be used as a color filter that absorbs other light, can be used.

[0247] Figure 10B shows an example in which the white light-emitting layer 113W is replaced with a blue light-emitting layer 113B in the configuration example shown in Figure 1B. By using the blue light-emitting layer 113B in each light-emitting device, the color conversion of light in the color conversion layer 135R and color conversion layer 135G can be performed more efficiently than when using the white light-emitting layer 113W.

[0248] Figure 10C shows an example of the configuration shown in Figure 10B, but without the colored layer 132B. As described above, since layer 113B emits blue light, even without the colored layer 132B, high-purity blue light can be extracted from the light-emitting device 130c. Furthermore, by not providing the colored layer 132B, there is no light loss that occurs when light passes through the colored layer 132B, so it is possible to extract higher-brightness blue light than when the colored layer 132B is present.

[0249] Figure 11A shows an example in which layer 137 is provided on the color conversion layer 135R and color conversion layer 135G in the configuration example shown in Figure 9D. Layer 137 is provided such that it has regions that overlap with the color conversion layer 135R and color conversion layer 135G. It is preferable that layer 137 be made of a material with a lower refractive index than the color conversion layer 135R and color conversion layer 135G. It is also preferable that layer 137 be made of a material with a lower refractive index than the resin layer 122. For example, layer 137 can be made of a resin with a lower refractive index than the resin layer 122. Alternatively, for example, layer 137 may be a layer of air. By providing layer 137, the light emitted by the color conversion layer 135R and color conversion layer 135G can be extracted more efficiently to the colored layer 132R and colored layer 132G, respectively, than when layer 137 is not provided.

[0250] Figure 11B shows an example in which layer 137 is provided on the side of colored layer 132R and colored layer 132G, unlike Figure 11A. This configuration can also achieve the same effects as Figure 11A.

[0251] Figure 12A shows a top view of a display device 100 different from that shown in Figure 1A. The pixel 110 shown in Figure 12A is composed of four types of subpixels: subpixel 11R, subpixel 11G, subpixel 11B, and subpixel 11S.

[0252] Of the four subpixels of pixel 110 shown in Figure 12A, three may be configured to have light-emitting devices, and the remaining one may be configured to have a light-receiving device (also called a light-receiving element).

[0253] For example, a pn-type or pin-type photodiode can be used as the light-receiving device. The light-receiving device functions as a photoelectric conversion device (also called a photoelectric conversion element) that detects light incident on it and generates an electric charge. The amount of charge generated from the light-receiving device is determined based on the amount of light incident on it.

[0254] The light-receiving device can detect either visible light or infrared light, or both. When detecting visible light, it can detect one or more colors such as blue, purple, blue-violet, green, yellow-green, yellow, orange, and red. When detecting infrared light, it is preferable because it enables the detection of objects even in dark places.

[0255] In particular, it is preferable to use an organic photodiode having a layer containing an organic compound as the light-receiving device. Organic photodiodes can be easily made thinner, lighter, and larger in area, and because they offer a high degree of freedom in shape and design, they can be applied to various display devices.

[0256] In one aspect of the present invention, an organic EL device is used as the light-emitting device, and an organic photodiode is used as the light-receiving device. The organic EL device and the organic photodiode can be formed on the same substrate. Therefore, an organic photodiode can be incorporated into a display device using an organic EL device.

[0257] A light-receiving device can detect light incident on it, generate an electric charge, and extract it as an electric current by driving it with a reverse bias applied between the pixel electrode and the common electrode.

[0258] The same manufacturing methods as for light-emitting devices can be applied to light-receiving devices. The island-shaped active layer (also called the photoelectric conversion layer) of the light-receiving device is not formed using a fine metal mask, but rather by processing after depositing a film that will become the active layer on one surface, thus enabling the formation of an island-shaped active layer with a uniform thickness. Furthermore, by providing a mask layer on the active layer, damage to the active layer during the manufacturing process of the display device can be reduced, thereby improving the reliability of the light-receiving device.

[0259] For details regarding the configuration and materials of the light-receiving device, refer to Embodiment 6.

[0260] Figure 12B shows a cross-sectional view between the dashed lines X3 and X4 in Figure 12A. Note that the cross-sectional view between the dashed lines X1 and X2 in Figure 12A can be found in Figure 1B, and the cross-sectional view between the dashed lines Y1 and Y2 can be found in Figure 9A or Figure 9B.

[0261] As shown in Figure 12B, the display device 100 has insulating layers (insulating layers 255a, 255b, and 255c) on layer 101, an emitting device 130a and a light-receiving device 150 on the insulating layers, a protective layer 131 covering the emitting device 130a and the light-receiving device 150, and a substrate 120 bonded to it by a resin layer 122. On the protective layer 131, a color conversion layer 135R and a coloring layer 132R are provided in positions overlapping with the emitting device 130a. In addition, an insulating layer 125 and an insulating layer 127 on the insulating layer 125 are provided in the region between adjacent emitting devices and light-receiving devices.

[0262] Figure 12B shows an example where the light-emitting device 130a emits light towards the substrate 120, and light is incident on the light-receiving device 150 from the substrate 120 side (see optical Lem and optical Lin).

[0263] The configuration of the sub-pixel 11R and the light-emitting device 130a of the sub-pixel 11R is as described above.

[0264] The light-receiving device 150 includes a pixel electrode 111S on an insulating layer 255c, a layer 155 on the pixel electrode 111S, a common layer 114 on layer 155, and a common electrode 115 on the common layer 114. Layer 155 includes at least an active layer.

[0265] The pixel electrode 111S can be formed from the same material and configuration as the pixel electrodes 111a, 111b, and 111c.

[0266] Here, layer 155 includes at least an active layer and preferably has multiple functional layers. For example, functional layers include carrier transport layers (hole transport layers and electron transport layers) and carrier block layers (hole block layers and electron block layers). It is also preferable to have one or more layers on the active layer. By having other layers between the active layer and the mask layer, it is possible to suppress the exposure of the active layer to the outermost surface during the manufacturing process of the display device and reduce damage to the active layer. This can improve the reliability of the light receiving device 150. Therefore, it is preferable that layer 155 has an active layer and a carrier block layer (hole block layer or electron block layer) or a carrier transport layer (electron transport layer or hole transport layer) on the active layer.

[0267] Layer 155 is provided on the light-receiving device 150 but not on the light-emitting device. However, functional layers other than the active layer included in layer 155 may have the same material as functional layers other than the light-emitting layer included in layer 113W or layer 113B. On the other hand, the common layer 114 is a continuous layer shared by the light-emitting device and the light-receiving device.

[0268] Here, layers common to both the light-receiving and light-emitting devices may have different functions in the light-emitting device and the light-receiving device. In this specification, components may be referred to based on their function in the light-emitting device. For example, a hole injection layer functions as a hole injection layer in the light-emitting device and as a hole transport layer in the light-receiving device. Similarly, an electron injection layer functions as an electron injection layer in the light-emitting device and as an electron transport layer in the light-receiving device. Furthermore, layers common to both the light-receiving and light-emitting devices may have the same function in the light-emitting device and the light-receiving device. A hole transport layer functions as a hole transport layer in both the light-emitting and light-receiving devices, and an electron transport layer functions as an electron transport layer in both the light-emitting and light-receiving devices.

[0269] A mask layer 118a is located between the layer 113W and the insulating layer 125, and a mask layer 118S is located between the layer 155 and the insulating layer 125. The mask layer 118a is a part of the mask layer provided in contact with the upper surface of the layer 113W when processing the layer 113W and remains. Also, the mask layer 118S is a part of the mask layer provided in contact with the upper surface of the layer 155 when processing the layer 155 which is a layer including an active layer and remains. The mask layer 118a and the mask layer 118S may have the same material or different materials.

[0270] In FIG. 12A, an example is shown in which the aperture ratio of the sub-pixel 11S (which can also be said to be the size of the size, light-emitting region or light-receiving region) is larger than those of the sub-pixels 11R, 11G, and 11B, but one aspect of the present invention is not limited to this. The aperture ratios of the sub-pixels 11R, 11G, 11B, and 11S can be appropriately determined respectively. The aperture ratios of the sub-pixels 11R, 11G, 11B, and 11S may be different from each other, or two or more of them may be equal or approximately equal.

[0271] The aperture ratio of the sub-pixel 11S may be higher than at least one of the sub-pixels 11R, 11G, and 11B. When the light-receiving area of the sub-pixel 11S is wide, it may be possible to more easily detect an object. For example, depending on the fineness of the display device, the circuit configuration of the sub-pixel, etc., the aperture ratio of the sub-pixel 11S may be higher than the aperture ratios of other sub-pixels.

[0272] Also, the aperture ratio of the sub-pixel 11S may be lower than at least one of the sub-pixels 11R, 11G, and 11B. When the light-receiving area of the sub-pixel 11S is narrow, the imaging range becomes narrow, and it becomes possible to suppress blurring of the imaging result and improve the resolution. Therefore, it is possible to perform high-definition or high-resolution imaging, which is preferable.

[0273] Thus, the sub-pixel 11S can have a detection wavelength, fineness, and aperture ratio suitable for the application.

[0274] In the display device according to one aspect of the present invention, since the EL layer is provided in an island shape for each light-emitting device, it is possible to suppress the generation of leakage current between sub-pixels. Thereby, crosstalk caused by unintended light emission can be prevented, and a display device with extremely high contrast can be realized. Further, for the island-shaped EL layer, the end portion and its vicinity that may be damaged during the manufacturing process of the display device are used as dummy regions and not used as light-emitting regions, thereby suppressing variations in the characteristics of the light-emitting devices. Further, by providing an insulating layer having a tapered shape at the end between adjacent island-shaped EL layers, it is possible to suppress the occurrence of steps during the formation of the common electrode, and to prevent the formation of a portion where the film thickness is locally thin in the common electrode. Thereby, in the common layer and the common electrode, it is possible to suppress the occurrence of connection failures due to the divided portions and the increase in electrical resistance due to the portions where the film thickness is locally thin. Thereby, the display device according to one aspect of the present invention can achieve both high definition and high display quality.

[0275] Further, in the display device according to one aspect of the present invention, light-emitting devices having the same light-emitting layer are used for three sub-pixels, and further, color conversion layers are used for two of the sub-pixels, thereby realizing sub-pixels that exhibit red and green light. Then, a coloring layer that transmits blue light is used for the sub-pixel that exhibits blue light. Thereby, it is possible to create three types of sub-pixels only by creating different types of one-color light-emitting devices. By using one type of light-emitting device to be created, it is possible to suppress the damage applied to the pixel electrode and the deterioration of the characteristics of the light-emitting device in each color sub-pixel compared to the case of creating three types of light-emitting devices. Further, since the number of processing times of the light-emitting layer using the photolithography method can be made one, it is possible to manufacture a display device with good yield.

[0276] This embodiment can be appropriately combined with other embodiments. Further, in this specification, when a plurality of configuration examples are shown in one embodiment, the configuration examples can be appropriately combined.

[0277] (Embodiment 2) In this embodiment, a method for manufacturing a display device according to one aspect of the present invention will be described with reference to Figures 13 to 18. Note that descriptions of the materials and formation methods of each element may be omitted if they are the same as those described in Embodiment 1. Furthermore, the details of the configuration of the light-emitting device will be described in Embodiment 5.

[0278] Figures 13 to 16, 17A, and 18 show side-by-side cross-sectional views of the section between dashed lines X1 and X2 shown in Figure 1A, and the cross-sectional view between dashed lines Y1 and Y2. Figures 17B to 17E show enlarged views of the end of the insulating layer 127 and its vicinity.

[0279] Thin films (insulating films, semiconductor films, conductive films, etc.) that constitute display devices can be formed using methods such as sputtering, chemical vapor deposition (CVD), vacuum deposition, pulsed laser deposition (PLD), and ALD. CVD methods include plasma-enhanced CVD (PECVD) and thermal CVD. One type of thermal CVD is metal-organic CVD (MOCVD).

[0280] Furthermore, thin films (insulating films, semiconductor films, conductive films, etc.) that constitute the display device can be formed by wet film deposition methods such as spin coating, dip coating, spray coating, inkjet printing, dispensing, screen printing, offset printing, doctor knife coating, slit coating, roll coating, curtain coating, or knife coating.

[0281] In particular, vacuum processes such as vapor deposition and solution processes such as spin coating and inkjet can be used to fabricate light-emitting devices. Examples of vapor deposition methods include physical vapor deposition (PVD) methods such as sputtering, ion plating, ion beam deposition, molecular beam deposition, and vacuum deposition, as well as chemical vapor deposition (CVD). 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.), and printing methods (inkjet, screen printing, offset printing, flexographic printing, gravure, or microcontact printing, etc.).

[0282] Furthermore, when processing the thin film that constitutes the display device, it can be processed using methods such as photolithography. Alternatively, the thin film may be processed by nanoimprint lithography, sandblasting, or lift-off methods. In addition, island-shaped thin films may be directly formed by a film deposition method using a shielding mask such as a metal mask.

[0283] There are two main methods of photolithography. One method involves forming a resist mask on the thin film to be processed, then processing the thin film by etching or other means, and finally removing the resist mask. The other method involves depositing a photosensitive thin film, then exposing and developing it to process the thin film into the desired shape.

[0284] 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 thereof. Other light sources such as ultraviolet light, KrF laser light, or ArF laser light can also be used. Exposure may also be performed using immersion lithography. Furthermore, extreme ultraviolet (EUV) light or X-rays may be used as the light source for exposure. An electron beam can also be used instead of the light source for exposure. Using extreme ultraviolet light, X-rays, or an electron beam is preferable because it allows for extremely fine processing. Note that a photomask is not required when exposure is performed by scanning a beam such as an electron beam.

[0285] For etching thin films, methods such as dry etching, wet etching, and sandblasting can be used.

[0286] First, insulating layers 255a, 255b, and 255c are formed on layer 101 in that order. Subsequently, pixel electrodes 111a, 111b, 111c, and a conductive layer 123 are formed on the insulating layer 255c (Figure 13A). For example, sputtering or vacuum deposition can be used to form the conductive film that will become the pixel electrode.

[0287] Next, it is preferable to perform a hydrophobic treatment on the pixel electrodes. Hydrophobic treatment can change the surface of the object to be treated from hydrophilic to hydrophobic, or increase the hydrophobicity of the surface of the object to be treated. By performing a hydrophobic treatment on the pixel electrodes, the adhesion between the pixel electrodes and the film (in this case, film 113w) formed in a later step can be improved, and film peeling can be suppressed. However, the hydrophobic treatment is not required.

[0288] Hydrophobic treatment can be performed, for example, by fluorine modification of the pixel electrodes. Fluorine modification can be performed, for example, by treatment with a fluorine-containing gas or heat treatment, or by plasma treatment in a fluorine-containing gas atmosphere. As the fluorine-containing gas, for example, fluorine gas can be used, for example, fluorocarbon gas can be used. As the fluorocarbon gas, for example, lower fluorinated carbon gases such as carbon tetrafluoride (CF4) gas, C4F6 gas, C2F6 gas, C4F8 gas, and C5F8 gas can be used. In addition, as the fluorine-containing gas, for example, SF6 gas, NF3 gas, CHF3 gas, etc. can be used. Furthermore, helium gas, argon gas, or hydrogen gas can be added to these gases as appropriate.

[0289] Furthermore, the surface of the pixel electrode can be made hydrophobic by performing plasma treatment in a gas atmosphere containing a group 18 element such as argon, followed by treatment with a silylation agent. Hexamethyldisilazane (HMDS), trimethylsilylimidazole (TMSI), etc., can be used as silylation agents. In addition, the surface of the pixel electrode can also be made hydrophobic by performing plasma treatment in a gas atmosphere containing a group 18 element such as argon, followed by treatment with a silane coupling agent.

[0290] By performing plasma treatment on the surface of the pixel electrode in a gas atmosphere containing a group 18 element such as argon, damage can be inflicted on the surface of the pixel electrode. This makes it easier for methyl groups contained in silylation agents such as HMDS to bond to the surface of the pixel electrode. Furthermore, silane coupling by silane coupling agents becomes more likely to occur. Thus, by performing plasma treatment on the surface of the pixel electrode in a gas atmosphere containing a group 18 element such as argon, followed by treatment with a silylation agent or a silane coupling agent, the surface of the pixel electrode can be made hydrophobic.

[0291] Treatment using silylation agents or silane coupling agents can be carried out by applying the silylation agent or silane coupling agent using, for example, a spin coating method or a dip method. Alternatively, treatment using silylation agents or silane coupling agents can be carried out by forming a film containing a silylation agent or a silane coupling agent on the pixel electrode, for example, using a gas phase method. In the gas phase method, first, a material containing a silylation agent or a material containing a silane coupling agent is volatilized to introduce the silylation agent or silane coupling agent into the atmosphere. Subsequently, a substrate on which the pixel electrode is formed is placed in this atmosphere. This allows a film containing a silylation agent or silane coupling agent to be formed on the pixel electrode, thereby hydrophobicizing the surface of the pixel electrode.

[0292] Next, a film 113w, which will later become layer 113W, is formed on the pixel electrode (Figure 13A). The film 113w (later layer 113W) contains at least two types of light-emitting materials.

[0293] As shown in Figure 13A, in the cross-sectional view between the dashed-dotted line Y1-Y2, no film 113w is formed on the conductive layer 123. For example, by using an area mask, the film 113w can be deposited only in the desired region. By employing a film deposition process using an area mask and a processing process using a resist mask, a light-emitting device can be manufactured using a relatively simple process.

[0294] As described in Embodiment 1, in one embodiment of the present invention, a highly heat-resistant material is used for the light-emitting device in the display device. Specifically, the heat resistance temperature of the compounds contained in the film 113w is preferably 100°C to 180°C, preferably 120°C to 180°C, and more preferably 140°C to 180°C. This improves the reliability of the light-emitting device. It also allows for an increase in the upper limit of the temperature that can be applied during the manufacturing process of the display device. Therefore, the range of materials and formation methods used in the display device can be broadened, leading to improved manufacturing yield and reliability.

[0295] The film 113w can be formed, for example, by a vapor deposition method, specifically a vacuum vapor deposition method. Further, the film 113w may be formed by a method such as a transfer method, a printing method, an inkjet method, or a coating method.

[0296] Subsequently, a mask film 118b that will later become the mask layer 118a and a mask film 119b that will later become the mask layer 119a are sequentially formed on the film 113w and on the conductive layer 123 (FIG. 13A).

[0297] In this embodiment, an example of forming a mask film with a two-layer structure of the mask film 118b and the mask film 119b is shown, but the mask film may have a single-layer structure or a laminated structure of three or more layers.

[0298] By providing a mask film on the film 113w, damage to the film 113w during the manufacturing process of the display device can be reduced, and the reliability of the light-emitting device can be enhanced.

[0299] For the mask film 118b, a film with high resistance to the processing conditions of the film 113w, specifically, a film with a large etching selectivity ratio with respect to the film 113w is used. For the mask film 119b, a film with a large etching selectivity ratio with respect to the mask film 118b is used.

[0300] Further, the mask film 118b and the mask film 119b are formed at a temperature lower than the heat resistance temperature of the film 113w. As the substrate temperature when forming the mask film 118b and the mask film 119b, typically, it is 200 °C or lower, preferably 150 °C or lower, more preferably 120 °C or lower, more preferably 100 °C or lower, and even more preferably 80 °C or lower.

[0301] Examples of the index of the heat resistance temperature include, for example, the glass transition point, the softening point, the melting point, the thermal decomposition temperature, the 5% weight loss temperature, etc. As the heat resistance temperature of the film 113w (that is, the layer 113W), it can be any of these temperatures that serve as the index of the heat resistance temperature, preferably the lowest of these temperatures.

[0302] As described above, in one embodiment of the present invention, a highly heat-resistant material is used for the light-emitting device. Therefore, the substrate temperature when forming the mask film can be set to 100°C or higher, 120°C or higher, or 140°C or higher. For example, the higher the deposition temperature of the inorganic insulating film, the denser and more barrier-oriented the film can be. Therefore, by forming the mask film at such a temperature, the damage to the film 113w can be further reduced, and the reliability of the light-emitting device can be improved.

[0303] It is preferable to use mask films 118b and 119b that can be removed by a wet etching method. By using a wet etching method, the damage to film 113w during processing of mask films 118b and 119b can be reduced compared to when a dry etching method is used.

[0304] For the formation of mask films 118b and 119b, for example, sputtering, ALD (thermal ALD, PEALD), CVD, and vacuum deposition can be used. Alternatively, they may be formed using the wet film formation method described above.

[0305] Furthermore, it is preferable that the mask film 118b, which is formed in contact with the film 113w, is formed using a method that causes less damage to the film 113w than the mask film 119b. For example, it is preferable to form the mask film 118b using the ALD method or vacuum deposition method rather than the sputtering method.

[0306] For mask films 118b and 119b, one or more types can be used, for example, from among metal films, alloy films, metal oxide films, semiconductor films, organic insulating films, inorganic insulating films, etc.

[0307] Mask films 118b and 119b can be made from metallic materials such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, titanium, aluminum, yttrium, zirconium, or tantalum, or from alloy materials containing such metallic materials. In particular, it is preferable to use low-melting-point materials such as aluminum or silver. It is preferable to use a metallic material capable of shielding ultraviolet rays in one or both of the mask films 118b and 119b, as this can suppress the irradiation of the film 113w with ultraviolet rays and thus suppress the degradation of the film 113w.

[0308] Furthermore, using a metal film or alloy film for one or both of the mask films 118b and 119b is preferable because it can suppress plasma damage to the film 113w and thus suppress degradation of the film 113w. Specifically, it is possible to suppress plasma damage to the film 113w in processes such as dry etching and ashing. In particular, it is preferable to use a metal film such as a tungsten film or an alloy film as the mask film 119b.

[0309] Furthermore, the mask films 118b and 119b can be made from metal oxides such as In-Ga-Zn oxide, indium oxide, In-Zn oxide, In-Sn oxide, indium titanium oxide (In-Ti oxide), indium tin zinc oxide (In-Sn-Zn oxide), indium titanium zinc oxide (In-Ti-Zn oxide), indium gallium tin zinc oxide (In-Ga-Sn-Zn oxide), and silicon-containing indium tin oxide, respectively.

[0310] In addition, one or more elements selected from aluminum, silicon, boron, yttrium, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, or magnesium may be used instead of gallium. In particular, it is preferable to use one or more elements selected from gallium, aluminum, or yttrium.

[0311] Furthermore, a film containing a material that has light-shielding properties against light, particularly ultraviolet light, can be used as the mask film. For example, a film that reflects ultraviolet light or a film that absorbs ultraviolet light can be used. Various materials can be used as the light-shielding material, such as metals, insulators, semiconductors, and metalloids that have light-shielding properties against ultraviolet light. However, since part or all of the mask film will be removed in a later process, it is preferable that the film be processable by etching, and in particular, that it has good processability.

[0312] For example, semiconductor materials such as silicon or germanium can be used as materials with high affinity to semiconductor manufacturing processes. Alternatively, oxides or nitrides of the above semiconductor materials can be used. Alternatively, nonmetallic materials such as carbon, or compounds thereof, can be used. Alternatively, metals such as titanium, tantalum, tungsten, chromium, and aluminum, or alloys containing one or more of these, can be used. Alternatively, oxides containing the above metals such as titanium oxide or chromium oxide, or nitrides such as titanium nitride, chromium nitride, or tantalum nitride can be used.

[0313] By using a mask film containing a material that has light-shielding properties against ultraviolet light, it is possible to suppress the irradiation of the EL layer with ultraviolet light during the exposure process. By suppressing damage to the EL layer from ultraviolet light, the reliability of the light-emitting device can be improved.

[0314] Furthermore, a film containing a material that has light-shielding properties against ultraviolet rays can be used as the material for the insulating film 125A, as described later, to achieve the same effect.

[0315] Furthermore, various inorganic insulating films that can be used in the protective layer 131 can be used as mask films 118b and 119b, respectively. In particular, oxide insulating films are preferred because they have higher adhesion to film 113w compared to nitride insulating films. For example, inorganic insulating materials such as aluminum oxide, hafnium oxide, and silicon oxide can be used as mask films 118b and 119b, respectively. For example, aluminum oxide films can be formed as mask films 118b and 119b using the ALD method. Using the ALD method is preferred because it reduces damage to the substrate (especially the EL layer).

[0316] For example, an inorganic insulating film (e.g., an aluminum oxide film) formed using the ALD method can be used as the mask film 118b, and an inorganic film (e.g., an In-Ga-Zn oxide film, a silicon film, or a tungsten film) formed using the sputtering method can be used as the mask film 119b.

[0317] Furthermore, the same inorganic insulating film can be used for both the mask film 118b and the insulating layer 125 that is formed later. For example, an aluminum oxide film formed using the ALD method can be used for both the mask film 118b and the insulating layer 125. Here, the same film formation conditions may be applied to the mask film 118b and the insulating layer 125, or different film formation conditions may be applied to each. For example, by forming the mask film 118b under the same conditions as the insulating layer 125, the mask film 118b can be made into an insulating film with high barrier properties against at least one of water and oxygen. On the other hand, since the mask film 118b is a layer that will be mostly or completely removed in a later process, it is preferable that it be easy to process. Therefore, it is preferable to form the mask film 118b under conditions where the substrate temperature during film formation is lower than that of the insulating layer 125.

[0318] Organic materials may be used in one or both of the mask films 118b and 119b. For example, as the organic material, a material that is soluble in a chemically stable solvent may be used, at least for the film located at the top of film 113w. Materials that are soluble in water or alcohol are particularly suitable. When forming such a film, it is preferable to dissolve the material in a solvent such as water or alcohol, apply it using a wet film formation method, and then perform a heat treatment to evaporate the solvent. At this time, performing the heat treatment under a reduced pressure atmosphere is preferable because it allows the solvent to be removed at a low temperature and in a short time, thereby reducing thermal damage to film 113w.

[0319] Mask films 118b and 119b may each be made of organic resins such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinylpyrrolidone, polyethylene glycol, polyglycerin, pullulan, water-soluble cellulose, alcohol-soluble polyamide resin, or fluoropolymers.

[0320] For example, an organic film (e.g., a PVA film) formed using either a vapor deposition method or the wet film formation method described above can be used as the mask film 118b, and an inorganic film (e.g., a silicon nitride film) formed using a sputtering method can be used as the mask film 119b.

[0321] As described in Embodiment 1, in one embodiment of the present invention, a portion of the mask film may remain as a mask layer in the display device.

[0322] Next, a resist mask 190 is formed on the mask film 119b (Figure 13A). The resist mask 190 can be formed by applying a photosensitive resin (photoresist), followed by exposure and development.

[0323] The resist mask 190 may be made using either a positive-type resist material or a negative-type resist material.

[0324] The resist mask 190 is provided in positions that overlap with the pixel electrodes 111a, 111b, and 111c, respectively. It is preferable that there is a region between adjacent pixel electrodes that does not overlap with the resist mask 190. It is also preferable that the resist mask 190 is provided in a position that overlaps with the conductive layer 123. This helps to suppress damage to the conductive layer 123 during the manufacturing process of the display device. It is not necessary to provide the resist mask 190 on the conductive layer 123.

[0325] Furthermore, it is preferable that the resist mask 190 be provided so as to cover from the edge of the film 113w to the edge of the conductive layer 123 (the edge on the film 113w side), as shown in the cross-sectional view between Y1 and Y2 in Figure 13A. This ensures that even after processing the mask films 118b and 119b, the edges of the mask layers 118a and 119a overlap with the edges of the film 113w. Also, since the mask layers 118a and 119a are provided so as to cover from the edge of the film 113w to the edge of the conductive layer 123 (the edge on the film 113w side), exposure of the insulating layer 255c can be suppressed even after processing the film 113w (see the cross-sectional view between Y1 and Y2 in Figure 14B). This prevents the insulating layers 255a to 255c and a portion of the insulating layer contained in layer 101 from being lost due to etching or the like, and prevents the conductive layer contained in layer 101 from being exposed. Therefore, it is possible to suppress the unintentional electrical connection of the conductive layer with other conductive layers. For example, it is possible to suppress a short circuit between the conductive layer and the common electrode 115.

[0326] Next, a resist mask 190 is used to remove a portion of the mask film 119b and form a mask layer 119a (Figure 13B). The mask layer 119a remains on the pixel electrodes 111a, 111b, and 111c, and on the conductive layer 123. After that, the resist mask 190 is removed (Figure 13C). Subsequently, the mask layer 119a is used as a mask (also called a hard mask) to remove a portion of the mask film 118b and form a mask layer 118a (Figure 14A).

[0327] Mask films 118b and 119b can be processed by either a wet etching method or a dry etching method, respectively. It is preferable to use a wet etching method for processing mask films 118b and 119b.

[0328] By using the wet etching method, the damage to the film 113w during processing of the mask films 118b and 119b can be reduced compared to using the dry etching method. When using the wet etching method, it is preferable to use, for example, a developer, an aqueous solution of tetramethylammonium hydroxide (TMAH), dilute hydrofluoric acid, oxalic acid, phosphoric acid, acetic acid, nitric acid, or a mixed solution containing two or more of these.

[0329] In the processing of the mask film 119b, the film 113w is not exposed, so there is a wider range of processing methods to choose from compared to the processing of the mask film 118b. Specifically, even when using an etching gas containing oxygen during the processing of the mask film 119b, the degradation of the film 113w can be suppressed.

[0330] Furthermore, when using a dry etching method for processing the mask film 118b, the degradation of the film 113w can be suppressed by not using an oxygen-containing gas as the etching gas. When using a dry etching method, it is preferable to use a gas containing noble gases (also called rare gases) such as CF4, C4F8, SF6, CHF3, Cl2, H2O, BCl3, or He as the etching gas.

[0331] For example, when using an aluminum oxide film formed by the ALD method as the mask film 118b, the mask film 118b can be processed by dry etching using CHF3 and He, or CHF3, He, and CH4. Also, when using an In-Ga-Zn oxide film formed by the sputtering method as the mask film 119b, the mask film 119b can be processed by wet etching using diluted phosphoric acid. Alternatively, it may be processed by dry etching using CH4 and Ar. Furthermore, when using a tungsten film formed by the sputtering method as the mask film 119b, the mask film 119b can be processed by dry etching using SF6, CF4, and O2, or CF4, Cl2, and O2.

[0332] The resist mask 190 can be removed, for example, by ashing using oxygen plasma. Alternatively, oxygen gas and noble gases (also called rare gases) such as CF4, C4F8, SF6, CHF3, Cl2, H2O, BCl3, or He may be used. Alternatively, the resist mask 190 may be removed by wet etching. In this case, since the mask film 118b is located on the outermost surface and the film 113w is not exposed, damage to the film 113w during the resist mask 190 removal process can be suppressed. Furthermore, the range of selectable methods for removing the resist mask 190 can be broadened.

[0333] Next, the film 113w is processed to form layer 113W. For example, mask layer 119a and mask layer 118a are used as a hard mask to remove a portion of film 113w and form layer 113W (Figure 14B).

[0334] As a result, as shown in Figure 14B, the stacked structures of layer 113W, mask layer 118a, and mask layer 119a remain on the pixel electrode 111a, pixel electrode 111b, and pixel electrode 111c, respectively.

[0335] Furthermore, it is preferable that the side surfaces of layer 113W are perpendicular or approximately perpendicular to the surface to be formed. For example, it is preferable that the angle between the surface to be formed and these side surfaces be 60° or more and 90° or less.

[0336] Here, when processing the film 113w, the surfaces of the pixel electrodes 111a, 111b, and 111c are not exposed to etching gas or etching solution. Therefore, the surface of each pixel electrode is not damaged by the etching process, and the condition of the interface between each pixel electrode and the EL layer can be maintained in good condition.

[0337] The film 113w is preferably processed by anisotropic etching. In particular, an anisotropic dry etching method is preferred. Alternatively, a wet etching method may be used.

[0338] Figure 14B shows an example of processing film 113w by dry etching. Inside the dry etching apparatus, the etching gas is converted into plasma. Therefore, the surface of the display device being fabricated is exposed to plasma (plasma 121). Here, it is preferable to use a metal film or alloy film for one or both of the mask layers 118a and 119a, as this suppresses plasma damage to the remaining portion of film 113w (the portion that becomes layer 113W) and thus suppresses the degradation of layer 113W. In particular, it is preferable to use a metal film such as a tungsten film or an alloy film as the mask layer 119a.

[0339] When using the dry etching method, the degradation of the film 113w can be suppressed by not using an oxygen-containing gas as the etching gas.

[0340] Furthermore, an etching gas containing oxygen may be used. By including oxygen in the etching gas, the etching rate can be increased. Therefore, etching can be performed under low power conditions while maintaining a sufficiently fast etching rate. As a result, damage to the film 113w can be suppressed. In addition, problems such as the adhesion of reaction products generated during etching can be suppressed.

[0341] When using the dry etching method, it is preferable to use an etching gas containing one or more noble gases (also called rare gases) such as H2, CF4, C4F8, SF6, CHF3, Cl2, H2O, BCl3, or He, Ar. Alternatively, it is preferable to use an etching gas containing one or more of these and oxygen. Or, oxygen gas may be used as the etching gas. Specifically, for example, a gas containing H2 and Ar, or a gas containing CF4 and He, can be used as the etching gas. Also, for example, a gas containing CF4, He, and oxygen can be used as the etching gas. Also, for example, a gas containing H2 and Ar, and a gas containing oxygen can be used as the etching gas.

[0342] As a dry etching apparatus, a dry etching apparatus having a high-density plasma source can be used. A dry etching apparatus having a high-density plasma source can be, for example, an inductively coupled plasma (ICP) etching apparatus. Alternatively, a capacitively coupled plasma (CCP) etching apparatus having parallel plate electrodes can be used. A capacitively coupled plasma etching apparatus having parallel plate electrodes may be configured to apply a high-frequency voltage to one electrode of the parallel plate electrodes. Alternatively, it may be configured to apply multiple different high-frequency voltages to one electrode of the parallel plate electrodes. Alternatively, it may be configured to apply a high-frequency voltage of the same frequency to each of the parallel plate electrodes. Alternatively, it may be configured to apply high-frequency voltages of different frequencies to each of the parallel plate electrodes.

[0343] Figure 14B shows an example where the edges of layer 113W are located outside the edges of pixel electrodes 111a, 111b, and 111c, respectively. This configuration allows for a higher aperture ratio of the pixels. Although not shown in Figure 14B, the etching process may result in the formation of recesses in areas of the insulating layer 255c that do not overlap with layer 113W.

[0344] Furthermore, since layer 113W covers the top and side surfaces of pixel electrodes 111a, 111b, and 111c, respectively, subsequent processes can be carried out without exposing the pixel electrodes. If the ends of the pixel electrodes are exposed, corrosion may occur during etching processes. Products generated by the corrosion of the pixel electrodes may be unstable; for example, in the case of wet etching, they may dissolve in the solution, and in the case of dry etching, there is a concern that they may scatter into the atmosphere. Dissolution of the products into the solution or scattering into the atmosphere may cause the products to adhere to the processed surface and the side surfaces of layer 113W, adversely affecting the characteristics of the light-emitting device or potentially forming leak paths between multiple light-emitting devices. In addition, in areas where the ends of the pixel electrodes are exposed, the adhesion between layers in contact with each other decreases, which may make layer 113W or the pixel electrodes more prone to peeling.

[0345] Therefore, by configuring layer 113W to cover the top and side surfaces of pixel electrodes 111a, 111b, and 111c, respectively, it is possible to improve, for example, the manufacturing yield and characteristics of the light-emitting device.

[0346] Furthermore, as described in Embodiment 1, since layer 113W covers the top and side surfaces of pixel electrodes 111a, 111b, and 111c respectively, a dummy region is provided in layer 113W outside the light-emitting region (the region located between pixel electrodes 111a, 111b, and 111c and the common electrode 115). Here, the edges of layer 113W may be damaged during the processing of the film 113w. Since the edges of layer 113W and their vicinity become dummy regions and are not used for light emission, even if they are damaged, it is unlikely to adversely affect the characteristics of the light-emitting device. On the other hand, since the light-emitting region of layer 113W is covered by the mask layer, it is not exposed to plasma, and damage from plasma is sufficiently suppressed. The mask layer is not limited to the upper surface of the flat portion of layer 113W that overlaps with the upper surfaces of the pixel electrodes 111a, 111b, and 111c, but is preferably provided to cover the upper surfaces of the inclined portion and the flat portion located outside the upper surfaces of the pixel electrodes 111a, 111b, and 111c. In this way, since the portion of layer 113W in which damage during the manufacturing process is suppressed is used as the light-emitting region, a light-emitting device with high luminous efficiency and a long lifespan can be realized.

[0347] Furthermore, in the region corresponding to the connection portion 140, the laminated structure of the mask layer 118a and the mask layer 119a remains on the conductive layer 123.

[0348] As mentioned above, in the cross-sectional view between Y1 and Y2 in Figure 14B, mask layers 118a and 119a are provided so as to cover the ends of layer 113W and the ends of conductive layer 123, and the upper surface of insulating layer 255c is not exposed. Therefore, it is possible to prevent insulating layers 255a to 255c and a portion of the insulating layer contained in layer 101 from being removed by etching or the like, and to prevent the conductive layer contained in layer 101 from being exposed. As a result, it is possible to suppress the conductive layer from being unintentionally electrically connected to other conductive layers.

[0349] As described above, in one aspect of the present invention, a resist mask 190 is formed on the mask film 119b, and a mask layer 119a is formed by removing a portion of the mask film 119b using the resist mask 190. Subsequently, a layer 113W is formed by removing a portion of the film 113w using the mask layer 119a as a hard mask. Thus, it can be said that a layer 113W is formed by processing the film 113w using a photolithography method. Note that a portion of the film 113w may be removed using the resist mask 190. After that, the resist mask 190 may be removed.

[0350] As described above, the distance between two adjacent layers 113W formed using photolithography can be reduced to 8 μm or less, 5 μm or less, 3 μm or less, 2 μm or less, or 1 μm or less. Here, this distance can be defined, for example, as the distance between opposing ends of adjacent layers 113W. By reducing the distance between island-shaped EL layers in this way, a display device with high resolution and a large aperture ratio can be provided.

[0351] Next, it is preferable to remove the mask layer 119a. Depending on subsequent processes, the mask layer 119a may remain on the display device. By removing the mask layer 119a at this stage, it is possible to suppress the remaining mask layer 119a on the display device. For example, if a conductive material is used for the mask layer 119a, removing the mask layer 119a in advance can suppress the generation of leakage current and the formation of capacitance due to the remaining mask layer 119a.

[0352] In this embodiment, the case where the mask layer 119a is removed is described as an example, but the mask layer 119a does not necessarily have to be removed. For example, if the mask layer 119a contains the aforementioned material that has light-shielding properties against ultraviolet rays, it is preferable to proceed to the next step without removing it, as this protects the island-shaped EL layer from ultraviolet rays.

[0353] The removal process for the mask layer 119a can be performed using the same method as the processing process for the mask layer 119a. In particular, by using a wet etching method, the damage to layer 113W during the removal of the mask layer 119a can be reduced compared to when using a dry etching method.

[0354] When a metal film or alloy film is used for the mask layer 119a, the presence of the mask layer 119a can suppress plasma damage to the EL layer. Therefore, the film can be processed using a dry etching method in the process up to the removal of the mask layer 119a. On the other hand, in the process of removing the mask layer 119a and in the processes after its removal, the film that suppresses plasma damage to the EL layer is gone, so it is preferable to process the film using a method that does not use plasma, such as a wet etching method.

[0355] Alternatively, the mask layer 119a may be removed by dissolving it in a solvent such as water or alcohol. Examples of alcohols include ethyl alcohol, methyl alcohol, isopropyl alcohol (IPA), or glycerin.

[0356] After removing the mask layer 119a, a drying treatment may be performed to remove water contained in layer 113W and water adsorbed on the surface of layer 113W. For example, a heat treatment can be performed in an inert gas atmosphere such as a nitrogen 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 it allows drying at a lower temperature.

[0357] Next, an insulating film 125A, which will later become the insulating layer 125, is formed to cover the pixel electrode 111a, pixel electrode 111b, pixel electrode 111c, layer 113W, and mask layer 118a (Figure 15A).

[0358] As described later, the insulating film 127a is formed in contact with the upper surface of the insulating film 125A. For this reason, it is preferable that the upper surface of the insulating film 125A has high adhesion to the resin composition used for the insulating film 127a (for example, a photosensitive resin composition containing acrylic resin). To improve this adhesion, it is preferable to hydrophobize (or increase the hydrophobicity of) the upper surface of the insulating film 125A by performing a surface treatment. For example, it is preferable to perform the treatment using a silylation 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. The aforementioned hydrophobic treatment may also be performed as the surface treatment.

[0359] Next, an insulating film 127a is formed on the insulating film 125A (Figure 15B).

[0360] It is preferable that the insulating film 125A and insulating film 127a are formed using a method that causes minimal damage to layer 113W. In particular, since insulating film 125A is formed in contact with the side surface of layer 113W, it is preferable that it be formed using a method that causes less damage to layer 113W than insulating film 127a.

[0361] Furthermore, insulating film 125A and insulating film 127a are formed at a temperature lower than the heat resistance temperature of layer 113W. In addition, by increasing the substrate temperature during film formation of insulating film 125A, it is possible to create a film with a low impurity concentration and high barrier properties against at least one of water and oxygen, even with a thin film thickness.

[0362] The substrate temperature when forming insulating film 125A and 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.

[0363] As described above, in one embodiment of the present invention, a heat-resistant material is used for the light-emitting device. Therefore, the substrate temperature when forming the insulating film 125A and 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 the inorganic insulating film, the denser and more barrier-oriented the film can be. Therefore, by depositing the insulating film 125A at such a temperature, the damage to the layer 113W can be further reduced, and the reliability of the light-emitting device can be improved.

[0364] As the insulating film 125A, it is preferable to form an insulating film with a thickness of 3 nm or more, 5 nm or more, or 10 nm or more, and a thickness of 200 nm or less, 150 nm or less, 100 nm or less, or 50 nm or less, within the above substrate temperature range.

[0365] The insulating film 125A is preferably formed using, for example, the ALD method. The ALD method is preferable because it can reduce film formation damage and allow for the formation of a highly covering film. For example, it is preferable to form an aluminum oxide film as the insulating film 125A using the ALD method.

[0366] In addition, the insulating film 125A may be formed using a sputtering method, CVD method, or PECVD method, which have a faster deposition rate than the ALD method. This allows for the production of highly reliable display devices with high productivity.

[0367] The insulating film 127a is preferably formed using the wet film formation method described above. The insulating film 127a is preferably formed using a photosensitive resin, for example, by spin coating, and more specifically, it is preferably formed using a photosensitive resin composition containing an acrylic resin.

[0368] Furthermore, it is preferable to perform a heat treatment (also called pre-baking) after the formation of the insulating film 127a. This heat treatment is performed at a temperature lower than the heat resistance temperature of layer 113W. The substrate temperature during the heat treatment is preferably 50°C to 200°C, more preferably 60°C to 150°C, and even more preferably 70°C to 120°C. This makes it possible to remove the solvent contained in the insulating film 127a.

[0369] Next, visible light or ultraviolet light is irradiated onto a portion of the insulating film 127a to expose that portion (Figure 16A). Here, if a positive-type photosensitive resin composition containing acrylic resin is used for the insulating film 127a, visible light or ultraviolet light is irradiated onto the area where the insulating layer 127 will not be formed in a later step using a mask 136. The insulating layer 127 is formed in the area sandwiched between any two of the pixel electrodes 111a, 111b, and 111c, and around the conductive layer 123. Therefore, as shown in Figure 16A, light 139 is irradiated onto the portion of the insulating film 127a that overlaps with the pixel electrode 111a, the portion that overlaps with the pixel electrode 111b, the portion that overlaps with the pixel electrode 111c, and the portion that overlaps with the conductive layer 123.

[0370] Furthermore, the width of the insulating layer 127 to be formed later can be controlled by the area exposed to light at this stage. In this embodiment, the insulating layer 127 is processed so that it has a portion that overlaps with the upper surface of the pixel electrode (Figure 2A). As shown in Figure 5A or Figure 5B, the insulating layer 127 does not have to have a portion that overlaps with the upper surface of the pixel electrode.

[0371] The light used for exposure preferably includes the i-line (wavelength 365 nm). Furthermore, the light used for exposure may also include at least one of the g-line (wavelength 436 nm) and the h-line (wavelength 405 nm).

[0372] In Figure 16A, an example is shown in which a positive-type photosensitive resin is used for the insulating film 127a and visible light or ultraviolet light is irradiated into the area where the insulating layer 127 is not formed. However, the present invention is not limited to this. For example, a negative-type photosensitive resin may be used for the insulating film 127a. In this case, visible light or ultraviolet light is irradiated into the area where the insulating layer 127 is formed.

[0373] Next, as shown in Figure 16B, development is performed to remove the exposed area of ​​the insulating film 127a and form the insulating layer 127b. The insulating layer 127b is formed in the region sandwiched between any two of the pixel electrodes 111a, 111b, and 111c, and in the region surrounding the conductive layer 123. Here, when acrylic resin is used for the insulating film 127a, it is preferable to use an alkaline solution as the developer, for example, an aqueous solution of tetramethylammonium hydroxide (TMAH) can be used.

[0374] Furthermore, after development, a process to remove development residue (so-called scum) may be performed. For example, residue can be removed by ashing using oxygen plasma. After each of the development processes described below, a process to remove residue may also be performed.

[0375] Furthermore, etching may be performed to adjust the surface height of the insulating layer 127b. The insulating layer 127b may also be processed, for example, by ashing using oxygen plasma.

[0376] Alternatively, after development and before post-baking, the entire substrate may be exposed to visible or ultraviolet light to irradiate the insulating layer 127b. The energy density of this exposure is 0 mJ / cm². 2 Even larger, 800 mJ / cm 2 The following is preferable: 0 mJ / cm 2 Larger, 500 mJ / cm 2The following is more preferable: Performing such exposure after development may improve the transparency of the insulating layer 127b. In addition, it may be possible to deform the insulating layer 127b into a tapered shape at a low temperature.

[0377] On the other hand, by not exposing the insulating layer 127b, 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 process. Therefore, it may be preferable not to expose the insulating layer 127b after development.

[0378] Next, a heat treatment (also called post-bake) is performed. As shown in Figure 17A, by performing the heat treatment, the insulating layer 127b can be deformed into an insulating layer 127 having a tapered shape on its side surface. This heat treatment is performed at a temperature lower than the heat resistance temperature of the EL layer. 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 atmospheric atmosphere or an inert gas atmosphere. The heating atmosphere may also be an atmospheric pressure atmosphere or a reduced pressure atmosphere. A reduced pressure atmosphere is preferable because it allows drying at a lower temperature. It is preferable to use a higher substrate temperature for the heat treatment in this step than for the heat treatment after the formation of the insulating film 127a (pre-bake). This improves the adhesion between the insulating layer 127 and the insulating layer 125, and also improves the corrosion resistance of the insulating layer 127.

[0379] Furthermore, depending on the material of the insulating layer 127, as well as the post-bake temperature, time, and atmosphere, a concave curved shape may be formed on the side surface of the insulating layer 127, as shown in Figures 4A and 4B. For example, the higher the temperature or the longer the post-bake conditions, the more likely the shape of the insulating layer 127 is to change, and a concave curved shape may be formed. Also, as mentioned above, if the insulating layer 127b is not exposed after development, the shape of the insulating layer 127 may change during post-bake.

[0380] Next, as shown in Figure 17A, etching is performed using the insulating layer 127 as a mask to remove the insulating film 125A and a portion of the mask layer 118a. This creates an opening in the mask layer 118a, exposing the upper surface of layer 113W and the conductive layer 123.

[0381] The etching process can be carried out by dry etching or wet etching. It is preferable that the insulating film 125A is deposited using the same material as the mask layer 118a, as this allows the etching process to be performed in a single step.

[0382] When using the dry etching method, it is preferable to use a chlorine-based gas. As chlorine-based gases, Cl2, BCl3, SiCl4, CCl4, etc., can be used individually or in mixtures of two or more gases. In addition, oxygen gas, hydrogen gas, helium gas, argon gas, etc., can be added individually or in mixtures of two or more gases as appropriate to the above chlorine-based gas. By using the dry etching method, regions with a thin film thickness in the mask layer 118a can be formed with good in-plane uniformity.

[0383] Furthermore, when using the dry etching method, by-products generated during dry etching may accumulate on the upper and side surfaces of the insulating layer 127. Therefore, components contained in the etching gas, components in the insulating film 125A, and components in the mask layer 118a may be present in the insulating layer 127 after the display device is completed.

[0384] Furthermore, it is preferable to perform the etching process using a wet etching method. By using a wet etching method, the damage applied to layer 113W can be reduced compared to when a dry etching method is used. For example, a 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, wet etching can be performed using a paddle method.

[0385] As described above, by providing the insulating layer 127, the insulating layer 125, and the mask layer 118a, it is possible to suppress connection failures caused by the divided portions and increases in electrical resistance caused by locally thin film thicknesses between each light-emitting device in the common layer 114 and the common electrode 115. As a result, the display device according to one embodiment of the present invention can improve the display quality.

[0386] Furthermore, after exposing a portion of layer 113W, further heat treatment may be performed. This heat treatment can remove water contained in the EL layer and water adsorbed on the surface of the EL layer. Also, this heat treatment may change the shape of the insulating layer 127. Specifically, the insulating layer 127 may spread to cover at least one of the following: the edge of the insulating layer 125, the edge of the mask layer 118a, and the upper surface of layer 113W. For example, the insulating layer 127 may take on the shape shown in Figures 3A and 3B. For example, the 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 it allows for dehydration at a lower temperature. However, it is preferable to appropriately set the temperature range for the above heat treatment, taking into consideration the heat resistance temperature of the EL layer. Furthermore, considering the heat resistance temperature of the EL layer, a temperature range of 70°C to 120°C is particularly preferred within the above temperature range.

[0387] If the insulating layer 125 and mask layer 118a are etched together after post-baking, side etching may cause the insulating layer 125 and mask layer 118a beneath the edges of the insulating layer 127 to disappear, forming a cavity. This cavity can cause unevenness on the surface forming the common layer 114 and common electrode 115, making it easier for the common layer 114 and common electrode 115 to break down. Therefore, it is preferable to perform the etching of the insulating layer 125 and mask layer 118a separately, before and after post-baking.

[0388] In the following section, a method for etching the insulating layer 125 and the mask layer 118a, performed separately before and after post-baking, will be described using Figures 17B to 17E.

[0389] First, Figure 17B shows an enlarged view of the layer 113W shown in Figure 16B, and the edge and vicinity of the insulating layer 127b. In other words, Figure 17B shows the insulating layer 127b formed by development.

[0390] Next, as shown in Figure 17C, etching is performed using the insulating layer 127b as a mask to remove a portion of the insulating film 125A and thin a portion of the mask layer 118a. As a result, the insulating layer 125 is formed beneath the insulating layer 127b. In addition, the surface of the thin portion of the mask layer 118a is exposed. In the following, the etching process using the insulating layer 127b as a mask may be referred to as the first etching process.

[0391] The first etching process can be carried out by a dry etching method or a wet etching method.

[0392] As shown in Figure 17C, by using the insulating layer 127b, which has a tapered side surface, as a mask for etching, the side surface of the insulating layer 125 and the upper end of the side surface of the mask layer 118a can be made tapered relatively easily.

[0393] As shown in Figure 17C, in the first etching process, the mask layer 118a is not completely removed, and the etching process is stopped when the film thickness is reduced. By leaving the corresponding mask layer 118a on layer 113W in this way, it is possible to prevent damage to layer 113W in subsequent processing steps.

[0394] In Figure 17C, the mask layer 118a is configured to have a thinner film thickness, but the present invention is not limited to this. For example, depending on the film thickness of the insulating film 125A and the mask layer 118a, the first etching process may be stopped before the insulating film 125A is processed into the insulating layer 125. Specifically, the first etching process may be stopped after only thinning a portion of the insulating film 125A. Furthermore, if the insulating film 125A is formed using the same material as the mask layer 118a, the boundary between the insulating film 125A and the mask layer 118a may become unclear, making it impossible to determine whether the insulating layer 125 has been formed or whether the film thickness of the mask layer 118a has been thinned.

[0395] Furthermore, Figure 17C shows an example where the shape of the insulating layer 127b is unchanged from that in Figure 17B, but the present invention is not limited to this. For example, the edge of the insulating layer 127b may droop and cover the edge of the insulating layer 125. Also, for example, the edge of the insulating layer 127b may come into contact with the upper surface of the mask layer 118a. As mentioned above, if the insulating layer 127b is not exposed after development, the shape of the insulating layer 127b may change.

[0396] Next, post-baking is performed. As shown in Figure 17D, post-baking can deform the insulating layer 127b into an insulating layer 127 having a tapered shape on its sides. As mentioned above, the shape of the insulating layer 127b may have already changed and acquired a tapered shape on its sides by the time the first etching process is completed.

[0397] In the first etching process, by not completely removing the mask layer 118a and leaving a thinned mask layer 118a, it is possible to prevent the layer 113W from being damaged and degraded during the heat treatment. Therefore, the reliability of the light-emitting device can be improved.

[0398] Next, as shown in Figure 17E, etching is performed using the insulating layer 127 as a mask to remove a portion of the mask layer 118a. This creates an opening in the mask layer 118a, exposing the upper surfaces of layer 113W and the conductive layer 123. In the following, the etching process using the insulating layer 127 as a mask may be referred to as the second etching process.

[0399] The edges of the insulating layer 125 are covered with the insulating layer 127. Figure 17E also shows an example where the insulating layer 127 covers a portion of the edge of the mask layer 118a (specifically, the tapered portion formed by the first etching process), while the tapered portion formed by the second etching process is exposed. In other words, this corresponds to the structure shown in Figures 2A and 2B.

[0400] As described above, by using a method that performs etching before and after post-bake, even if the insulating layer 125 and the mask layer 118a are side-etched in the first etching process, creating a cavity under the edge of the insulating layer 127, the insulating layer 127 can fill the cavity by performing post-bake afterward. Subsequently, in the second etching process, the mask layer 118a, which has become thinner, is etched, resulting in less side etching and making it less likely for cavities to form. Even if cavities do form, they can be made extremely small. Therefore, the surface on which the common layer 114 and the common electrode 115 are formed can be made flatter.

[0401] Furthermore, as shown in Figures 3A, 4B, and 5B, the insulating layer 127 may cover the entire edge of the mask layer 118a. For example, the edge of the insulating layer 127 may droop and cover the edge of the mask layer 118a. Also, for example, the edge of the insulating layer 127 may be in contact with the upper surface of layer 113W. As mentioned above, if the insulating layer 127b is not exposed after development, the shape of the insulating layer 127b may change easily.

[0402] The second etching process is preferably carried out by a wet etching method. By using a wet etching method, the damage to layer 113W can be reduced compared to when a dry etching method is used. The wet etching method can be carried out using an alkaline solution or the like.

[0403] Next, a common layer 114 and a common electrode 115 are formed on the insulating layer 127 and layer 113W in that order (Figure 18A), and then a protective layer 131 is formed (Figure 18B). When applying a configuration in which a color conversion layer and a colored layer are placed on the protective layer 131, as shown in Figure 1B, the protective layer 131 is formed to be approximately flat, then the color conversion layer is placed on the protective layer 131, and the colored layer is placed on the color conversion layer. Then, the substrate 120 is bonded to the protective layer 131 using the resin layer 122 to create the display device (Figure 1B). Also, when applying a configuration in which the colored layer and color conversion layer are placed on the substrate 120 side, as shown in Figure 8A, the colored layer and color conversion layer are placed on the substrate 120 in advance, and the display device is created by bonding the substrate 120.

[0404] The common layer 114 can be formed by methods such as vapor deposition (including vacuum deposition), transfer, printing, inkjet, and coating.

[0405] For the formation of the common electrode 115, for example, sputtering or vacuum deposition can be used. Alternatively, a film formed by deposition and a film formed by sputtering may be laminated together.

[0406] Methods for forming the protective layer 131 include vacuum deposition, sputtering, CVD, and ALD.

[0407] As described above, in the manufacturing method of the display device of this embodiment, the island-shaped layers 113W are formed not using a fine metal mask, but by processing after a film is deposited on one surface, so that the island-shaped layers 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 resolution or aperture ratio is high and the distance between subpixels is extremely short, it is possible to suppress contact between layers 113W in adjacent subpixels. Therefore, it is possible to suppress the generation of leakage current between subpixels. This makes it possible to prevent crosstalk caused by unintended light emission and to realize a display device with extremely high contrast.

[0408] Furthermore, in the method for manufacturing the display device of this embodiment, three sub-pixels of different colors can be manufactured by manufacturing only one color light-emitting device. Therefore, damage to the pixel electrodes in each sub-pixel of a different color is suppressed, thus preventing a decrease in the characteristics of the light-emitting device. In addition, since the number of processing steps for the light-emitting layer using photolithography can be reduced to one, the display device can be manufactured with a high yield.

[0409] Furthermore, the manufacturing method of the display device according to this embodiment enables high-brightness emission in each sub-pixel. In addition, each sub-pixel can achieve emission with high color purity.

[0410] Furthermore, by providing an insulating layer 127 having a tapered shape at its end between adjacent island-shaped EL layers, it is possible to suppress the occurrence of step breaks during the formation of the common layer 114 and common electrode 115, and to prevent the formation of locally thin film areas in the common layer 114 and common electrode 115. As a result, it is possible to suppress connection failures caused by the separated areas and increases in electrical resistance caused by locally thin film areas in the common layer 114 and common electrode 115. Therefore, a display device according to one aspect of the present invention can achieve both high resolution and high display quality.

[0411] This embodiment can be combined with other embodiments as appropriate.

[0412] (Embodiment 3) In this embodiment, a display device according to one aspect of the present invention will be described with reference to Figures 19 and 20.

[0413] [Pixel layout] This embodiment primarily describes a pixel layout different from that shown in Figure 1A. There are no particular limitations on the arrangement of subpixels, and various methods can be applied. Examples of subpixel arrangements include stripe arrangements, S-stripe arrangements, matrix arrangements, delta arrangements, Bayer arrangements, and pentile arrangements.

[0414] In this embodiment, the top surface shape of the sub-pixel shown in the figure corresponds to the top surface shape of the light-emitting region (or light-receiving region).

[0415] Examples of the top surface shape of a sub-pixel include polygons such as triangles, quadrilaterals (including rectangles and squares), and pentagons, as well as polygons with rounded corners, ellipses, or circles.

[0416] Furthermore, the circuit layout constituting the sub-pixel is not limited to the sub-pixel range shown in the figure, but may be arranged outside of it.

[0417] The pixel 110 shown in Figure 19A has an S-stripe array applied to it. The pixel 110 shown in Figure 19A is composed of three subpixels: subpixel 110a, subpixel 110b, and subpixel 110c.

[0418] The pixel 110 shown in Figure 19B includes a sub-pixel 110a with a roughly trapezoidal top surface shape with rounded corners, a sub-pixel 110b with a roughly triangular top surface shape with rounded corners, and a sub-pixel 110c with a roughly quadrilateral or hexagonal top surface shape with rounded corners. Furthermore, sub-pixel 110b has a larger light-emitting area than sub-pixel 110a. In this way, the shape and size of each sub-pixel can be determined independently. For example, sub-pixels with more reliable light-emitting devices can be made smaller in size.

[0419] A Pentile array is applied to pixels 124a and 124b shown in Figure 19C. Figure 19C shows an example in which pixels 124a having sub-pixels 110a and 110b, and pixels 124b having sub-pixels 110b and 110c are arranged alternately.

[0420] A delta array is applied to pixels 124a and 124b shown in Figures 19D to 19F. Pixel 124a has two subpixels (subpixels 110a and 110b) in the top row (1st row) and one subpixel (subpixel 110c) in the bottom row (2nd row). Pixel 124b has one subpixel (subpixel 110c) in the top row (1st row) and two subpixels (subpixels 110a and 110b) in the bottom row (2nd row).

[0421] Figure 19D shows an example where each subpixel has a roughly square top shape with rounded corners, Figure 19E shows an example where each subpixel has a circular top shape, and Figure 19F shows an example where each subpixel has a roughly hexagonal top shape with rounded corners.

[0422] In Figure 19F, each subpixel is located inside a densely packed hexagonal region. When focusing on one subpixel, it is arranged so that it is surrounded by six other subpixels. Furthermore, subpixels that emit light of the same color are not adjacent to each other. For example, when focusing on subpixel 110a, three subpixels 110b and three subpixels 110c are arranged alternately around it.

[0423] Figure 19G shows an example where the subpixels of each color are arranged in a zigzag pattern. Specifically, in a plan view, the upper edges of two subpixels aligned in the column direction (for example, subpixels 110a and 110b, or subpixels 110b and 110c) are offset.

[0424] In each pixel shown in Figures 19A to 19G, it is preferable, for example, that sub-pixel 110a be sub-pixel R that emits red light, sub-pixel 110b be sub-pixel G that emits green light, and sub-pixel 110c be sub-pixel B that emits blue light. However, the configuration of the sub-pixels is not limited to this, and the colors emitted by the sub-pixels and their order can be determined as appropriate. For example, sub-pixel 110b may be sub-pixel R that emits red light, and sub-pixel 110a may be sub-pixel G that emits green light.

[0425] In photolithography, the finer the pattern being processed, the more significant the effects of light diffraction become. This compromises the fidelity of the transfer of the photomask pattern through exposure, making it difficult to process the resist mask into the desired shape. Therefore, even if the photomask pattern is rectangular, patterns with rounded corners are likely to be formed. Consequently, the top surface shape of subpixels may be a polygon with rounded corners, an ellipse, or a circle.

[0426] Furthermore, in a method for manufacturing a display device according to one aspect of the present invention, the EL layer is processed into an island shape using a resist mask. The resist film formed on the EL layer needs to be cured at a temperature lower than the heat resistance temperature of the EL layer. Therefore, depending on the heat resistance temperature of the EL layer material and the curing temperature of the resist material, the curing of the resist film may be insufficient. A resist film that is not sufficiently cured may take a shape that deviates from the desired shape during processing. As a result, the top surface shape of the EL layer may become a polygon with rounded corners, an ellipse, or a circle. For example, if an attempt is made to form a resist mask with a square top surface, a resist mask with a circular top surface may be formed, resulting in a circular top surface shape for the EL layer.

[0427] Furthermore, in order to achieve the desired shape of the upper surface of the EL layer, a technique (OPC (Optical Proximity Correction) technique) may be used to pre-correct the mask pattern so that the design pattern and the transferred pattern match. Specifically, in the OPC technique, a correction pattern is added to the corners of the shape on the mask pattern.

[0428] As shown in Figures 20A to 20I, a pixel can be configured to have four types of subpixels.

[0429] A stripe array is applied to the pixels 110 shown in Figures 20A to 20C.

[0430] Figure 20A shows an example where each subpixel has a rectangular top surface shape, Figure 20B shows an example where each subpixel has a top surface shape formed by connecting two semicircles and a rectangle, and Figure 20C shows an example where each subpixel has an elliptical top surface shape.

[0431] A matrix array is applied to the pixels 110 shown in Figures 20D to 20F.

[0432] Figure 20D shows an example where each subpixel has a square top surface shape, Figure 20E shows an example where each subpixel has a roughly square top surface shape with rounded corners, and Figure 20F shows an example where each subpixel has a circular top surface shape.

[0433] Figures 20G and 20H show an example where one pixel 110 is composed of 2 rows and 3 columns.

[0434] Pixel 110, shown in Figure 20G, has three subpixels (subpixels 110a, 110b, and 110c) in the top row (row 1) and one subpixel (subpixel 110d) in the bottom row (row 2). In other words, pixel 110 has subpixel 110a in the left column (column 1), subpixel 110b in the middle column (column 2), subpixel 110c in the right column (column 3), and subpixel 110d across these three columns.

[0435] The pixel 110 shown in Figure 20H has three subpixels (subpixels 110a, 110b, and 110c) in the top row (1st row) and three subpixels 110d in the bottom row (2nd row). In other words, the pixel 110 has subpixels 110a and 110d in the left column (1st column), subpixels 110b and 110d in the middle column (2nd column), and subpixels 110c and 110d in the right column (3rd column). As shown in Figure 20H, by aligning the arrangement of subpixels in the top and bottom rows, it becomes possible to efficiently remove dust and other debris that may occur during the manufacturing process. Therefore, a display device with high display quality can be provided.

[0436] Figure 20I shows an example where one pixel 110 is composed of 3 rows and 2 columns.

[0437] Pixel 110, shown in Figure 20I, has a sub-pixel 110a in the top row (1st row), a sub-pixel 110b in the middle row (2nd row), a sub-pixel 110c spanning from the 1st to the 2nd row, and one sub-pixel (sub-pixel 110d) in the bottom row (3rd row). In other words, pixel 110 has sub-pixels 110a and 110b in the left column (1st column), a sub-pixel 110c in the right column (2nd column), and a sub-pixel 110d spanning these two columns.

[0438] The pixel 110 shown in Figures 20A to 20I is composed of four subpixels: subpixel 110a, subpixel 110b, subpixel 110c, and subpixel 110d.

[0439] Sub-pixels 110a, 110b, 110c, and 110d can each be configured to have a light-emitting device that emits light of a different color. Examples of sub-pixels 110a, 110b, 110c, and 110d include sub-pixels of four colors: R, G, B, and white (W); sub-pixels of four colors: R, G, B, and Y; or sub-pixels of R, G, B, and infrared (IR).

[0440] In each pixel 110 shown in Figures 20A to 20I, it is preferable, for example, that sub-pixel 110a be sub-pixel R that emits red light, sub-pixel 110b be sub-pixel G that emits green light, sub-pixel 110c be sub-pixel B that emits blue light, and sub-pixel 110d be sub-pixel W that emits white light, sub-pixel Y that emits yellow light, or sub-pixel IR that emits near-infrared light. With such a configuration, in the pixels 110 shown in Figures 20G and 20H, the layout of R, G, and B becomes a stripe arrangement, which can improve the display quality. Also, in the pixels 110 shown in Figure 20I, the layout of R, G, and B becomes a so-called S-stripe arrangement, which can improve the display quality.

[0441] Furthermore, the pixel 110 may have subpixels that have a light-receiving device.

[0442] In each pixel 110 shown in Figures 20A to 20I, one of the sub-pixels 110a to 110d may be a sub-pixel having a light-receiving device.

[0443] In each pixel 110 shown in Figures 20A to 20I, it is preferable, for example, that sub-pixel 110a be a sub-pixel R that emits red light, sub-pixel 110b be a sub-pixel G that emits green light, sub-pixel 110c be a sub-pixel B that emits blue light, and sub-pixel 110d be a sub-pixel S having a light-receiving device. With such a configuration, in the pixels 110 shown in Figures 20G and 20H, the layout of R, G, and B becomes a stripe arrangement, which can improve the display quality. Also, in the pixels 110 shown in Figure 20I, the layout of R, G, and B becomes a so-called S-stripe arrangement, which can improve the display quality.

[0444] The wavelength of light detected by the sub-pixel S, which has a light-receiving device, is not particularly limited. The sub-pixel S can be configured to detect either visible light or infrared light, or both.

[0445] As shown in Figures 20J and 20K, a pixel can be configured to have five types of subpixels.

[0446] Figure 20J shows an example where one pixel 110 is composed of 2 rows and 3 columns.

[0447] Pixel 110, shown in Figure 20J, has three subpixels (subpixel 110a, subpixel 110b, and subpixel 110c) in the top row (1st row) and two subpixels (subpixel 110d and subpixel 110e) in the bottom row (2nd row). In other words, pixel 110 has subpixels 110a and 110d in the left column (1st column), subpixel 110b in the middle column (2nd column), subpixel 110c in the right column (3rd column), and subpixel 110e extending from the 2nd to the 3rd column.

[0448] Figure 20K shows an example where one pixel 110 is composed of 3 rows and 2 columns.

[0449] Pixel 110, shown in Figure 20K, has subpixel 110a in the top row (1st row), subpixel 110b in the middle row (2nd row), subpixel 110c spanning from the 1st to the 2nd row, and two subpixels (subpixel 110d and subpixel 110e) in the bottom row (3rd row). In other words, pixel 110 has subpixels 110a, 110b, and 110d in the left column (1st column), and subpixels 110c and 110e in the right column (2nd column).

[0450] In each pixel 110 shown in Figures 20J and 20K, it is preferable, for example, to set sub-pixel 110a as sub-pixel R that emits red light, sub-pixel 110b as sub-pixel G that emits green light, and sub-pixel 110c as sub-pixel B that emits blue light. With such a configuration, in the pixel 110 shown in Figure 20J, the layout of R, G, and B becomes a stripe arrangement, which can improve the display quality. Also, in the pixel 110 shown in Figure 20K, the layout of R, G, and B becomes a so-called S-stripe arrangement, which can improve the display quality.

[0451] Furthermore, in each pixel 110 shown in Figures 20J and 20K, it is preferable to apply a sub-pixel S having a photodetector to at least one of the sub-pixels 110d and 110e. When photodetectors are used for both sub-pixels 110d and 110e, the configurations of the photodetectors may differ from each other. For example, at least a portion of the wavelength ranges of light they detect may differ. Specifically, one of the sub-pixels 110d and 110e may have a photodetector that mainly detects visible light, and the other may have a photodetector that mainly detects infrared light.

[0452] Furthermore, in each pixel 110 shown in Figures 20J and 20K, it is preferable to apply a sub-pixel S having a light-receiving device to one of the sub-pixels 110d and 110e, and a sub-pixel having a light-emitting device that can be used as a light source to the other. For example, it is preferable that one of the sub-pixels 110d and 110e is a sub-pixel IR having a light-emitting device that emits infrared light, and the other is a sub-pixel S having a light-receiving device that detects infrared light.

[0453] In a pixel having sub-pixels R, G, B, IR, and S, an image can be displayed using sub-pixels R, G, and B, while sub-pixel IR is used as a light source to detect the reflected infrared light emitted by sub-pixel IR at sub-pixel S.

[0454] As described above, in one aspect of the present invention, a display device can be configured to have pixels having subpixels with light-emitting devices, and various layouts can be applied to these pixels. Furthermore, in one aspect of the present invention, a display device can be configured to have pixels having both light-emitting devices and light-receiving devices. In this case as well, various layouts can be applied.

[0455] This embodiment can be combined with other embodiments as appropriate.

[0456] (Embodiment 4) In this embodiment, a display device according to one aspect of the present invention will be described with reference to Figures 21 to 31.

[0457] The display device of this embodiment can be a high-definition display device. Therefore, the display device of this embodiment can be used, for example, as a display unit for information terminals (wearable devices) such as wristwatches and bracelets, and as a display unit for wearable devices that can be worn on the head, such as VR devices such as head-mounted displays (HMDs) and AR devices such as glasses.

[0458] Furthermore, the display device of this embodiment can be a high-resolution display device or a large-screen display device. Therefore, the display device of this embodiment can be used in electronic devices with relatively large screens, such as television equipment, desktop or notebook personal computers, computer monitors, digital signage, and large game machines such as pachinko machines, as well as in the display units of digital cameras, digital video cameras, digital photo frames, mobile phones, portable game consoles, personal information terminals, and audio playback devices.

[0459] [Display Module] Figure 21A shows a perspective view of the 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 display device 100A, but may be any of the display devices 100B to 100F described later.

[0460] The display module 280 has substrates 291 and 292. The display module 280 has a display unit 281. The display unit 281 is an area in the display module 280 that displays an image, and is an area in which light from each pixel provided in the pixel unit 284, which will be described later, can be seen.

[0461] Figure 21B shows a schematic perspective view illustrating the configuration of the substrate 291. On the substrate 291, a circuit section 282, a pixel circuit section 283 on the circuit section 282, and a pixel section 284 on the pixel circuit section 283 are stacked. In addition, a terminal section 285 for connecting to the FPC 290 is provided in the portion of the substrate 291 that does not overlap with the pixel section 284. The terminal section 285 and the circuit section 282 are electrically connected by a wiring section 286 composed of multiple wires.

[0462] The pixel section 284 has a plurality of pixels 284a arranged periodically. The right side of Figure 21B shows an enlarged view of one pixel 284a. Various configurations described in the previous embodiment can be applied to the pixel 284a. Figure 21B shows an example where the pixel has a configuration similar to that of the pixel 110 shown in Figure 1A.

[0463] The pixel circuit section 283 has a plurality of pixel circuits 283a arranged periodically.

[0464] A single pixel circuit 283a is a circuit that controls the driving of multiple elements in a single pixel 284a. A single pixel circuit 283a can be configured to have three circuits that control the light emission of a single light-emitting device. For example, a single pixel circuit 283a can be configured to have at least one selection transistor, one current control transistor (driving 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 type display device.

[0465] The circuit section 282 has circuits for driving each pixel circuit 283a of the pixel circuit section 283. For example, it is preferable to have one or both of a gate line drive circuit and a source line drive circuit. In addition, it may have at least one of the following: an arithmetic circuit, a memory circuit, a power supply circuit, etc.

[0466] The FPC290 functions as wiring for supplying video signals or power potential, etc., to the circuit section 282 from an external source. An IC may also be mounted on the FPC290.

[0467] The display module 280 can be configured such that one or both of the pixel circuit section 283 and the circuit section 282 are superimposed on the lower side of the pixel section 284, thereby enabling an extremely high aperture ratio (effective display area ratio) of the display section 281. For example, the aperture ratio of the display section 281 can be 40% or more and less than 100%, preferably 50% or more and 95%, and more preferably 60% or more and 95%. Furthermore, it is possible to arrange the pixels 284a at an extremely high density, enabling an extremely high resolution of the display section 281. For example, it is preferable that the pixels 284a in the display section 281 are arranged with a resolution of 20000 ppi or more, preferably 3000 ppi or more, more preferably 5000 ppi or more, and even more preferably 6000 ppi or more, and with a resolution of 20000 ppi or less, or 30000 ppi or less.

[0468] Because such a display module 280 is extremely high-resolution, it can be suitably used in VR devices such as HMDs or AR devices such as glasses. For example, even in a configuration where the display part of the display module 280 is viewed through lenses, the display module 280 has an extremely high-resolution display part 281, so even when the display part is magnified with lenses, 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 parts. For example, it can be suitably used in the display part of wearable electronic devices such as watches.

[0469] [Display device 100A] The display device 100A shown in Figure 22A comprises a substrate 301, light-emitting devices 130a to 130c that emit white light, a colored layer 132R that transmits red light, a color conversion layer 135R that converts white light to red light, a colored layer 132G that transmits green light, a color conversion layer 135G that converts white light to green light, a colored layer 132B that transmits blue light, a capacitor 240, and a transistor 310.

[0470] As shown in Figure 21B, sub-pixel 11R has a light-emitting device 130a, a color conversion layer 135R, and a coloring layer 132R; sub-pixel 11G has a light-emitting device 130b, a color conversion layer 135G, and a coloring layer 132G; and sub-pixel 11B has a light-emitting device 130c and a coloring layer 132B. In sub-pixel 11R, the light emitted from light-emitting device 130a is extracted as red light (R) to the outside of the display device 100A via the color conversion layer 135R and the coloring layer 132R. In sub-pixel 11G, the light emitted from light-emitting device 130b is extracted as green light (G) to the outside of the display device 100A via the color conversion layer 135G and the coloring layer 132G. In sub-pixel 11B, the light emitted from light-emitting device 130c is extracted as blue light (B) to the outside of the display device 100A via the coloring layer 132B.

[0471] Substrate 301 corresponds to substrate 291 in Figures 21A and 21B. The laminated structure from substrate 301 to insulating layer 255c corresponds to layer 101 in Embodiment 1.

[0472] The transistor 310 is a transistor having a channel-forming region in the substrate 301. For example, a semiconductor substrate such as a single-crystal silicon substrate can be used as the substrate 301. The transistor 310 comprises a portion 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 of the substrate 301 doped with impurities and functions as either a source or a drain. The insulating layer 314 covers the side surface of the conductive layer 311 and functions as a sidewall insulating layer.

[0473] Furthermore, an element isolation layer 315 is provided between two adjacent transistors 310 so as to be embedded in the substrate 301.

[0474] Furthermore, an insulating layer 261 is provided covering the transistor 310, and a capacitance 240 is provided on the insulating layer 261.

[0475] The capacitor 240 has a conductive layer 241, a conductive layer 245, and an insulating layer 243 located between them. The conductive layer 241 acts as one electrode of the capacitor 240, the conductive layer 245 acts as the other electrode of the capacitor 240, and the insulating layer 243 acts as the dielectric of the capacitor 240.

[0476] The conductive layer 241 is provided on the insulating layer 261 and embedded in the insulating layer 254. The conductive layer 241 is electrically connected to either the source or drain of the transistor 310 by a plug 271 embedded in the insulating layer 261. The insulating layer 243 is provided covering the conductive layer 241. The conductive layer 245 is provided in the region that overlaps with the conductive layer 241 via the insulating layer 243.

[0477] Furthermore, it is preferable to provide a conductive layer surrounding the outside of the display unit 281 (or pixel unit 284) in at least one of the conductive layers of layer 101. This conductive layer can also be called a guard ring. By providing this conductive layer, it is possible to suppress the application of high voltage to elements such as transistors and light-emitting devices due to charging caused by ESD (electrostatic discharge) or plasma processes, which could lead to the destruction of these elements.

[0478] An insulating layer 255a is provided covering the capacitance 240, an insulating layer 255b is provided on the insulating layer 255a, and an insulating layer 255c is provided on the insulating layer 255b. Light-emitting devices 130a, 130b, and 130c are provided on the insulating layer 255c. Figure 22A shows an example in which light-emitting devices 130a, 130b, and 130c have the same structure as the laminated structure shown in Figure 1B. An insulator is provided in the region between adjacent light-emitting devices. In Figure 22A and other figures, an insulating layer 125 and an insulating layer 127 on the insulating layer 125 are provided in this region.

[0479] A mask layer 118a is located on the layer 113W of the light-emitting device 130a, on the layer 113W of the light-emitting device 130b, and on the layer 113W of the light-emitting device 130c, respectively.

[0480] Pixel electrodes 111a, 111b, and 111c are electrically connected to either the source or drain of transistor 310 by plugs 256 embedded in insulating layers 243, 255a, 255b, and 255c, a conductive layer 241 embedded in insulating layer 254, and a plug 271 embedded in insulating layer 261. The height of the upper surface of insulating layer 255c and the height of the upper surface of plug 256 are equal or approximately equal. Various conductive materials can be used for the plugs. Figure 22A, etc., shows an example in which the pixel electrode has a two-layer structure consisting of a reflective electrode and a transparent electrode on the reflective electrode.

[0481] Furthermore, a protective layer 131 is provided on the light-emitting devices 130a, 130b, and 130c. On the protective layer 131, a color conversion layer 135R and a coloring layer 132R are laminated in a position overlapping with the light-emitting device 130a, a color conversion layer 135G and a coloring layer 132G are laminated in a position overlapping with the light-emitting device 130b, and a coloring layer 132B is provided in a position overlapping with the light-emitting device 130c. The substrate 120 is bonded to the coloring layers 132R, 132G, and 132B by a resin layer 122. Details of the components from the light-emitting devices to the substrate 120 can be found in Embodiment 1. The substrate 120 corresponds to the substrate 292 in Figure 21A.

[0482] The display device shown in Figure 22B is an example having a light-emitting device 130a, a light-emitting device 130b, and a light-receiving device 150. Although not shown, the display device also has a light-emitting device 130c. The configuration of layer 101 in the display device shown in Figure 22B is not limited to the configuration shown in Figure 22A, and any of the configurations shown in Figures 23 to 27 may be applied.

[0483] The light-receiving device 150 comprises a pixel electrode 111S, a layer 155, a common layer 114, and a common electrode 115, all stacked together. For details of the display device having the light-receiving device, refer to Embodiments 1 and 6.

[0484] [Display device 100B] The display device 100B shown in Figure 23 has a configuration in which transistors 310A and 310B, each with a channel formed on a semiconductor substrate, are stacked. In the following description of the display device, parts that are the same as those described earlier may be omitted.

[0485] 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.

[0486] Here, it is preferable to provide an insulating layer 345 on the lower surface of substrate 301B. It is also preferable to provide an insulating layer 346 on top of the insulating layer 261 provided on substrate 301A. Insulating layers 345 and 346 are insulating layers that function as protective layers and can suppress the diffusion of impurities into substrates 301B and 301A. As insulating layers 345 and 346, inorganic insulating films that can be used for the protective layer 131 can be used.

[0487] A plug 343 is provided on the substrate 301B, penetrating both the substrate 301B and the insulating layer 345. It is preferable to provide an insulating layer 344 covering the sides of the plug 343. The insulating layer 344 functions as a protective layer and can suppress the diffusion of impurities into the substrate 301B. An inorganic insulating film, usable for the protective layer 131, can be used as the insulating layer 344.

[0488] Furthermore, a conductive layer 342 is provided on the back side of the substrate 301B (the side opposite to the substrate 120 side), beneath the insulating layer 345. Preferably, the conductive layer 342 is provided so as to be embedded in the insulating layer 335. Also, preferably, the underside of the conductive layer 342 and the insulating layer 335 (the side facing the substrate 301A) is flattened. Here, the conductive layer 342 is electrically connected to the plug 343.

[0489] On the other hand, the substrate 301A has a conductive layer 341 provided on an insulating layer 346. Preferably, the conductive layer 341 is provided so as to be embedded in the insulating layer 336. Furthermore, it is preferable that the upper surfaces of the conductive layer 341 and the insulating layer 336 are flattened.

[0490] The conductive layer 341 and the conductive layer 342 are bonded together, thereby electrically connecting the substrate 301A and the substrate 301B. 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 bonding of the conductive layer 341 and the conductive layer 342 can be improved.

[0491] It is preferable to use the same conductive material for conductive layer 341 and conductive layer 342. For example, a metal film containing an element selected from Al, Cr, Cu, Ta, Ti, Mo, and W, or a metal nitride film (titanium nitride film, molybdenum nitride film, tungsten nitride film) composed of the above elements can be used. In particular, it is preferable to use copper for conductive layer 341 and conductive layer 342. This makes it possible to apply Cu-Cu (copper-copper) direct bonding technology (a technology that achieves electrical conductivity by connecting Cu (copper) pads to each other).

[0492] [Display device 100C] The display device 100C shown in Figure 24 has a configuration in which conductive layer 341 and conductive layer 342 are joined via bumps 347.

[0493] As shown in Figure 24, the conductive layer 341 and the conductive layer 342 can be electrically connected by providing a bump 347 between them. The bump 347 can be formed using a conductive material including, for example, gold (Au), nickel (Ni), indium (In), or tin (Sn). Solder may also be used as the bump 347. An adhesive layer 348 may also 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 Figure 23 may be omitted.

[0494] [Display device 100D] The display device 100D shown in Figure 25 differs from the display device 100A mainly in its transistor configuration.

[0495] Transistor 320 is an OS transistor in which a metal oxide (also called an oxide semiconductor) is applied to the semiconductor layer where the channel is formed.

[0496] The transistor 320 has 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.

[0497] Substrate 331 corresponds to substrate 291 in Figures 21A and 21B. The laminated structure from substrate 331 to insulating layer 255c corresponds to layer 101 in Embodiment 1. An insulating substrate or a semiconductor substrate can be used as substrate 331.

[0498] An insulating layer 332 is provided on the 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 detaching from the semiconductor layer 321 to the insulating layer 332. As the insulating layer 332, for example, a film that is less susceptible to hydrogen or oxygen diffusion than a silicon oxide film can be used, such as an aluminum oxide film, a hafnium oxide film, or a silicon nitride film.

[0499] A conductive layer 327 is provided on an insulating layer 332, and an insulating layer 326 is provided covering the conductive layer 327. The conductive layer 327 functions as the first gate electrode of the transistor 320, and a portion of the insulating layer 326 functions as the first gate insulating layer. It is preferable to use an oxide insulating film, such as a silicon oxide film, for at least the portion of the insulating layer 326 that is in contact with the semiconductor layer 321. It is preferable that the upper surface of the insulating layer 326 is flattened.

[0500] The semiconductor layer 321 is provided on the insulating layer 326. Preferably, the semiconductor layer 321 has a metal oxide (also called an oxide semiconductor) film having semiconductor properties. A pair of conductive layers 325 are provided in contact with the semiconductor layer 321 and function as a source electrode and a drain electrode.

[0501] An insulating layer 328 is provided covering the top and side surfaces of a pair of conductive layers 325, as well as the side surfaces of the semiconductor layer 321, and an insulating layer 264 is provided on the insulating layer 328. The insulating layer 328 functions as a barrier layer to prevent impurities such as water or hydrogen from diffusing into the semiconductor layer 321 from the insulating layer 264, etc., and to prevent oxygen from detaching from the semiconductor layer 321. An insulating film similar to that used for the insulating layer 332 can be used for the insulating layer 328.

[0502] An opening is provided in the insulating layer 328 and the insulating layer 264 that reaches the semiconductor layer 321. Inside this opening, the insulating layer 323 and the conductive layer 324 are embedded, in contact with the sides of the insulating layer 264, the insulating layer 328, and the conductive layer 325, as well as the 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.

[0503] The upper surfaces of the conductive layer 324, the insulating layer 323, and the insulating layer 264 are flattened so that their heights are the same or approximately the same, and the insulating layer 329 and insulating layer 265 are provided covering them.

[0504] Insulating layers 264 and 265 function as interlayer insulating layers. Insulating layer 329 functions as a barrier layer to prevent impurities such as water or hydrogen from diffusing into the transistor 320 from insulating layer 265, etc. As insulating layer 329, an insulating film similar to that used for insulating layers 328 and 332 can be used.

[0505] A plug 274, which is electrically connected to one of the pair of conductive layers 325, is provided so as to be embedded in the insulating layers 265, 329, and 264. Here, it is preferable that the plug 274 has a conductive layer 274a that covers the sides of the openings of the insulating layers 265, 329, 264, and 328, and a part of the upper surface of the conductive layer 325, and a conductive layer 274b that is in contact with the upper surface of the conductive layer 274a. In this case, it is preferable to use a conductive material that does not easily allow hydrogen and oxygen to diffuse as the conductive layer 274a.

[0506] [Display device 100E] The display device 100E shown in Figure 26 has a configuration in which transistors 320A and 320B, each having an oxide semiconductor in the semiconductor on which the channel is formed, are stacked.

[0507] For details regarding transistors 320A and 320B, and their peripheral configurations, please refer to the display device 100D described above.

[0508] In this example, we have used a configuration in which two transistors having oxide semiconductors are stacked, but this is not the only option. For example, a configuration in which three or more transistors are stacked may also be used.

[0509] [Display device 100F] The display device 100F shown in Figure 27 has a configuration in which a transistor 310 with a channel formed on a substrate 301 and a transistor 320 containing a metal oxide in the semiconductor layer where the channel is formed are stacked.

[0510] An insulating layer 261 is provided covering the transistor 310, and a conductive layer 251 is provided on the insulating layer 261. An insulating layer 262 is provided covering the conductive layer 251, and a conductive layer 252 is provided on the insulating layer 262. The conductive layers 251 and 252 each function as wiring. An insulating layer 263 and an insulating layer 332 are provided covering the conductive layer 252, and a transistor 320 is provided on the insulating layer 332. An insulating layer 265 is provided covering the transistor 320, and a capacitor 240 is provided on the insulating layer 265. The capacitor 240 and the transistor 320 are electrically connected by a plug 274.

[0511] Transistor 320 can be used as a transistor constituting a pixel circuit. Transistor 310 can also be used as a transistor constituting a pixel circuit, or as a transistor constituting a drive circuit (gate line drive circuit, source line drive circuit) for driving the pixel circuit. Furthermore, transistors 310 and 320 can be used as transistors constituting various circuits such as arithmetic circuits or memory circuits.

[0512] This configuration allows for the formation of not only pixel circuits but also drive circuits directly beneath the light-emitting device, making it possible to miniaturize the display device compared to cases where the drive circuits are located around the display area.

[0513] [Display device 100G] Figure 28 shows a perspective view of the display device 100G, and Figure 29A shows a cross-sectional view of the display device 100G.

[0514] The display device 100G has a configuration in which substrate 152 and substrate 151 are bonded together. In Figure 28, substrate 152 is clearly indicated by a dashed line.

[0515] The display device 100G includes a display unit 162, a connection unit 140, a circuit 164, wiring 165, etc. Figure 28 shows an example in which IC 173 and FPC 172 are mounted on the display device 100G. Therefore, the configuration shown in Figure 28 can also be described as a display module having the display device 100G, an IC (integrated circuit), and an FPC.

[0516] The connection portion 140 is provided on the outside of the display unit 162. The connection portion 140 can be provided along one or more sides of the display unit 162. There may be one or more connection portions 140. Figure 28 shows an example in which the connection portion 140 is provided so as to surround all four sides of the display unit 162. At the connection portion 140, the common electrode of the light-emitting device and the conductive layer are electrically connected, and a potential can be supplied to the common electrode.

[0517] For example, a scan line drive circuit can be used as circuit 164.

[0518] The wiring 165 has the function of supplying signals and power to the display unit 162 and the circuit 164. These signals and power are input to the wiring 165 from an external source via the FPC 172, or from the IC 173.

[0519] Figure 28 shows an example in which IC 173 is provided on the substrate 151 using the COG (Chip On Glass) method or COF (Chip On Film) method, etc. IC 173 can be an IC having, for example, a scan line drive circuit or a signal line drive circuit. Note that the display device 100G and the display module may be configured without an IC. Alternatively, the IC may be mounted on an FPC using the COF method, etc.

[0520] Figure 29A 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 unit 140, and a portion of the area including the end are cut.

[0521] The display device 100G shown in Figure 29A has, between substrates 151 and 152, a transistor 201, a transistor 205, light-emitting devices 130a to 130c that emit white light, a color conversion layer 135R that converts white light to red light, a colored layer 132R that transmits red light, a color conversion layer 135G that converts white light to green light, a colored layer 132G that transmits green light, a colored layer 132B that transmits blue light, and the like.

[0522] Light-emitting devices 130a, 130b, and 130c each have a structure similar to the stacked structure shown in Figure 1B, except that the pixel electrode configuration differs. For details of the light-emitting devices, please refer to Embodiment 1.

[0523] The light-emitting device 130a, which overlaps with the color conversion layer 135R and the coloring layer 132R, has a conductive layer 112a, a conductive layer 126a on the conductive layer 112a, and a conductive layer 129a on the conductive layer 126a. All of the conductive layers 112a, 126a, and 129a can be called pixel electrodes, or only a part of them can be called pixel electrodes.

[0524] The light-emitting device 130b, which overlaps with the color conversion layer 135G and the coloring layer 132G, has a conductive layer 112b, a conductive layer 126b on the conductive layer 112b, and a conductive layer 129b on the conductive layer 126b. All of the conductive layers 112b, 126b, and 129b can be called pixel electrodes, or only a part of them can be called pixel electrodes.

[0525] The light-emitting device 130c, which overlaps with the colored layer 132B, has a conductive layer 112c, a conductive layer 126c on the conductive layer 112c, and a conductive layer 129c on the conductive layer 126c. All of the conductive layers 112c, 126c, and 129c can be called pixel electrodes, or only a part of them can be called pixel electrodes.

[0526] The conductive layer 112a is connected to the conductive layer 222b of the transistor 205 through an opening provided in the insulating layer 214. The edge of the conductive layer 126a is located outside the edge of the conductive layer 112a. The edges of the conductive layer 126a and the conductive layer 129a are aligned or approximately aligned. For example, conductive layers that function as reflective electrodes can be used for conductive layers 112a and 126a, and a conductive layer that functions as a transparent electrode can be used for conductive layer 129a.

[0527] Since conductive layers 112b, 126b, 129b, and 112c, 126c, and 129c are the same as conductive layers 112a, 126a, and 129a, a detailed explanation is omitted.

[0528] The conductive layers 112a, 112b, and 112c have recesses formed to cover the openings provided in the insulating layer 214. Layer 128 is embedded in these recesses.

[0529] Layer 128 has the function of flattening the recesses of conductive layers 112a, 112b, and 112c. Conductive layers 126a, 126b, and 126c are provided on conductive layers 112a, 112b, 112c, and layer 128, respectively, and are electrically connected to conductive layers 112a, 112b, and 112c. Therefore, regions overlapping with the recesses of conductive layers 112a, 112b, and 112c can also be used as light-emitting regions, thereby increasing the aperture ratio of the pixels.

[0530] Layer 128 may be an insulating layer or a conductive layer. Various inorganic insulating materials, organic insulating materials, and conductive materials can be used for layer 128 as appropriate. In particular, it is preferable that layer 128 be formed using an insulating material, and especially preferable that it be formed using an organic insulating material. For example, an organic insulating material that can be used for the insulating layer 127 described above can be applied to layer 128.

[0531] The top and side surfaces of conductive layers 126a and 129a are covered by layer 113W. Similarly, the top and side surfaces of conductive layers 126b and 129b are covered by layer 113W, and the top and side surfaces of conductive layers 126c and 129c are covered by layer 113W. Therefore, the entire regions where conductive layers 126a, 126b, and 126c are provided can be used as light-emitting regions for light-emitting devices 130a, 130b, and 130c, respectively, thereby increasing the aperture ratio of the pixels.

[0532] A portion of the top surface and sides of layer 113W are covered by insulating layers 125 and 127. A mask layer 118a is located between layer 113W and insulating layer 125. A common layer 114 is provided on layer 113W, insulating layer 125, and insulating layer 127, and a common electrode 115 is provided on the common layer 114. The common layer 114 and the common electrode 115 are each continuous films provided in common to multiple light-emitting devices.

[0533] Furthermore, a protective layer 131 is provided on the light-emitting devices 130a, 130b, and 130c. 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 coloring layer 132R, a color conversion layer 135R, a coloring layer 132G, a color conversion layer 135G, and a coloring layer 132B. A solid encapsulation structure or a hollow encapsulation structure can be applied to seal the light-emitting devices. In Figure 29A, the space between the substrate 152 and the substrate 151 is filled with the adhesive layer 142, and a solid encapsulation structure is applied. Alternatively, the space may be filled with an inert gas (such as nitrogen or argon), and a hollow encapsulation structure may be applied. In this case, the adhesive layer 142 may be provided so as not to overlap with the light-emitting devices. The space may also be filled with a resin different from the adhesive layer 142, which is provided in a frame shape.

[0534] The protective layer 131 is provided at least on the display unit 162, and preferably so as to cover the entire display unit 162. It is preferable that the protective layer 131 covers not only the display unit 162, but also the connection unit 140 and the circuit 164. Furthermore, it is preferable that the protective layer 131 extends to the edges of the display device 100G. On the other hand, in the connection unit 204, there is a portion where the protective layer 131 is not provided in order to electrically connect the FPC 172 and the conductive layer 166.

[0535] A connection portion 204 is provided in the region of substrate 151 where substrate 152 does not overlap. At the connection portion 204, wiring 165 is electrically connected to FPC 172 via conductive layer 166 and connection layer 242. The conductive layer 166 is shown as an example of a laminated structure consisting of a conductive film obtained by processing the same conductive film as conductive layers 112a, 112b, and 112c, a conductive film obtained by processing the same conductive film as conductive layers 126a, 126b, and 126c, and a conductive film obtained by processing the same conductive film as conductive layers 129a, 129b, and 129c. On the upper surface of the connection portion 204, the conductive layer 166 is exposed. This allows the connection portion 204 and FPC 172 to be electrically connected via the connection layer 242.

[0536] For example, after the protective layer 131 is deposited on the entire surface of the display device 100G, the conductive layer 166 can be exposed by removing the area of ​​the protective layer 131 that overlaps with the conductive layer 166 using a mask.

[0537] Alternatively, a laminated structure of at least one organic layer and a conductive layer may be provided on the conductive layer 166, and a protective layer 131 may be provided on the laminated structure. Then, a starting point for peeling (a part that triggers peeling) may be formed on the laminated structure using a laser or a sharp blade (e.g., a needle or cutter), and the laminated structure and the protective layer 131 on it may be selectively removed, exposing 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 relatively while rotating it. Alternatively, an adhesive tape may be attached to the substrate 151 and peeled off. Due to the low 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 for the selective removal of the region of the protective layer 131 that overlaps with the conductive layer 166. If any organic layers remain on the conductive layer 166, they can be removed with an organic solvent or the like.

[0538] As the organic layer, for example, at least one organic layer used in layer 113W (a layer that functions as a light-emitting layer, a carrier block layer, a carrier transport layer, or a carrier implantation layer) can be used. The organic layer may be formed simultaneously with the deposition of layer 113W, or it may be provided separately. The conductive layer can be formed using the same process and materials as the common electrode 115. For example, it is preferable to form an ITO film as both the common electrode 115 and the conductive layer. When a laminated structure is used for the common electrode 115, at least one layer from among the layers constituting the common electrode 115 is provided as the conductive layer.

[0539] Furthermore, the upper surface of the conductive layer 166 may be covered with a mask to prevent the protective layer 131 from being formed on the conductive layer 166. As the mask, for example, a metal mask (area metal mask) may be used, or an adhesive or suction 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 has been formed.

[0540] Using this method, a region of the connection portion 204 where the protective layer 131 is not provided can be formed, and in that region, the conductive layer 166 and the FPC 172 can be electrically connected via the connection layer 242.

[0541] In the connection portion 140, a conductive layer 123 is provided on the insulating layer 214. The conductive layer 123 is shown as an example of a laminated structure consisting of a conductive film obtained by processing the same conductive film as conductive layers 112a, 112b, and 112c, a conductive film obtained by processing the same conductive film as conductive layers 126a, 126b, and 126c, and a conductive film obtained by processing the same conductive film as conductive layers 129a, 129b, and 129c. The ends of the conductive layer 123 are covered by a mask layer 118a, an insulating layer 125, and an insulating layer 127. A common layer 114 is provided on the conductive layer 123, and a common electrode 115 is provided on the common layer 114. The conductive layer 123 and the common electrode 115 are electrically connected via the common layer 114. Note that the common layer 114 does not necessarily have to be formed in the connection portion 140. In this case, the conductive layer 123 and the common electrode 115 are in direct contact and electrically connected.

[0542] The display device 100G is a top-emission type. The light emitted by the light-emitting device is emitted towards the substrate 152. It is preferable to use a material with high transmittance to visible light for the substrate 152. The pixel electrodes contain a material that reflects visible light, and the counter electrodes (common electrodes 115) contain a material that transmits visible light.

[0543] The laminated structure from the substrate 151 to the insulating layer 214 corresponds to layer 101 in Embodiment 1.

[0544] Both transistors 201 and 205 are formed on the substrate 151. These transistors can be manufactured using the same materials and the same process.

[0545] On the substrate 151, insulating layers 211, 213, 215, and 214 are provided in this order. A portion of insulating layer 211 functions as a gate insulating layer for each transistor. A portion of insulating layer 213 functions as a gate insulating layer for each transistor. Insulating layer 215 is provided covering the transistors. Insulating layer 214 is provided covering the transistors and functions as a planarization layer. The number of gate insulating layers and insulating layers covering the transistors are not limited and may be a single layer or two or more layers, respectively.

[0546] It is preferable to use a material that does not easily absorb impurities such as water and hydrogen for at least one layer of the insulating layer covering the transistor. This allows the insulating layer to function as a barrier layer. With such a configuration, the intrusion of impurities from the outside into the transistor can be effectively suppressed, thereby improving the reliability of the display device.

[0547] It is preferable to use inorganic insulating films for insulating layers 211, 213, and 215. Examples of inorganic insulating films that can be used include silicon nitride, silicon oxide nitride, silicon oxide, silicon nitride, aluminum oxide, and aluminum nitride. Alternatively, hafnium oxide, yttrium oxide, zirconium oxide, gallium oxide, tantalum oxide, magnesium oxide, lanthanum oxide, cerium oxide, neodymium oxide, and the like may also be used. Furthermore, two or more of the above insulating films may be laminated together.

[0548] For the insulating layer 214, which functions as a planarizing layer, an organic insulating layer is preferably used. Materials that can be used for the organic insulating layer include acrylic resin, polyimide resin, epoxy resin, polyamide resin, polyimidoamide resin, siloxane resin, benzocyclobutene resin, phenol 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 suppresses the formation of depressions in the insulating layer 214 during processing of conductive layers 112a, 126a, or 129a. Alternatively, depressions may be provided in the insulating layer 214 during processing of conductive layers 112a, 126a, or 129a.

[0549] Transistors 201 and 205 have 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 source and drain electrodes, 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.

[0550] The transistor structure of the display device of this embodiment is not particularly limited. For example, planar transistors, staggered transistors, inverse staggered transistors, etc., can be used. Furthermore, either a top-gate or bottom-gate transistor structure may be used. Alternatively, gates may be provided above and below the semiconductor layer in which the channel is formed.

[0551] Transistors 201 and 205 are configured in which a semiconductor layer on which a channel is formed is sandwiched between two gates. The transistors may be driven by connecting the two gates and supplying them with the same signal. Alternatively, the threshold voltage of the transistors may be controlled by applying a potential to control the threshold voltage to one of the two gates and a potential to drive the other gate.

[0552] The crystallinity of the semiconductor material used in the transistor is not particularly limited; amorphous semiconductors, single-crystal semiconductors, or semiconductors with crystalline properties other than single crystals (microcrystalline semiconductors, polycrystalline semiconductors, or semiconductors with crystalline regions in part) may be used. Using a single-crystal semiconductor or a semiconductor with crystalline properties is preferable because it can suppress the degradation of transistor characteristics.

[0553] The semiconductor layer of the transistor preferably has a metal oxide (also called an oxide semiconductor). In other words, the display device of this embodiment preferably uses a transistor (hereinafter referred to as an OS transistor) that uses a metal oxide in the channel formation region.

[0554] Examples of crystalline oxide semiconductors include CAAC (C-Axis-Aligned Crystalline)-OS and nc (nanocrystalline)-OS.

[0555] Alternatively, a transistor using silicon as the channel-forming region (Si transistor) may be used. Examples of silicon include single-crystal silicon, polycrystalline silicon, and amorphous silicon. In particular, it is preferable to use a transistor having low-temperature polysilicon (LTPS (Low Temperature Poly Silicon)) in the semiconductor layer (hereinafter also referred to as an LTPS transistor). LTPS transistors have high field-effect mobility and good frequency characteristics.

[0556] By using Si transistors such as LTPS transistors, circuits that need to be driven at high frequencies (e.g., source driver circuits) can be fabricated on the same board as the display unit. This simplifies the external circuits implemented in the display device, reducing component and mounting costs.

[0557] OS transistors have extremely high field-effect mobility compared to transistors using amorphous silicon. Furthermore, OS transistors exhibit remarkably low source-drain leakage current (hereinafter also referred to as off-current) in the off state, allowing them to retain charge stored in a capacitor connected in series with the transistor for extended periods. Additionally, the application of OS transistors can reduce the power consumption of display devices.

[0558] Furthermore, to increase the luminescence brightness of the light-emitting device included in the 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 the drive transistor included in the pixel circuit. Compared to Si transistors, OS transistors have a higher breakdown voltage between the source and drain, allowing a higher voltage to be applied between the source and drain of the OS transistor. Therefore, by using an OS transistor as the drive transistor included in the pixel circuit, the amount of current flowing through the light-emitting device can be increased, thereby increasing the luminescence brightness of the light-emitting device.

[0559] Furthermore, when the transistor operates in the saturation region, OS transistors exhibit smaller changes in source-drain current in response to changes in gate-source voltage compared to Si transistors. Therefore, by using OS transistors as driving transistors in the pixel circuit, the current flowing between the source and drain can be precisely controlled by changes in gate-source voltage, thereby controlling the amount of current flowing to the light-emitting device. This allows for a wider range of tonal gradations in the pixel circuit.

[0560] Furthermore, in terms of the saturation characteristics of the current flowing when a transistor operates in the saturation region, OS transistors can supply a more stable current (saturation current) than Si transistors, even when the source-drain voltage gradually increases. Therefore, by using OS transistors as driving transistors, a stable current can be supplied to the light-emitting device even if there are variations in the current-voltage characteristics of the EL device. In other words, when operating in the saturation region, the source-drain current remains almost unchanged even when the source-drain voltage is increased, thus stabilizing the luminescence brightness of the light-emitting device.

[0561] As described above, by using OS transistors in the drive transistors included in the pixel circuit, it is possible to achieve "suppression of black level floating," "increase in luminescence brightness," "multi-gradation," and "suppression of variations in light-emitting devices."

[0562] The semiconductor layer preferably comprises, for example, indium, M (where M is one or more 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 selected from aluminum, gallium, yttrium, and tin.

[0563] In particular, it is preferable to use an oxide containing indium (In), gallium (Ga), and zinc (Zn) (also written 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 written as IAZO). Alternatively, it is preferable to use an oxide containing indium (In), aluminum (Al), gallium (Ga), and zinc (Zn) (also written as IAGZO).

[0564] When the semiconductor layer is an In-M-Zn oxide, it is preferable that the atomic ratio of In in the In-M-Zn oxide is greater than or equal to the atomic ratio of M. The atomic ratios of the metal elements in such an In-M-Zn oxide include: In:M:Zn=1:1:1 or near thereto, In:M:Zn=1:1:1.2 or near thereto, In:M:Zn=1:3:2 or near thereto, In:M:Zn=1:3:4 or near thereto, In:M:Zn=2:1:3 or near thereto, In:M:Zn=3:1:2 or near thereto, In:M:Zn=4:2: Examples include compositions of 3 or nearby, In:M:Zn=4:2:4.1 or nearby, In:M:Zn=5:1:3 or nearby, In:M:Zn=5:1:6 or nearby, In:M:Zn=5:1:7 or nearby, In:M:Zn=5:1:8 or nearby, In:M:Zn=6:1:6 or nearby, In:M:Zn=5:2:5 or nearby, etc. Note that nearby compositions include a range of ±30% of the desired atomic ratio.

[0565] For example, when describing an atomic ratio of In:Ga:Zn = 4:2:3 or a composition close to that, it includes cases where, when In is set to 4, Ga is between 1 and 3, and Zn is between 2 and 4. Also, when describing an atomic ratio of In:Ga:Zn = 5:1:6 or a composition close to that, it includes cases where, when In is set to 5, Ga is greater than 0.1 and 2 or less, and Zn is between 5 and 7. Furthermore, when describing an atomic ratio of In:Ga:Zn = 1:1:1 or a composition close to that, it includes cases where, when In is set to 1, Ga is greater than 0.1 and 2 or less, and Zn is greater than 0.1 and 2 or less.

[0566] The transistors in circuit 164 and the transistors in display unit 162 may have the same structure or different structures. The structures of the multiple transistors in circuit 164 may all be the same or there may be two or more different structures. Similarly, the structures of the multiple transistors in display unit 162 may all be the same or there may be two or more different structures.

[0567] All of the transistors in the display unit 162 may be OS transistors, all of the transistors in the display unit 162 may be Si transistors, or some of the transistors in the display unit 162 may be OS transistors and the rest may be Si transistors.

[0568] For example, by using both LTPS transistors and OS transistors in the display unit 162, a display device with low power consumption and high driving capability can be realized. The configuration combining LTPS transistors and OS transistors is sometimes referred to as LTPO. In a more preferable example, it is preferable to apply OS transistors to transistors that function as switches to control conduction and non-conduction between wiring, and to apply LTPS transistors to transistors that control current.

[0569] For example, one of the transistors in the display unit 162 functions as a transistor for controlling the current flowing to the light-emitting device, and can also be called a drive transistor. One of the source and drain of the drive transistor is electrically connected to the pixel electrode of the light-emitting device. It is preferable to use an LTPS transistor for this drive transistor. This makes it possible to increase the current flowing to the light-emitting device in the pixel circuit.

[0570] On the other hand, the other transistor in the display unit 162 functions as a switch for controlling the selection and deselection of pixels, and can also be called a selection transistor. The gate of the selection transistor is electrically connected to the gate line, and one of the source and drain is electrically connected to the source line (signal line). It is preferable to use an OS transistor for the selection transistor. This makes it possible to maintain the gradation of pixels even when the frame frequency is significantly reduced (e.g., 1 fps or less), and thus power consumption can be reduced by stopping the driver when displaying still images.

[0571] Thus, a display device according to one aspect of the present invention can combine a high aperture ratio, high resolution, high display quality, and low power consumption.

[0572] Furthermore, one embodiment of the present invention is a display device having an OS transistor and a light-emitting device with an MML (metal maskless) structure. This configuration makes it possible to extremely reduce the leakage current that can flow through the transistor and the leakage current that can flow between adjacent light-emitting devices (also called lateral leakage current or side leakage current). With this configuration, when an image is displayed on the display device, the observer can observe one or more of the following: image sharpness, image clarity, high saturation, and high contrast ratio. Moreover, by having an extremely low leakage current that can flow through the transistor and lateral leakage current between light-emitting devices, it is possible to minimize light leakage (so-called black floating) that may occur when displaying black.

[0573] In particular, among MML-structured light-emitting devices, applying the aforementioned SBS structure results in a configuration where the layers constituting the light-emitting device (e.g., organic layers) are separated between adjacent light-emitting devices, thereby eliminating or significantly reducing side leakage.

[0574] Figures 29B and 29C show other examples of transistor configurations.

[0575] Transistors 209 and 210 each have a conductive layer 221 that functions as a gate electrode, an insulating layer 211 that functions as a gate insulating layer, a semiconductor layer 231 having a channel forming 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 that functions as a gate insulating layer, a conductive layer 223 that functions 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 forming region 231i. The insulating layer 225 is located at least between the conductive layer 223 and the channel forming region 231i. Furthermore, an insulating layer 218 covering the transistor may be provided.

[0576] In the transistor 209 shown in Figure 29B, an example is shown where the insulating layer 225 covers the top and sides of the semiconductor layer 231. The conductive layers 222a and 222b are connected to the low-resistance region 231n through openings provided in the insulating layers 225 and 215, respectively. Of the conductive layers 222a and 222b, one functions as the source electrode and the other as the drain electrode.

[0577] On the other hand, in the transistor 210 shown in Figure 29C, 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 structure shown in Figure 29C can be fabricated by processing the insulating layer 225 using the conductive layer 223 as a mask. In Figure 29C, an insulating layer 215 is provided covering the insulating layer 225 and the conductive layer 223, and the conductive layer 222a and conductive layer 222b are connected to the low-resistance region 231n, respectively, through openings provided in the insulating layer 215.

[0578] In the display device 100G shown in Figure 29A, the substrate 152 is provided with a coloring layer 132R and a color conversion layer 135R, a coloring layer 132G and a color conversion layer 135G, and a coloring layer 132B on the substrate 151 side. Of the multiple light-emitting devices in the display device 100G, the light-emitting device 130a of the sub-pixel that emits red light overlaps with the color conversion layer 135R and the coloring layer 132R, the light-emitting device 130b of the sub-pixel that emits green light overlaps with the color conversion layer 135G and the coloring layer 132G, and the light-emitting device 130c of the sub-pixel that emits blue light overlaps with the coloring layer 132B. It is preferable to provide a light-shielding layer 117 on the substrate 152 side. The light-shielding layer 117 can be provided between adjacent light-emitting devices, in connection parts 140, circuits 164, etc. Furthermore, various optical components can be placed on the outside of the substrate 152.

[0579] Substrates 151 and 152 can be made from materials that can be used for substrate 120, as shown in Figure 1B, etc.

[0580] As the adhesive layer 142, a material that can be used for the resin layer 122 shown in Figure 1B, etc., can be applied.

[0581] As the connecting layer 242, an anisotropic conductive film (ACF), an anisotropic conductive paste (ACP), etc., can be used.

[0582] [Display device 100H] The display device 100H shown in Figure 30A differs from the display device 100G mainly in that it is a bottom-emission type display device.

[0583] The light emitted by the light-emitting device is projected onto the substrate 151. It is preferable to use a material with high transparency to visible light for the substrate 151. On the other hand, the light transmittance of the material used for the substrate 152 is not a requirement.

[0584] It is preferable to form a light-shielding layer 117 between the substrate 151 and the transistor 201, and between the substrate 151 and the transistor 205. Figure 30A shows an example in which a light-shielding layer 117 is provided on the substrate 151, an insulating layer 153 is provided on the light-shielding layer 117, and transistors 201, 205, etc. are provided on the insulating layer 153. In addition, a color conversion layer 135R and a coloring layer 132R, a color conversion layer 135G and a coloring layer 132G, and a coloring layer 132B (not shown) are provided on the insulating layer 215.

[0585] The light-emitting device 130a, which overlaps with the color conversion layer 135R and the coloring layer 132R, has a conductive layer 112a, a conductive layer 126a on the conductive layer 112a, and a conductive layer 129a on the conductive layer 126a.

[0586] The light-emitting device 130b, which overlaps with the color conversion layer 135G and the coloring layer 132G, has a conductive layer 112b, a conductive layer 126b on the conductive layer 112b, and a conductive layer 129b on the conductive layer 126b.

[0587] Furthermore, although not shown in the figures, the light-emitting device 130c that overlaps with the colored layer 132B has a conductive layer 112c, a conductive layer 126c on the conductive layer 112c, and a conductive layer 129c on the conductive layer 126c.

[0588] The conductive layers 112a, 112b, 112c (not shown), 126a, 126b, 126c (not shown), 129a, 129b, and 129c (not shown) are each made of a material with high transmittance to visible light. It is preferable to use a material that reflects visible light for the common electrode 115.

[0589] Furthermore, while Figures 29A and 30A show examples where the upper surface of layer 128 has a flat portion, the shape of layer 128 is not particularly limited. Figures 30B to 30D show modified examples of layer 128.

[0590] As shown in Figures 30B and 30D, the upper surface of layer 128 can be configured to have a shape in which the center and its vicinity are recessed in a cross-sectional view, that is, a shape having a concave curved surface.

[0591] Furthermore, as shown in Figure 30C, the upper surface of layer 128 can be configured to have a shape that bulges in the center and its vicinity in a cross-sectional view, that is, a shape with a convex curved surface.

[0592] Furthermore, the upper surface of layer 128 may have one or both of a convex and a concave surface. Also, the number of convex and concave surfaces on the upper surface of layer 128 is not limited and can be one or more.

[0593] Furthermore, the height of the top surface of layer 128 and the heights of the top surfaces of conductive layers 112a, 112b, and 112c may be the same, approximately the same, or different from each other. For example, the height of the top surface of layer 128 may be lower or higher than the heights of the top surfaces of conductive layers 112a, 112b, and 112c.

[0594] Furthermore, Figure 30B can be seen as an example in which layer 128 is housed inside a recess formed in the conductive layer 112a. On the other hand, as shown in Figure 30D, layer 128 may exist outside the recess formed in the conductive layer 112a, that is, the width of the upper surface of layer 128 may be wider than that of the recess.

[0595] [Display device 100J] The display device 100J shown in Figure 31 differs from the display device 100G mainly in that it has a light receiving device 150.

[0596] The light-receiving device 150 includes a conductive layer 112S, a conductive layer 126S on the conductive layer 112S, and a conductive layer 129S on the conductive layer 126S.

[0597] The conductive layer 112S is connected to the conductive layer 222b of the transistor 205 through an opening provided in the insulating layer 214.

[0598] The top and side surfaces of conductive layer 126S and conductive layer 129S are covered by layer 155. Layer 155 has at least an active layer.

[0599] A portion of the top surface and sides of layer 155 are covered by insulating layers 125 and 127. A mask layer 118S is located between layer 155 and insulating layer 125. A common layer 114 is provided on layer 155, insulating layer 125, and insulating layer 127, and a common electrode 115 is provided on the common layer 114. The common layer 114 is a continuous film provided in common to both the light-receiving device and the light-emitting device.

[0600] The display device 100J can, for example, apply the pixel layout shown in Figures 20A to 20K, as described in Embodiment 3. For details of the display device having a light-receiving device, refer to Embodiments 1 and 6.

[0601] This embodiment can be combined with other embodiments as appropriate.

[0602] (Embodiment 5) This embodiment describes a light-emitting device that can be used in a display device according to one aspect of the present invention.

[0603] [Light-emitting devices] As shown in Figure 32A, the light-emitting device has an EL layer 763 between a pair of electrodes (lower electrode 761 and upper electrode 762). The EL layer 763 can be composed of multiple layers, such as layer 780, light-emitting layer 771, and layer 790.

[0604] The light-emitting layer 771 has at least a light-emitting substance (also called a light-emitting material).

[0605] When the lower electrode 761 is the anode and the upper electrode 762 is the cathode, layer 780 has one or more of the following: a layer containing a material with high hole injection properties (hole injection layer), a layer containing a material with high hole transport properties (hole transport layer), and a layer containing a material with high electron blocking properties (electron blocking layer). Similarly, layer 790 has one or more of the following: a layer containing a material with high electron injection properties (electron injection layer), a layer containing a material with high electron transport properties (electron transport layer), and a layer containing a material with high hole blocking properties (hole blocking layer). When the lower electrode 761 is the cathode and the upper electrode 762 is the anode, layers 780 and 790 have the opposite configurations to those described above.

[0606] A configuration having a layer 780, an emissive layer 771, and a layer 790 provided between a pair of electrodes can function as a single emissive unit, and in this specification, the configuration shown in Figure 32A is referred to as a single structure.

[0607] Furthermore, Figure 32B shows a modified example of the EL layer 763 of the light-emitting device shown in Figure 32A. Specifically, the light-emitting device shown in Figure 32B has a layer 781 on the 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.

[0608] When the lower electrode 761 is the anode and the upper electrode 762 is the cathode, for example, layer 781 can be a hole injection layer, layer 782 a hole transport layer, layer 791 an electron transport layer, and layer 792 an electron injection layer. Also, when the lower electrode 761 is the cathode and the upper electrode 762 is the anode, layer 781 can be an electron injection layer, layer 782 an electron transport layer, layer 791 a hole transport layer, and layer 792 a hole injection layer. By using such a layer structure, carriers can be efficiently injected into the light-emitting layer 771, and the efficiency of carrier recombination within the light-emitting layer 771 can be increased.

[0609] As shown in Figures 32C and 32D, a configuration in which multiple light-emitting layers (light-emitting layer 771, light-emitting layer 772, light-emitting layer 773) are provided between layer 780 and layer 790 is also a variation of the single structure. Although Figures 32C and 32D show an example with three light-emitting layers, the number of light-emitting layers in a single-structure light-emitting device may be two or four or more. Furthermore, a single-structure light-emitting device may have a buffer layer between the two light-emitting layers.

[0610] Furthermore, as shown in Figures 32E and 32F, a configuration in which multiple light-emitting units (light-emitting units 763a and 763b) are connected in series via a charge generation layer 785 (also called an intermediate layer) is referred to as a tandem structure in this specification. The tandem structure may also be called a stacked structure. By using a tandem structure, a light-emitting device capable of high-brightness emission can be created. In addition, compared to a single structure, the tandem structure can reduce the current required to obtain the same brightness, thereby improving reliability.

[0611] Figures 32D and 32F show examples in which the display device has a layer 764 that overlaps with the light-emitting device. Figure 32D shows an example in which layer 764 overlaps with the light-emitting device shown in Figure 32C, and Figure 32F shows an example in which layer 764 overlaps with the light-emitting device shown in Figure 32E. In Figures 32D and 32F, 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.

[0612] Layer 764 can be either a color conversion layer or a color filter (coloring layer), or both.

[0613] In Figures 32C and 32D, the light-emitting layers 771, 772, and 773 may each be made of light-emitting materials that emit light of the same color, or even the same light-emitting material. For example, light-emitting materials that emit blue light may each be used for the light-emitting layers 771, 772, and 773. In subpixels that emit blue light, the blue light emitted by the light-emitting device can be extracted. In subpixels that emit red light and subpixels that emit green light, by providing a color conversion layer as layer 764 as shown in Figure 32D, the blue light emitted by the light-emitting device can be converted into longer wavelength light, and red or green light can be extracted. It is also preferable to use both a color conversion layer and a coloring layer as layer 764. Some of the light emitted by the light-emitting device may be transmitted directly without being converted by the color conversion layer. By extracting the light that has passed through the color conversion layer via the coloring layer, the color of light other than the desired color can be absorbed by the coloring layer, and the color purity of the light emitted by the subpixel can be increased.

[0614] Furthermore, in Figures 32C and 32D, the light-emitting layers 771, 772, and 773 may each be made of light-emitting materials that emit light of different colors. When the light emitted by the light-emitting layers 771, 772, and 773 are complementary colors, the light from each layer mixes together to produce white light emission as a whole. For example, a single-structure light-emitting d...

Claims

1. It comprises a first insulating layer, a first pixel electrode, a second pixel electrode, a first layer, a second layer, a second insulating layer, a third insulating layer, and a common electrode. The first pixel electrode has a region located above the first insulating layer and functions as one of a pair of electrodes of the first light-emitting device. The second pixel electrode has a region located above the first insulating layer and functions as one of a pair of electrodes of the second light-emitting device. The first layer has a region in contact with the upper surface of the first pixel electrode, a region in contact with the side surface of the first pixel electrode, a region in contact with the side surface of a recess provided in the first insulating layer, and a region in contact with the bottom surface of a recess provided in the first insulating layer, and functions as the light-emitting layer of the first light-emitting device. The second layer has a region in contact with the upper surface of the second pixel electrode, a region in contact with the side surface of the second pixel electrode, a region in contact with the side surface of the recess provided in the first insulating layer, and a region in contact with the bottom surface of the recess provided in the first insulating layer, and functions as the light-emitting layer of the second light-emitting device. The second insulating layer has a region that overlaps with the upper surface of the first layer, a region that is in contact with the side surface of the first layer, a region that is in contact with the bottom surface of the recess of the first insulating layer, a region that is in contact with the side surface of the second layer, and a region that overlaps with the upper surface of the second layer. The aforementioned second insulating layer has an inorganic material, The third insulating layer has a region located above the second insulating layer, The third insulating layer comprises an organic material, The common electrode has a region located above the first layer, a region located above the third insulating layer, and a region located above the second layer, and functions as the other of a pair of electrodes of the first light-emitting device and as the other of a pair of electrodes of the second light-emitting device. A display device in which the end of the second insulating layer is covered with the third insulating layer.

2. It comprises a first insulating layer, a first pixel electrode, a second pixel electrode, a first layer, a second layer, a second insulating layer, a third insulating layer, and a common electrode. The first pixel electrode has a region located above the first insulating layer and functions as one of a pair of electrodes of the first light-emitting device. The second pixel electrode has a region located above the first insulating layer and functions as one of a pair of electrodes of the second light-emitting device. The first layer has a region in contact with the upper surface of the first pixel electrode, a region in contact with the side surface of the first pixel electrode, a region in contact with the side surface of a recess provided in the first insulating layer, and a region in contact with the bottom surface of a recess provided in the first insulating layer, and functions as the light-emitting layer of the first light-emitting device. The second layer has a region in contact with the upper surface of the second pixel electrode, a region in contact with the side surface of the second pixel electrode, a region in contact with the side surface of the recess provided in the first insulating layer, and a region in contact with the bottom surface of the recess provided in the first insulating layer, and functions as the light-emitting layer of the second light-emitting device. The second insulating layer has a region that overlaps with the upper surface of the first layer, a region that is in contact with the side surface of the first layer, a region that is in contact with the bottom surface of the recess of the first insulating layer, a region that is in contact with the side surface of the second layer, and a region that overlaps with the upper surface of the second layer. The aforementioned second insulating layer has an inorganic material, The third insulating layer has a region located above the second insulating layer, The third insulating layer comprises an organic material, The third insulating layer has a convex curved shape on its upper surface. The common electrode has a region located above the first layer, a region located above the third insulating layer, and a region located above the second layer, and functions as the other of a pair of electrodes of the first light-emitting device and as the other of a pair of electrodes of the second light-emitting device. A display device in which the end of the second insulating layer is covered with the third insulating layer.

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