Display 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

Display device, display module, and electronic device

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

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

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

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

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

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

[0007] International Publication No. 2018 / 087625

[0008] An object of one embodiment of the present invention is to provide a high-resolution display device.An object of one embodiment of the present invention is to provide a high-resolution display device.An object of one embodiment of the present invention is to provide a highly reliable display device.An object of one embodiment of the present invention is to provide a display device capable of displaying at high luminance.An object of one embodiment of the present invention is to provide a display device with high color purity.

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

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

[0011] One embodiment of the present invention is a display device including 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, and an insulating layer, wherein each of the first to third light-emitting devices includes a first light-emitting material that emits blue light and a second light-emitting material that emits light having a wavelength longer than blue. The first color conversion layer overlaps with the first light-emitting device and has a function of converting part of light emitted from the first light-emitting device into red light. The second color conversion layer overlaps with the second light-emitting device and has a function of converting part of light emitted from the second light-emitting device into green light. The first coloring layer overlaps with the third light-emitting device and has a function of transmitting blue light of the light emitted by the third light-emitting device. The insulating layer is located between the first light-emitting device and the second light-emitting device, which are adjacent to each other.

[0012] In addition, in the above, it is preferable that the device has a second colored layer overlapping the first light-emitting device and the first color conversion layer, and a third colored layer overlapping the second light-emitting device and the second color conversion layer, the second colored layer having a function of transmitting red light out of the light converted by the first color conversion layer, the third colored layer having a function of transmitting green light out of the light converted by the second color conversion layer, and the first colored layer and the second colored layer have an overlapping region with each other.

[0013] Furthermore, in the above, it is preferable that 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, and 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 first light-emitting material and a second light-emitting material.

[0014] In the above, it is preferable that the common electrode has both transparency and reflectivity with respect to visible light.

[0015] Another embodiment of the present invention is a display device including 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 coloring layer, and an insulating layer, in which the first to third light-emitting devices each include a first light-emitting material that emits blue light and a second light-emitting material that emits light having a wavelength longer than blue. The first color conversion layer overlaps with the first light-emitting device and has a function of converting part of light emitted from the first light-emitting device into red light. The second color conversion layer overlaps with the second light-emitting device and has a function of converting part of light emitted from the second light-emitting device into green light. The first coloring layer overlaps with the third light-emitting device and has a function of transmitting blue light of the light emitted by the third light-emitting device. The insulating layer is located between the first light-emitting device and the second light-emitting device, which are adjacent to each other.

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

[0017] In the above, it is preferable that 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, and 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, and the first to fourth pixel electrodes are all formed of the same material, and the first to third light-emitting layers all have a first light-emitting material and a second light-emitting material, and the active layer has a function as a photoelectric conversion layer.

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

[0019] Another embodiment 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. Each of the first to third light-emitting devices contains a light-emitting material that emits blue light. The first color conversion layer overlaps with the first light-emitting device and has a function of converting part of light emitted from the first light-emitting device into red light. The second color conversion layer overlaps with the second light-emitting device and has a function of converting part of light emitted from the second light-emitting device into red light. a first coloring layer provided to overlap the first color conversion layer and having a function of transmitting red light out of the light converted by the first color conversion layer; a second coloring layer provided to overlap the second color conversion layer and having a function of transmitting green light out of the light converted by the second color conversion layer; the first coloring layer and the second coloring layer having an overlapping region with each other; and an insulating layer located between adjacent first and second light emitting devices.

[0020] In the above, it is preferable that the device has a third colored layer overlapping the third light-emitting device, the third colored layer has a function of transmitting blue light among the light emitted by the third light-emitting device, and the second colored layer and the third colored layer have an overlapping region with each other.

[0021] Furthermore, in the above, it is preferable that 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, and that the first to third pixel electrodes are all formed of the same material, and that the first to third light-emitting layers all contain a light-emitting material.

[0022] In the above, it is preferable that the common electrode has both transparency and reflectivity with respect to visible light.

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

[0024] In the above, the insulating layer preferably has a convex curved upper surface.

[0025] Another embodiment of the present invention is a display module including the display device described above and at least one of a connector and an integrated circuit.

[0026] Another embodiment of the present invention is an electronic device including the above-described display module and at least one of a housing, a battery, a camera, a speaker, and a microphone.

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

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

[0029] Note that the description of these effects does not preclude the existence of other effects. One embodiment of the present invention does not necessarily have all of these effects. Effects other than these can be extracted from the description in the specification, drawings, and claims.

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

[0031] Hereinafter, embodiments will be described in detail with reference to the drawings. However, the present invention is not limited to the following description, and it will be readily understood by those skilled in the art that various changes can be made in form and detail without departing from the spirit and scope of the present invention. Therefore, the present invention should not be interpreted as being limited to the description of the embodiments shown below.

[0032] In the configuration of the invention described below, the same parts or parts having similar functions are denoted by the same reference numerals in different drawings, and repeated explanations thereof will be omitted. Furthermore, when referring to similar functions, the same hatching pattern may be used and no particular reference numeral may be assigned.

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

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

[0035] In this specification, etc., a device fabricated using a metal mask or an FMM (fine metal mask, high-resolution metal mask) may be referred to as a device with an MM (metal mask) structure. In this specification, etc., a device fabricated without using a metal mask or an FMM may be referred to as a device with an MML (metal maskless) structure.

[0036] In this specification and the like, a structure in which at least light-emitting layers are separately fabricated for light-emitting devices with different emission wavelengths may be referred to as an SBS (Side By Side) structure. The SBS structure allows the materials and configuration to be optimized for each light-emitting device, increasing the freedom in material and configuration selection and facilitating improvements in brightness and reliability.

[0037] In addition, in this specification and the like, holes or electrons may be referred to as "carriers." Specifically, a hole injection layer or an electron injection layer may be referred to as a "carrier injection layer," a hole transport layer or an electron transport layer may be referred to as a "carrier transport layer," and a hole block layer or an electron block layer may be referred to as a "carrier block layer." Note that the above-mentioned carrier injection layer, carrier transport layer, and carrier block layer may not be clearly distinguishable from each other depending on their cross-sectional shapes or characteristics. Furthermore, one layer may have two or three functions among the carrier injection layer, carrier transport layer, and carrier block layer.

[0038] In this specification and the like, a light-emitting device has an EL layer between a pair of electrodes. The EL layer has at least a light-emitting layer. Here, layers (also referred to as functional layers) included in the EL layer include a light-emitting layer, a carrier injection layer (a hole injection layer and an electron injection layer), a carrier transport layer (a hole transport layer and an electron transport layer), a carrier block layer (a hole block layer and an electron block layer), and the like.

[0039] In this specification and the like, a tapered shape refers to a shape in which at least a portion of the side surface of a structure is inclined with respect to the substrate surface (or the surface on which the structure is to be formed). For example, it refers to a shape having a region in which the angle (also called the taper angle) between the inclined side surface and the substrate surface (or the surface on which the structure is to be formed) is less than 90°. Note that the side surface of the structure and the substrate surface (or the surface on which the structure is to be formed) do not necessarily need to be completely flat, and may be approximately planar with a slight curvature or approximately planar with a slight unevenness.

[0040] Embodiment 1 In this embodiment, a display device of one embodiment of the present invention will be described with reference to FIGS.

[0041] A display device of one embodiment of the present invention includes a first light-emitting device, a second light-emitting device, and a third light-emitting device, each having an EL layer with the same structure; 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 a light-emitting device having an EL layer with the same configuration, layers other than the pixel electrode (e.g., a light-emitting layer) included in the light-emitting device can be made common to multiple sub-pixels. Therefore, multiple sub-pixels can share a continuous film. However, some layers included in the light-emitting device have relatively high conductivity. When multiple sub-pixels share a highly conductive layer as a continuous film, leakage current may occur between the sub-pixels. In particular, as display devices become higher in definition or aperture ratio and the distance between sub-pixels becomes smaller, this leakage current becomes significant and may cause a deterioration in the display quality of the display device.

[0043] Therefore, in a display device according to one embodiment of the present invention, at least a part of the layers constituting the EL layer in each light-emitting device is formed in an island shape. Since at least a part of the layers constituting the EL layer is separated for each light-emitting device, crosstalk between adjacent subpixels can be suppressed. This allows the display device to achieve both high resolution and high display quality.

[0044] In this specification, the term "island-like" refers to a state in which two or more layers made of the same material and formed in the same process are physically separated. For example, an island-like light-emitting layer refers to a state in which the light-emitting layer is physically separated from the adjacent light-emitting layer.

[0045] For example, island-shaped light-emitting layers can be formed by vacuum deposition using a metal mask. However, this method can result in deviations in the shape and position of the island-shaped light-emitting layers from the design due to various factors, such as the accuracy of the metal mask, misalignment between the metal mask and the substrate, deflection of the metal mask, and spreading of the contours of the formed film due to vapor scattering, making it difficult to achieve high-definition and high-aperture ratio displays. Furthermore, during deposition, the contours of the layer can become blurred, resulting in thin edges. In other words, the thickness of the island-shaped light-emitting layer can vary depending on the location. Furthermore, when producing large, high-resolution, or high-definition display devices, there is a concern that low manufacturing yields may be caused by low dimensional accuracy of the metal mask and deformation due to heat, etc.

[0046] Therefore, when manufacturing a display device according to one embodiment 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, a pixel electrode is formed for each subpixel, and then the light-emitting layer is formed over the plurality of pixel electrodes. Then, the light-emitting layer is processed by photolithography to form one island-shaped light-emitting layer for each pixel electrode. This allows the light-emitting layer to be divided into subpixels, and an island-shaped light-emitting layer to be formed for each subpixel.

[0047] For example, if a display device is composed of three types of light-emitting devices, namely, a light-emitting device that emits blue light, a light-emitting device that emits green light, and a light-emitting device that emits red light, three types of island-shaped light-emitting layers can be formed by repeating the deposition of the light-emitting layer and processing by photolithography three times.

[0048] Here, 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 colors formed second or later may be damaged by the previous process. This may result in a higher driving voltage for the light-emitting devices of the colors formed second or later. Furthermore, the pixel electrodes are more likely to be damaged if they are formed third than if they are formed second, which has a greater impact on the characteristics of the light-emitting device.

[0049] Furthermore, it is preferable to form the light-emitting layer and process the light-emitting layer using photolithography as few times as possible, since this allows for a reduction in manufacturing costs and an improvement in manufacturing yield.

[0050] Therefore, in a display device according to one embodiment of the present invention, three subpixels are provided with a light-emitting device having the same light-emitting layer (which may also be referred to as the same light-emitting material), and two of the subpixels are provided with different color conversion layers. Specifically, one of the two subpixels is provided with a color conversion layer that converts light into red, and the other is provided with a color conversion layer that converts light into green. The remaining subpixel does not include a color conversion layer. Here, a display device according to one embodiment of the present invention preferably uses a light-emitting device that emits white or blue light. The light-emitting device preferably includes at least a light-emitting layer (or a light-emitting material) that emits blue light, which has a shorter wavelength (i.e., higher energy) than red and green light. This allows the color conversion layer 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. The light-emitting layer according to one embodiment of the present invention will be described in detail in Embodiment 5.

[0051] In addition, in the display device of one embodiment of the present invention, it is preferable to use different coloring layers for the three subpixels. Specifically, it is preferable to use a coloring layer that transmits red light for the subpixel having the color conversion layer that converts light into red, a coloring layer that transmits green light for the subpixel having the color conversion layer that converts light into green, and a coloring layer that transmits blue light for the subpixel not using a color conversion layer. This makes it possible to realize subpixels that emit red light, green light, and blue light, respectively, and to perform full-color display.

[0052] As described above, the light-emitting device according to one embodiment of the present invention emits white or blue light. The light is converted by a color conversion layer into red light and then output from a subpixel that emits red light. The light is converted by a color conversion layer into green light and then output from a subpixel that emits green light. The light is output as is (i.e., white or blue) from a subpixel that emits blue light. Furthermore, the light (after color conversion) output from each light-emitting device is extracted by the coloring layer. Specifically, in the subpixel that emits red light, only red light is extracted by the coloring layer (light other than red is filtered out) from the light output from the color conversion layer. In the subpixel that emits green light, only green light is extracted by the coloring layer (light other than green is filtered out). In the subpixel that emits blue light, only blue light is extracted by the coloring layer (light other than blue is filtered out) from the white or blue light emitted by the light-emitting device. This allows the display device according to one embodiment of the present invention to enhance the color purity of the light emitted by each subpixel.

[0053] As described above, in the display device according to one embodiment of the present invention, light-emitting devices having the same light-emitting layer are used for the three subpixels. Therefore, by simply processing one light-emitting layer into an island shape once, three subpixels of different colors can be formed. Therefore, damage to pixel electrodes in the subpixels of each color can be suppressed, and degradation of the characteristics of the light-emitting devices can be suppressed.

[0054] Furthermore, in the manufacturing method of a display device according to one embodiment of the present invention, the light-emitting layer can be processed by photolithography only once; therefore, display devices can be manufactured with high yield.

[0055] When the light-emitting layer is processed into an island shape, a structure in which the light-emitting layer is processed using photolithography directly above the light-emitting layer is conceivable. In this structure, the light-emitting layer may be damaged (e.g., damaged by processing), resulting in a significant loss of reliability. Therefore, when manufacturing a display device according to one embodiment of the present invention, it is preferable to form a mask layer (also referred to as a sacrificial layer, a protective layer, or the like) on a functional layer (e.g., a carrier block layer, a carrier transport layer, or a carrier injection layer, more specifically, a hole block layer, an electron transport layer, or an electron injection layer) located above the light-emitting layer, and then process the light-emitting layer and the functional layer into an island shape. By applying this method, a highly reliable display device can be provided. By providing another layer, such as a functional layer, between the light-emitting layer and the mask layer, the light-emitting layer can be prevented from being exposed to the outermost surface during the manufacturing process of the display device, thereby reducing damage to the light-emitting layer.

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

[0057] Furthermore, when the light-emitting layer is processed into an island shape, it is preferable to process a layer located below the light-emitting layer (e.g., a carrier injection layer, a carrier transport layer, or a carrier block layer; more specifically, a hole injection layer, a hole transport layer, an electron block layer, or the like) into an island shape in the same pattern as the light-emitting layer. Processing a layer located below the light-emitting layer into an island shape in the same pattern as the light-emitting layer can reduce leakage current (also referred to as lateral leakage current) that may occur between adjacent subpixels. For example, when a hole injection layer is shared between adjacent subpixels, lateral leakage current may occur due to the hole injection layer. In contrast, in the display device of one embodiment of the present invention, the hole injection layer can be processed into an island shape in the same pattern as the light-emitting layer, so that lateral leakage current between adjacent subpixels is substantially eliminated or can be extremely reduced.

[0058] Here, for example, when processing is performed using a photolithography method, various damages may be inflicted on the EL layer due to heating during the preparation of a resist mask, and exposure to an etching solution or etching gas during processing and removal of the resist mask. Furthermore, when a mask layer is provided on the EL layer, the EL layer may be affected by heating, an etching solution, an etching gas, etc. during the formation, processing, and removal of the mask layer.

[0059] Furthermore, if the processes performed after the deposition of the EL layer are performed at a temperature higher than the heat resistance temperature of the EL layer, the EL layer may be deteriorated, and the luminous efficiency and reliability of the light-emitting device may decrease.

[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 higher and 180°C or lower, more preferably 120°C or higher and 180°C or lower, and even more preferably 140°C or higher and 180°C or lower.

[0061] Examples of heat resistance temperature indicators include glass transition point (Tg), softening point, melting point, thermal decomposition temperature, and 5% weight loss temperature. For example, the glass transition point of the material contained in each layer constituting the EL layer can be used as an indicator of the heat resistance temperature. Furthermore, when the layer is a mixed layer made of multiple materials, the glass transition point of the material contained in the largest amount can be used. Alternatively, the lowest glass transition point 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 on and 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 damage to the light-emitting layer.

[0063] In particular, it is preferable to increase the heat resistance temperature of the light-emitting layer, which can prevent the light-emitting layer from being damaged by heating, resulting in a decrease in light-emitting efficiency and a shortened lifespan.

[0064] By increasing the heat resistance temperature of the light-emitting device, the reliability of the light-emitting device can be improved. In addition, the temperature range in the manufacturing process of the display device can be widened, which leads to improvement in manufacturing yield and reliability.

[0065] In a light-emitting device that emits different colors, it is not necessary to form all layers constituting the EL layer separately; some layers can be formed in the same process. In a manufacturing method of a display device according to one embodiment of the present invention, after some layers constituting the EL layer are formed in an island shape for each color, at least a part of the mask layer is removed, and the remaining layers constituting the EL layer (sometimes referred to as a common layer) and a common electrode (also referred to as an upper electrode) are formed in common (as a single film) for each color. 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 layer with relatively high conductivity among the EL layers. Therefore, if the carrier injection layer comes into contact with the side surface of a part of the EL layer formed in an island shape or with the side surface of the pixel electrode, the light-emitting device may be short-circuited. Even when the carrier injection layer is provided in an island shape and a common electrode is formed in common for each color, the light-emitting device may be short-circuited if the common electrode comes into contact with the side surface of the EL layer or the side surface of the pixel electrode.

[0067] Therefore, the display device of one embodiment of the present invention includes an insulating layer that covers at least the side surfaces of the island-shaped light-emitting layers. In addition, the insulating layer preferably covers part of the top surface of the island-shaped light-emitting layers.

[0068] This prevents at least a portion of the island-shaped EL layer and the pixel electrode from coming into contact with the carrier injection layer or the common electrode, thereby preventing short circuits in the light-emitting device and improving the reliability of the light-emitting device.

[0069] In addition, it is preferable that the end of the insulating layer has a tapered shape with a taper angle of less than 90° in a cross-sectional view. This can prevent a step in the common layer and common electrode provided on the insulating layer, thereby suppressing poor connection between the common layer and the common electrode. Furthermore, it can prevent the common electrode from being locally thinned due to the step at the end of the insulating layer, thereby suppressing an increase in the electrical resistance of the common electrode.

[0070] In this specification and the like, the term "step discontinuity" refers to a 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 or the like).

[0071] As described above, the island-shaped light-emitting layer manufactured by the manufacturing method of the display device according to one embodiment of the present invention is not formed using a fine metal mask, but is formed by forming the light-emitting layer on the entire surface and then processing it. Therefore, a high-definition display device or a display device with a high aperture ratio, which has been difficult to achieve until now, can be realized. Furthermore, since the light-emitting layer can be formed separately for each color, a display device with extremely vivid, high contrast, and high display quality can be realized. Furthermore, by providing a mask layer on the light-emitting layer, damage to the light-emitting layer during the manufacturing process of the display device can be reduced, thereby improving the reliability of the light-emitting device.

[0072] Furthermore, while it is difficult to achieve a spacing of less than 10 μm between adjacent light-emitting devices using, for example, a fine metal mask, the photolithography method of one embodiment of the present invention can narrow the spacing between adjacent light-emitting devices, adjacent EL layers, or adjacent pixel electrodes to, for example, 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. Furthermore, 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, or even 50 nm or less. This significantly reduces the area of ​​the non-light-emitting region that may exist between two light-emitting devices, enabling the aperture ratio to approach 100%. For example, in a display device of one embodiment of the present invention, the aperture ratio can be 40% or more, 50% or more, 60% or more, 70% or more, 80% or more, or even 90% or more, but less than 100%.

[0073] Increasing the aperture ratio of a display device can improve the reliability of the display device. More specifically, when the lifetime of a display device using an organic EL device and having an aperture ratio of 10% is taken as the reference, the lifetime of a display device having an aperture ratio of 20% (i.e., an aperture ratio twice as high as the reference) is approximately 3.25 times longer, and the lifetime of a display device having an aperture ratio of 40% (i.e., an aperture ratio four times as high as the reference) is approximately 10.6 times longer. As such, as the aperture ratio increases, the current density flowing through the organic EL device can be reduced, thereby improving the lifetime of the display device. In the display device of one embodiment of the present invention, the aperture ratio can be increased, thereby improving the display quality of the display device. Furthermore, as the aperture ratio of the display device increases, an excellent effect is achieved, such as a significant improvement in the reliability (particularly the lifetime) of the display device.

[0074] Furthermore, the processing size of the light-emitting layer itself can be made much smaller than when a fine metal mask is used. For example, when a metal mask is used to separately fabricate light-emitting layers, thickness variations occur between the center and edges of the processed light-emitting layer, resulting in a smaller effective area that can be used as a light-emitting region compared to the overall area of ​​the processed light-emitting layer. On the other hand, the above-described manufacturing method processes a film formed to a uniform thickness, allowing island-shaped light-emitting layers to be formed with a uniform thickness. Therefore, even if the processing size of the light-emitting layer is fine, almost the entire area can be used as a light-emitting region. This makes it possible to manufacture a display device that combines high definition and a high aperture ratio. Furthermore, it is possible to achieve a smaller and lighter display device.

[0075] Specifically, the display device of one embodiment of the present invention can have a resolution of, for example, 2000 ppi or more, preferably 3000 ppi or more, more preferably 5000 ppi or more, and still more preferably 6000 ppi or more, and can have a resolution of 20000 ppi or less, or 30000 ppi or less.

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

[0077] FIG. 1A shows a top view of a display device 100. The display device 100 has a display section in which a plurality of pixels 110 are arranged, and a connection section 140 outside the display section. A plurality of subpixels (subpixel 11R, subpixel 11G, subpixel 11B) are arranged in a matrix in the display section. FIG. 1A shows two rows and six columns of subpixels, which together form two rows and two columns of pixels 110. The connection section 140 can also be called a cathode contact section.

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

[0079] The top surface shape of the subpixel may be, for example, a triangle, a quadrangle (including a rectangle, a diamond, and a square), a polygon such as a pentagon, a polygon with rounded corners, an ellipse, or a circle.

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

[0081] 1A shows the subpixels 11R, 11G, and 11B as having the same or approximately the same aperture ratio (which can also be referred to as the size or the size of the light-emitting region), but this is not a limitation of one embodiment of the present invention. The aperture ratios of the subpixels 11R, 11G, and 11B can be determined as appropriate. The aperture ratios of the subpixels 11R, 11G, and 11B may be different from one another, or two or more of them may be the same or approximately the same.

[0082] A stripe arrangement is applied to the pixel 110 shown in FIG. 1A. The pixel 110 shown in FIG. 1A is composed of three subpixels: subpixel 11R, subpixel 11G, and subpixel 11B. The subpixels 11R, 11G, and 11B emit light of different colors. Examples of the subpixels 11R, 11G, and 11B include subpixels of three colors: red (R), green (G), and blue (B), and subpixels of three colors: yellow (Y), cyan (C), and magenta (M). The number of types of subpixels is not limited to three, and may be four or more. Examples of the four subpixels include subpixels of four colors: R, G, B, and white (W), subpixels of four colors: R, G, B, and Y, and subpixels of R, G, B, and infrared light (IR).

[0083] In this specification and the like, the row direction may be referred to as the X direction, and the column direction may be referred to as the Y direction. The X direction and the Y direction intersect, for example, perpendicularly (see FIG. 1A ). FIG. 1A shows an example in which subpixels of different colors are arranged side by side in the X direction, and subpixels of the same color are arranged side by side in the Y direction.

[0084] 1A shows an example in which the connection unit 140 is located below the display unit in a plan view, but this is not particularly limited. The connection unit 140 only needs to be located in at least one of the upper, right, left, and lower sides of the display unit in a plan view, and may be located so as to surround all four sides of the display unit. The shape of the top surface of the connection unit 140 may be strip-shaped, L-shaped, U-shaped, frame-shaped, or the like. Furthermore, the connection unit 140 may be singular or plural.

[0085] FIG. 1B shows a cross-sectional view taken along dashed line X1-X2 in FIG. 1A. FIG. 1C shows a top view of layer 113W. FIGS. 2A and 2B show enlarged views of a portion of the cross-sectional view shown in FIG. 1B. FIGS. 3 to 6 show modifications of FIG. 2. FIGS. 7A, 8A to 8C, 9C and 9D, 10A to 10C, and 11A and 11B show modifications of FIG. 1B. FIGS. 7B to 7E show cross-sectional views of modifications of pixel electrodes. FIG. 7F shows a modification of FIG. 7A. FIGS. 9A and 9B show cross-sectional views taken along dashed line Y1-Y2 in FIG. 1A.

[0086] The subpixel 11R has a light-emitting device 130a that emits white light and a color conversion layer 135R that converts the white light into red light, so that 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 subpixel 11R further includes a coloring layer 132R that transmits red light. A portion of the white light emitted by the light-emitting device 130a may be transmitted directly without being converted by the color conversion layer 135R. Furthermore, the color-converted light may contain not only red light but also light of wavelengths other than red. By extracting the light that has transmitted through the color conversion layer 135R via the coloring layer 132R, the color non-red light is absorbed by the coloring layer 132R, thereby enhancing the color purity of the light emitted by the subpixel 11R.

[0088] The subpixel 11G has 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 have the same structure as the light-emitting device 130a. As a result, the light emitted by 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 subpixel 11G further includes a coloring layer 132G that transmits green light. A portion of the white light emitted by the light-emitting device 130b may be transmitted directly without being converted by the color conversion layer 135G. Furthermore, the color-converted light may contain not only green light but also light of wavelengths other than green. By extracting the light that has transmitted through the color conversion layer 135G via the coloring layer 132G, the coloring layer 132G absorbs the light other than the green light, thereby enhancing the color purity of the light emitted by the subpixel 11G.

[0090] The subpixel 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 have the same structure as the light-emitting devices 130a and 130b. Light emitted from the light-emitting device 130c is extracted as blue light to the outside of the display device. As described above, the display device 100 of one embodiment of the present invention can achieve the subpixels 11R, 11G, and 11B that emit red light, green light, and blue light, respectively, with high color purity.

[0091] Here, examples of blue light include light whose emission spectrum has a peak wavelength of 400 nm or more and less than 480 nm, examples of green light include light whose emission spectrum has a peak wavelength of 480 nm or more and less than 580 nm, and examples of red light include light whose emission spectrum has a peak wavelength of 580 nm or more and less than 700 nm.

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

[0093] It is preferable to use one or both of a phosphor and quantum dots (QDs) for the color conversion layer. Quantum dots, in particular, have a narrow peak width in the emission spectrum, and can emit light with good color purity. This can improve the display quality of the display device.

[0094] The color conversion layer can be formed by a droplet ejection method (for example, an inkjet method), a coating method, an imprint method, various printing methods (screen printing, offset printing), etc. A color conversion film such as a quantum dot film may also be used.

[0095] When processing a film to be used as a color conversion layer, it is preferable to use a photolithography method. Photolithography methods include a method in which a resist mask is formed on a 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 the thin film is processed into a desired shape by exposure and development. 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 into a photoresist, and processing the thin film using a photolithography method.

[0096] The material constituting the quantum dots is not particularly limited, and examples thereof include a Group 14 element, a Group 15 element, a Group 16 element, a compound consisting of multiple Group 14 elements, a compound of an element belonging to Groups 4 to 14 and a Group 16 element, a compound of a Group 2 element and a Group 16 element, a compound of a Group 13 element and a Group 15 element, a compound of a Group 13 element and a Group 17 element, a compound of a Group 14 element and a Group 15 element, a compound of a Group 11 element and a Group 17 element, 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, and tellurium 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 of the quantum dots include tantalum nitride, titanium oxide, zirconium oxide, silicon nitride, germanium nitride, aluminum oxide, barium titanate, a compound of selenium, zinc, and cadmium, a compound of indium, arsenic, and phosphorus, a compound of cadmium, selenium, and sulfur, a compound of cadmium, selenium, and tellurium, a compound of indium, gallium, and arsenic, a compound of indium, gallium, and selenium, a compound of indium, selenium, and sulfur, a compound of copper, indium, and sulfur, and combinations thereof. Also, so-called alloy-type quantum dots, whose composition is expressed in any ratio, may be used.

[0098] Quantum dot structures include core, core-shell, and core-multishell types. Quantum dots have a high proportion of surface atoms, making them 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. By attaching the protective agent or providing the protective group, aggregation can be prevented and solubility in a solvent can be increased. It is also possible to reduce reactivity and improve electrical stability.

[0099] Since the band gap of quantum dots increases as their size decreases, their size can be adjusted appropriately to obtain light of the desired wavelength. As the crystal size decreases, the emission of quantum dots shifts toward the blue side, i.e., toward higher energy. Therefore, by changing the size of the quantum dots, the emission wavelength can be adjusted across the wavelength ranges of the ultraviolet, visible, and infrared spectral regions. The size (diameter) of the quantum dots is, for example, 0.5 nm or more and 20 nm or less, preferably 1 nm or more and 10 nm or less. The narrower the size distribution of quantum dots, the narrower the emission spectrum, and the more excellent the color purity of the light emitted. The shape of the quantum dots is not particularly limited and may be spherical, rod-shaped, disc-shaped, or other shapes. Quantum rods, which are rod-shaped quantum dots, have the function of emitting directional light.

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

[0101] 1B , in the display device 100, insulating layers (insulating layer 255a, insulating layer 255b, and insulating layer 255c) are provided on a layer 101 including a transistor (not shown). Light-emitting devices 130a, 130b, and 130c are provided on the insulating layer, and a protective layer 131 is provided to cover these light-emitting devices. A color conversion layer 135R and a coloring layer 132R are stacked on the protective layer 131 to have an area overlapping with the light-emitting device 130a. A color conversion layer 135G and a coloring layer 132G are stacked on the protective layer 131 to have an area overlapping with the light-emitting device 130b. A coloring layer 132B is provided 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. In addition, an insulating layer 125 and an insulating layer 127 on the insulating layer 125 are provided in the region between adjacent light emitting devices.

[0102] 1B shows multiple cross sections of insulating layer 125 and insulating layer 127, but when display device 100 is viewed from above, insulating layer 125 and insulating layer 127 are each connected to one another. That is, display device 100 can be configured to have, for example, one insulating layer 125 and one insulating layer 127. Note that display device 100 may have multiple insulating layers 125 that are separated from one another, or may have multiple insulating layers 127 that are separated from one another.

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

[0104] The layer 101 can have, for example, a stacked structure in which a plurality of transistors (not shown) are provided on a substrate and an insulating layer is provided to cover the transistors. The insulating layer over the transistors may have a single-layer structure or a stacked structure. FIG. 1B illustrates insulating layers over the transistors, including an insulating layer 255a, an insulating layer 255b over the insulating layer 255a, and an insulating layer 255c over the insulating layer 255b. These insulating layers may have a recess between adjacent light-emitting devices. FIG. 1B and other figures illustrate an example in which a recess is provided in the insulating layer 255c. Note that the insulating layer 255c does not necessarily have a recess between adjacent light-emitting devices. Note that the insulating layers over the transistors (insulating layers 255a to 255c) can also be considered as part of the layer 101.

[0105] The insulating layers 255a, 255b, and 255c can each be suitably formed using various inorganic insulating films such as an oxide insulating film, a nitride insulating film, an oxynitride insulating film, or a nitride oxide insulating film. The insulating layers 255a and 255c are preferably formed using an oxide insulating film or an oxynitride insulating film such as a silicon oxide film, a silicon oxynitride film, or an aluminum oxide film. The insulating layer 255b is preferably formed using a nitride insulating film or a nitride oxide insulating film such as a silicon nitride film or a silicon nitride oxide film. More specifically, the insulating layers 255a and 255c are preferably formed using silicon oxide films, and the insulating layer 255b is preferably formed using a silicon nitride film. The insulating layer 255b preferably functions as an etching protective film.

[0106] In this specification and the like, an oxynitride refers to a material whose composition contains more oxygen than nitrogen, and a nitride oxide refers to a material whose composition contains more nitrogen than oxygen. For example, silicon oxynitride refers to a material whose composition contains more oxygen than nitrogen, and silicon nitride oxide refers to a material whose composition contains more nitrogen than oxygen.

[0107] A configuration example of the layer 101 will be described later in the fourth embodiment.

[0108] The light emitting device 130a, the light emitting device 130b, and the light emitting device 130c all emit white (W) light.

[0109] As the light-emitting device, for example, an OLED (organic light-emitting diode) or a QLED (quantum-dot light-emitting diode) is preferably used. Examples of the light-emitting material contained in the light-emitting device include a fluorescent material (fluorescent material), a phosphorescent material (phosphorescent material), a material that exhibits thermally activated delayed fluorescence (thermally activated delayed fluorescence (TADF) material), and an inorganic compound (quantum dot material, etc.). Furthermore, an LED such as a micro LED (light-emitting diode) can also be used as the light-emitting device.

[0110] The light emitting device can emit light of infrared, red, green, blue, cyan, magenta, yellow, white, etc. Furthermore, the color purity can be improved by providing the light emitting device with a microcavity structure.

[0111] For the structure and materials of the light-emitting device, reference can be made to Embodiment Mode 5.

[0112] Of the pair of electrodes that a light-emitting device has, one electrode functions as an anode and the other electrode functions as a cathode. In the following, an example in which the pixel electrode functions as the anode and the common electrode functions as the cathode will be described.

[0113] The light-emitting device 130a included in the subpixel 11R has a pixel electrode 111a on the 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 referred to as an EL layer.

[0114] The light-emitting device 130b included in the subpixel 11G has a pixel electrode 111b on the 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 referred to as an EL layer.

[0115] The light-emitting device 130c included in the subpixel 11B has 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 referred to as an EL layer.

[0116] In this specification and the like, among the EL layers included in the light-emitting devices, layers provided in an island shape for each light-emitting device are all referred to as layers 113W, and a layer shared by a plurality of light-emitting devices is referred to as a common layer 114. Note that in this specification and the like, the layer 113W may be referred to as an island-shaped EL layer, an EL layer formed in an island shape, or the like, without including the common layer 114.

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

[0118] The pixel electrodes 111a, 111b, and 111c each preferably have a tapered edge. Specifically, the pixel electrodes 111a, 111b, and 111c each preferably have a tapered edge with a taper angle of less than 90°. When the edges of these pixel electrodes have a tapered edge, the layer 113W provided along the side surface of the pixel electrode also has a tapered edge. Tapering the side surface of the pixel electrode can improve the coverage of the EL layer provided along the side surface of the pixel electrode.

[0119] 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 shapes of the pixel electrodes 111a, 111b, and 111c, but this is not limiting. 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 FIG. 1B , an insulating layer (also referred to as a partition wall, bank, spacer, etc.) covering the upper end of the pixel electrode 111a is not provided between the pixel electrode 111a and the layer 113W. Furthermore, an insulating layer covering the upper end of the pixel electrode 111b is not provided between the pixel electrode 111b and the layer 113W. Similarly, an insulating layer covering the upper end of the pixel electrode 111c is not provided between the pixel electrode 111c and the layer 113W. This allows the distance between adjacent light-emitting devices to be extremely narrow. This allows a high-definition or high-resolution display device to be realized. Furthermore, a mask for forming the insulating layer is not required, thereby reducing the manufacturing cost of the display device.

[0121] Furthermore, by using a structure in which an insulating layer covering an edge of the pixel electrode is not provided between the pixel electrode and the EL layer, in other words, by using a structure in which an insulating layer is not provided between the pixel electrode and the EL layer, light from the EL layer can be efficiently extracted. Therefore, the display device of one embodiment of the present invention can have extremely low viewing angle dependence. By reducing the viewing angle dependence, the visibility of images in the display device can be improved. For example, in the display device of one embodiment of the present invention, the viewing angle (the maximum angle at which a certain contrast ratio is maintained when the screen is viewed from an oblique direction) can be set to a range of 100° to less than 180°, preferably 150° to 170°. Note that the above viewing angle can be applied to both the vertical and horizontal directions.

[0122] The light-emitting device of the present embodiment may have a single structure (a structure having only one light-emitting unit) or a tandem structure (a structure having multiple light-emitting units). The light-emitting unit has at least one light-emitting layer.

[0123] The layer 113W includes at least a light-emitting layer. For example, the layer 113W can include a light-emitting material that emits blue light and a light-emitting material that emits visible light with a wavelength longer than blue. For example, the layer 113W can include a light-emitting material that emits blue light and a light-emitting material that emits yellow light, or a light-emitting material that emits blue light, a light-emitting material that emits green light, and a light-emitting material that emits red light.

[0124] Furthermore, when a light-emitting device with a tandem structure is used, the layer 113W preferably has a structure including a plurality of light-emitting units that emit white light, and a charge generation layer is preferably provided between each of the light-emitting units. By adopting a tandem structure, a light-emitting device capable of emitting light with high brightness can be realized.

[0125] Additionally, each layer 113W may include one or more of a hole injection layer, a hole transport layer, a hole blocking layer, a charge generating layer, an electron blocking layer, an electron transport layer, and an electron injection layer.

[0126] For example, layer 113W may have a hole injection layer, a hole transport layer, a light-emitting layer, and an electron transport layer in this order. Alternatively, layer 113W may have an electron blocking layer between the hole transport layer and the light-emitting layer. Alternatively, layer 113W may have a hole blocking layer between the electron transport layer and the light-emitting layer. Alternatively, layer 113W may have an electron injection layer on the electron transport layer.

[0127] For example, layer 113W may have an electron injection layer, an electron transport layer, an emitting layer, and a hole transport layer in this order. Alternatively, layer 113W may have a hole blocking layer between the electron transport layer and the emitting layer. Alternatively, layer 113W may have an electron blocking layer between the hole transport layer and the emitting layer. Alternatively, layer 113W may have a hole injection layer on the hole transport layer.

[0128] As described above, the layer 113W preferably includes a light-emitting layer and a carrier transport layer (electron transport layer or hole transport layer) on the light-emitting layer. Alternatively, the layer 113W preferably includes a light-emitting layer and a carrier block layer (hole block layer or electron block layer) on the light-emitting layer. Alternatively, the layer 113W preferably includes 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 layer 113W is exposed during the manufacturing process of the display device, providing one or both of the carrier transport layer and the carrier block layer on the light-emitting layer can prevent the light-emitting layer from being exposed to the outermost surface and reduce damage to the light-emitting layer. This can improve the reliability of the light-emitting device.

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

[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 on and 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 damage to the light-emitting layer.

[0131] Furthermore, it is preferable that the light-emitting layer has a high heat resistance temperature, which can prevent the light-emitting layer from being damaged by heating, resulting in a decrease in light-emitting efficiency and a shortened lifespan.

[0132] The light-emitting layer includes a light-emitting substance (also referred to as a light-emitting material, a light-emitting organic compound, a guest material, or the like) and an organic compound (also referred to as a host material, or the like). The light-emitting layer contains a larger amount of the organic compound than the light-emitting substance, and therefore the Tg of the organic compound can be used as an index of the heat resistance temperature of the light-emitting layer.

[0133] Also, for example, layer 113W can have a first light-emitting unit, a charge generating layer on the first light-emitting unit, and a second light-emitting unit on the charge generating layer.

[0134] The second light-emitting unit preferably has an emitting layer and a carrier transport layer (electron transport layer or hole transport layer) on the emitting layer. Alternatively, the second light-emitting unit preferably has an emitting layer and a carrier block layer (hole block layer or electron block layer) on the emitting layer. Alternatively, the second light-emitting unit preferably has an emitting layer, a carrier block layer on the 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, providing one or both of a carrier transport layer and a carrier block layer on the emitting layer can prevent the emitting layer from being exposed to the outermost surface and reduce damage to the emitting layer. This can improve the reliability of the light-emitting device. Note that when three or more emitting units are included, the uppermost emitting unit preferably has an emitting layer and one or both of a carrier transport layer and a carrier block layer on the emitting layer.

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

[0136] 1B shows an example in which the edge of the layer 113W is positioned further outward than the edge of the pixel electrode 111a. Note that, although the following description will be given using the pixel electrode 111a and the layer 113W as an example, the same can be said for the pixel electrode 111b and the layer 113W, and the pixel electrode 111c and the layer 113W.

[0137] 1B, the layer 113W is formed so as to cover the edge of the pixel electrode 111a. With this configuration, it is possible to use the entire upper surface of the pixel electrode as a light-emitting region, which makes it 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 side surfaces of the pixel electrodes with the EL layer, contact between the pixel electrodes and the common electrode 115 can be prevented, thereby preventing short circuits in the light-emitting device. Furthermore, the distance between the light-emitting region of the EL layer (i.e., the region overlapping with the pixel electrode) and the edge of the EL layer can be increased. Since the edge of the EL layer may be damaged by processing, using an area away from the edge of the EL layer as the light-emitting region may 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 with a mask layer during the manufacturing process of the display device, and damage to the first region is significantly reduced. Therefore, a light-emitting device with high light-emitting efficiency and a long life can be realized. On the other hand, the second region includes the edge of the EL layer and its vicinity, and includes a portion that may be damaged by exposure to plasma during the manufacturing process of the display device. By not using the second region as a light-emitting region, variation in the characteristics of the light-emitting device can be suppressed.

[0140] The width L3 shown in FIGS. 1B and 1C corresponds to the width of the first region 113_1 (light-emitting region) in the layer 113W. The widths L1 and L2 shown in FIGS. 1B and 1C correspond to the width of the second region 113_2 (dummy region) in the layer 113W. As shown in FIG. 1C, the second region 113_2 is provided to surround the first region 113_1. Therefore, the width of the second region 113_2 can be confirmed at two locations, left and right, in cross-sectional views such as FIG. 1B. The width of the second region 113_2 can be the width L1 or the width L2. For example, the shorter of the widths L1 and L2 may be used. The widths L1 to L3 can be confirmed in cross-sectional observation images. Although a cross-sectional view in the X direction is described as an example in this embodiment, the widths of the light-emitting region and the dummy region can also be confirmed in a cross-sectional view in the Y direction.

[0141] The enlarged view in Fig. 2A shows the width L2 of the second region 113_2. The second region 113_2 is a portion of the layer 113W where at least one of the mask layer 118a, the insulating layer 125, and the insulating layer 127 overlap. In addition, a portion of the layer 113W located outside the edge of the top surface of the pixel electrode, such as the region 103 shown in Fig. 5B, 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 can uniformize the quality of the light-emitting region and suppress variations in the characteristics of the light-emitting device. On the other hand, a narrower dummy region is preferable because it widens the light-emitting region and increases the aperture ratio of the pixel. 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, for example, in a small, high-resolution display device such as a display device for a wearable device, 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 (light-emitting region) is a region where EL light emission is obtained. Furthermore, in the island-shaped EL layer, both the first region (light-emitting region) and the second region (dummy region) are regions where PL (Photoluminescence) light emission is obtained. From these facts, it can be said that the first region and the second region can be distinguished by checking the EL light emission and the PL light emission.

[0144] The common electrode 115 is shared by the light-emitting devices 130a, 130b, and 130c. The common electrode 115 shared by the plurality of light-emitting devices is electrically connected to a conductive layer 123 provided in the connection portion 140 (see FIGS. 9A and 9B). The conductive layer 123 is preferably made of the same material and formed in the same process as the pixel electrodes 111a, 111b, and 111c.

[0145] 9A shows an example in which a common layer 114 is provided on the conductive layer 123, and the conductive layer 123 and the common electrode 115 are electrically connected to each other via the common layer 114. The common layer 114 does not need to be provided in the connection portion 140. In FIG. 9B, the conductive layer 123 and the common electrode 115 are directly connected to each other. For example, by using a mask (also called an area mask or a rough metal mask to distinguish it from a fine metal mask) for defining a film formation area, the regions where the common layer 114 and the common electrode 115 are formed can be changed.

[0146] 1B , a mask layer 118a is positioned over the layer 113W of the light-emitting device 130a, the layer 113W of the light-emitting device 130b, and the layer 113W of the light-emitting device 130c. The mask layer is provided to surround the first region 113_1 (light-emitting region). In other words, the mask layer has an opening in a portion overlapping the light-emitting region. The top surface shape of the mask layer is identical, approximately identical, or similar to that of the second region 113_2 shown in FIG. 1C . The mask layer 118a is a remaining portion of the mask layer that was provided in contact with the top surface of the layer 113W when processing the layer 113W. In this way, a display device according to one embodiment of the present invention may have a portion of the mask layer used to protect the EL layer during fabrication remaining.

[0147] In FIG. 1B , one end of the mask layer 118a (the end opposite the light-emitting region, the outer end) is aligned or approximately aligned with the end of the 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 the layer 113W. Here, the other end of the mask layer 118a preferably overlaps the layer 113W and the pixel electrode 111a (or the pixel electrode 111b or the pixel electrode 111c). In this case, the other end of the mask layer 118a is likely to be formed on a substantially flat surface of the layer 113W. Furthermore, the mask layer 118a remains, for example, between the top 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] In addition, when the edges are aligned or approximately aligned, and when the top surface shapes are the same or approximately aligned, it can be said that at least a portion of the contours of the stacked layers overlap in a planar view. For example, this includes cases where the upper and lower layers are processed using the same mask pattern or a portion of the same mask pattern. However, strictly speaking, the contours may not overlap, and the upper layer may be located inside the lower layer, or outside the lower layer. In these cases, it is also said that the edges are approximately aligned, or the top surface shapes are approximately aligned.

[0149] The side surface of the layer 113W is covered with the insulating layer 125. The insulating layer 127 overlaps the side surface of the layer 113W with the insulating layer 125 interposed therebetween.

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

[0151] By covering a portion of the top surface and the side surfaces of the layer 113W with at least one of the insulating layer 125, the insulating layer 127, and the mask layer 118a, the common layer 114 (or the common electrode 115) is prevented from contacting the pixel electrodes 111a, 111b, and 111c, and the side surfaces of the layer 113W, thereby preventing short circuits in the light-emitting device, thereby improving the reliability of the light-emitting device.

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

[0153] Furthermore, for example, a material that is reflective to visible light is used for each pixel electrode (pixel electrode 111a, pixel electrode 111b, and pixel electrode 111c), and a material that is both transparent and reflective to visible light is used for the common electrode 115. This makes it possible to realize a top-emission display device having a microcavity formed by the common electrode 115, common layer 114, layer 113W, and each pixel electrode.

[0154] In the above case, in the light-emitting device 130a, a portion of the white light emitted by the layer 113W passes through the common electrode 115, which is both transparent and reflective to visible light, while the remaining light is reflected by the common electrode 115. This reflected light undergoes multiple reflections within the microcavity, eliminating light other than red and increasing the intensity of the red light. The red light then passes through the common electrode 115. In other words, by employing a microcavity structure, the light-emitting device 130a can emit red light with higher color purity than when the microcavity structure is not employed. 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] Although the above example shows the application of a microcavity structure to a light-emitting device of a top-emission display device, this is not the only possible application. For example, a bottom-emission display device can be realized by using a material that is reflective to visible light for the common electrode 115 and a material that is both transparent and reflective to visible light for each pixel electrode.

[0156] It is preferable that the insulating layer 125 contacts the side surface of the layer 113W (see the end of the layer 113W and the area in the vicinity thereof surrounded by a dashed line in FIG. 2A). By configuring the insulating layer 125 to contact the layer 113W, peeling of the layer 113W can be prevented. By closely adhering the insulating layer 125 and the layer 113W, the adjacent layers 113W and the like are fixed or bonded by the insulating layer 125. This can improve the reliability of the light-emitting device. Furthermore, the manufacturing yield of the light-emitting device can be increased.

[0157] 1B , the insulating layer 125 and the insulating layer 127 cover part of the top surface and both the side surfaces of the layer 113W, which can further prevent peeling of the EL layer and improve the reliability of the light-emitting device and the manufacturing yield of the light-emitting device.

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

[0159] 1B shows a configuration in which the end of pixel electrode 111a is covered with layer 113W, and insulating layer 125 is in contact with the side surface of layer 113W. Similarly, the end of pixel electrode 111b is covered with layer 113W, and insulating layer 125 is in contact with the side surface of layer 113W. Furthermore, the end of pixel electrode 111c is covered with layer 113W, and 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 recess formed in the insulating layer 125. The insulating layer 127 can be configured to overlap a portion of the top surface and the side surfaces of the layer 113W via the insulating layer 125. It is preferable that the insulating layer 127 cover at least a portion of the side surfaces of the insulating layer 125.

[0161] By providing the insulating layers 125 and 127, the gaps between adjacent island-shaped layers can be filled, which reduces the extreme unevenness of the surface on which a layer (e.g., a carrier injection layer, a common electrode, etc.) is formed on the island-shaped layers, thereby making the surface flatter, thereby improving the coverage of the carrier injection layer, the common electrode, etc.

[0162] The common layer 114 and the common electrode 115 are provided over the layer 113W, the mask layer 118a, the insulating layer 125, and the insulating layer 127. Before the insulating layer 125 and the insulating layer 127 are provided, a step exists between a region where the pixel electrode and the island-shaped EL layer are provided (a region where the light-emitting device is located) and a region where the pixel electrode and the island-shaped EL layer are not provided (a region between the light-emitting devices). The display device of one embodiment of the present invention includes the insulating layer 125 and the insulating layer 127, which can flatten the step and improve the coverage of the common layer 114 and the common electrode 115. Therefore, poor connection due to a step in the common layer 114 or the common electrode 115 can be suppressed. Furthermore, the step can suppress an increase in the electrical resistance of the common electrode 115 caused by a local thinning of the common electrode 115.

[0163] The upper surface of the insulating layer 127 preferably has a highly flat shape, but may have a convex portion, a convex curved surface, a concave curved surface, or a concave portion. For example, the upper surface of the insulating layer 127 preferably has a highly flat, smooth convex curved surface shape.

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

[0165] The insulating layer 125 can be an insulating layer containing an inorganic material. For example, an inorganic insulating film such as an oxide insulating film, a nitride insulating film, an oxynitride insulating film, or a nitride oxide insulating film can be used for the insulating layer 125. The insulating layer 125 may have a single-layer structure or a stacked-layer structure. Examples of oxide insulating films include a silicon oxide film, an aluminum oxide film, a magnesium oxide film, an indium gallium zinc oxide film, a gallium oxide film, a germanium oxide film, an yttrium oxide film, a zirconium oxide film, a lanthanum oxide film, a neodymium oxide film, a hafnium oxide film, and a tantalum oxide film. Examples of nitride insulating films include a silicon nitride film and an aluminum nitride film. Examples of oxynitride insulating films include a silicon oxynitride film and an aluminum oxynitride film. Examples of nitride oxide insulating films include a silicon nitride oxide film and an aluminum nitride oxide film. In particular, aluminum oxide is preferable because it has a high etching selectivity with respect to the EL layer and functions to protect the EL layer in the formation of the insulating layer 127 described later. In particular, by using an inorganic insulating film such as an aluminum oxide film, a hafnium oxide film, or a silicon oxide film formed by atomic layer deposition (ALD) as the insulating layer 125, it is possible to form an insulating layer 125 that has few pinholes and has an excellent function of protecting the EL layer. The insulating layer 125 may also have a stacked structure of a film formed by ALD and a film formed by sputtering. For example, the insulating layer 125 may have a stacked structure of an aluminum oxide film formed by ALD and a silicon nitride film formed by sputtering.

[0166] The insulating layer 125 preferably functions as a barrier insulating layer against at least one of water and oxygen. The insulating layer 125 preferably has a function of suppressing diffusion of at least one of water and oxygen. The insulating layer 125 preferably has a function of capturing or fixing (also referred to as gettering) at least one of water and oxygen.

[0167] Note that in this specification and the like, a barrier insulating layer refers to an insulating layer having barrier properties. In addition, in this specification and the like, the barrier properties refer to a function of suppressing the diffusion of a corresponding substance (also referred to as low permeability) or a function of capturing or fixing (also referred to as gettering) a corresponding substance.

[0168] The insulating layer 125 has a function as a barrier insulating layer or a gettering function, which can suppress the intrusion of impurities (typically, at least one of water and oxygen) that can diffuse into each light-emitting device from the outside. With this configuration, a highly reliable light-emitting device and further a highly reliable display device can be provided.

[0169] The insulating layer 125 preferably has a low impurity concentration. This can prevent impurities from entering the EL layer from the insulating layer 125 and causing deterioration of the EL layer. Furthermore, a low impurity concentration in the insulating layer 125 can improve the barrier properties against at least one of water and oxygen. For example, it is desirable that the insulating layer 125 has a sufficiently low hydrogen concentration or a sufficiently low carbon concentration, or preferably both of them.

[0170] The insulating layer 125 and the mask layer 118a may be made of the same material. 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 recognized as a single layer. In other words, one layer may be observed to be provided in contact with a portion of the top surface and side surfaces of the layer 113W, and the insulating layer 127 may be observed to cover at least a portion of the side surfaces of the one layer.

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

[0172] An insulating layer containing an organic material can be suitably used as the insulating layer 127. As the organic material, a photosensitive organic resin is preferably used, for example, a photosensitive resin composition containing an acrylic resin is preferably used. Note that in this specification and the like, the term "acrylic resin" does not refer only to polymethacrylic acid ester or methacrylic resin, but may refer to all acrylic polymers in a broad sense.

[0173] The insulating layer 127 may also be made of acrylic resin, polyimide resin, epoxy resin, imide resin, polyamide resin, polyimideamide resin, silicone resin, siloxane resin, benzocyclobutene-based resin, phenolic resin, or precursors of these resins. The insulating layer 127 may also be made of organic materials such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinylpyrrolidone, polyethylene glycol, polyglycerin, pullulan, water-soluble cellulose, or alcohol-soluble polyamide resin. The photosensitive resin may also be a photoresist. Either a positive-type material or a negative-type material may be used as the photosensitive organic resin.

[0174] The insulating layer 127 may be made of a material that absorbs visible light. By having the insulating layer 127 absorb light emitted from the light-emitting device, it is possible to suppress light leakage (stray light) from the light-emitting device to an adjacent light-emitting device through the insulating layer 127. This can improve the display quality of the display device. Furthermore, since the display quality can be improved without using a polarizing plate in the display device, it is possible to reduce the weight and thickness of the display device.

[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 for color filters (color filter materials). In particular, using a resin material in which two or more color filter materials are laminated or mixed is preferable because it can enhance the visible light blocking effect. In particular, mixing three or more color filter materials makes it possible to form a black or nearly black resin layer.

[0176] Next, the structure of the insulating layer 127 and its vicinity will be described using Figures 2A and 2B. Figure 2A is an enlarged cross-sectional view of the insulating layer 127 between the light-emitting device 130a of the subpixel emitting red light and the light-emitting device 130b of the subpixel emitting green light, and a region including the periphery thereof. The following description will be given using the insulating layer 127 between two adjacent light-emitting devices, 130a and 130b, as an example, but the same applies to the insulating layer 127 between the light-emitting device 130b and 130c. Figure 2B is an enlarged view of the end of the insulating layer 127 on the layer 113W shown in Figure 2A and its vicinity. Note that the common layer 114 and common electrode 115 are omitted from Figure 2B.

[0177] As shown in FIG. 2A , a layer 113W is provided covering the pixel electrode 111a, and a layer 113W is provided covering the pixel electrode 111b. A mask layer 118a is provided in contact with a portion of the upper surface of the layer 113W. An insulating layer 125 is provided in contact with the upper and side surfaces of the mask layer 118a, the side surfaces of the layer 113W, and the upper surface of the insulating layer 255c. The insulating layer 125 also covers a portion of the upper surface of the layer 113W. An insulating layer 127 is provided in contact with the upper surface of the insulating layer 125. The insulating layer 127 overlaps a portion of the upper surface and the side surfaces of the layer 113W via the insulating layer 125 and is in contact with at least a portion of the side surfaces of the insulating layer 125. A common layer 114 is provided covering the layer 113W, the mask layer 118a, the insulating layer 125, and the 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 FIG. 2A , the region between the two layers 113W). At this time, at least a portion of the insulating layer 127 is disposed in a position sandwiched between the side edge of one EL layer and the side edge of the other EL layer. By providing such an insulating layer 127, it is possible to prevent the formation of divided portions and locally thin portions in the common layer 114 and common electrode 115 formed on the island-shaped EL layers and insulating layer 127.

[0179] 2B , the insulating layer 127 preferably has a tapered shape at its edge with a taper angle θ1 in a cross-sectional view of the display device. The taper angle θ1 is the angle between the side surface (or edge) of the insulating layer 127 and the substrate surface. However, the taper angle θ1 is not limited to the substrate surface, and may be the angle between the top surface of the flat portion of the layer 113W or the top surface of the flat portion of the pixel electrode 111b and the side surface (or edge) 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 forming the end of the insulating layer 127 in such a tapered shape, the common layer 114 and the common electrode 115 provided on the insulating layer 127 can be formed with good coverage, and the occurrence of discontinuities or local thinning of the common layer 114 or the common electrode 115 can be suppressed. This improves the in-plane uniformity of the film thickness of the common layer 114 and the common electrode 115, thereby improving the display quality of the display device.

[0181] 2A , in a cross-sectional view of the display device, the upper surface of the insulating layer 127 preferably has a convex curved shape. The convex curved shape of the upper surface of the insulating layer 127 preferably bulges gently toward the center. Furthermore, the convex curved portion at the center of the upper surface of the insulating layer 127 preferably smoothly connects to the tapered portions at the edges. By forming the insulating layer 127 in this shape, the common layer 114 and the common electrode 115 can be formed with good coverage over the entire insulating layer 127.

[0182] 2B , the end of the insulating layer 127 is preferably positioned outside the end of the insulating layer 125. This reduces the unevenness of the surface on which the common layer 114 and the common electrode 115 are formed, and improves the coverage of the common layer 114 and the common electrode 115.

[0183] 2B , the insulating layer 125 preferably has a tapered shape at its end with a taper angle θ2 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, the taper angle θ2 is not limited to the substrate surface, and may be the angle between the side surface of the insulating layer 125 and the upper surface of the flat portion of the layer 113W or the upper surface of the flat portion of the pixel electrode 111b.

[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] 2B, the mask layer 118a preferably has a tapered shape at its end with a taper angle θ3 in a cross-sectional view of the display device. The taper angle θ3 is the angle between the side (or end) of the mask layer 118a and the substrate surface. However, the taper angle θ3 is not limited to the substrate surface, and may be the angle between the top surface of the flat portion of the layer 113W or the top surface of the flat portion of the pixel electrode 111b and the side 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 forming the mask layer 118a in 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] The end of the mask layer 118a is preferably positioned outside the end of the insulating layer 125. This reduces the unevenness of the surface on which the common layer 114 and the common electrode 115 are formed, and improves the coverage of the common layer 114 and the common electrode 115.

[0188] As will be described in detail in Embodiment 2, if the insulating layer 125 and the mask layer 118a are etched at the same time, side etching may cause the insulating layer 125 and the mask layer 118a below the edges of the insulating layer 127 to disappear, forming cavities. These cavities may cause unevenness on the surfaces on which the common layer 114 and the common electrode 115 are formed, making the common layer 114 and the common electrode 115 more likely to break apart. Therefore, by performing the etching process in two stages and performing a heat treatment between the two etching processes, even if cavities are formed in the first etching process, the heat treatment deforms the insulating layer 127, thereby filling the cavities. Furthermore, because the second etching process involves etching a thin film, the amount of side etching is reduced, making it less likely that cavities will form. Even if cavities do form, they can be kept extremely small. This prevents unevenness from forming on the surfaces on which the common layer 114 and the common electrode 115 are formed, and also prevents the common layer 114 and the common electrode 115 from breaking apart. Since the etching process is performed twice in this manner, the taper angles θ2 and θ3 may be different from each other. Alternatively, the taper angles θ2 and θ3 may be the same. Alternatively, the taper angles θ2 and θ3 may be smaller than the 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, FIG. 2B shows an example in which the insulating layer 127 contacts and covers the inclined surface located at the end of the mask layer 118a formed by the first etching process, while the inclined surface located at the end of the mask layer 118a formed by the second etching process is exposed. These two inclined surfaces may be distinguishable because they have 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] 3A and 3B also show an example in which the insulating layer 127 covers the entire side surface of the mask layer 118a. Specifically, in FIG. 3B, the insulating layer 127 contacts and covers both of the two inclined surfaces. This is preferable because it further reduces the unevenness of the surface on which the common layer 114 and the common electrode 115 are formed. FIG. 3B shows an example in which the end of the insulating layer 127 is located outside the end of the mask layer 118a. As shown in FIG. 2B, the end of the insulating layer 127 may be located inside the end of the mask layer 118a, or may be aligned or approximately aligned with the end of the mask layer 118a. Also, as shown in FIG. 3B, the insulating layer 127 may contact the layer 113W.

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

[0192] 4A and 4B show an example in which the insulating layer 127 has a concave curved shape (also referred to as a constricted portion, recess, dent, or depression) on the side surface. Depending on the material and forming conditions (heating temperature, heating time, heating atmosphere, etc.) of the insulating layer 127, the concave curved shape may be formed on the side surface of the insulating layer 127.

[0193] 4A shows an example in which the insulating layer 127 covers a part of the side surface of the mask layer 118a and the remaining part of the side surface of the mask layer 118a is exposed, while FIG. 4B shows an example in which the insulating layer 127 contacts and covers the entire side surface of the mask layer 118a.

[0194] 2 to 4, it is preferable that one end of the insulating layer 127 overlaps the upper surface of the pixel electrode 111a, and the other end of the insulating layer 127 overlaps the upper surface of the pixel electrode 111b. This structure allows the end of the insulating layer 127 to be formed on a substantially flat region of the layer 113W. This makes it relatively easy to form the tapered shapes of the insulating layer 127, the insulating layer 125, and the mask layer 118a. Furthermore, film peeling between the layer 113W and the pixel electrode 111a or 111b can be suppressed. On the other hand, the smaller the overlapping portion between the upper surface of the pixel electrode and the insulating layer 127, the wider the light-emitting region of the light-emitting device, which increases the aperture ratio, which is preferable.

[0195] Note that the insulating layer 127 does not have to overlap the upper surface of the pixel electrode. As shown in FIG. 5A , the insulating layer 127 may not overlap the upper surface of the pixel electrode, but one end of the insulating layer 127 may overlap a side surface of the pixel electrode 111a, and the other end of the insulating layer 127 may overlap a side surface of the pixel electrode 111b. Also, as shown in FIG. 5B , the insulating layer 127 may not overlap the pixel electrode, but may be provided in a region sandwiched between the pixel electrodes 111a and 111b. In FIGS. 5A and 5B , part or all of the upper surface of the inclined portion and flat portion (region 103) of the upper surface of the layer 113W located outside the upper surface of the pixel electrode are covered by the mask layer 118a, the insulating layer 125, and the insulating layer 127. Even with this configuration, it is possible to reduce the unevenness of the surface on which the common layer 114 and the common electrode 115 are formed, and improve the coverage of the common layer 114 and the common electrode 115, compared to a configuration in which the mask layer 118a, the insulating layer 125, and the insulating layer 127 are not provided. Note that the region 103 can be called a dummy region.

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

[0197] 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 FIG. 6B , the upper surface of the insulating layer 127 has a shape that gently bulges toward the center, i.e., a convex curved surface, and a shape that is recessed in the center and its vicinity, i.e., a concave curved surface. Also, in FIG. 6B , the convex curved portion of the upper surface of the insulating layer 127 has a shape that smoothly connects to the tapered portions at the ends. Even when the insulating layer 127 has such a shape, the common layer 114 and the common electrode 115 can be formed with good coverage over the entire insulating layer 127.

[0198] 6B , one method for forming the insulating layer 127 with a concave curved surface in the center thereof is exposure using a multi-tone mask (typically, a half-tone mask or a gray-tone mask). The multi-tone mask is a mask capable of performing exposure at three exposure levels: an exposed portion, an intermediately exposed portion, and an unexposed portion, and is an exposure mask that transmits light with a variety of intensities. This makes it possible to form the insulating layer 127 with regions of multiple thicknesses (typically, two types) using only a single photomask (a single exposure and development process).

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

[0200] Although not shown, 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, a portion of the insulating layer 127 disappears in the center of the insulating layer 127 shown in Fig. 6B, exposing the surface of the insulating layer 125. In this case, the insulating layer 127 may have a shape that can cover the common layer 114 and the common electrode 115.

[0201] 2 to 6 , the insulating layer 127, the insulating layer 125, and the mask layer 118a are provided, thereby enabling the common layer 114 and the common electrode 115 to be formed with good coverage. Furthermore, the formation of divided portions and locally thin portions in the common layer 114 and the common electrode 115 can be prevented. Therefore, between the light-emitting devices, poor connection between the common layer 114 and the common electrode 115 due to the divided portions and an increase in electrical resistance due to locally thin portions can be suppressed. This allows the display device of one embodiment of the present invention to have improved display quality.

[0202] It is preferable to provide a protective layer 131 on the light-emitting device 130a, the light-emitting device 130b, and the light-emitting device 130c. The reliability of the light-emitting device can be improved by providing the protective layer 131. The protective layer 131 may have a single-layer structure or a stacked structure of two or more layers.

[0203] There is no limitation on the conductivity of the protective layer 131. The protective layer 131 can be made of at least one of an insulating film, a semiconductor film, and a conductive film.

[0204] By having the protective layer 131 be an inorganic film, it is possible to prevent oxidation of the common electrode 115, to prevent impurities (moisture, oxygen, etc.) from entering the light-emitting device, and to suppress deterioration of the light-emitting device and improve the reliability of the display device.

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

[0206] Alternatively, an inorganic film containing In—Sn oxide (also referred to as ITO), In—Zn oxide, Ga—Zn oxide, Al—Zn oxide, indium gallium zinc oxide (In—Ga—Zn oxide, also referred to as IGZO), or the like can be used for the protective layer 131. The inorganic film preferably has high resistance, specifically, preferably has higher resistance than the common electrode 115. The inorganic film may further contain nitrogen.

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

[0208] For example, a stacked structure of an aluminum oxide film and a silicon nitride film on the aluminum oxide film, or a stacked structure of an aluminum oxide film and an IGZO film on the aluminum oxide film can be used as the protective layer 131. By using such a stacked structure, impurities (water, oxygen, etc.) can be prevented from entering the EL layer side.

[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 the organic insulating materials that can be used for the insulating layer 127.

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

[0211] A light-shielding layer may be provided on the surface of the substrate 120 facing the resin layer 122. Various optical members may be disposed on the outer side of the substrate 120 (the surface opposite to the resin layer 122). Examples of optical members include a polarizing plate, a retardation plate, a light diffusion layer (such as a diffusion film), an anti-reflection layer, and a light-collecting film. Furthermore, a surface protection layer such as an anti-static film that suppresses the adhesion of dust, a water-repellent film that makes it difficult for dirt to adhere, a hard coat film that suppresses the occurrence of scratches during use, or an impact absorbing layer may be disposed on the outer side of the substrate 120. For example, a glass layer or a silica layer (SiO ｘ The surface protection layer can be preferably formed of a material such as DLC (diamond-like carbon), aluminum oxide (AlO ｘ ), polyester-based materials, or polycarbonate-based materials may also be used. Note that it is preferable to use a material with high transmittance to visible light for the surface protection layer. It is also preferable to use a material with high hardness for the surface protection layer.

[0212] The substrate 120 can be made of glass, quartz, ceramics, sapphire, resin, metal, alloy, semiconductor, or the like. A material that transmits light is used for the substrate on the side from which light from the light-emitting device is extracted. Using a flexible material for the substrate 120 can increase the flexibility of the display device. Alternatively, a polarizing plate may be used as the substrate 120.

[0213] The substrate 120 may be made of polyester resin such as polyethylene terephthalate (PET) or polyethylene naphthalate (PEN), polyacrylonitrile resin, acrylic resin, polyimide resin, polymethyl methacrylate resin, polycarbonate (PC) resin, polyethersulfone (PES) resin, polyamide resin (nylon, aramid, etc.), polysiloxane resin, cycloolefin resin, polystyrene resin, polyamideimide resin, polyurethane resin, polyvinyl chloride resin, polyvinylidene chloride resin, polypropylene resin, polytetrafluoroethylene (PTFE) resin, ABS resin, cellulose nanofiber, etc. The substrate 120 may be made of glass having a thickness sufficient to provide flexibility.

[0214] When a circularly polarizing plate is superimposed on a display device, it is preferable that the display device has a substrate with high optical isotropy. A substrate with high optical isotropy has small birefringence (or a small amount of birefringence).

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

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

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

[0218] The resin layer 122 can be made of various curable adhesives, such as a photo-curable adhesive (e.g., an ultraviolet curable adhesive), a reactive curable adhesive, a thermosetting adhesive, or an anaerobic adhesive. Examples of such adhesives include epoxy resin, acrylic resin, silicone resin, phenolic resin, polyimide resin, imide resin, PVC (polyvinyl chloride) resin, PVB (polyvinyl butyral) resin, and EVA (ethylene vinyl acetate) resin. Materials with low moisture permeability, such as epoxy resin, are particularly preferred. Two-component resins may also be used. Adhesive sheets or the like may also be used.

[0219] 7A, 8A to 8C, 9C and 9D, 10A to 10C, and 11A and 11B show modifications of FIG. 1B.

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

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

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

[0223] 7A , the top and side surfaces of the pixel electrodes 111a, 111b, and 111c are covered with the conductive layers 116a, 116b, and 116c, respectively. Therefore, when films above the conductive layers 116a, 116b, and 116c are removed by wet etching, the etching solution can be prevented from coming into contact with the pixel electrodes 111a, 111b, and 111c, thereby preventing the pixel electrodes from being altered due to galvanic corrosion or the like. This allows for a wider range of material options for the pixel electrodes 111a, 111b, and 111c. Furthermore, because the layer 113W is in contact with the conductive layers 116a, 116b, and 116c, the adhesion between the layer 113W and the conductive layers is uniform.

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

[0225] The pixel electrode 111 shown in FIG. 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 (e.g., In—Si—Sn oxide (also referred to as ITSO)) as the conductive layer 116. The pixel electrode 111 shown in FIG. 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 (e.g., ITSO) as the conductive layer 116. An 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 are in contact with each other, electrolytic corrosion may occur 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 also 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 the conductive layers 116a, 116b, and 116c may be different from one another. For example, as shown in FIG. 7F, it is preferable that the thickness of the conductive layer 116a be greater than the thickness of the conductive layer 116b. Specifically, it is preferable that the thickness of the conductive layer 116a be set so as to enhance red light, the thickness of the conductive layer 116b be set so as to enhance green light, and the thickness of the conductive layer 116c be set so as to enhance blue light. This allows for a microcavity structure to be realized, and the color purity of each light-emitting device to be improved.

[0228] 1B shows an example in which a color conversion layer 135R and a coloring layer 132R are provided directly on the light-emitting device 130a via a protective layer 131. Also shown is an example in which a color conversion layer 135G and a coloring layer 132G are provided directly on the light-emitting device 130b via a protective layer 131. Also shown is an example in which a coloring layer 132B is provided directly on the light-emitting device 130c via a protective layer 131. This configuration can improve the accuracy of alignment between the light-emitting device and the color conversion layer or coloring layer. Furthermore, by positioning the light-emitting device and the coloring layer closer to each other, color mixing can be suppressed and viewing angle characteristics can be improved, which is preferable.

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

[0230] 8B and 8C , the display device may be provided with a lens 133. The lens 133 is preferably provided so as to overlap the light-emitting device. By providing the lens 133, light emitted by the light-emitting device can be extracted to the outside of the display device more efficiently than in the case where the lens 133 is not provided.

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

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

[0233] 8B, light emitted from the light-emitting device passes through the color conversion layer and the colored layer, and then passes through the lens 133 to be extracted to the outside of the display device. By positioning the light-emitting device and the colored layer close to each other, color mixing can be suppressed and viewing angle characteristics can be improved, which is preferable. Alternatively, the lens 133 may be provided on the light-emitting device, and the color conversion layer and the colored layer may be provided on the lens 133.

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

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

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

[0237] At a position overlapping with the light-emitting device 130a and the light-emitting device 130b, a lens 133 may be provided in contact with the substrate 120, an insulating layer 134 may be provided in contact with the lens 133, a colored layer may be provided in contact with the insulating layer 134, and a color conversion layer may be provided in contact with the colored layer. At a position overlapping with the light-emitting device 130c, a lens 133 may be provided in contact with the substrate 120, an insulating layer 134 may be provided in contact with the lens 133, and a colored layer may be provided 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 to red (green) light by the color conversion layer, and only the red (green) light of the converted light passes through the colored layer and the lens 133 before being extracted to the outside of the display device. Furthermore, only the blue light of the light emitted from the light-emitting device 130c passes through the colored layer and the lens 133 before being extracted to the outside of the display device.

[0238] 1B, 8B, etc. show examples in which a layer having a planarizing function is used as the protective layer 131, but as shown in FIGS. 8A and 8C, the protective layer 131 does not have to have a planarizing function. For example, by using an organic film for the protective layer 131, the upper surface of the protective layer 131 can be made flat. Furthermore, the protective layer 131 shown in FIGS. 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 each of light-emitting devices 130a, 130b, and 130c via a protective layer 131, and a substrate 120 on which colored layer 132R and color conversion layer 135R, colored layer 132G and color conversion layer 135G, and colored layer 132B are provided is bonded to lens 133 and protective layer 131 by a resin layer 122.

[0240] Unlike in FIG. 9C , the lens 133 may be provided on the substrate 120, and the color conversion layer 135R and colored layer 132R, the color conversion layer 135G and colored layer 132G, and the colored layer 132B may be formed directly on the protective layer 131. In this manner, one of the lens and the colored layer may be provided on the protective layer 131, and the other may be provided on the substrate 120. Furthermore, when comparing the color conversion layer 135R (color conversion layer 135G) with 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 convex surface of the lens 133 may face either the substrate 120 side or the light-emitting device side. However, from the viewpoint of ease of fabrication, when the lens 133 is provided on the light-emitting device side, it is preferable that the convex surface face the substrate 120 side. On the other hand, when the lens 133 is provided on the substrate 120 side, it is preferable that the convex surface face 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 a resin can be used for the lens. Also, a material containing at least one of an oxide and a sulfide can be used for the lens. The lens 133 is preferably formed using a material having a refractive index higher than that of the resin layer 122. For example, a microlens array can be used as the lens 133. The lens 133 may be formed directly on the substrate 120 or the light-emitting device, or a separately formed lens may be bonded thereto.

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

[0244] By providing a colored layer so as to overlap the light-emitting device, external light reflection can be significantly reduced, which is preferable. Furthermore, by having a light-emitting device with a microcavity structure, external light reflection can be further reduced. Thus, by applying either a colored layer or a microcavity structure, or preferably both, to the display device, external light reflection can be sufficiently suppressed without using an optical component such as a circular polarizer. By not using a circular polarizer in the display device, attenuation of the light emitted from the light-emitting device can be suppressed, and the light extraction efficiency of the light-emitting device can be increased. This reduces the power consumption of the display device.

[0245] It is also preferable to have an area where colored layers of different colors overlap each other. The area where colored layers of different colors overlap each other can function as a light-blocking layer. This can further reduce external light reflection. Even if light emitted by the color conversion layer 135R and light emitted by the color conversion layer 135G mixes between the colored layer 132R and the colored layer 132G, the mixed light can be prevented from escaping to the outside. Even if light emitted by the color conversion layer 135G and light emitted by the light-emitting device 130c mixes between the colored layer 132G and the colored layer 132B, the mixed light can be prevented from escaping to the outside. Even if light emitted by the color conversion layer 135R and light emitted by the light-emitting device 130c mixes between the colored layer 132R and the colored layer 132B, the mixed light can be prevented from escaping to the outside.

[0246] FIG. 10A illustrates an example in which a light-shielding layer 117 is added to the substrate 120 in addition to the configuration example shown in FIG. 8A . The light-shielding layer 117 is preferably provided between adjacent light-emitting devices in a planar view. With such a configuration, the light-shielding layer 117 can block light mixed between adjacent color conversion layers, etc., and prevent the mixed light from escaping to the outside. The light-shielding layer 117 preferably includes 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 include a pigment that absorbs visible light. The light-shielding layer 117 may be, for example, a resin that contains carbon black as a pigment and functions as a black matrix, or a resin that can be used as a color filter that transmits red, blue, or green light and absorbs other light.

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

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

[0249] FIG. 11A illustrates an example of the configuration example shown in FIG. 9D , in which a layer 137 is provided on the color conversion layer 135R and the color conversion layer 135G. The layer 137 is provided so as to have an overlapping area with the color conversion layer 135R and the color conversion layer 135G, respectively. The layer 137 is preferably formed of a material having a lower refractive index than the color conversion layer 135R and the color conversion layer 135G. The layer 137 is also preferably formed of a material having a lower refractive index than the resin layer 122. For example, the layer 137 can be formed of a resin having a lower refractive index than the resin layer 122. The layer 137 may also be an air layer, for example. By providing the layer 137, light emitted by the color conversion layer 135R and the color conversion layer 135G can be extracted more efficiently to the colored layer 132R and the colored layer 132G, respectively, than when the layer 137 is not provided.

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

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

[0252] Of the four sub-pixels included in the pixel 110 shown in FIG. 12A, three may be configured to have a light-emitting device, and the remaining one may be configured to have a light-receiving device (also referred to as a light-receiving element).

[0253] The light receiving device may be, for example, a pn-type or pin-type photodiode. The light receiving device functions as a photoelectric conversion device (also called a photoelectric conversion element) that detects light incident on the light receiving device and generates electric charges. The amount of electric charges generated by the light receiving device is determined based on the amount of light incident on the light receiving device.

[0254] The light-receiving device can detect one or both of visible light and infrared light. When detecting visible light, it can detect one or more of colors such as blue, purple, blue-purple, green, yellow-green, yellow, orange, and red. When detecting infrared light, it is possible to detect an object even in a dark place, which is preferable.

[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 thin, lightweight, and large in area, and have a high degree of freedom in shape and design, making them applicable to a variety of display devices.

[0256] In one embodiment 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, the organic photodiode can be built into a display device using the organic EL device.

[0257] The light-receiving device is driven by applying a reverse bias between the pixel electrode and the common electrode, so that it can detect light incident on the light-receiving device, generate electric charges, and extract them as a current.

[0258] The same manufacturing method as for the light-emitting device can be applied to the light-receiving device. The island-shaped active layer (also called a photoelectric conversion layer) of the light-receiving device is formed by depositing a film to become the active layer on the entire surface and then processing it, rather than using a fine metal mask. Therefore, the island-shaped active layer can be formed 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] The sixth embodiment can be referred to for the configuration and materials of the light receiving device.

[0260] Fig. 12B shows a cross-sectional view taken along dashed line X3-X4 in Fig. 12A. For a cross-sectional view taken along dashed line X1-X2 in Fig. 12A, Fig. 1B can be referred to, and for a cross-sectional view taken along dashed line Y1-Y2 in Fig. 12A, Fig. 9A or Fig. 9B can be referred to.

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

[0262] FIG. 12B shows an example in which the light emitting device 130a emits light toward the substrate 120 side, and light is incident on the light receiving device 150 from the substrate 120 side (see light Lem and light Lin).

[0263] The sub-pixel 11R and the light-emitting device 130a included in the sub-pixel 11R have the same configuration as described above.

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

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

[0266] Here, the layer 155 includes at least an active layer and preferably has multiple functional layers. Examples of functional layers include a carrier transport layer (hole transport layer and electron transport layer) and a carrier block layer (hole block layer and electron block layer). It is also preferable to have one or more layers on the active layer. By providing another layer between the active layer and the mask layer, exposure of the active layer to the outermost surface during the manufacturing process of the display device can be suppressed, thereby reducing damage to the active layer. This improves the reliability of the light-receiving device 150. Therefore, the layer 155 preferably 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 a layer provided in light-receiving device 150 but not in 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, common layer 114 is a continuous layer shared by the light-emitting device and the light-receiving device.

[0268] Here, a layer shared by a light-receiving device and a light-emitting device may have different functions in the light-emitting device and in the light-receiving device. In this specification, components may be referred to based on their functions 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, a layer shared by a light-receiving device and a light-emitting device may have the same function in the light-emitting device and in the light-receiving device. A hole transport layer functions as a hole transport layer in both the light-emitting device and the light-receiving device, and an electron transport layer functions as an electron transport layer in both the light-emitting device and the light-receiving device.

[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 remaining portion of a mask layer that was provided in contact with the upper surface of the layer 113W when the layer 113W was processed. The mask layer 118S is a remaining portion of a mask layer that was provided in contact with the upper surface of the layer 155, which is a layer including an active layer, when the layer 155 was processed. The mask layers 118a and 118S may be made of the same material or different materials.

[0270] 12A shows an example in which the aperture ratio (which can also be referred to as the size, the size of the light-emitting region, or the size of the light-receiving region) of subpixel 11S is larger than that of subpixels 11R, 11G, and 11B, but one aspect of the present invention is not limited to this. The aperture ratios of subpixels 11R, 11G, 11B, and 11S can each be determined appropriately. The aperture ratios of subpixels 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 subpixel 11S may have a higher aperture ratio than at least one of the subpixels 11R, 11G, and 11B. The larger light-receiving area of ​​the subpixel 11S may make it easier to detect an object. For example, depending on the resolution of the display device, the circuit configuration of the subpixels, and the like, the aperture ratio of the subpixel 11S may be higher than the aperture ratios of the other subpixels.

[0272] Furthermore, the subpixel 11S may have a lower aperture ratio than at least one of the subpixels 11R, 11G, and 11B. If the light-receiving area of ​​the subpixel 11S is small, the imaging range is narrowed, which makes it possible to suppress blurring in the imaging result and improve the resolution. This is preferable because it enables high-definition or high-resolution imaging.

[0273] In this way, the sub-pixel 11S can have a detection wavelength, resolution, and aperture ratio suited to the application.

[0274] In a display device according to one embodiment of the present invention, an EL layer is provided in an island shape for each light-emitting device, thereby suppressing leakage current between subpixels. This prevents crosstalk due to unintended light emission, enabling a display device with extremely high contrast. Furthermore, the edges of the island-shaped EL layer, which may be damaged during the manufacturing process of the display device, and their vicinity are used as dummy regions and are not used as light-emitting regions, thereby suppressing variations in the characteristics of the light-emitting devices. Furthermore, by providing an insulating layer having a tapered edge between adjacent island-shaped EL layers, discontinuities during the formation of a common electrode can be suppressed, and locally thin portions of the common electrode can be prevented. This suppresses connection defects due to disconnected portions in the common layer and the common electrode, and increases in electrical resistance due to locally thin portions. This enables the display device according to one embodiment of the present invention to achieve both high resolution and high display quality.

[0275] In addition, in a display device according to one embodiment of the present invention, three subpixels are formed using light-emitting devices having the same light-emitting layer, and two of the subpixels are formed using color conversion layers, thereby realizing subpixels that emit red and green light. The subpixel that emits blue light uses a colored layer that transmits blue light. This allows subpixels of three colors to be fabricated by fabricating only one type of light-emitting device. By fabricating only one type of light-emitting device, damage to pixel electrodes in the subpixels of each color can be suppressed, and degradation of the light-emitting device characteristics can be suppressed, compared to fabricating three types of light-emitting devices. Furthermore, since the light-emitting layer needs to be processed only once using photolithography, display devices can be fabricated with a high yield.

[0276] This embodiment mode can be combined with other embodiment modes as appropriate. In addition, in this specification, when a plurality of configuration examples are shown in one embodiment mode, the configuration examples can be combined as appropriate.

[0277] 13 to 18. Note that with regard to materials and formation methods of elements, descriptions of the same parts as those described in Embodiment 1 may be omitted. In addition, details of the structure of a light-emitting device will be described in Embodiment 5.

[0278] 13 to 16, 17A, and 18 show cross-sectional views taken along dashed dotted lines X1-X2 and Y1-Y2 in Fig. 1A side by side. Fig. 17B to 17E show enlarged views of the end of insulating layer 127 and its vicinity.

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

[0280] Furthermore, thin films (insulating films, semiconductor films, conductive films, etc.) constituting the display device can be formed by a wet film formation method such as spin coating, dipping, spray coating, inkjet, dispensing, screen printing, offset printing, doctor knife, slit coating, roll coating, curtain coating, or knife coating.

[0281] In particular, vacuum processes such as vapor deposition and solution processes such as spin coating and inkjet printing can be used to fabricate light-emitting devices. Vapor deposition methods include physical vapor deposition (PVD) methods such as sputtering, ion plating, ion beam deposition, molecular beam deposition, and vacuum deposition, and chemical vapor deposition (CVD). In particular, functional layers included in the EL layer (hole injection layer, hole transport layer, hole blocking layer, light-emitting layer, electron blocking layer, electron transport layer, electron injection layer, charge generation layer, etc.) can be formed by vapor deposition (vacuum deposition, etc.), coating methods (dip coating, die coating, bar coating, spin coating, spray coating, etc.), printing methods (inkjet printing, screen (stencil printing), offset (lithographic printing), flexography (relief printing), gravure, microcontact printing, etc.), etc.

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

[0283] There are two typical photolithography methods: one is to form a resist mask on the thin film to be processed, process the thin film by etching or the like, and then remove the resist mask; the other is to form a photosensitive thin film, and then process the thin film into the desired shape by exposure and development.

[0284] In photolithography, the light used for exposure may be, for example, i-line (wavelength 365 nm), g-line (wavelength 436 nm), h-line (wavelength 405 nm), or a mixture of these. Other light sources that can be used include ultraviolet light, KrF laser light, ArF laser light, etc. Exposure may also be performed by immersion exposure technology. Extreme ultraviolet (EUV) light or X-rays may also be used as the light used for exposure. An electron beam may also be used instead of the light used for exposure. Extreme ultraviolet light, X-rays, or an electron beam are preferred because they enable extremely fine processing. When exposure is performed by scanning a beam such as an electron beam, a photomask is not required.

[0285] For etching the thin film, dry etching, wet etching, sandblasting, or the like can be used.

[0286] First, an insulating layer 255a, an insulating layer 255b, and an insulating layer 255c are formed in this order on the layer 101. Then, a pixel electrode 111a, a pixel electrode 111b, a pixel electrode 111c, and a conductive layer 123 are formed on the insulating layer 255c (FIG. 13A). The conductive film that becomes the pixel electrode can be formed by, for example, sputtering or vacuum evaporation.

[0287] Next, it is preferable to perform a hydrophobic treatment on the pixel electrodes. The hydrophobic treatment can change the surface of the treatment target from hydrophilic to hydrophobic, or can increase the hydrophobicity of the surface of the treatment target. By performing the hydrophobic treatment on the pixel electrodes, the adhesion between the pixel electrodes and a film (here, film 113w) to be formed in a later process can be increased, and film peeling can be suppressed. Note that the hydrophobic treatment is not necessarily required.

[0288] The hydrophobic treatment can be performed by, for example, fluorine modification of the pixel electrodes. The fluorine modification can be performed by, for example, a treatment or heat treatment using a fluorine-containing gas, a plasma treatment in a fluorine-containing gas atmosphere, or the like. As the fluorine-containing gas, for example, fluorine gas can be used, and for example, fluorocarbon gas can be used. As the fluorocarbon gas, for example, carbon tetrafluoride (CF４ ) Gas, C ４ F ６ Gas, C ２ F ６ Gas, C ４ F ８ Gas, C ５ F ８ A low-grade fluorocarbon gas such as SF6 can be used. ６ Gas, NF ３ Gas, CHF ３ Gases such as helium gas, argon gas, or hydrogen gas can be added to these gases as appropriate.

[0289] The surface of the pixel electrode can be hydrophobized by performing a plasma treatment on the surface of the pixel electrode in a gas atmosphere containing a Group 18 element such as argon, followed by a treatment using a silylating agent. Examples of the silylating agent that can be used include hexamethyldisilazane (HMDS) and trimethylsilylimidazole (TMSI). Furthermore, the surface of the pixel electrode can be hydrophobized by performing a plasma treatment on the surface of the pixel electrode in a gas atmosphere containing a Group 18 element such as argon, followed by a treatment using 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, it is possible to damage the surface of the pixel electrode. This makes it easier for methyl groups contained in a silylating agent such as HMDS to bond to the surface of the pixel electrode. Furthermore, silane coupling by a silane coupling agent is more likely to occur. As described above, by performing plasma treatment on the surface of the pixel electrode in a gas atmosphere containing a Group 18 element such as argon, and then performing treatment using a silylating agent or a silane coupling agent, it is possible to hydrophobize the surface of the pixel electrode.

[0291] Treatment using a silylating agent or a silane coupling agent can be performed by applying the silylating agent or the silane coupling agent using, for example, a spin coating method or a dipping method. Treatment using a silylating agent or a silane coupling agent can also be performed by, for example, using a vapor phase method to form a film containing a silylating agent or a film containing a silane coupling agent on a pixel electrode or the like. In the vapor phase method, first, a material containing a silylating agent or a material containing a silane coupling agent is volatilized to incorporate the silylating agent or the silane coupling agent into an atmosphere. Next, a substrate on which a pixel electrode or the like is formed is placed in this atmosphere. This allows a film containing the silylating agent or the silane coupling agent to be formed on the pixel electrode, thereby making the surface of the pixel electrode hydrophobic.

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

[0293] 13A , in the cross-sectional view taken along dashed dotted line Y1-Y2, the film 113w is not formed on the conductive layer 123. For example, by using an area mask, the film 113w can be formed only in a desired region. By employing a film formation process using an area mask and a processing process using a resist mask, a light-emitting device can be fabricated through a relatively simple process.

[0294] As described in Embodiment 1, in the display device of one embodiment of the present invention, a material with high heat resistance is used for the light-emitting device. Specifically, the heat resistance temperature of each compound contained in the film 113w is preferably 100° C. or higher and 180° C. or lower, preferably 120° C. or higher and 180° C. or lower, and more preferably 140° C. or higher and 180° C. or lower. This can improve the reliability of the light-emitting device. Furthermore, the upper limit of the temperature to which the display device can be subjected in the manufacturing process can be increased. Therefore, the range of choices for materials and formation methods used in the display device can be expanded, which can improve the manufacturing yield and reliability.

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

[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 formed in this order on the film 113w and the conductive layer 123 (FIG. 13A).

[0297] In this embodiment, an example is shown in which the mask film is formed with a two-layer structure of mask film 118b and mask film 119b, 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 over 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 improved.

[0299] The mask film 118b is made of a film that is highly resistant to the processing conditions of the film 113w, specifically, a film that has a high etching selectivity with respect to the film 113w.The mask film 119b is made of a film that has a high etching selectivity with respect to the mask film 118b.

[0300] Furthermore, the mask films 118b and 119b are formed at a temperature lower than the heat-resistant temperature of the film 113w. The substrate temperature when forming the mask films 118b and 119b is typically 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 heat resistance temperature index include a glass transition point, a softening point, a melting point, a thermal decomposition temperature, a 5% weight loss temperature, etc. The heat resistance temperature of the film 113w (i.e., the layer 113W) can be any of these temperatures that serve as an index of the heat resistance temperature, preferably the lowest temperature among them.

[0302] As described above, in the display device of one embodiment of the present invention, a material with high heat resistance is used for the light-emitting device. Therefore, the substrate temperature during the formation of the mask film can be set to 100° C. or higher, 120° C. or higher, or 140° C. or higher. For example, the inorganic insulating film can be made denser and have a higher barrier property as the film formation temperature increases. Therefore, by forming the mask film at such a temperature, 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 a film that can be removed by wet etching for the mask films 118b and 119b, since wet etching can reduce damage to the film 113w during processing of the mask films 118b and 119b compared to dry etching.

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

[0305] It is preferable that the mask film 118b formed on and in contact with the film 113w be formed using a formation 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 the vacuum deposition method rather than the sputtering method.

[0306] The mask film 118b and the mask film 119b may each be made of one or more of a metal film, an alloy film, a metal oxide film, a semiconductor film, an organic insulating film, an inorganic insulating film, or the like.

[0307] For the mask film 118b and the mask film 119b, for example, a metal material such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, titanium, aluminum, yttrium, zirconium, or tantalum, or an alloy material containing such a metal material, can be used. In particular, it is preferable to use a low-melting-point material such as aluminum or silver. Using a metal material capable of blocking ultraviolet rays for one or both of the mask film 118b and the mask film 119b is preferable because it can prevent ultraviolet rays from being irradiated onto the film 113w and thereby prevent deterioration of the film 113w.

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

[0309] Furthermore, for the mask film 118b and the mask film 119b, 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 indium tin oxide containing silicon can be used.

[0310] Instead of the gallium, 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, and magnesium may be used. In particular, it is preferable to use one or more elements selected from gallium, aluminum, and yttrium.

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

[0312] For example, semiconductor materials such as silicon or germanium can be used as materials that are highly compatible with semiconductor manufacturing processes. Alternatively, oxides or nitrides of the above semiconductor materials can be used. Alternatively, non-metallic 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, and tantalum nitride can be used.

[0313] By using a film containing a material having a light-blocking property against ultraviolet rays as the mask film, it is possible to prevent the EL layer from being exposed to ultraviolet rays during an exposure process, etc. By preventing the EL layer from being damaged by ultraviolet rays, it is possible to improve the reliability of the light-emitting device.

[0314] The same effect can be achieved when a film containing a material that blocks ultraviolet light is used as the material for the insulating film 125A described later.

[0315] Furthermore, the mask films 118b and 119b can each be made of any of various inorganic insulating films that can be used for the protective layer 131. In particular, oxide insulating films are preferable because they have higher adhesion to the film 113w than nitride insulating films. For example, inorganic insulating materials such as aluminum oxide, hafnium oxide, and silicon oxide can each be used for the mask films 118b and 119b. For example, aluminum oxide films can be formed as the mask films 118b and 119b using the ALD method. Using the ALD method is preferable because it can reduce damage to the underlying layer (particularly the EL layer).

[0316] For example, an inorganic insulating film (e.g., an aluminum oxide film) formed using an 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 a sputtering method can be used as the mask film 119b.

[0317] The same inorganic insulating film can be used for both the mask film 118b and the insulating layer 125 to be formed later. For example, an aluminum oxide film formed using an ALD method can be used for both the mask film 118b and the insulating layer 125. The mask film 118b and the insulating layer 125 may be formed under the same or different film formation conditions. For example, by forming the mask film 118b under the same conditions as the insulating layer 125, the mask film 118b can be 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 is removed mostly or entirely in a later process, it is preferable that it be easily processed. Therefore, it is preferable that the mask film 118b be formed under conditions where the substrate temperature during film formation is lower than that of the insulating layer 125.

[0318] An organic material may be used for one or both of the mask films 118b and 119b. For example, a material that can be dissolved in a chemically stable solvent may be used as the organic material for at least the film located at the top of the film 113w. In particular, a material that dissolves in water or alcohol is preferably used. When forming a film of such a material, it is preferable to apply the material dissolved in a solvent such as water or alcohol by a wet film formation method, and then perform a heat treatment to evaporate the solvent. In this case, 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 the film 113w.

[0319] The mask film 118b and the mask film 119b may each be made of an organic resin such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinylpyrrolidone, polyethylene glycol, polyglycerin, pullulan, water-soluble cellulose, alcohol-soluble polyamide resin, or a fluororesin such as a perfluoropolymer.

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

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

[0322] Next, a resist mask 190 is formed on the mask film 119b (FIG. 13A). The resist mask 190 can be formed by applying a photosensitive resin (photoresist) and then exposing and developing it.

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

[0324] The resist masks 190 are provided at positions overlapping with the pixel electrodes 111a, 111b, and 111c, respectively. Note that 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 at a position overlapping with the conductive layer 123. This can prevent the conductive layer 123 from being damaged during the manufacturing process of the display device. Note that the resist mask 190 does not necessarily have to be provided on the conductive layer 123.

[0325] Furthermore, as shown in the cross-sectional view between Y1 and Y2 in FIG. 13A , the resist mask 190 is preferably provided so as to cover the end of the film 113w to the end of the conductive layer 123 (the end on the film 113w side). This ensures that the ends of the mask layers 118a and 119a overlap with the end of the film 113w even after the mask films 118b and 119b are processed. Furthermore, because the mask layers 118a and 119a are provided so as to cover the end of the film 113w to the end of the conductive layer 123 (the end on the film 113w side), exposure of the insulating layer 255c can be suppressed even after the film 113w is processed (see the cross-sectional view between Y1 and Y2 in FIG. 14B ). This prevents the insulating layers 255a to 255c and parts of the insulating layers included in the layer 101 from being removed by etching or the like, thereby preventing the conductive layers included in the layer 101 from being exposed. Therefore, it is possible to prevent the conductive layer from being unintentionally electrically connected to another conductive layer, and for example, it is possible to prevent 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, thereby forming a mask layer 119a (FIG. 13B). The mask layer 119a remains on the pixel electrodes 111a, 111b, and 111c, and on the conductive layer 123. Then, the resist mask 190 is removed (FIG. 13C). Next, using the mask layer 119a as a mask (also referred to as a hard mask), a portion of the mask film 118b is removed, thereby forming a mask layer 118a (FIG. 14A).

[0327] The mask films 118b and 119b can be processed by wet etching or dry etching, respectively, and it is preferable to use wet etching for processing the mask films 118b and 119b.

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

[0329] In processing mask film 119b, film 113w is not exposed, so the range of processing methods available is wider than in processing mask film 118b. Specifically, even when a gas containing oxygen is used as an etching gas in processing mask film 119b, deterioration of film 113w can be suppressed.

[0330] Furthermore, when dry etching is used to process the mask film 118b, deterioration of the film 113w can be suppressed by not using a gas containing oxygen as the etching gas. ４ , C ４ F ８ , S.F. ６ , CHF ３ , Cl ２ , H ２ O, BCl ３ It is preferable to use a gas containing a noble gas (also called a rare gas) such as He as the etching gas.

[0331] For example, when an aluminum oxide film formed by the ALD method is used as the mask film 118b, CHF ３ and He or CHF ３ and He and CH ４In addition, when an In—Ga—Zn oxide film formed by sputtering is used as the mask film 119b, the mask film 119b can be processed by wet etching using diluted phosphoric acid. ４ In addition, when a tungsten film formed by sputtering is used as the mask film 119b, SF ６ , C.F. ４ and O ２ , or CF ４ and Cl ２ and O ２ The mask film 119b can be processed by dry etching using the above method.

[0332] The resist mask 190 can be removed by, for example, ashing using oxygen plasma. Alternatively, ashing using oxygen gas and CF ４ , C ４ F ８ , S.F. ６ , CHF ３ , Cl ２ , H ２ O, BCl ３ Alternatively, a noble gas (also referred to as a rare gas) such as He may be used. Alternatively, the resist mask 190 may be removed by wet etching. At this time, the mask film 118b is located on the outermost surface and the film 113w is not exposed, so that damage to the film 113w can be suppressed in the process of removing the resist mask 190. Furthermore, the range of options for the method of removing the resist mask 190 can be widened.

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

[0334] As a result, as shown in FIG. 14B, a laminated structure of the layer 113W, the mask layer 118a, and the mask layer 119a remains on the pixel electrodes 111a, 111b, and 111c, respectively.

[0335] The side surfaces of the layer 113W are preferably perpendicular or substantially perpendicular to the surface on which the layer 113W is to be formed. For example, the angle between the surface on which the layer 113W is to be formed and the side surfaces is preferably 60° to 90°.

[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, etc. Therefore, the surfaces of the pixel electrodes are not damaged by the etching process, and the state 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, particularly anisotropic dry etching, or wet etching.

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

[0339] When dry etching is used, deterioration of the film 113w can be suppressed by not using a gas containing oxygen as the etching gas.

[0340] Alternatively, a gas containing oxygen may be used as the etching gas. 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 high etching rate. This can suppress damage to the film 113w. Furthermore, problems such as adhesion of reaction products that occur during etching can be suppressed.

[0341] When dry etching is used, for example, H ２ , C.F. ４ , C ４ F ８ , S.F. ６ , CHF ３ , Cl ２ , H ２ O, BCl ３ It is preferable to use a gas containing one or more of the following gases as the etching gas: H, Ar, etc., or a noble gas (also called a rare gas) such as He, Ar, etc. Alternatively, it is preferable to use a gas containing one or more of these gases and oxygen as the etching gas. Alternatively, oxygen gas may be used as the etching gas. Specifically, for example, H ２ and a gas containing Ar, or CF ４ A gas containing CF and He can be used as an etching gas. ４ A gas containing He and oxygen can be used as the etching gas. ２ A gas containing Ar and a gas containing oxygen can be used as the etching gas.

[0342] The dry etching apparatus may be a dry etching apparatus having a high-density plasma source. Examples of the dry etching apparatus having a high-density plasma source include an inductively coupled plasma (ICP) etching apparatus. Alternatively, a capacitively coupled plasma (CCP) etching apparatus having parallel-plate electrodes may be used. The capacitively coupled plasma etching apparatus having parallel-plate electrodes may be configured to apply a high-frequency voltage to one of the parallel-plate electrodes. Alternatively, it may be configured to apply a plurality of different high-frequency voltages to one 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] 14B shows an example in which the edges of the layer 113W are located outside the edges of the pixel electrodes 111a, 111b, and 111c. This configuration increases the pixel aperture ratio. Although not shown in FIG. 14B, the etching process may result in the formation of recesses in the insulating layer 255c in areas that do not overlap with the layer 113W.

[0344] Furthermore, because the layer 113W covers the top and side surfaces of the pixel electrodes 111a, 111b, and 111c, respectively, subsequent processes can be performed without exposing the pixel electrodes. Exposed edges of the pixel electrodes may cause corrosion during etching processes, etc. Products resulting from the corrosion of the pixel electrodes may be unstable. For example, they may dissolve in solution during wet etching, or may disperse into the atmosphere during dry etching. Dissolving the products in solution or scattering into the atmosphere may result in the products adhering to the processed surface and the side surfaces of the layer 113W, adversely affecting the characteristics of the light-emitting devices or forming leak paths between multiple light-emitting devices. Furthermore, in areas where the edges of the pixel electrodes are exposed, the adhesion between adjacent layers may be reduced, potentially making the layer 113W or the pixel electrodes more susceptible to peeling.

[0345] Therefore, by configuring the layer 113W to cover the upper and side surfaces of the 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 the first embodiment, the layer 113W covers the upper and side surfaces of the pixel electrodes 111a, 111b, and 111c, respectively, so that a dummy region is provided in the layer 113W outside the light-emitting region (the region located between the pixel electrodes 111a, 111b, and 111c and the common electrode 115). Here, the end of the layer 113W may be damaged during processing of the film 113w. The end of the layer 113W and its vicinity serve as a dummy region and are not used for light emission, so even if damage occurs, it is unlikely to adversely affect the characteristics of the light-emitting device. Meanwhile, the light-emitting region of the layer 113W is covered by the mask layer, so it is not exposed to plasma, and damage from plasma is sufficiently suppressed. The mask layer is preferably provided not only to cover the upper surface of the flat portion of the layer 113W that overlaps with the upper surfaces of the pixel electrodes 111a, 111b, and 111c, but also to cover the upper surfaces of the inclined and flat portions located outside the upper surfaces of the pixel electrodes 111a, 111b, and 111c. In this way, a portion of the layer 113W that is less susceptible to damage during the manufacturing process is used as the light-emitting region, thereby achieving a light-emitting device with high light-emitting efficiency and a long life.

[0347] 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] 14B , the mask layers 118a and 119a are provided to cover the ends of the layer 113W and the conductive layer 123, and the top surface of the insulating layer 255c is not exposed. Therefore, the insulating layers 255a to 255c and parts of the insulating layers included in the layer 101 are removed by etching or the like, which can prevent the conductive layers included in the layer 101 from being exposed. Therefore, the conductive layers can be prevented from being unintentionally electrically connected to other conductive layers.

[0349] As described above, in one embodiment of the present invention, the resist mask 190 is formed over the mask film 119b, and part of the mask film 119b is removed using the resist mask 190 to form the mask layer 119a. Then, part of the film 113w is removed using the mask layer 119a as a hard mask to form the layer 113W. Therefore, it can be said that the layer 113W is formed by processing the film 113w by photolithography. Note that part of the film 113w may be removed using the resist mask 190. Then, the resist mask 190 may be removed.

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

[0351] Next, it is preferable to remove the mask layer 119a. Depending on the subsequent process, the mask layer 119a may remain on the display device. By removing the mask layer 119a at this stage, it is possible to prevent the mask layer 119a from remaining on the display device. For example, when a conductive material is used for the mask layer 119a, removing the mask layer 119a in advance can prevent the remaining mask layer 119a from causing leakage current and capacitance.

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

[0353] The removal process of the mask layer 119 a can be performed using a method similar to that used in the processing of the mask layer 119 a. In particular, by using a wet etching method, damage to the layer 113W can be reduced when removing the mask layer 119 a compared to when using a dry etching method.

[0354] When a metal film or an alloy film is used for the mask layer 119a, the mask layer 119a can prevent the EL layer from being damaged by plasma. Therefore, the film can be processed using a dry etching method in the steps up to the removal of the mask layer 119a. On the other hand, in the step of removing the mask layer 119a and in the steps thereafter, the film that prevents the EL layer from being damaged by plasma is no longer present. Therefore, it is preferable to process the film using a method that does not use plasma, such as a wet etching method.

[0355] The mask layer 119a may also be removed by dissolving it in a solvent such as water or alcohol, such as 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 the layer 113W and water adsorbed to the surface of the layer 113W. For example, 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 enables drying at a lower temperature.

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

[0358] As will be described later, the insulating film 127a is formed in contact with the upper surface of the insulating film 125A. Therefore, it is preferable that the upper surface of the insulating film 125A has high adhesion to the resin composition (e.g., a photosensitive resin composition containing an acrylic resin) used for the insulating film 127a. To improve this adhesion, it is preferable to perform a surface treatment to hydrophobize (or increase the hydrophobicity of) the upper surface of the insulating film 125A. For example, it is preferable to perform the treatment using a silylating agent such as hexamethyldisilazane (HMDS). By hydrophobizing the upper surface of the insulating film 125A in this way, the insulating film 127a can be formed with good adhesion. The surface treatment may be the hydrophobization treatment described above.

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

[0360] The insulating films 125A and 127a are preferably formed by a formation method that causes less damage to the layer 113W. In particular, since the insulating film 125A is formed in contact with the side surface of the layer 113W, it is preferably formed by a formation method that causes less damage to the layer 113W than the insulating film 127a.

[0361] The insulating films 125A and 127a are formed at a temperature lower than the heat-resistant temperature of the layer 113W. By increasing the substrate temperature during film formation, the insulating film 125A can have a low impurity concentration and a high barrier property against at least one of water and oxygen, even if it is thin.

[0362] The substrate temperature when forming the insulating film 125A and the insulating film 127a is preferably 60°C or higher, 80°C or higher, 100°C or higher, or 120°C or higher, and 200°C or lower, 180°C or lower, 160°C or lower, 150°C or lower, or 140°C or lower, respectively.

[0363] As described above, in the display device of one embodiment of the present invention, a material with high heat resistance is used for the light-emitting device. Therefore, the substrate temperatures during the formation of the insulating film 125A and the insulating film 127a can be set to 100° C. or higher, 120° C. or higher, or 140° C. or higher, respectively. For example, the higher the deposition temperature of an inorganic insulating film, the denser the film can be and the higher the barrier property it can have. Therefore, by depositing the insulating film 125A at such a temperature, damage to the layer 113W can be further reduced, and the reliability of the light-emitting device can be improved.

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

[0365] The insulating film 125A is preferably formed by, for example, an ALD method. The ALD method is preferable because it can reduce film formation damage and form a film with high coverage. The insulating film 125A is preferably formed as an aluminum oxide film by, for example, an ALD method.

[0366] Alternatively, the insulating film 125A may be formed by a sputtering method, a CVD method, or a PECVD method, which have a faster film formation rate than an ALD method. This enables a highly reliable display device to be manufactured with high productivity.

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

[0368] After the insulating film 127a is formed, heat treatment (also referred to as pre-baking) is preferably performed. The heat treatment is performed at a temperature lower than the upper temperature limit of the layer 113W. The substrate temperature during the heat treatment is preferably 50° C. to 200° C., more preferably 60° C. to 150° C., and still more preferably 70° C. to 120° C. This allows the solvent contained in the insulating film 127a to be removed.

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

[0370] The width of the insulating layer 127 to be formed later can be controlled by the region to be exposed to light. In this embodiment, the insulating layer 127 is processed so as to have a portion overlapping with the upper surface of the pixel electrode (FIG. 2A). As shown in FIG. 5A or 5B, the insulating layer 127 does not necessarily have a portion overlapping with the upper surface of the pixel electrode.

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

[0372] 16A shows an example in which a positive photosensitive resin is used for the insulating film 127a and visible light or ultraviolet light is irradiated onto the region where the insulating layer 127 is not formed, but the present invention is not limited to this. For example, a negative photosensitive resin may be used for the insulating film 127a. In this case, visible light or ultraviolet light is irradiated onto the region where the insulating layer 127 is formed.

[0373] 16B , development is performed to remove the exposed areas of the insulating film 127a, thereby forming an insulating layer 127b. The insulating layer 127b is formed in a region sandwiched between any two of the pixel electrodes 111a, 111b, and 111c, and in a region surrounding the conductive layer 123. When an acrylic resin is used for the insulating film 127a, it is preferable to use an alkaline solution as the developer, such as a tetramethylammonium hydroxide aqueous solution (TMAH).

[0374] After the development, a step of removing the residue (so-called scum) remaining after the development may be carried out. For example, the residue can be removed by ashing using oxygen plasma. A step of removing the residue may also be carried out after each of the development steps described below.

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

[0376] After development and before post-baking, the entire substrate may be exposed to visible light or ultraviolet light to irradiate the insulating layer 127b. The energy density of the exposure is 0 mJ / cm. ２ Larger than 800 mJ / cm ２ It is preferable that the dose is 0 mJ / cm or less. ２ Greater than 500 mJ / cm ２ By performing such exposure after development, the transparency of the insulating layer 127b can be improved in some cases, and the insulating layer 127b can be deformed into a tapered shape at a low temperature in some cases.

[0377] On the other hand, by not exposing the insulating layer 127b to light, it may be easier to change the shape of the insulating layer 127b or to deform the insulating layer 127 into a tapered shape in a later step. Therefore, it may be preferable not to expose the insulating layer 127b to light after development.

[0378] Next, heat treatment (also referred to as post-baking) is performed. As shown in FIG. 17A , heat treatment can transform the insulating layer 127b into the insulating layer 127 having tapered side surfaces. The heat treatment is performed at a temperature lower than the 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 air atmosphere or an inert gas atmosphere. The heating atmosphere may be an atmospheric pressure atmosphere or a reduced-pressure atmosphere. A reduced-pressure atmosphere is preferable because drying can be performed at a lower temperature. The substrate temperature in this heat treatment step is preferably higher than that in the heat treatment (pre-baking) performed after the formation of the insulating film 127a. This can improve adhesion between the insulating layer 127 and the insulating layer 125 and also improve the corrosion resistance of the insulating layer 127.

[0379] Depending on the material of the insulating layer 127 and the temperature, time, and atmosphere of the post-baking, a concave curved shape may be formed on the side surface of the insulating layer 127, as shown in Figures 4A and 4B. For example, the higher the temperature or the longer the post-baking time, the more likely the shape of the insulating layer 127 is to change, and a concave curved shape may be formed. Furthermore, as described above, if the developed insulating layer 127b is not exposed to light, the shape of the insulating layer 127 may be more likely to change during post-baking.

[0380] 17A, an etching process is performed using the insulating layer 127 as a mask to remove the insulating film 125A and a portion of the mask layer 118a, thereby forming an opening in the mask layer 118a and exposing the upper surfaces of the layer 113W and the conductive layer 123.

[0381] The etching treatment can be performed by dry etching or wet etching. Note that it is preferable to form the insulating film 125A using the same material as the mask layer 118a, because the etching treatment can be performed in one step.

[0382] When dry etching is used, it is preferable to use a chlorine-based gas.２ , BCl ３ , SiCl ４ , CCl ４ The dry etching method can be used to form thin regions of the mask layer 118a with good in-plane uniformity.

[0383] Furthermore, when dry etching is used, by-products generated by the dry etching may be deposited on the upper surface and side surfaces of insulating layer 127. As a result, components contained in the etching gas, components contained in insulating film 125A, components contained in mask layer 118a, etc. may be contained in insulating layer 127 after the display device is completed.

[0384] Furthermore, the etching process is preferably performed by wet etching. By using wet etching, damage to the layer 113W can be reduced compared to when dry etching is used. For example, wet etching 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 by 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 prevent poor connection between the light-emitting devices due to disconnection of the common layer 114 and the common electrode 115 and an increase in electrical resistance due to a locally thin portion of the film thickness, thereby improving the display quality of the display device of one embodiment of the present invention.

[0386] After a portion of the layer 113W is exposed, further heat treatment may be performed. This heat treatment can remove water contained in the EL layer and water adsorbed to the surface of the EL layer. Furthermore, this heat treatment may change the shape of the insulating layer 127. Specifically, the insulating layer 127 may expand to cover at least one of the end of the insulating layer 125, the end of the mask layer 118a, and the top surface of the layer 113W. For example, the insulating layer 127 may have the shape shown in FIGS. 3A and 3B . For example, heat treatment can be performed in an inert gas atmosphere or a reduced-pressure atmosphere. The heat treatment can be performed at a substrate temperature of 50° C. to 200° C., preferably 60° C. to 150° C., and more preferably 70° C. to 120° C. A reduced-pressure atmosphere is preferable because it enables dehydration at a lower temperature. However, it is preferable to appropriately set the temperature range of the heat treatment, taking into account the heat resistance temperature of the EL layer. In addition, when the heat resistance temperature of the EL layer is taken into consideration, a temperature of 70° C. or more and 120° C. or less is particularly suitable within the above temperature range.

[0387] Here, if the insulating layer 125 and the mask layer 118a are etched together after the post-bake, side etching may cause the insulating layer 125 and the mask layer 118a below the end of the insulating layer 127 to disappear, forming a cavity. Such a cavity may cause unevenness on the surface on which the common layer 114 and the common electrode 115 are formed, making it more likely that discontinuities will occur in the common layer 114 and the common electrode 115. Therefore, it is preferable to perform the etching of the insulating layer 125 and the mask layer 118a separately, before and after the post-bake.

[0388] A method of performing etching of the insulating layer 125 and the mask layer 118a separately before and after post-baking will be described below with reference to FIGS. 17B to 17E.

[0389] First, Fig. 17B shows an enlarged view of the layer 113W shown in Fig. 16B and the end portion and vicinity of the insulating layer 127b, i.e., the insulating layer 127b formed by development.

[0390] 17C, an etching process is performed using insulating layer 127b as a mask to remove a portion of insulating film 125A and thin a portion of mask layer 118a. As a result, insulating layer 125 is formed below insulating layer 127b. The surface of the thin portion of mask layer 118a is exposed. Note that, hereinafter, the etching process using insulating layer 127b as a mask may be referred to as the first etching process.

[0391] The first etching process can be performed by dry etching or wet etching.

[0392] As shown in FIG. 17C, by performing etching using insulating layer 127b having tapered side surfaces as a mask, the side surfaces of insulating layer 125 and the upper end portions of the side surfaces of mask layer 118a can be tapered relatively easily.

[0393] 17C, the first etching process does not completely remove the mask layer 118a, but stops when the film thickness is reduced. In this way, by leaving the corresponding mask layer 118a on the layer 113W, it is possible to prevent the layer 113W from being damaged in subsequent processes.

[0394] 17C illustrates a configuration in which the thickness of the mask layer 118a is thinned, but the present invention is not limited to this. For example, depending on the thickness of the insulating film 125A and the thickness of 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 a portion of the insulating film 125A is thinned. 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 thickness of the mask layer 118a has been thinned.

[0395] 17C shows an example in which the shape of insulating layer 127b is unchanged from that of FIG. 17B, but the present invention is not limited to this. For example, the end of insulating layer 127b may droop and cover the end of insulating layer 125. Also, for example, the end of insulating layer 127b may contact the upper surface of mask layer 118a. As described above, if the developed insulating layer 127b is not exposed to light, the shape of insulating layer 127b may be easily changed.

[0396] 17D, post-baking can transform the insulating layer 127b into an insulating layer 127 having tapered side surfaces. As described above, the shape of the insulating layer 127b may have already changed to have tapered side surfaces by the time the first etching process is completed.

[0397] By not completely removing the mask layer 118a in the first etching process and leaving the mask layer 118a in a thinner state, it is possible to prevent the layer 113W from being damaged and deteriorated in the heat treatment, thereby improving the reliability of the light-emitting device.

[0398] 17E, an etching process is performed using the insulating layer 127 as a mask to remove a portion of the mask layer 118a, thereby forming an opening in the mask layer 118a and exposing the top surfaces of the layer 113W and the conductive layer 123. Note that hereinafter, the etching process using the insulating layer 127 as a mask may be referred to as a second etching process.

[0399] The end of insulating layer 125 is covered with insulating layer 127. Also, Fig. 17E shows an example in which part of the end of mask layer 118a (specifically, the tapered portion formed by the first etching process) is covered with insulating layer 127, and the tapered portion formed by the second etching process is exposed. In other words, this corresponds to the structure shown in Figs. 2A and 2B.

[0400] As described above, when the method of performing etching before and after post-baking is used, 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-baking thereafter. The second etching process then etches the thinner mask layer 118a, reducing the amount of side etching and making it less likely that a cavity will form. Even if a cavity does form, it can be made extremely small. This allows the surface on which the common layer 114 and the common electrode 115 are formed to be flatter.

[0401] 3A, 4B, and 5B, the insulating layer 127 may cover the entire end of the mask layer 118a. For example, the end of the insulating layer 127 may droop and cover the end of the mask layer 118a. Furthermore, for example, the end of the insulating layer 127 may contact the top surface of the layer 113W. As described above, if the developed insulating layer 127b is not exposed to light, the shape of the insulating layer 127b may be easily deformed.

[0402] The second etching process is preferably performed by wet etching, which can reduce damage to the layer 113W compared to dry etching. Wet etching can be performed using an alkaline solution or the like.

[0403] Next, the common layer 114 and the common electrode 115 are formed in this order on the insulating layer 127 and the layer 113W ( FIG. 18A ), and then the protective layer 131 is formed ( FIG. 18B ). When applying a configuration having a color conversion layer and a colored layer on the protective layer 131, such as that shown in FIG. 1B , the protective layer 131 is formed substantially flat, and then the color conversion layer is provided on the protective layer 131, and then the colored layer is provided on the color conversion layer. Then, a display device can be fabricated by bonding a substrate 120 onto the protective layer 131 using a resin layer 122 ( FIG. 1B ). When applying a configuration having a colored layer and a color conversion layer on the substrate 120, such as that shown in FIG. 8A , the display device can be fabricated by first providing the colored layer and the color conversion layer on the substrate 120 and then bonding the substrate 120.

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

[0405] The common electrode 115 can be formed by, for example, sputtering or vacuum deposition. Alternatively, a film formed by deposition and a film formed by sputtering may be stacked.

[0406] The protective layer 131 may be formed by vacuum deposition, sputtering, CVD, ALD, or the like.

[0407] As described above, in the manufacturing method of the display device of this embodiment, the island-shaped layer 113W is formed by forming a film over the entire surface and then processing it, rather than using a fine metal mask. This allows the island-shaped layer to be formed with a uniform thickness. This makes it possible to realize a high-definition display device or a display device with a high aperture ratio. Furthermore, even if the definition or aperture ratio is high and the distance between subpixels is extremely short, the layers 113W in adjacent subpixels can be prevented from contacting each other. Therefore, leakage current between subpixels can be suppressed. This prevents crosstalk due to unintended light emission, and realizes a display device with extremely high contrast.

[0408] In addition, in the manufacturing method of the display device of this embodiment, three color sub-pixels can be manufactured by simply manufacturing one color light-emitting device. Therefore, damage to the pixel electrode in each color sub-pixel can be suppressed, and deterioration of the characteristics of the light-emitting device can be suppressed. Furthermore, since the number of times of processing the light-emitting layer using photolithography can be limited to one, the display device can be manufactured with a high yield.

[0409] Furthermore, by the manufacturing method of the display device of this embodiment mode, each subpixel can emit light with high luminance and high color purity.

[0410] Furthermore, by providing the insulating layer 127 having a tapered edge between adjacent island-shaped EL layers, it is possible to suppress the occurrence of discontinuities during the formation of the common layer 114 and the common electrode 115, and also to prevent the formation of locally thin portions in the common layer 114 and the common electrode 115. This makes it possible to suppress the occurrence of poor connection due to the disconnected portions in the common layer 114 and the common electrode 115, and the occurrence of an increase in electrical resistance due to the locally thin portions. Therefore, the display device of one embodiment of the present invention can achieve both high resolution and high display quality.

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

[0412] Embodiment 3 In this embodiment, a display device of one embodiment of the present invention will be described with reference to FIGS.

[0413] [Pixel Layout] In this embodiment, pixel layouts different from that shown in FIG. 1A will be mainly described. There are no particular limitations on the arrangement of sub-pixels, and various methods can be applied. Examples of sub-pixel arrangements include a stripe arrangement, an S-stripe arrangement, a matrix arrangement, a delta arrangement, a Bayer arrangement, and a pentile arrangement.

[0414] The top surface shape of the sub-pixels shown in the drawings in this embodiment mode corresponds to the top surface shape of the light-emitting region (or light-receiving region).

[0415] The top surface shape of the subpixel may be, for example, a triangle, a quadrangle (including a rectangle and a square), a polygon such as a pentagon, a polygon with rounded corners, an ellipse, or a circle.

[0416] Furthermore, the layout of the circuits constituting the sub-pixels is not limited to the range of the sub-pixels shown in the drawings, and may be arranged outside of the range.

[0417] An S-stripe arrangement is applied to the pixel 110 shown in Fig. 19A. The pixel 110 shown in Fig. 19A is composed of three subpixels: a subpixel 110a, a subpixel 110b, and a subpixel 110c.

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

[0419] The Pentile arrangement is applied to the pixels 124a and 124b shown in Fig. 19C. Fig. 19C shows an example in which the pixel 124a having the subpixels 110a and 110b and the pixel 124b having the subpixels 110b and 110c are arranged alternately.

[0420] 19D to 19F, a delta arrangement is applied to the pixels 124a and 124b. The pixel 124a has two subpixels (subpixel 110a and subpixel 110b) in the upper row (first row) and one subpixel (subpixel 110c) in the lower row (second row). The pixel 124b has one subpixel (subpixel 110c) in the upper row (first row) and two subpixels (subpixel 110a and subpixel 110b) in the lower row (second row).

[0421] Figure 19D shows an example in which each sub-pixel has an approximately rectangular top surface shape with rounded corners, Figure 19E shows an example in which each sub-pixel has a circular top surface shape, and Figure 19F shows an example in which each sub-pixel has an approximately hexagonal top surface shape with rounded corners.

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

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

[0424] 19A to 19G, it is preferable that the subpixel 110a be the subpixel R that emits red light, the subpixel 110b be the subpixel G that emits green light, and the subpixel 110c be the subpixel B that emits blue light. Note that the configuration of the subpixels is not limited to this, and the colors that the subpixels emit and their arrangement order can be determined appropriately. For example, the subpixel 110b may be the subpixel R that emits red light, and the subpixel 110a may be the subpixel G that emits green light.

[0425] In photolithography, the finer the pattern to be processed, the more significant the effect of light diffraction becomes. This reduces the fidelity of the photomask pattern when it is transferred by exposure, making it difficult to process the resist mask into the desired shape. Therefore, even if the photomask pattern is rectangular, a pattern with rounded corners is likely to be formed. As a result, the top surface shape of the subpixel may become a polygon with rounded corners, an ellipse, a circle, or the like.

[0426] Furthermore, in a manufacturing method of a display device according to one embodiment 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 material for the EL layer and the curing temperature of the resist material, the resist film may not be cured sufficiently. A resist film that is not cured sufficiently may have a shape that is different 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, a circle, or the like. For example, when a resist mask with a square top surface shape is formed, a resist mask with a circular top surface shape may be formed, resulting in a circular top surface shape of the EL layer.

[0427] In order to form the top surface of the EL layer into a desired shape, a technique for correcting a mask pattern in advance (OPC (Optical Proximity Correction) technique) may be used so that the design pattern and the transfer pattern coincide with each other. Specifically, the OPC technique adds a correction pattern to the corners of figures on the mask pattern.

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

[0429] A stripe arrangement is applied to the pixel 110 shown in FIGS. 20A to 20C.

[0430] Figure 20A is an example in which each subpixel has a rectangular top surface shape, Figure 20B is an example in which each subpixel has a top surface shape that is a combination of two semicircles and a rectangle, and Figure 20C is an example in which each subpixel has an elliptical top surface shape.

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

[0432] Figure 20D is an example in which each sub-pixel has a square top surface shape, Figure 20E is an example in which each sub-pixel has an approximately square top surface shape with rounded corners, and Figure 20F is an example in which each sub-pixel has a circular top surface shape.

[0433] 20G and 20H show an example in which one pixel 110 is configured in two rows and three columns.

[0434] 20G has three subpixels (subpixels 110a, 110b, and 110c) in the top row (first row) and one subpixel (subpixel 110d) in the bottom row (second row). In other words, pixel 110 has subpixel 110a in the left column (first column), subpixel 110b in the center column (second column), subpixel 110c in the right column (third column), and subpixels 110d across these three columns.

[0435] The pixel 110 shown in FIG. 20H has three subpixels (subpixels 110a, 110b, and 110c) in the top row (first row) and three subpixels 110d in the bottom row (second row). In other words, the pixel 110 has subpixels 110a and 110d in the left column (first column), subpixels 110b and 110d in the center column (second column), and subpixels 110c and 110d in the right column (third column). By aligning the subpixels in the top and bottom rows as shown in FIG. 20H, it is possible to efficiently remove dust and other particles that may occur during the manufacturing process. Therefore, a display device with high display quality can be provided.

[0436] FIG. 20I shows an example in which one pixel 110 is configured in three rows and two columns.

[0437] 20I has subpixel 110a in the top row (first row), subpixel 110b in the middle row (second row), subpixel 110c spanning from the first to second rows, and one subpixel (subpixel 110d) in the bottom row (third row). In other words, pixel 110 has subpixels 110a and 110b in the left column (first column), subpixel 110c in the right column (second column), and subpixel 110d spanning these two columns.

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

[0439] The subpixels 110a, 110b, 110c, and 110d may each have a light-emitting device that emits light of a different color, such as subpixels of four colors R, G, B, and white (W), subpixels of four colors R, G, B, and Y, or subpixels of R, G, B, and infrared light (IR).

[0440] 20A to 20I , it is preferable that, for example, the subpixel 110a be the subpixel R that emits red light, the subpixel 110b be the subpixel G that emits green light, the subpixel 110c be the subpixel B that emits blue light, and the subpixel 110d be any one of the subpixels W that emit white light, Y that emit yellow light, and IR that emit near-infrared light. With such a configuration, the pixel 110 shown in FIGS. 20G and 20H has a stripe layout of R, G, and B, thereby improving display quality. Furthermore, the pixel 110 shown in FIG. 20I has a so-called S-stripe layout of R, G, and B, thereby improving display quality.

[0441] The pixel 110 may also have sub-pixels that include light-receiving devices.

[0442] In each pixel 110 shown in FIGS. 20A to 20I, any one of the subpixels 110a to 110d may be a subpixel having a light-receiving device.

[0443] 20A to 20I , it is preferable that, for example, the subpixel 110a be the subpixel R that emits red light, the subpixel 110b be the subpixel G that emits green light, the subpixel 110c be the subpixel B that emits blue light, and the subpixel 110d be the subpixel S that has a light-receiving device. With this configuration, the pixels 110 shown in FIGS. 20G and 20H have a stripe layout of R, G, and B, which can improve display quality. Furthermore, the pixel 110 shown in FIG. 20I has a so-called S-stripe layout of R, G, and B, which can improve display quality.

[0444] The wavelength of light detected by the subpixel S having the light receiving device is not particularly limited, and the subpixel S can be configured to detect either or both of visible light and infrared light.

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

[0446] FIG. 20J shows an example in which one pixel 110 is configured in two rows and three columns.

[0447] 20J has three subpixels (subpixels 110a, 110b, and 110c) in the top row (first row) and two subpixels (subpixels 110d and 110e) in the bottom row (second row). In other words, pixel 110 has subpixels 110a and 110d in the left column (first column), subpixel 110b in the center column (second column), subpixel 110c in the right column (third column), and subpixel 110e from the second column to the third column.

[0448] FIG. 20K shows an example in which one pixel 110 is configured in three rows and two columns.

[0449] 20K has subpixel 110a in the top row (first row), subpixel 110b in the middle row (second row), subpixel 110c across the first and second rows, and two subpixels (subpixels 110d and 110e) in the bottom row (third row). In other words, pixel 110 has subpixels 110a, 110b, and 110d in the left column (first column), and subpixels 110c and 110e in the right column (second column).

[0450] 20J and 20K, it is preferable that the subpixel 110a be the subpixel R that emits red light, the subpixel 110b be the subpixel G that emits green light, and the subpixel 110c be the subpixel B that emits blue light. In this configuration, the pixel 110 shown in FIG. 20J has a stripe layout of R, G, and B, which can improve display quality. Furthermore, the pixel 110 shown in FIG. 20K has a so-called S-stripe layout of R, G, and B, which can improve display quality.

[0451] 20J and 20K, it is preferable to use a subpixel S having a light-receiving device in at least one of the subpixels 110d and 110e. When a light-receiving device is used in both the subpixels 110d and 110e, the configurations of the light-receiving devices may be different from each other. For example, the wavelength ranges of light detected may differ from each other. Specifically, one of the subpixels 110d and 110e may have a light-receiving device that mainly detects visible light, and the other may have a light-receiving device that mainly detects infrared light.

[0452] 20J and 20K, it is preferable that one of the subpixels 110d and 110e is a subpixel S having a light-receiving device, and the other is a subpixel having a light-emitting device that can be used as a light source. For example, it is preferable that one of the subpixels 110d and 110e is a subpixel IR having a light-emitting device that emits infrared light, and the other is a subpixel S having a light-receiving device that detects infrared light.

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

[0454] As described above, the display device of one embodiment of the present invention can employ various layouts for a pixel having a subpixel including a light-emitting device. Furthermore, the display device of one embodiment of the present invention can employ a pixel having both a light-emitting device and a light-receiving device. In this case, various layouts can also be employed.

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

[0456] Embodiment 4 In this embodiment, a display device of one embodiment of the present invention will be described with reference to FIGS.

[0457] The display device of the present embodiment can be a high-definition display device, and can therefore be used, for example, as a display unit for a wristwatch-type or bracelet-type information terminal (wearable device), as well as a display unit for a wearable device that can be worn on the head, such as a head-mounted display (HMD) for VR, or a glasses-type AR device.

[0458] The display device of this embodiment can be a high-resolution display device or a large-sized display device. Therefore, the display device of this embodiment can be used in electronic devices having relatively large screens, such as television devices, desktop or notebook personal computers, computer monitors, digital signage, and large game machines such as pachinko machines, as well as in display units of digital cameras, digital video cameras, digital photo frames, mobile phones, portable game machines, personal digital assistants, and sound reproduction devices.

[0459] 21A shows a perspective view of a display module 280. The display module 280 includes a display device 100A and an FPC 290. Note that the display device included in the display module 280 is not limited to the display device 100A, and may be any of the display devices 100B to 100F described below.

[0460] The display module 280 has a substrate 291 and a substrate 292. The display module 280 has a display portion 281. The display portion 281 is a region that displays an image in the display module 280, and is a region where light from each pixel provided in a pixel portion 284 (described later) can be viewed.

[0461] 21B is a perspective view schematically illustrating the configuration on the substrate 291 side. A circuit portion 282, a pixel circuit portion 283 on the circuit portion 282, and a pixel portion 284 on the pixel circuit portion 283 are stacked on the substrate 291. A terminal portion 285 for connecting to the FPC 290 is provided in a portion of the substrate 291 that does not overlap with the pixel portion 284. The terminal portion 285 and the circuit portion 282 are electrically connected by a wiring portion 286 composed of a plurality of wirings.

[0462] The pixel section 284 has a plurality of periodically arranged pixels 284a. An enlarged view of one pixel 284a is shown on the right side of Fig. 21B. The various configurations described in the previous embodiments can be applied to the pixel 284a. Fig. 21B shows an example in which the pixel 284a has a configuration similar to that of the pixel 110 shown in Fig. 1A.

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

[0464] One pixel circuit 283a is a circuit that controls the driving of multiple elements included in one pixel 284a. One pixel circuit 283a can be configured to have three circuits that control the light emission of one light-emitting device. For example, the pixel circuit 283a can be configured to have at least one selection transistor, one current control transistor (drive transistor), and a capacitor for each light-emitting device. In this case, a gate signal is input to the gate of the selection transistor, and a source signal is input to the source. This realizes an active matrix display device.

[0465] The circuit portion 282 includes a circuit for driving each pixel circuit 283 a of the pixel circuit portion 283. For example, the circuit portion 282 preferably includes one or both of a gate line driver circuit and a source line driver circuit. In addition, the circuit portion 282 may include at least one of an arithmetic circuit, a memory circuit, a power supply circuit, and the like.

[0466] The FPC 290 functions as wiring for supplying a video signal, a power supply potential, or the like from the outside to the circuit portion 282. An IC may be mounted on the FPC 290.

[0467] The display module 280 can be configured such that one or both of the pixel circuit unit 283 and the circuit unit 282 are provided overlapping the pixel unit 284, thereby enabling the aperture ratio (effective display area ratio) of the display unit 281 to be extremely high. For example, the aperture ratio of the display unit 281 can be set to 40% or more and less than 100%, preferably 50% or more and 95% or less, and more preferably 60% or more and 95% or less. Furthermore, the pixels 284a can be arranged at an extremely high density, enabling the resolution of the display unit 281 to be extremely high. For example, it is preferable that the pixels 284a be arranged in the display unit 281 at a resolution of 2000 ppi or more, preferably 3000 ppi or more, more preferably 5000 ppi or more, and even more preferably 6000 ppi or more, and 20000 ppi or less, or 30000 ppi or less.

[0468] Because such a display module 280 has extremely high resolution, it can be suitably used in VR devices such as HMDs or eyeglass-type AR devices. For example, even in a configuration in which the display unit of the display module 280 is viewed through lenses, the display module 280 has an extremely high-resolution display unit 281, so even if the display unit is enlarged with lenses, the pixels are not visible, allowing for a highly immersive display. Furthermore, the display module 280 is not limited to this, and can be suitably used in electronic devices with relatively small display units. For example, it can be suitably used in the display unit of a wearable electronic device such as a wristwatch.

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

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

[0471] 21A and 21B. The layered structure from the substrate 301 to the insulating layer 255c corresponds to the layer 101 in the first embodiment.

[0472] The transistor 310 has a channel formation region in a substrate 301. The substrate 301 can be, for example, a semiconductor substrate such as a single crystal silicon substrate. The transistor 310 includes a part of the substrate 301, a conductive layer 311, a low-resistance region 312, an insulating layer 313, and an insulating layer 314. The conductive layer 311 functions as a gate electrode. The insulating layer 313 is located between the substrate 301 and the conductive layer 311 and functions as a gate insulating layer. The low-resistance region 312 is a region in which the substrate 301 is doped with impurities and functions as one of a source and a drain. The insulating layer 314 is provided to cover a side surface of the conductive layer 311 and functions as a sidewall insulating layer.

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

[0474] In addition, an insulating layer 261 is provided to cover the transistor 310 , and a capacitor 240 is provided over the insulating layer 261 .

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

[0476] The conductive layer 241 is provided over the insulating layer 261 and is buried in the insulating layer 254. The conductive layer 241 is electrically connected to one of the source and the drain of the transistor 310 by a plug 271 buried in the insulating layer 261. The insulating layer 243 is provided to cover the conductive layer 241. The conductive layer 245 is provided in a region overlapping with the conductive layer 241 with the insulating layer 243 interposed therebetween.

[0477] Note that at least one of the conductive layers included in the layer 101 preferably includes a conductive layer surrounding the outside of the display portion 281 (or the pixel portion 284). The conductive layer can also be called a guard ring. By providing the conductive layer, it is possible to prevent elements such as transistors and light-emitting devices from being damaged by a high voltage applied to the elements due to charging caused by a process using ESD (electrostatic discharge) or plasma.

[0478] An insulating layer 255a is provided to cover the capacitor 240, an insulating layer 255b is provided on the insulating layer 255a, and an insulating layer 255c is provided on the insulating layer 255b. The light-emitting device 130a, the light-emitting device 130b, and the light-emitting device 130c are provided on the insulating layer 255c. FIG. 22A shows an example in which the light-emitting device 130a, the light-emitting device 130b, and the light-emitting device 130c have the same stacked structure as the stacked structure shown in FIG. 1B. An insulator is provided in the region between adjacent light-emitting devices. In FIG. 22A and other drawings, 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] The pixel electrode 111a, the pixel electrode 111b, and the pixel electrode 111c are electrically connected to one of the source and drain of the transistor 310 via a plug 256 embedded in the insulating layer 243, the insulating layer 255a, the insulating layer 255b, and the insulating layer 255c, a conductive layer 241 embedded in the insulating layer 254, and a plug 271 embedded in the insulating layer 261. The height of the top surface of the insulating layer 255c and the height of the top surface of the plug 256 are the same or approximately the same. Various conductive materials can be used for the plug. Figure 22A and other figures show 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] A protective layer 131 is provided on the light-emitting devices 130a, 130b, and 130c. A color conversion layer 135R and a colored layer 132R are stacked on the protective layer 131 at a position overlapping the light-emitting device 130a, a color conversion layer 135G and a colored layer 132G are stacked at a position overlapping the light-emitting device 130b, and a colored layer 132B is provided at a position overlapping the light-emitting device 130c. A substrate 120 is bonded to the colored layers 132R, 132G, and 132B by a resin layer 122. For details of the components from the light-emitting devices to the substrate 120, see Embodiment 1. The substrate 120 corresponds to the substrate 292 in FIG. 21A .

[0482] The display device shown in Fig. 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 the layer 101 included in the display device shown in Fig. 22B is not limited to the configuration shown in Fig. 22A, and any of the configurations shown in Figs. 23 to 27 may be applied.

[0483] The light receiving device 150 includes a pixel electrode 111S, a layer 155, a common layer 114, and a common electrode 115, which are stacked together. For details of the display device including the light receiving device, reference can be made to Embodiments 1 and 6.

[0484] 23 has a configuration in which a transistor 310A and a transistor 310B, each having a channel formed in a semiconductor substrate, are stacked. Note that in the following description of the display device, descriptions of parts that are the same as those of the display device described above may be omitted.

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

[0487] The substrate 301B is provided with a plug 343 that penetrates the substrate 301B and an insulating layer 345. Here, it is preferable to provide an insulating layer 344 to cover the side surface of the plug 343. The insulating layer 344 is an insulating layer that functions as a protective layer and can suppress the diffusion of impurities into the substrate 301B. The insulating layer 344 can be an inorganic insulating film that can be used for the protective layer 131.

[0488] Furthermore, a conductive layer 342 is provided on the back surface of the substrate 301B (the surface opposite to the substrate 120 side), below the insulating layer 345. The conductive layer 342 is preferably provided so as to be embedded in the insulating layer 335. Furthermore, the lower surfaces of the conductive layer 342 and the insulating layer 335 (the surface on the substrate 301A side) are preferably flattened. Here, the conductive layer 342 is electrically connected to the plug 343.

[0489] On the other hand, in the substrate 301A, a conductive layer 341 is provided on an insulating layer 346. The conductive layer 341 is preferably provided so as to be embedded in the insulating layer 336. In addition, the upper surfaces of the conductive layer 341 and the insulating layer 336 are preferably flattened.

[0490] The substrate 301A and the substrate 301B are electrically connected by bonding the conductive layer 341 and the conductive layer 342. Here, by improving the flatness of the surface formed by the conductive layer 342 and the insulating layer 335 and the surface formed by the conductive layer 341 and the insulating layer 336, the conductive layer 341 and the conductive layer 342 can be favorably bonded to each other.

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

[0492] [Display Device 100C] A display device 100C shown in FIG. 24 has a configuration in which a conductive layer 341 and a conductive layer 342 are joined via a bump 347.

[0493] 24 , by providing a bump 347 between the conductive layer 341 and the conductive layer 342, the conductive layer 341 and the conductive layer 342 can be electrically connected. The bump 347 can be formed using a conductive material containing, for example, gold (Au), nickel (Ni), indium (In), tin (Sn), or the like. Alternatively, for example, solder may be used as the bump 347. An adhesive layer 348 may be provided between the insulating layer 345 and the insulating layer 346. When the bump 347 is provided, the insulating layer 335 and the insulating layer 336 shown in FIG. 23 may not be provided.

[0494] [Display Device 100D] A display device 100D shown in FIG. 25 differs from the display device 100A mainly in the configuration of the transistors.

[0495] The transistor 320 is a transistor (OS transistor) in which a metal oxide (also referred to as an oxide semiconductor) is used for a semiconductor layer in which a channel is formed.

[0496] The transistor 320 includes a semiconductor layer 321 , an insulating layer 323 , a conductive layer 324 , a pair of conductive layers 325 , an insulating layer 326 , and a conductive layer 327 .

[0497] 21A and 21B. The stacked structure from the substrate 331 to the insulating layer 255c corresponds to the layer 101 in Embodiment 1. The substrate 331 can be an insulating substrate or a semiconductor substrate.

[0498] An insulating layer 332 is provided over a substrate 331. The insulating layer 332 functions as a barrier layer that prevents impurities such as water or hydrogen from diffusing from the substrate 331 to the transistor 320 and prevents oxygen from being released from the semiconductor layer 321 toward the insulating layer 332. The insulating layer 332 can be, for example, a film through which hydrogen or oxygen is less likely to diffuse than a silicon oxide film, such as an aluminum oxide film, a hafnium oxide film, or a silicon nitride film.

[0499] A conductive layer 327 is provided over the insulating layer 332, and an insulating layer 326 is provided to cover the conductive layer 327. The conductive layer 327 functions as a first gate electrode of the transistor 320, and part of the insulating layer 326 functions as a first gate insulating layer. An oxide insulating film such as a silicon oxide film is preferably used for at least a portion of the insulating layer 326 that is in contact with the semiconductor layer 321. The top surface of the insulating layer 326 is preferably planarized.

[0500] The semiconductor layer 321 is provided over the insulating layer 326. The semiconductor layer 321 preferably includes a metal oxide (also referred to as an oxide semiconductor) film having semiconductor properties. A pair of conductive layers 325 is provided over and in contact with the semiconductor layer 321 and functions as a source electrode and a drain electrode.

[0501] An insulating layer 328 is provided to cover top surfaces and side surfaces of the pair of conductive layers 325 and side surfaces of the semiconductor layer 321, and an insulating layer 264 is provided over the insulating layer 328. The insulating layer 328 functions as a barrier layer that prevents impurities such as water or hydrogen from diffusing from the insulating layer 264 or the like into the semiconductor layer 321 and prevents oxygen from being released from the semiconductor layer 321. The insulating layer 328 can be an insulating film similar to the insulating layer 332.

[0502] Openings reaching the semiconductor layer 321 are provided in the insulating layer 328 and the insulating layer 264. Inside the openings, an insulating layer 323 and a conductive layer 324 are buried, which are in contact with side surfaces of the insulating layer 264, the insulating layer 328, and the conductive layer 325 and an upper surface of the semiconductor layer 321. The conductive layer 324 functions as a second gate electrode, and the insulating layer 323 functions as a second gate insulating layer.

[0503] The top surfaces of the conductive layer 324, the insulating layer 323, and the insulating layer 264 are planarized so that their heights are the same or approximately the same, and insulating layers 329 and 265 are provided to cover them.

[0504] The insulating layer 264 and the insulating layer 265 function as interlayer insulating layers. The insulating layer 329 functions as a barrier layer that prevents impurities such as water or hydrogen from diffusing from the insulating layer 265 or the like to the transistor 320. The insulating layer 329 can be formed using an insulating film similar to the insulating layer 328 and the insulating layer 332.

[0505] A plug 274 electrically connected to one of the pair of conductive layers 325 is provided to be embedded in the insulating layer 265, the insulating layer 329, and the insulating layer 264. Here, the plug 274 preferably includes a conductive layer 274a covering the side surfaces of the openings of the insulating layer 265, the insulating layer 329, the insulating layer 264, and the insulating layer 328 and part of the top surface of the conductive layer 325, and a conductive layer 274b in contact with the top surface of the conductive layer 274a. In this case, the conductive layer 274a is preferably made of a conductive material through which hydrogen and oxygen do not easily diffuse.

[0506] [Display Device 100E] A display device 100E illustrated in FIG. 26 has a stacked structure of a transistor 320A and a transistor 320B each including an oxide semiconductor as a semiconductor in which a channel is formed.

[0507] The transistor 320A, the transistor 320B, and the surrounding configurations thereof can be referred to the display device 100D.

[0508] Although two transistors including an oxide semiconductor are stacked here, the present invention is not limited to this structure, and for example, three or more transistors may be stacked.

[0509] [Display Device 100F] A display device 100F shown in FIG. 27 has a stacked structure of a transistor 310 in which a channel is formed in a substrate 301 and a transistor 320 in which a channel is formed and a semiconductor layer containing metal oxide.

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

[0511] The transistor 320 can be used as a transistor that forms a pixel circuit. The transistor 310 can be used as a transistor that forms a pixel circuit or a driver circuit (gate line driver circuit, source line driver circuit) that drives the pixel circuit. The transistors 310 and 320 can be used as transistors that form various circuits such as an arithmetic circuit or a memory circuit.

[0512] By using this configuration, not only pixel circuits but also driving circuits etc. can be formed directly below the light-emitting device, making it possible to make the display device smaller than when driving circuits are provided around the periphery of the display area.

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

[0514] The display device 100G has a configuration in which a substrate 152 and a substrate 151 are bonded together. In Fig. 28, the 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, and the like. Fig. 28 shows an example in which an IC 173 and an FPC 172 are mounted on the display device 100G. Therefore, the configuration shown in Fig. 28 can also be said to be a display module including the display device 100G, an IC (integrated circuit), and an FPC.

[0516] The connection portion 140 is provided on the outside of the display portion 162. The connection portion 140 can be provided along one side or multiple sides of the display portion 162. The number of connection portions 140 may be single or multiple. Fig. 28 shows an example in which the connection portion 140 is provided so as to surround the four sides of the display portion 162. The connection portion 140 electrically connects the common electrode of the light-emitting device and the conductive layer, and can supply a potential to the common electrode.

[0517] The circuit 164 can be, for example, a scanning line driver circuit.

[0518] The wiring 165 has a function of supplying signals and power to the display portion 162 and the circuit 164. The signals and power are input to the wiring 165 from the outside via the FPC 172 or input to the wiring 165 from the IC 173.

[0519] 28 shows an example in which an IC 173 is provided on a substrate 151 by a chip-on-glass (COG) method, a chip-on-film (COF) method, or the like. For example, an IC having a scanning line driver circuit or a signal line driver circuit can be used as the IC 173. The display device 100G and the display module may not include an IC. Alternatively, the IC may be mounted on an FPC by a COF method or the like.

[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 portion 140, and a portion of the area including the end portion are cut away.

[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 into red light, a coloring layer 132R that transmits red light, a color conversion layer 135G that converts white light into green light, a coloring layer 132G that transmits green light, and a coloring layer 132B that transmits blue light.

[0522] The light-emitting devices 130a, 130b, and 130c each have the same structure as the stacked structure shown in Fig. 1B except for the configuration of the pixel electrodes. For details of the light-emitting devices, refer to Embodiment 1.

[0523] The light-emitting device 130a overlapping the color conversion layer 135R and the colored layer 132R includes a conductive layer 112a, a conductive layer 126a on the conductive layer 112a, and a conductive layer 129a on the conductive layer 126a. The conductive layers 112a, 126a, and 129a may all be called pixel electrodes, or some of them may be called pixel electrodes.

[0524] The light-emitting device 130b overlapping the color conversion layer 135G and the colored layer 132G includes 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 layer 112b, the conductive layer 126b, and the conductive layer 129b may be called pixel electrodes, or only some of them may be called pixel electrodes.

[0525] The light-emitting device 130c overlapping 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 may be called pixel electrodes, or some of them may be called pixel electrodes.

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

[0527] The conductive layers 112b, 126b, 129b, 112c, 126c, and 129c are similar to the conductive layers 112a, 126a, and 129a, and therefore detailed description thereof will be omitted.

[0528] Recesses are formed in the conductive layers 112a, 112b, and 112c so as to cover the openings provided in the insulating layer 214. A layer 128 is buried in the recesses.

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

[0530] The layer 128 may be an insulating layer or a conductive layer. Various inorganic insulating materials, organic insulating materials, and conductive materials can be used as appropriate for the layer 128. In particular, the layer 128 is preferably formed using an insulating material, and more preferably using an organic insulating material. For example, the organic insulating material that can be used for the insulating layer 127 can be used for the layer 128.

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

[0532] A portion of the top surface and side surfaces of layer 113W are covered with 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 common layer 114. Common layer 114 and common electrode 115 are each a continuous film provided in common to a plurality of light-emitting devices.

[0533] 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 sealing structure or a hollow sealing structure can be applied to seal the light-emitting devices. In FIG. 29A , the space between the substrates 152 and 151 is filled with the adhesive layer 142, thereby applying a solid sealing structure. Alternatively, the space may be filled with an inert gas (such as nitrogen or argon), thereby applying a hollow sealing structure. In this case, the adhesive layer 142 may be provided so as not to overlap the light-emitting devices. Alternatively, the space may be filled with a resin different from the frame-shaped adhesive layer 142.

[0534] The protective layer 131 is preferably provided in at least the display portion 162 and is provided so as to cover the entire display portion 162. The protective layer 131 is preferably provided so as to cover not only the display portion 162 but also the connection portion 140 and the circuit 164. The protective layer 131 is preferably provided up to the edge of the display device 100G. On the other hand, in the connection portion 204, the FPC 172 and the conductive layer 166 are electrically connected to each other, so that a portion where the protective layer 131 is not provided is generated.

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

[0536] For example, after the protective layer 131 is formed over the entire surface of the display device 100G, a mask is used to remove the region of the protective layer 131 that overlaps with the conductive layer 166, thereby exposing the conductive layer 166.

[0537] Alternatively, a laminated structure of at least one organic layer and a conductive layer may be provided on the conductive layer 166, and the protective layer 131 may be provided on the laminated structure. A peeling initiation point (a portion that triggers peeling) may then be formed on the laminated structure using a laser or a sharp blade (e.g., a needle or cutter), selectively removing the laminated structure and the protective layer 131 thereon to expose the conductive layer 166. For example, the protective layer 131 can be selectively removed by pressing an adhesive roller against the substrate 151 and moving the roller relative to the substrate while rotating. Alternatively, adhesive tape may be attached to the substrate 151 and peeled off. Because of poor adhesion between the organic layer and the conductive layer, or between the organic layers themselves, separation occurs at the interface between the organic layer and the conductive layer or within the organic layer. This allows selective removal of the region of the protective layer 131 that overlaps with the conductive layer 166. If an organic layer or the like remains on the conductive layer 166, it can be removed using an organic solvent or the like.

[0538] As the organic layer, for example, at least one organic layer (a layer functioning as a light-emitting layer, a carrier blocking layer, a carrier transport layer, or a carrier injection layer) used in the layer 113W can be used. The organic layer may be formed simultaneously with the formation of the layer 113W, or may be provided separately. The conductive layer can be formed in the same process and with the same material as the common electrode 115. For example, it is preferable to form an ITO film as the common electrode 115 and the conductive layer. Note that when a stacked structure is used for the common electrode 115, at least one layer of the layers constituting the common electrode 115 is provided as the conductive layer.

[0539] Furthermore, the top surface of the conductive layer 166 may be covered with a mask so that the protective layer 131 is not formed on the conductive layer 166. As the mask, for example, a metal mask (area metal mask) or an adhesive or adhesive tape or film may be used. By forming the protective layer 131 with the mask in place and then removing the mask, the conductive layer 166 can be kept exposed even after the protective layer 131 is formed.

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

[0541] In the connection portion 140, a conductive layer 123 is provided on the insulating layer 214. The conductive layer 123 has an example of a stacked structure including a conductive film obtained by processing the same conductive film as the conductive layers 112a, 112b, and 112c, a conductive film obtained by processing the same conductive film as the conductive layers 126a, 126b, and 126c, and a conductive film obtained by processing the same conductive film as the conductive layers 129a, 129b, and 129c. The end of the conductive layer 123 is covered with 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. 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 with each other and electrically connected.

[0542] The display device 100G is a top-emission type. Light emitted by the light-emitting device is emitted toward the substrate 152. The substrate 152 is preferably made of a material that is highly transparent to visible light. The pixel electrodes contain a material that reflects visible light, and the counter electrode (common electrode 115) contains a material that transmits visible light.

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

[0544] The transistor 201 and the transistor 205 are both formed over a substrate 151. These transistors can be manufactured using the same material and through the same process.

[0545] An insulating layer 211, an insulating layer 213, an insulating layer 215, and an insulating layer 214 are provided over the substrate 151 in this order. A part of the insulating layer 211 functions as a gate insulating layer for each transistor. A part of the insulating layer 213 functions as a gate insulating layer for each transistor. The insulating layer 215 is provided to cover the transistor. The insulating layer 214 is provided to cover the transistor and functions as a planarization layer. Note that the number of gate insulating layers and the number of insulating layers covering the transistors are not limited, and each may be a single layer or two or more layers.

[0546] At least one insulating layer covering the transistor is preferably made of a material that is resistant to the diffusion of impurities such as water and hydrogen. This allows the insulating layer to function as a barrier layer. With this structure, it is possible to effectively prevent impurities from entering the transistor from the outside, thereby improving the reliability of the display device.

[0547] It is preferable to use an inorganic insulating film for each of the insulating layers 211, 213, and 215. Examples of the inorganic insulating film that can be used include a silicon nitride film, a silicon oxynitride film, a silicon oxide film, a silicon nitride oxide film, an aluminum oxide film, and an aluminum nitride film. Alternatively, a hafnium oxide film, an yttrium oxide film, a zirconium oxide film, a gallium oxide film, a tantalum oxide film, a magnesium oxide film, a lanthanum oxide film, a cerium oxide film, and a neodymium oxide film may also be used. Two or more of the above insulating films may be stacked.

[0548] An organic insulating layer is preferably used for the insulating layer 214, which functions as a planarization layer. Materials that can be used for the organic insulating layer include acrylic resin, polyimide resin, epoxy resin, polyamide resin, polyimideamide resin, siloxane resin, benzocyclobutene-based resin, phenolic resin, and precursors of these resins. The insulating layer 214 may also have a stacked 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 can prevent recesses from being formed in the insulating layer 214 during processing of the conductive layer 112a, the conductive layer 126a, the conductive layer 129a, or the like. Alternatively, recesses may be formed in the insulating layer 214 during processing of the conductive layer 112a, the conductive layer 126a, the conductive layer 129a, or the like.

[0549] The transistor 201 and the transistor 205 each include a conductive layer 221 that functions as a gate electrode, an insulating layer 211 that functions as a gate insulating layer, conductive layers 222a and 222b that function as a source electrode and a drain electrode, a semiconductor layer 231, an insulating layer 213 that functions as a gate insulating layer, and a conductive layer 223 that functions as a gate electrode. Here, the same hatching pattern is applied to multiple layers obtained by processing the same conductive film. The insulating layer 211 is located between the conductive layer 221 and the semiconductor layer 231. The insulating layer 213 is located between the conductive layer 223 and the semiconductor layer 231.

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

[0551] The transistor 201 and the transistor 205 have a structure in which a semiconductor layer in which a channel is formed is sandwiched between two gates. The two gates may be connected and the same signal may be supplied to drive the transistor. Alternatively, the threshold voltage of the transistor may be controlled by applying a potential for controlling the threshold voltage to one of the two gates and a potential for driving to the other.

[0552] The crystallinity of a semiconductor material used for a transistor is not particularly limited, and any of an amorphous semiconductor, a single crystal semiconductor, and a semiconductor having crystallinity other than a single crystal (a microcrystalline semiconductor, a polycrystalline semiconductor, or a semiconductor having a crystalline region in part) may be used. The use of a single crystal semiconductor or a crystalline semiconductor is preferable because it can suppress deterioration of transistor characteristics.

[0553] The semiconductor layer of the transistor preferably includes a metal oxide (also referred to as an oxide semiconductor). That is, the display device of this embodiment preferably includes a transistor using a metal oxide for a channel formation region (hereinafter referred to as an OS transistor).

[0554] Examples of crystalline oxide semiconductors include c-axis-aligned crystalline (CAAC)-OS and nanocrystalline (nc)-OS.

[0555] Alternatively, a transistor using silicon for a channel formation region (Si transistor) may be used. Examples of silicon include single crystal silicon, polycrystalline silicon, and amorphous silicon. In particular, a transistor having low temperature polysilicon (LTPS) in a semiconductor layer (hereinafter also referred to as an LTPS transistor) is preferably used. An LTPS transistor has high field-effect mobility and favorable frequency characteristics.

[0556] By using Si transistors such as LTPS transistors, circuits that need to be driven at high frequencies (such as source driver circuits) can be built on the same substrate as the display unit, which simplifies the external circuits mounted on the display device and reduces component and mounting costs.

[0557] An OS transistor has significantly higher field-effect mobility than a transistor using amorphous silicon. Furthermore, an OS transistor has significantly lower source-drain leakage current in an off state (hereinafter also referred to as off-state current), and can retain charge accumulated in a capacitor connected in series with the transistor for a long period of time. Furthermore, the use of an OS transistor can reduce the power consumption of a display device.

[0558] Furthermore, to increase the light emission luminance of a light-emitting device included in a pixel circuit, it is necessary to increase the amount of current flowing through the light-emitting device. To achieve this, it is necessary to increase the source-drain voltage of a driving transistor included in the pixel circuit. Since an OS transistor has a higher source-drain breakdown voltage than a Si transistor, a high voltage can be applied between the source and drain of the OS transistor. Therefore, by using an OS transistor as the driving transistor included in a pixel circuit, it is possible to increase the amount of current flowing through the light-emitting device and increase the light emission luminance of the light-emitting device.

[0559] Furthermore, when a transistor operates in the saturation region, an OS transistor can reduce the change in source-drain current with respect to a change in gate-source voltage compared to a Si transistor. Therefore, by using an OS transistor as a driving transistor included in a pixel circuit, the current flowing between the source and drain can be precisely controlled by changing the gate-source voltage, thereby controlling the amount of current flowing through the light-emitting device. This allows for a larger gradation in the pixel circuit.

[0560] Furthermore, in terms of the saturation characteristics of the current that flows when a transistor operates in the saturation region, an OS transistor can pass a more stable current (saturation current) than a Si transistor, even when the source-drain voltage gradually increases. Therefore, by using an OS transistor as a driving transistor, a stable current can be passed through a light-emitting device, even when the current-voltage characteristics of an EL device vary. In other words, when an OS transistor operates in the saturation region, the source-drain current of the OS transistor remains almost unchanged even when the source-drain voltage increases, thereby stabilizing the light-emitting luminance of the light-emitting device.

[0561] As described above, by using an OS transistor for a driving transistor included in a pixel circuit, it is possible to achieve "suppression of black floating," "increase in light emission luminance," "multiple gradations," "suppression of variations in light-emitting devices," and the like.

[0562] The semiconductor layer preferably contains, for example, indium, M (wherein M is one or more elements selected from gallium, aluminum, silicon, boron, yttrium, tin, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, and magnesium), and zinc. In particular, M is preferably one or more elements selected from aluminum, gallium, yttrium, and tin.

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

[0564] When the semiconductor layer is an In-M-Zn oxide, the atomic ratio of In in the In-M-Zn oxide is preferably equal to or greater than the atomic ratio of M. The atomic ratio of metal elements in such an In-M-Zn oxide may be In:M:Zn=1:1:1 or a composition thereabout, In:M:Zn=1:1:1 or a composition thereabout, In:M:Zn=1:1:1.2 or a composition thereabout, In:M:Zn=1:3:2 or a composition thereabout, In:M:Zn=1:3:4 or a composition thereabout, In:M:Zn=2:1:3 or a composition thereabout, In:M:Zn=3:1:2 or a composition thereabout, In:M:Zn=4:2: Examples of suitable compositions include a composition of In:M:Zn = 4:2:4.1 or a composition of In:M:Zn = 5:1:3 or a composition of In:M:Zn = 5:1:6 or a composition of In:M:Zn = 5:1:7 or a composition of In:M:Zn = 5:1:8 or a composition of In:M:Zn = 6:1:6 or a composition of In:M:Zn = 5:2:5 or a composition of In:M:Zn = 5:2:5. Note that the term "composition of a similar ratio" includes a range of ±30% of the desired atomic ratio.

[0565] For example, when describing a composition having an atomic ratio of In:Ga:Zn = 4:2:3 or thereabout, this includes a case where, when In is taken as 4, Ga is 1 to 3 and Zn is 2 to 4. Furthermore, when describing a composition having an atomic ratio of In:Ga:Zn = 5:1:6 or thereabout, this includes a case where, when In is taken as 5, Ga is more than 0.1 and 2 or less and Zn is 5 to 7. Furthermore, when describing a composition having an atomic ratio of In:Ga:Zn = 1:1:1 or thereabout, this includes a case where, when In is taken as 1, Ga is more than 0.1 and 2 or less and Zn is more than 0.1 and 2 or less.

[0566] The transistors included in the circuit 164 may have the same structure as or different from the transistors included in the display portion 162. The transistors included in the circuit 164 may all have the same structure or may have two or more types of structures. Similarly, the transistors included in the display portion 162 may all have the same structure or may have two or more types of structures.

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

[0568] For example, by using both an LTPS transistor and an OS transistor in the display portion 162, a display device with low power consumption and high driving capability can be realized. A structure in which an LTPS transistor and an OS transistor are combined is sometimes referred to as LTPO. Note that, as a more preferred example, it is preferable to use an OS transistor as a transistor that functions as a switch for controlling conduction / non-conduction between wirings, and to use an LTPS transistor as a transistor for controlling current.

[0569] For example, one of the transistors included in the display portion 162 functions as a transistor for controlling a current flowing through a light-emitting device and can also be called a driving transistor. One of the source and drain of the driving transistor is electrically connected to a pixel electrode of the light-emitting device. The driving transistor is preferably an LTPS transistor. This can increase the current flowing through the light-emitting device in the pixel circuit.

[0570] On the other hand, another transistor included in the display portion 162 functions as a switch for controlling pixel selection / non-selection and can also be called a selection transistor. The gate of the selection transistor is electrically connected to a gate line, and one of the source and drain is electrically connected to a source line (signal line). An OS transistor is preferably used as the selection transistor. This allows the gradation of a pixel to be maintained even when the frame frequency is significantly reduced (for example, 1 fps or less). Therefore, power consumption can be reduced by stopping the driver when displaying a still image.

[0571] As described above, the display device of one embodiment of the present invention can have a high aperture ratio, high definition, high display quality, and low power consumption.

[0572] A display device according to one embodiment of the present invention includes an OS transistor and a light-emitting device with a metal maskless (MML) structure. This structure significantly reduces leakage current that may flow through the transistor and leakage current that may flow between adjacent light-emitting devices (also referred to as lateral leakage current or side leakage current). Furthermore, when an image is displayed on the display device, the viewer can observe one or more of image clarity, image sharpness, high saturation, and a high contrast ratio. The extremely low leakage current that may flow through the transistor and lateral leakage current between the light-emitting devices significantly reduces light leakage during black display (so-called floating black).

[0573] In particular, among light-emitting devices with an MML structure, by applying the SBS structure described above, the layers (e.g., organic layers) constituting the light-emitting device are configured to be separated between adjacent light-emitting devices, thereby eliminating or extremely reducing side leakage.

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

[0575] The transistor 209 and the transistor 210 each include a conductive layer 221 functioning as a gate electrode, an insulating layer 211 functioning as a gate insulating layer, a semiconductor layer 231 including a channel formation region 231i and a pair of low-resistance regions 231n, a conductive layer 222a connected to one of the pair of low-resistance regions 231n, a conductive layer 222b connected to the other of the pair of low-resistance regions 231n, an insulating layer 225 functioning as a gate insulating layer, a conductive layer 223 functioning as a gate electrode, and an insulating layer 215 covering the conductive layer 223. The insulating layer 211 is located between the conductive layer 221 and the channel formation region 231i. The insulating layer 225 is located at least between the conductive layer 223 and the channel formation region 231i. Furthermore, an insulating layer 218 covering the transistor may be provided.

[0576] 29B shows an example in which the insulating layer 225 covers the top surface and side surfaces of the semiconductor layer 231. The conductive layer 222a and the conductive layer 222b are connected to the low-resistance region 231n through openings provided in the insulating layer 225 and the insulating layer 215, respectively. One of the conductive layer 222a and the conductive layer 222b functions as a source electrode, and the other functions as a drain electrode.

[0577] 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 insulating layer 225 is processed using the conductive layer 223 as a mask, thereby manufacturing the structure shown in FIG. 29C . In FIG. 29C , the insulating layer 215 is provided to cover the insulating layer 225 and the conductive layer 223, and the conductive layer 222a and the conductive layer 222b are connected to the low-resistance region 231n through openings provided in the insulating layer 215.

[0578] In the display device 100G shown in FIG. 29A , 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 are provided on the surface of the substrate 152 facing the substrate 151. Of the light-emitting devices included in the display device 100G, the light-emitting device 130a included in the subpixel emitting red light overlaps the color conversion layer 135R and the coloring layer 132R, the light-emitting device 130b included in the subpixel emitting green light overlaps the color conversion layer 135G and the coloring layer 132G, and the light-emitting device 130c included in the subpixel emitting blue light overlaps the coloring layer 132B. A light-shielding layer 117 is preferably provided on the surface of the substrate 152 facing the substrate 151. The light-shielding layer 117 may be provided between adjacent light-emitting devices, in the connection portion 140, or in the circuit 164. In addition, various optical members can be arranged on the outside of the substrate 152 .

[0579] The substrate 151 and the substrate 152 can be made of the same material as can be used for the substrate 120 shown in FIG. 1B and the like.

[0580] The adhesive layer 142 may be made of a material that can be used for the resin layer 122 shown in FIG. 1B and the like.

[0581] The connection layer 242 may be an anisotropic conductive film (ACF), an anisotropic conductive paste (ACP), or the like.

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

[0583] Light emitted from the light-emitting device is emitted toward the substrate 151. A material that is highly transparent to visible light is preferably used for the substrate 151. On the other hand, the light-transmitting property of the material used for the substrate 152 does not matter.

[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. Fig. 30A shows an example in which the light-shielding layer 117 is provided on the substrate 151, the insulating layer 153 is provided on the light-shielding layer 117, and the transistor 201, the transistor 205, and the like 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 overlapping the color conversion layer 135R and the coloring layer 132R includes 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 overlapping the color conversion layer 135G and the coloring layer 132G includes a conductive layer 112b, a conductive layer 126b on the conductive layer 112b, and a conductive layer 129b on the conductive layer 126b.

[0587] Although not shown, the light-emitting device 130c overlapping 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, and 112c (not shown), the conductive layers 126a, 126b, and 126c (not shown), and the conductive layers 129a, 129b, and 129c (not shown) are each made of a material that is highly transparent to visible light. The common electrode 115 is preferably made of a material that reflects visible light.

[0589] 29A and 30A show examples in which the upper surface of the layer 128 has a flat portion, but there are no particular limitations on the shape of the layer 128. Figures 30B to 30D show modified examples of the layer 128.

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

[0591] As shown in FIG. 30C, the upper surface of layer 128 may be configured to have a shape in which the center and its vicinity bulge in cross section, that is, a shape having a convex curve.

[0592] The upper surface of layer 128 may have one or both of a convex curved surface and a concave curved surface. The number of convex curved surfaces and the number of concave curved surfaces that the upper surface of layer 128 has are not limited, and may be one or more.

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

[0594] 30B can also be considered an example in which layer 128 is contained within a recess formed in conductive layer 112a. On the other hand, as shown in FIG. 30D, layer 128 may be present outside the recess formed in conductive layer 112a, that is, the width of the top surface of layer 128 may be wider than the recess.

[0595] [Display Device 100J] The display device 100J shown in FIG. 31 differs from the display device 100G mainly in that the display device 100J includes 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 a conductive layer 222b included in the transistor 205 through an opening provided in the insulating layer 214.

[0598] The upper and side surfaces of the conductive layer 126S and the conductive layer 129S are covered with a layer 155. The layer 155 includes at least an active layer.

[0599] A portion of the top surface and side surfaces of layer 155 are covered with 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 common layer 114. Common layer 114 is a continuous film provided in common to the light-receiving device and the light-emitting device.

[0600] 20A to 20K described in Embodiment 3 can be applied to the display device 100J. For details of the display device including the light-receiving device, refer to Embodiments 1 and 6.

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

[0602] Embodiment 5 In this embodiment, a light-emitting device that can be used for a display device according to one embodiment of the present invention will be described.

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

[0604] The light-emitting layer 771 contains at least a light-emitting substance (also referred to as a light-emitting material).

[0605] When the lower electrode 761 is an anode and the upper electrode 762 is a cathode, the layer 780 includes one or more of a layer containing a substance with high hole-injecting properties (hole-injecting layer), a layer containing a substance with high hole-transporting properties (hole-transporting layer), and a layer containing a substance with high electron-blocking properties (electron-blocking layer). The layer 790 includes one or more of a layer containing a substance with high electron-injecting properties (electron-injecting layer), a layer containing a substance with high electron-transporting properties (electron-transporting layer), and a layer containing a substance with high hole-blocking properties (hole-blocking layer). When the lower electrode 761 is a cathode and the upper electrode 762 is an anode, the layers 780 and 790 have the opposite structures to those described above.

[0606] A structure including the layer 780, the light-emitting layer 771, and the layer 790 provided between a pair of electrodes can function as a single light-emitting unit, and the structure of FIG. 32A is referred to as a single structure in this specification.

[0607] 32B shows a modified example of the EL layer 763 included in the light-emitting device shown in Fig. 32A. Specifically, the light-emitting device shown in Fig. 32B has a layer 781 on a lower electrode 761, a layer 782 on the layer 781, a light-emitting layer 771 on the layer 782, a layer 791 on the light-emitting layer 771, a layer 792 on the layer 791, and an upper electrode 762 on the layer 792.

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

[0609] 32C and 32D, a variation of the single structure is 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. While an example having three light-emitting layers is shown in FIGS. 32C and 32D, the number of light-emitting layers in a single-structure light-emitting device may be two, or may be four or more. Furthermore, a light-emitting device with a single structure may have a buffer layer between the two light-emitting layers.

[0610] 32E and 32F, a configuration in which a plurality of light-emitting units (light-emitting unit 763a and light-emitting unit 763b) are connected in series via a charge generation layer 785 (also referred to as an intermediate layer) is referred to as a tandem structure in this specification. Note that the tandem structure may also be referred to as a stack structure. By using a tandem structure, a light-emitting device capable of emitting light with high brightness can be obtained. Furthermore, compared to a single structure, a tandem structure can reduce the current required to obtain the same brightness, thereby improving reliability.

[0611] 32D and 32F are examples of display devices having a layer 764 overlapping with the light-emitting device. Fig. 32D is an example in which the layer 764 overlaps with the light-emitting device shown in Fig. 32C, and Fig. 32F is an example in which the layer 764 overlaps with the light-emitting device shown in Fig. 32E. In Fig. 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] The layer 764 can be a color conversion layer, a color filter (coloring layer), or both.

[0613] 32C and 32D , the light-emitting layers 771, 772, and 773 may be made of light-emitting materials that emit light of the same color, or even the same light-emitting material. For example, the light-emitting layers 771, 772, and 773 may each be made of a light-emitting material that emits blue light. In the subpixel that emits blue light, blue light emitted by the light-emitting device can be extracted. In the subpixel that emits red light and the subpixel that emits green light, a color conversion layer can be provided as the layer 764 shown in FIG. 32D to convert the blue light emitted by the light-emitting device into light with a longer wavelength, thereby extracting red or green light. Furthermore, it is preferable to use both a color conversion layer and a colored layer as the layer 764. A portion 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 through the colored layer, light other than the desired color can be absorbed by the colored layer, thereby improving the color purity of the light emitted by the subpixel.

[0614] 32C and 32D , light-emitting layers 771, 772, and 773 may each contain a light-emitting substance that emits light of a different color. When the light emitted by light-emitting layers 771, 772, and 773 is complementary in color, the light is mixed to produce white light overall. For example, a light-emitting device with a single structure preferably has a light-emitting layer containing a light-emitting substance that emits blue light and a light-emitting layer containing a light-emitting substance that emits visible light with a wavelength longer than blue.

[0615] A color filter may be provided as layer 764 shown in Figure 32D. When white light passes through the color filter, light of a desired color can be obtained.

[0616] For example, when a light-emitting device with a single structure has three light-emitting layers, it preferably has a light-emitting layer containing a light-emitting material that emits red (R) light, a light-emitting layer containing a light-emitting material that emits green (G) light, and a light-emitting layer containing a light-emitting material that emits blue (B) light. The stacking order of the light-emitting layers may be R, G, B from the anode side, or R, B, G from the anode side, etc. In this case, a buffer layer may be provided between R and G or B.

[0617] Furthermore, for example, when a light-emitting device with a single structure has two light-emitting layers, a structure having one light-emitting layer containing a light-emitting substance that emits blue (B) light and another light-emitting layer containing a light-emitting s...

Claims

1. 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, wherein the first pixel electrode has a region located above the first insulating layer and functions as one of a pair of electrodes of a 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 a 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 the recess provided in the first insulating layer, and functions as a 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 a 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 a light-emitting layer of the second light-emitting device, the second insulating layer has a region overlapping the upper surface of the first layer, a region in contact with the side surface of the first layer, a region in contact with the bottom surface of the recess of the first insulating layer, a region in contact with the side surface of the second layer, and a region overlapping the upper surface of the second layer, the second insulating layer contains an inorganic material, the third insulating layer has a region located above the second insulating layer, the third insulating layer contains 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 also functions as the other of a pair of electrodes of the second light-emitting device, an end portion of the second insulating layer is covered with the third insulating layer, a display device.

2. 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, wherein the first pixel electrode has a region located above the first insulating layer and functions as one of a pair of electrodes of a 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 a 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 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 a 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 a light-emitting layer of the second light-emitting device. The second insulating layer has a region overlapping the upper surface of the first layer, a region in contact with the side surface of the first layer, a region in contact with the bottom surface of the recess of the first insulating layer, a region in contact with the side surface of the second layer, and a region overlapping the upper surface of the second layer. The second insulating layer contains an inorganic material. The third insulating layer has a region located above the second insulating layer. The third insulating layer contains an organic material. The upper surface of the third insulating layer has a convex curved surface shape. 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, functions as the other electrode of the pair of electrodes of the first light-emitting device, and functions as the other electrode of the pair of electrodes of the second light-emitting device. An end portion of the second insulating layer is covered with the third insulating layer, a display device.