Method for manufacturing a display device

Abstract

Provided is a manufacturing method for high-definition display devices. Also provided is a display device exhibiting both high display quality and high definition. This display device manufacturing method comprises: forming a first EL film and a first sacrifice film on first and second pixel electrodes; etching the first sacrifice film to form a first sacrifice layer; etching the first EL film to form a first EL layer and exposing the second pixel electrode; forming a second EL film and a second sacrifice film; etching the second sacrifice film to form a second sacrifice layer; etching the second EL film to form a second EL layer; forming an insulating film that covers the first sacrifice layer, the first EL layer, the second sacrifice layer, and the second EL layer; and etching the insulating film to form an insulating layer that has a region in contact with the side surface of the first EL layer and a region in contact with the side surface of the second EL layer.

Description

[Technical Field]

[0001] One aspect of the present invention relates to a display device. Another aspect of the present invention relates to a method for manufacturing a display device.

[0002] It should be noted that one aspect of the present invention is not limited to the above-mentioned technical field. Examples of technical fields of one aspect of the present invention disclosed herein include semiconductor devices, display devices, light-emitting devices, energy storage devices, memory devices, electronic devices, lighting devices, input devices, input / output devices, methods for driving them, or methods for manufacturing them. A semiconductor device refers to any device that can function by utilizing semiconductor properties. [Background technology]

[0003] In recent years, there has been a growing demand for higher resolution display panels. Examples of devices requiring high-resolution display panels include smartphones, tablet devices, and notebook computers. Furthermore, stationary display devices such as television sets and monitors also require higher resolution and greater detail. Among the devices demanding the highest resolution are those used for virtual reality (VR) and augmented reality (AR).

[0004] Examples of display devices applicable to display panels include liquid crystal displays, light-emitting devices equipped with light-emitting devices such as organic EL (Electro Luminescence) devices and light-emitting diodes (LEDs), and electronic paper that displays information using electrophoresis.

[0005] For example, the basic structure of an organic EL device (also called an organic EL element) consists of a layer containing a light-emitting organic compound sandwiched between a pair of electrodes. By applying a voltage to this device, light can be obtained from the light-emitting organic compound. Display devices using such organic EL devices do not require a backlight, which is necessary for liquid crystal displays and the like, thus enabling the realization of thin, lightweight, high-contrast, and low-power display devices. For example, an example of a display device using an organic EL device is described in Patent Document 1. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2002-324673 [Overview of the project] [Problems that the invention aims to solve]

[0007] One aspect of the present invention aims to provide a method for manufacturing a high-definition display device. Another aspect of the present invention aims to provide a display device that combines high display quality and high resolution. Another aspect of the present invention aims to provide a display device with high contrast. Another aspect of the present invention aims to provide a highly reliable display device.

[0008] One aspect of the present invention aims to provide a display device having a novel configuration, or a method for manufacturing a display device. Another aspect of the present invention aims to provide a method for manufacturing the above-mentioned display device with a high yield. Another aspect of the present invention aims to mitigate at least one of the problems of the prior art.

[0009] Furthermore, the description of these problems does not preclude the existence of other problems. Moreover, one aspect of the present invention does not need to solve all of these problems. Other problems can be identified from the description in the specification, drawings, claims, etc.

Means for Solving the Problem

[0010] One aspect of the present invention includes a first step of forming a first pixel electrode and a second pixel electrode, a second step of forming a first EL film on the first pixel electrode and the second pixel electrode, a third step of forming a first sacrificial film covering the first EL film, a fourth step of etching the first sacrificial film to form a first sacrificial layer having a region overlapping with the first pixel electrode, a fifth step of etching the first EL film to form a first EL layer having a region overlapping with the first sacrificial layer and exposing the second pixel electrode, a sixth step of forming a second EL film on the first sacrificial layer and the second pixel electrode, a seventh step of forming a second sacrificial film covering the second EL film, an eighth step of etching the second sacrificial film to form a second sacrificial layer having a region overlapping with the second pixel electrode, a ninth step of etching the second EL film to form a second EL layer having a region overlapping with the second sacrificial layer, a tenth step of forming an insulating film covering the upper surface and side surfaces of the first sacrificial layer, the side surface of the first EL layer, the upper surface and side surfaces of the second sacrificial layer, and the side surface of the second EL layer, an eleventh step of etching the insulating film to form a first insulating layer having regions in contact with the side surface of the first EL layer and the side surface of the second EL layer and exposing the first sacrificial layer and the second sacrificial layer, and a twelfth step of removing the first sacrificial layer and the second sacrificial layer. It is a method for manufacturing a display device having these steps.

[0011] One aspect of the present invention includes: a first step of forming a first pixel electrode and a second pixel electrode; a second step of forming a first EL film on the first pixel electrode and the second pixel electrode; a third step of forming a first sacrificial film covering the first EL film; a fourth step of etching the first sacrificial film to form a first sacrificial layer having a region overlapping with the first pixel electrode; a fifth step of etching the first EL film to form a first EL layer having a region overlapping with the first sacrificial layer and exposing the second pixel electrode; a sixth step of forming a second EL film on the first sacrificial layer and the second pixel electrode; a seventh step of forming a second sacrificial film covering the second EL film; an eighth step of etching the second sacrificial film to form a second sacrificial layer having a region overlapping with the second pixel electrode; a ninth step of etching the second EL film to form a second EL layer having a region overlapping with the second sacrificial layer; a tenth step of forming an insulating film covering the upper surface and side surfaces of the first sacrificial layer, the side surface of the first EL layer, the upper surface and side surfaces of the second sacrificial layer, and the side surface of the second EL layer; an eleventh step of etching the insulating film to form a first insulating layer having regions in contact with the side surface of the first EL layer and the side surface of the second EL layer, and forming a second insulating layer on the first sacrificial layer and a third insulating layer on the second sacrificial layer; and a twelfth step of removing the first sacrificial layer and the second sacrificial layer, and removing the second insulating layer and the third insulating layer. This is a method for manufacturing a display device.

[0012] In the method for manufacturing the display device described above, the first sacrificial film preferably has one or more of a metal film, an alloy film, a metal oxide film, a semiconductor film, or an inorganic insulating film. Also, in the fifth step, the etching of the first EL film preferably uses dry etching with an etching gas that does not contain oxygen gas.

[0013] In the method for manufacturing the display device described above, the etching gas that does not contain oxygen gas is preferably one or more selected from CF4, C4F8, SF6, CHF3, Cl2, H2O, BCl3, H2, or noble gases.

[0014] In the method for manufacturing the display device described above, it is preferable to include a step between the third and fourth steps in which a first protective layer having an area overlapping with the first pixel electrode is formed. Furthermore, in the fourth step, it is preferable to etch the first sacrificial film using the first protective layer as a mask to form the first sacrificial layer.

[0015] In the method for manufacturing the display device described above, it is preferable to have a step of removing the first protective layer between the fifth step and the sixth step.

[0016] In the method for manufacturing the display device described above, it is preferable to have a 13th step after the 12th step, in which a common electrode is formed that covers the upper surface of the first EL layer, the upper surface of the second EL layer, and the upper surface and side surface of the first insulating layer.

[0017] In the method for manufacturing the display device described above, it is preferable to have a step between the 12th step and the 13th step of forming a layer that covers the upper surface of the first EL layer, the upper surface of the second EL layer, and the upper surface and side surface of the first insulating layer. Furthermore, it is preferable that the layer contains a material with high electron injection properties.

[0018] In the method for manufacturing the display device described above, it is preferable to have a step between the 12th step and the 13th step of forming a layer that covers the upper surface of the first EL layer, the upper surface of the second EL layer, and the upper surface and sides of the first insulating layer. Furthermore, it is preferable that the layer has a laminated structure of a first layer containing a material with high electron transport properties and a second layer on the first layer containing a material with high electron injection properties.

[0019] In the method for manufacturing the display device described above, it is preferable to have a step between the 12th step and the 13th step of forming a layer that covers the upper surface of the first EL layer, the upper surface of the second EL layer, and the upper surface and side surface of the first insulating layer. Furthermore, it is preferable that the layer contains a material with high hole injection properties.

[0020] In the method for manufacturing the display device described above, it is preferable to have a step between the 12th step and the 13th step of forming a layer that covers the upper surface of the first EL layer, the upper surface of the second EL layer, and the upper surface and side surface of the first insulating layer. Furthermore, it is preferable that the layer has a laminated structure of a first layer containing a material with high hole transport properties and a second layer on the first layer containing a material with high hole injection properties.

[0021] One aspect of the present invention comprises: a first step of forming a first pixel electrode and a second pixel electrode; a second step of depositing an EL film on the first and second pixel electrodes; a third step of forming a sacrificial film covering the EL film; a fourth step of etching the sacrificial film to form a first sacrificial layer having a region overlapping with the first pixel electrode and a second sacrificial layer having a region overlapping with the second pixel electrode; and etching the EL film to form a first EL layer having a region overlapping with the first sacrificial layer and a second sacrificial layer having a region overlapping with the second sacrificial layer. The method for manufacturing a display device comprises: a fifth step of forming an EL layer; a sixth step of forming an insulating film that covers the upper and side surfaces of the first sacrificial layer, the side surfaces of the first EL layer, the upper and side surfaces of the second sacrificial layer, and the side surfaces of the second EL layer; a seventh step of etching the insulating film to form a first insulating layer having a region in contact with the side surfaces of the first EL layer and a region in contact with the side surfaces of the second EL layer, and exposing the first and second sacrificial layers; and an eighth step of removing the first and second sacrificial layers. The EL film has an emissive layer that emits white light.

[0022] One aspect of the present invention comprises a first step of forming a first pixel electrode and a second pixel electrode, a second step of forming an EL film on the first pixel electrode and the second pixel electrode, a third step of forming a sacrificial film covering the EL film, a fourth step of etching the sacrificial film to form a first sacrificial layer having a region overlapping with the first pixel electrode and a second sacrificial layer having a region overlapping with the second pixel electrode, a fifth step of etching the EL film to form a first EL layer having a region overlapping with the first sacrificial layer and a second EL layer having a region overlapping with the second sacrificial layer, and the first The method for manufacturing a display device comprises: a sixth step of forming an insulating film that covers the top and side surfaces of the sacrificial layer, the side surfaces of the first EL layer, the top and side surfaces of the second sacrificial layer, and the side surfaces of the second EL layer; a seventh step of etching the insulating film to form a first insulating layer having a region in contact with the side surfaces of the first EL layer and a region in contact with the side surfaces of the second EL layer, and forming a second insulating layer on the first sacrificial layer and a third insulating layer on the second sacrificial layer; and an eighth step of removing the first sacrificial layer and the second sacrificial layer, and removing the second insulating layer and the third insulating layer. The EL film has an emitting layer that emits white light. [Effects of the Invention]

[0023] According to one aspect of the present invention, a method for manufacturing a high-definition display device can be provided. Alternatively, a display device that combines high display quality and high resolution can be provided. Alternatively, a display device with high contrast can be provided. Alternatively, a highly reliable display device can be provided.

[0024] According to one aspect of the present invention, a display device having a novel configuration, or a method for manufacturing a display device, can be provided. Alternatively, a method for manufacturing the above-described display device with high yield can be provided. According to one aspect of the present invention, at least one of the problems of the prior art can be mitigated.

[0025] Furthermore, the description of these effects does not preclude the existence of other effects. Moreover, one aspect of the present invention does not necessarily have to possess all of these effects. Other effects can be extracted from the description in the specification, drawings, claims, etc. [Brief explanation of the drawing]

[0026] Figures 1A to 1D show examples of the configuration of a display device. Figures 2A and 2B show examples of display device configurations. Figures 3A and 3B show examples of display device configurations. Figures 4A and 4B show examples of the configuration of a display device. Figures 5A and 5B show examples of display device configurations. Figures 6A to 6C show examples of display device configurations. Figures 7A to 7C show examples of display device configurations. Figures 8A to 8C show examples of the configuration of a display device. Figures 9A to 9C show examples of display device configurations. Figures 10A and 10B show examples of display device configurations. Figure 11 shows an example of a display device configuration. Figures 12A to 12C show examples of display device configurations. Figures 13A to 13E show examples of methods for manufacturing a display device. Figures 14A to 14E show examples of methods for manufacturing a display device. Figures 15A to 15D show examples of methods for manufacturing a display device. Figures 16A to 16D show examples of methods for manufacturing a display device. Figures 17A to 17D show examples of methods for manufacturing a display device. Figure 18 shows an example of a method for manufacturing a display device. Figures 19A to 19C show examples of the configuration of a display device. Figures 20A to 20D show examples of methods for manufacturing a display device. Figures 21A to 21E show examples of methods for manufacturing a display device. Figure 22 shows an example of a method for manufacturing a display device. Figure 23 is a perspective view showing an example of a display device. Figures 24A and 24B are cross-sectional views showing an example of a display device. Figure 25A is a cross-sectional view showing an example of a display device. Figure 25B is a cross-sectional view showing an example of a transistor. Figures 26A and 26B are perspective views showing an example of a display module. Figure 27 is a cross-sectional view showing an example of a display device. Figure 28 is a cross-sectional view showing an example of a display device. Figure 29 is a cross-sectional view showing an example of a display device. Figures 30A and 30B show examples of electronic devices. Figures 31A to 31D show examples of electronic devices. Figures 32A to 32F show examples of electronic devices. Figures 33A to 33F show examples of electronic devices. [Modes for carrying out the invention]

[0027] The embodiments will be described below with reference to the drawings. However, it will be readily apparent to those skilled in the art that the embodiments can be implemented in many different ways, and their form and details can be modified in various ways without departing from the spirit and scope thereof. Accordingly, the present invention shall not be construed as being limited to the contents of the following embodiments.

[0028] In the configuration of the invention described below, the same reference numerals are used in common across different drawings for identical parts or parts having similar functions, and repeated explanations are omitted. Furthermore, when referring to similar functions, the hatch patterns are the same, and reference numerals may not be assigned.

[0029] In the figures described herein, the size of each component, the thickness of the layers, or the area may be exaggerated for clarity. Therefore, the scale is not necessarily limited to those figures.

[0030] Furthermore, ordinal numbers such as "the first," "the second," etc., used in this specification are added to avoid confusion of constituent elements and do not imply any numerical limitation.

[0031] In this specification, the terms "film" and "layer" are interchangeable. For example, the terms "conductive layer" or "insulating layer" may be interchangeable with the terms "conductive film" or "insulating film."

[0032] In this specification, the term "EL layer" refers to a layer (also called a light-emitting layer) provided between a pair of electrodes of a light-emitting device and containing at least a light-emitting substance, or a laminate containing a light-emitting layer.

[0033] In this specification, a display panel, which is one form of a display device, has the function of displaying (outputting) images or the like on its display surface. Therefore, a display panel is one form of an output device.

[0034] In this specification, a display panel on which a connector such as an FPC (Flexible Printed Circuit) or TCP (Tape Carrier Package) is attached, or on which an IC is mounted on the board using a COG (Chip On Glass) method, may be referred to as a display panel module, display module, or simply a display panel.

[0035] (Embodiment 1) This embodiment describes an example of the configuration of a display device according to one aspect of the present invention, and an example of a method for manufacturing the display device.

[0036] One aspect of the present invention is a display device having light-emitting devices (also called light-emitting elements). The display device has two light-emitting devices that emit light of at least different colors. Each light-emitting device has a pair of electrodes and an EL layer between them. The light-emitting devices are preferably organic EL devices (organic electroluminescent devices). Two or more light-emitting devices that emit different colors each have an EL layer containing a different material. For example, a full-color display device can be realized by having three types of light-emitting devices that emit red (R), green (G), or blue (B) light, respectively.

[0037] When creating EL layers for different colored light-emitting devices, it is known that they are formed using a vapor deposition method employing shadow masks such as metal masks (MM) and fine metal masks (FMM). However, with this method, deviations from the design occur in the shape and position of island-like organic films due to various factors such as the precision of the shadow mask, misalignment between the shadow mask and the substrate, deflection of the shadow mask, and the spreading of the contour of the deposited film due to vapor scattering, making it difficult to achieve high resolution and high aperture ratio. Therefore, measures have been taken to artificially increase resolution (also called pixel density) by applying special pixel arrangement methods such as pentile arrangements.

[0038] In this specification, shadow masks such as metal masks (MM) and fine metal masks (FMM) may be referred to as metal masks (MM). Furthermore, devices fabricated using metal masks (MM) may be referred to as metal mask (MM) structures. Devices fabricated without using metal masks may be referred to as metal mask-less (MML) structures.

[0039] In this specification, a structure in which different light-emitting layers are created or painted for each color of light-emitting device (e.g., red (R), green (G), and blue (B)) may be referred to as an SBS (Side By Side) structure. Also, in this specification, a light-emitting device capable of emitting white light may be referred to as a white light-emitting device. A white light-emitting device can be combined with a colored layer (e.g., a color filter) to create a full-color display light-emitting device.

[0040] One aspect of the present invention involves processing an EL layer into a fine pattern without using a metal mask. This makes it possible to realize a display device with high resolution and a high aperture ratio, which have been difficult to achieve until now. Furthermore, because the EL layer can be differentiated, it is possible to realize a display device with extremely vivid colors, high contrast, and high display quality.

[0041] Here, for simplicity, we will describe the case where two different EL layers are created for a two-color light-emitting device. First, a first EL film and a first sacrificial film are laminated and formed covering the two pixel electrodes. Next, the first sacrificial film is etched to form a first sacrificial layer having a region that overlaps with one of the pixel electrodes (the first pixel electrode). Subsequently, the first EL film is etched to form a first EL layer having a region that overlaps with the first sacrificial layer, while exposing the other pixel electrode (the second pixel electrode). This allows the first EL layer and the first sacrificial layer on the first pixel electrode to be formed.

[0042] Next, the second EL film and the second sacrificial film are laminated together. Then, the second sacrificial film is etched to form a second sacrificial layer having a region that overlaps with the second pixel electrode. Next, the second EL film is etched to form a second EL layer having a region that overlaps with the second sacrificial layer. In this way, the second EL layer and the second sacrificial layer on the second pixel electrode can be formed. In this manner, the first EL layer and the second EL layer can be manufactured separately.

[0043] Next, an insulating film is formed covering the top and sides of the first sacrificial layer, the sides of the first EL layer, the top and sides of the second sacrificial layer, and the sides of the second EL layer. Subsequently, the insulating film is etched to form a protective insulating layer having regions in contact with the sides of the first EL layer and regions in contact with the sides of the second EL layer, while exposing the first sacrificial layer and the second sacrificial layer. Finally, the first and second sacrificial layers are removed and a common electrode is formed, thereby enabling the creation of two-color light-emitting devices.

[0044] By providing protective insulating layers on the sides of the first EL layer and the second EL layer, it is possible to suppress the intrusion of oxygen, moisture, or their constituent elements into the interior from the sides of the EL layer, thereby creating a highly reliable display device.

[0045] Furthermore, by repeating the above process, it is possible to create different EL layers for three or more light-emitting devices, thereby realizing a display device with three or four or more light-emitting devices.

[0046] In the case of a formation method using a metal mask, for example, it is difficult to make the spacing between different colored EL layers less than 10 μm, but with the above method, it is possible to narrow it to 3 μm or less, 2 μm or less, or even 1 μm or less. For example, by using an exposure apparatus for LSIs, it is possible to narrow the spacing to 500 nm or less, 200 nm or less, 100 nm or less, and even 50 nm or less. This makes it possible to significantly reduce the area of ​​the non-emitting region that may exist between two light-emitting devices, and to bring the aperture ratio closer to 100%. For example, the aperture ratio can be 50% or more, 60% or more, 70% or more, 80% or more, and even 90% or more, and it is also possible to achieve less than 100%.

[0047] Furthermore, the pattern of the EL layer itself can be made extremely small compared to when a metal mask is used. Also, for example, when a metal mask is used to create different EL layers, variations in thickness occur between the center and edges of the pattern, so the effective area that can be used as an emitting region is small relative to the total area of ​​the pattern. On the other hand, with the above manufacturing method, the pattern is formed by processing a film deposited to a uniform thickness, so the thickness can be made uniform within the pattern, and even if the pattern is fine, almost the entire area can be used as an emitting region. Therefore, with the above manufacturing method, it is possible to achieve both high resolution and a high aperture ratio.

[0048] Thus, the above manufacturing method makes it possible to realize a display device that integrates minute light-emitting devices. Therefore, there is no need to apply a special pixel arrangement method such as the pentile method to artificially increase the resolution. Thus, it is possible to realize a display device with a resolution of 500 ppi or more, 1000 ppi or more, 2000 ppi or more, 3000 ppi or more, or even 5000 ppi or more, using a so-called stripe arrangement in which R, G, and B are each arranged in one direction.

[0049] In the following section, a more specific configuration example and manufacturing method example of a display device according to one aspect of the present invention will be described with reference to the drawings.

[0050] <Configuration Example 1> Figure 1A shows a schematic top view of a display device 100 according to one embodiment of the present invention. The display device 100 has multiple light-emitting devices 110R that emit red light, multiple light-emitting devices 110G that emit green light, and multiple light-emitting devices 110B that emit blue light. In Figure 1A, the labels R, G, and B are added within the light-emitting area of ​​each light-emitting device to simplify the distinction between them.

[0051] Light-emitting devices 110R, 110G, and 110B are each arranged in a matrix. Figure 1A shows a so-called stripe arrangement, in which light-emitting devices of the same color are arranged in one direction. Note that the arrangement method of the light-emitting devices is not limited to this; other arrangement methods such as delta arrangement and zigzag arrangement may be applied, and pentile arrangement can also be used.

[0052] The light-emitting devices 110R, 110G, and 110B preferably use EL devices such as OLEDs (Organic Light Emitting Diodes) or QLEDs (Quantum-dot Light Emitting Diodes). Examples of light-emitting materials for EL devices include fluorescent materials, phosphorescent materials, inorganic compounds (such as quantum dot materials), and thermally activated delayed fluorescence (TADF) materials.

[0053] Figure 1B shows a schematic cross-sectional view corresponding to the dashed line A1-A2 in Figure 1A.

[0054] Figure 1B shows cross-sections of light-emitting devices 110R, 110G, and 110B provided on the substrate 101. Light-emitting device 110R has a pixel electrode 111R, an EL layer 112R, a layer 116, and a common electrode 113. Light-emitting device 110G has a pixel electrode 111G, an EL layer 112G, a layer 116, and a common electrode 113. Light-emitting device 110B has a pixel electrode 111B, an EL layer 112B, a layer 116, and a common electrode 113.

[0055] Note that in some cases, the light-emitting devices 110R, 110G, and 110B may not be distinguished, or they may be collectively referred to as light-emitting device 110. Similarly, the pixel electrodes 111R, 111G, and 111B may not be distinguished, or they may be collectively referred to as pixel electrode 111. The EL layers 112R, 112G, and 112B may not be distinguished, or they may be collectively referred to as EL layer 112. In addition, similar notations may be used for other elements.

[0056] Light-emitting device 110R has an EL layer 112R between the pixel electrode 111R and the common electrode 113. The EL layer 112R has a luminescent organic compound that emits light with intensity in at least the red wavelength range. Light-emitting device 110G has an EL layer 112G between the pixel electrode 111G and the common electrode 113. The EL layer 112G has a luminescent organic compound that emits light with intensity in at least the green wavelength range. Light-emitting device 110B has an EL layer 112B between the pixel electrode 111B and the common electrode 113. The EL layer 112B has a luminescent organic compound that emits light with intensity in at least the blue wavelength range. The EL layers 112R, 112G, and 112B each emit light of different colors.

[0057] Each of the EL layers 112R, 112G, and 112B may have, in addition to a layer containing a light-emitting organic compound (light-emitting layer), one or more of the following: an electron injection layer, an electron transport layer, a hole injection layer, and a hole transport layer.

[0058] Light-emitting device 110R has a layer 116 between the EL layer 112R and the common electrode 113. Light-emitting device 110G has a layer 116 between the EL layer 112G and the common electrode 113. Light-emitting device 110B has a layer 116 between the EL layer 112B and the common electrode 113.

[0059] Layer 116 can be a layer containing a material with high carrier injection capabilities. For example, by using a material with high electron injection capabilities in layer 116, layer 116 can function as an electron injection layer. However, layer 116 is not limited to functioning as an electron injection layer. For example, a material with high hole injection capabilities may be used in layer 116 to give layer 116 the function of a hole injection layer. Furthermore, a configuration without layer 116 is also possible.

[0060] Layer 116 is provided as a continuous layer common to each light-emitting device. By using a common layer 116 for each light-emitting device, the manufacturing process can be simplified and manufacturing costs can be reduced.

[0061] Pixel electrodes 111R, 111G, and 111B are provided for each light-emitting device. A common electrode 113 is provided as a continuous layer common to each light-emitting device. A conductive film that is transparent to visible light is used on either each pixel electrode or the common electrode 113, and a conductive film that is reflective is used on the other. By making each pixel electrode transparent and the common electrode 113 reflective, a bottom-emission type display device can be made, and conversely, by making each pixel electrode reflective and the common electrode 113 transparent, a top-emission type display device can be made. Furthermore, by making both each pixel electrode and the common electrode 113 transparent, a dual-emission type display device can be made.

[0062] In Figure 1A, etc., an example is shown where the width of the pixel electrode 111 is smaller than the width of the EL layer 112, that is, the edge of the pixel electrode 111 is located inside the edge of the EL layer 112. However, the present invention is not limited to this example. The width of the pixel electrode 111 may be larger than the width of the EL layer 112, that is, the edge of the pixel electrode 111 may be located outside the edge of the EL layer 112. Alternatively, the width of the pixel electrode 111 may be equal to the width of the EL layer 112, that is, the edge of the pixel electrode 111 may coincide with the edge of the EL layer 112.

[0063] The display device 100 has an insulating layer 131. The insulating layer 131 is provided to cover the ends of the pixel electrodes 111R, 111G, and 111B. The ends of the insulating layer 131 are preferably tapered.

[0064] In this specification, a tapered shape refers to a shape in which at least a portion of the side surface of the structure is inclined with respect to the substrate surface. For example, it is preferable to have a region in which the angle between the inclined side surface and the substrate surface (also called the taper angle) is less than 90°.

[0065] Each of the EL layers 112R, 112G, and 112B has a region in contact with the upper surface of the pixel electrode and a region in contact with the surface of the insulating layer 131. The edges of the EL layers 112R, 112G, and 112B are located on the insulating layer 131.

[0066] As shown in Figure 1B, a gap is provided between the two EL layers in light-emitting devices of different colors. It is preferable that the EL layers 112R, 112G, and 112B are arranged so that they do not touch each other. This effectively prevents current from flowing through two adjacent EL layers and causing unintended light emission. Therefore, contrast can be enhanced, and a display device with high display quality can be realized.

[0067] As shown in Figure 1B, an insulating layer 133 is provided between two EL layers on the insulating layer 131. The insulating layer 133 has a region in contact with the side surface of the EL layer 112 and a region in contact with the upper surface of the insulating layer 131. Specifically, between EL layer 112R and EL layer 112G, the insulating layer 133 has a region in contact with the side surface of EL layer 112R and a region in contact with the side surface of EL layer 112G. Between EL layer 112G and EL layer 112B, the insulating layer 133 has a region in contact with the side surface of EL layer 112G and a region in contact with the side surface of EL layer 112B. Although not shown in Figure 1B, between EL layer 112R and EL layer 112B, the insulating layer 133 has a region in contact with the side surface of EL layer 112R and a region in contact with the side surface of EL layer 112B.

[0068] The insulating layer 133 has a region that is in contact with the side surface of the EL layer 112 and functions as a protective insulating layer for the EL layer 112. By providing the insulating layer 133, it is possible to suppress the intrusion of oxygen, moisture, or their constituent elements into the interior from the side surface of the EL layer 112, resulting in a highly reliable display device. Furthermore, by providing the insulating layer 133, it is possible to suppress the adhesion of components of layer 116 to the side surface of the EL layer 112, thereby suppressing the generation of leakage current in the light-emitting device 110.

[0069] Figure 2A shows an enlarged view of the region P enclosed by the dashed line in Figure 1B. Here, if the width 133w of the insulating layer 133 in the region in contact with the side surface of the EL layer 112 is large, the spacing between the EL layers 112 may increase, resulting in a lower aperture ratio. Conversely, if the width 133w of the insulating layer 133 is small, the effect of suppressing the intrusion of oxygen, moisture, or their constituent elements into the interior from the side surface of the EL layer 112 may be reduced. The width 133w of the insulating layer 133 in the region in contact with the side surface of the EL layer 112 is preferably 3 nm to 200 nm, more preferably 3 nm to 150 nm, more preferably 5 nm to 150 nm, more preferably 5 nm to 100 nm, more preferably 10 nm to 100 nm, and more preferably 10 nm to 50 nm. By setting the width 133w of the insulating layer 133 within the above range, a display device with a high aperture ratio and high reliability can be made.

[0070] Furthermore, the width 133w of the insulating layer 133 can be the width of the insulating layer 133 in the region that is in contact with the side surface of the EL layer 112 and sandwiched between the EL layer 112G and layer 116.

[0071] The insulating layer 133 can be made of, for example, aluminum oxide, magnesium oxide, hafnium oxide, gallium oxide, indium gallium zinc oxide, silicon oxide, silicon oxide nitride, silicon nitride, or silicon oxide nitride. The insulating layer 133 may also be made by laminating these materials.

[0072] In this specification, "oxide-nitride" refers to a material in which the oxygen content is greater than the nitrogen content, and "nitride oxide" refers to a material in which the nitrogen content is greater than the oxygen content. For example, when "silicon oxynitride" is written, it refers to a material in which the oxygen content is greater than the nitrogen content, and when "silicon nitride oxide" is written, it refers to a material in which the nitrogen content is greater than the oxygen content.

[0073] The insulating layer 133 can be formed using sputtering, chemical vapor deposition (CVD), molecular beam epitaxy (MBE), pulsed laser deposition (PLD), atomic layer deposition (ALD), and other methods. The ALD method, which provides good coverage, is preferably used for forming the insulating layer 133.

[0074] The display device 100 shown in Figure 1B, etc., shows an example where the height of the end face of the insulating layer 133 in contact with the EL layer 112G is the same as the height of the top surface of the EL layer 112G. However, the present invention is not limited to this. The height of the end face of the insulating layer 133 in contact with the EL layer 112G may be different from the height of the top surface of the EL layer 112G.

[0075] In this specification, the term "end face of a layer" refers to the side surface when the surface in contact with the surface to be formed on the layer is considered the bottom surface. For example, the end face of the insulating layer 133 refers to the side surface when the surface in contact with the EL layer 112, which is the surface to be formed on the insulating layer 133, is considered the bottom surface. Also, in this specification, the term "height of the end face of a layer" refers to the height from the substrate to the highest point of the end face of the layer. The term "height of the top face of a layer" refers to the height from the substrate to the highest point of the top surface of the layer.

[0076] Layer 116 is provided covering the insulating layer 133 and the EL layer 112. Layer 116 has regions that are in contact with the upper surface and end surface of the insulating layer 133, and the upper surface of the EL layer 112.

[0077] As shown in Figure 2A, the height of the upper surface of the insulating layer 131 in the region overlapping with the insulating layer 133 may be lower than the height of the upper surface of the insulating layer 131 in the region overlapping with the EL layer 112G. Alternatively, the height of the upper surface of the insulating layer 131 in the region overlapping with the insulating layer 133 may be equal to, or approximately equal to, the height of the upper surface of the insulating layer 131 in the region overlapping with the EL layer 112G. In this specification, "approximately equal height" means that one of the two heights being compared is between 0.8 and 1.2.

[0078] This section describes an example configuration of a light-emitting device. Here, we will use the light-emitting device 110G as an example.

[0079] Figure 2B shows an example configuration of the light-emitting device 110G. The light-emitting device 110G has an EL layer 112G and a layer 116 between a pair of electrodes (pixel electrode 111G and common electrode 113). The EL layer 112G can have a configuration with multiple layers such as layer 530, light-emitting layer 511, and layer 520. The light-emitting layer 511 has, for example, a light-emitting compound.

[0080] Layer 530 may have a configuration comprising one or more carrier injection layers and carrier transport layers. The carrier transport layer may, for example, be a laminated structure of a carrier injection layer and a carrier transport layer on the carrier injection layer. The carrier transport layer is a layer containing a material with high carrier transport properties. Layer 520 is a layer containing a material with high carrier transport properties.

[0081] For example, in a light-emitting device in which the pixel electrode 111 is the anode and the common electrode 113 is the cathode, layer 530 may be a layer containing a material with high hole transport properties (hereinafter referred to as the hole transport layer), layer 520 may be a layer containing a material with high electron transport properties (hereinafter referred to as the electron transport layer), and layer 116 may be a layer containing a material with high electron injection properties (hereinafter referred to as the electron injection layer). Layer 530 may also be a laminated structure of a layer containing a material with high hole injection properties (hereinafter referred to as the hole injection layer) and a hole transport layer on the hole injection layer.

[0082] For example, in a light-emitting device where the pixel electrode 111 is the cathode and the common electrode 113 is the anode, layer 530 can be an electron transport layer, layer 520 a hole transport layer, and layer 116 a hole injection layer. Layer 530 may be a stacked structure of an electron injection layer and an electron transport layer on top of the electron injection layer.

[0083] The specific configuration of the light-emitting device will be explained below.

[0084] The light-emitting device has at least a light-emitting layer. The light-emitting device may also have layers other than the light-emitting layer that include a material with high hole injection properties, a material with high hole transport properties, a hole-blocking material, a material with high electron transport properties, an electron-blocking material, a material with high electron injection properties, or a bipolar material (a material with high electron transport and hole transport properties).

[0085] The light-emitting device may use either low-molecular-weight compounds or high-molecular-weight compounds, and may also contain inorganic compounds. The layers constituting the light-emitting device can be formed by methods such as vapor deposition (including vacuum deposition), transfer, printing, inkjet, and coating.

[0086] For example, a light-emitting device can have a configuration that includes one or more layers from among a hole injection layer, a hole transport layer, a hole blocking layer, an electron blocking layer, an electron transport layer, and an electron injection layer.

[0087] The hole injection layer is a layer that injects holes from the anode into the hole transport layer, and is a layer containing a material with high hole injection capabilities. Examples of materials with high hole injection capabilities include aromatic amine compounds and composite materials containing hole transport materials and acceptor materials (electron-accepting materials).

[0088] The hole transport layer is a layer that transports holes injected from the anode by the hole injection layer to the light-emitting layer. The hole transport layer is a layer containing a hole-transporting material. The hole-transporting material is 10 -6 cm 2Materials having a hole mobility of / Vs or higher are preferred. However, other materials can also be used as long as they have higher hole transport capabilities than electron transport. Preferred hole transport materials are those with high hole transport capabilities, such as π-electron-rich heteroaromatic compounds (e.g., carbazole derivatives, thiophene derivatives, furan derivatives, etc.) and aromatic amines (compounds having an aromatic amine skeleton).

[0089] The electron transport layer is a layer that transports electrons injected from the cathode by the electron injection layer to the light-emitting layer. The electron transport layer is a layer containing an electron-transporting material. The electron-transporting material is 1 × 10⁻¹⁶ -6 cm 2 Materials having an electron mobility of / Vs or higher are preferred. However, other materials can also be used as long as they have higher electron transport capabilities than holes. Electron transport materials include metal complexes having a quinoline skeleton, metal complexes having a benzoquinoline skeleton, metal complexes having an oxazole skeleton, metal complexes having a thiazole skeleton, etc., as well as oxadiazole derivatives, triazole derivatives, imidazole derivatives, oxazole derivatives, thiazole derivatives, phenanthroline derivatives, quinoline derivatives having a quinoline ligand, benzoquinoline derivatives, quinoxaline derivatives, dibenzoquinoxaline derivatives, pyridine derivatives, bipyridine derivatives, pyrimidine derivatives, and other π-electron-deficient heteroaromatic compounds containing nitrogen-containing heteroaromatic compounds.

[0090] The electron injection layer is a layer that injects electrons from the cathode to the electron transport layer, and is a layer containing a material with high electron injection properties. The material with high electron injection properties can be alkali metals, alkaline earth metals, or compounds thereof. A composite material containing both an electron transport material and a donor material (electron-donating material) can also be used as the material with high electron injection properties.

[0091] The electron injection layer includes, for example, lithium, cesium, lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF2), 8-(quinolinolato)lithium (abbreviated as Liq), 2-(2-pyridyl)phenolate (abbreviated as LiPP), 2-(2-pyridyl)-3-pyridinolatritium (abbreviated as LiPPy), 4-phenyl-2-(2-pyridyl)phenolate (abbreviated as LiPPP), and lithium oxide (LiO2). x ), alkali metals such as cesium carbonate, alkaline earth metals, or compounds thereof can be used.

[0092] Alternatively, an electron-transporting material may be used as the electron injection layer described above. For example, a compound having a lone pair of electrons and an electron-deficient heteroaromatic ring can be used as the electron-transporting material. Specifically, a compound having at least one of a pyridine ring, a diazine ring (pyrimidine ring, pyrazine ring, pyridazine ring), or a triazine ring can be used.

[0093] Furthermore, it is preferable that the lowest unoccupied molecular orbital (LUMO) of an organic compound containing a lone pair of electrons is between -3.6 eV and -2.3 eV. In general, the highest occupied molecular orbital (HOMO) level and LUMO level of an organic compound can be estimated by methods such as cyclic voltammetry (CV), photoelectron spectroscopy, optical absorption spectroscopy, and inverse photoelectron spectroscopy.

[0094] For example, 4,7-diphenyl-1,10-phenanthroline (abbreviated as BPhen), 2,9-bis(naphthalene-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviated as NBPhen), diquinoxalino[2,3-a:2',3'-c]phenazine (abbreviated as HATNA), and 2,4,6-tris[3'-(pyridine-3-yl)biphenyl-3-yl]-1,3,5-triazine (abbreviated as TmPPPyTz) can be used in organic compounds containing lone pairs of electrons. NBPhen has a higher glass transition temperature (Tg) and superior heat resistance compared to BPhen.

[0095] The luminescent layer is a layer containing a luminescent material. The luminescent layer may contain one or more types of luminescent materials. The luminescent material can be any material that exhibits a luminescent color such as blue, purple, blue-violet, green, yellow-green, yellow, orange, or red. Furthermore, a material that emits near-infrared light can also be used as the luminescent material.

[0096] Examples of luminescent materials include fluorescent materials, phosphorescent materials, TADF materials, and quantum dot materials.

[0097] Examples of fluorescent materials include pyrene derivatives, anthracene derivatives, triphenylene derivatives, fluorene derivatives, carbazole derivatives, dibenzothiophene derivatives, dibenzofuran derivatives, dibenzoquinoxaline derivatives, quinoxaline derivatives, pyridine derivatives, pyrimidine derivatives, phenanthrene derivatives, and naphthalene derivatives.

[0098] Examples of phosphorescent materials include organometallic complexes (especially iridium complexes) having a 4H-triazole skeleton, 1H-triazole skeleton, imidazole skeleton, pyrimidine skeleton, pyrazine skeleton, or pyridine skeleton; organometallic complexes (especially iridium complexes) using phenylpyridine derivatives having electron-withdrawing groups as ligands; platinum complexes; and rare earth metal complexes.

[0099] The light-emitting layer may contain one or more types of organic compounds (host material, assist material, etc.) in addition to the light-emitting substance (guest material). One or more of these organic compounds may be hole-transporting materials and / or electron-transporting materials. Alternatively, one or more of these organic compounds may be bipolar materials or TADF materials.

[0100] The light-emitting layer preferably comprises, for example, a phosphorescent material and a combination of a hole-transporting material and an electron-transporting material that readily forms an excitation complex. This configuration allows for efficient emission using ExTET (Exciplex-Triplet Energy Transfer), which is energy transfer from the excitation complex to the light-emitting substance (phosphorescent material). By selecting a combination that forms an excitation complex that exhibits emission overlapping with the wavelength of the lowest-energy absorption band of the light-emitting substance, energy transfer becomes smoother, and light emission can be obtained efficiently. This configuration simultaneously achieves high efficiency, low-voltage operation, and a long lifespan for the light-emitting device.

[0101] The configuration shown in Figure 2B, which has a pair of electrodes (pixel electrode 111G and common electrode 113) with layers 530, light-emitting layer 511, layer 520, and layer 116 between them, can function as a single light-emitting unit, and this configuration is referred to as a single structure in this specification.

[0102] By providing an insulating layer 133 in contact with the side surface of the EL layer 112, it is possible to suppress the intrusion of oxygen, moisture, or their constituent elements into the interior from the side surfaces of the layer 530, the light-emitting layer 511, and the layer 520, thereby creating a highly reliable display device. Preferably, the insulating layer 133 is in contact with at least the side surface of the light-emitting layer 511.

[0103] As shown in Figure 3A, layer 116 may have a laminated structure. Figure 3A shows an example in which layer 116 has a laminated structure of layer 116a and layer 116b on top of layer 116a.

[0104] For example, in a light-emitting device where the pixel electrode 111 is the anode and the common electrode 113 is the cathode, layer 116a can be an electron transport layer and layer 116b can be an electron injection layer. Alternatively, a layer 520 functioning as an electron transport layer, layer 116a functioning as an electron transport layer, and layer 116b functioning as an electron injection layer can be stacked in this order between the light-emitting layer 511 and the common electrode 113. In this case, it can be said that a configuration with two stacked electron transport layers is achieved. Compared to the case where an electron transport layer of the desired thickness is formed with only layer 520, forming the electron transport layer with two layers, layer 520 and layer 116a, reduces the step height of the EL layer 112G, improves the step height coverage of the layer formed on the EL layer 112G (for example, the common electrode 113), and suppresses the occurrence of defects such as step breaks and porosity in the layer.

[0105] For example, in a light-emitting device where the pixel electrode 111 is the cathode and the common electrode 113 is the anode, layer 116a can be used as a hole transport layer and layer 116b as a hole injection layer. Alternatively, a layer 520 functioning as a hole transport layer, layer 116a functioning as a hole transport layer, and layer 116b functioning as a hole injection layer can be stacked in this order between the light-emitting layer 511 and the common electrode 113. In this case, it can be said that a configuration with two stacked hole transport layers is achieved. Compared to the case where a hole transport layer of the desired thickness is formed using only layer 520, forming the hole transport layer with two layers, layer 520 and layer 116a, reduces the step height of the EL layer 112G, improves the step height coverage of the layer formed on the EL layer 112G (for example, the common electrode 113), and suppresses the occurrence of defects such as step breaks and porosity in the layer.

[0106] Furthermore, layer 116a may have a laminated structure of two or more layers. Also, layer 116b may have a laminated structure of two or more layers.

[0107] Figure 1A and others show an example configuration in which the display device 100 has a layer 116, but as shown in Figure 3B, a configuration without layer 116 is also possible. In the case of a configuration without layer 116, the common electrode 113 is provided in contact with the insulating layer 133 and the EL layer 112G. The common electrode 113 has a region that is in contact with the upper surface and end surface of the insulating layer 133 and the upper surface of the EL layer 112G. By providing the insulating layer 133 on the side surface of the EL layer 112, contact between the common electrode 113 and the side surface of the EL layer 112 can be suppressed, and a short circuit of the light-emitting device 110 can be suppressed. In particular, providing the insulating layer 133 on the side surface of the light-emitting layer 511 is preferable as it can suppress a short circuit of the light-emitting device 110.

[0108] Figure 2B shows a configuration in which the light-emitting device 110G has one light-emitting layer 511, but the present invention is not limited to this. The light-emitting device 110G may have multiple light-emitting layers. Figure 4A shows a configuration in which multiple light-emitting layers (light-emitting layer 511, light-emitting layer 512, light-emitting layer 513) are provided between layer 530 and layer 520. Note that a configuration in which multiple light-emitting layers are provided between layer 530 and layer 520, as shown in Figure 4A, can also be called a single structure.

[0109] The light-emitting materials of light-emitting layers 511, 512, and 513 may be the same material or different materials. Figure 4A shows an example where the light-emitting device 110G has three light-emitting layers, but the present invention is not limited to this. The number of light-emitting layers in the light-emitting device 110G is not particularly limited. The light-emitting device 110G may have two light-emitting layers, or four or more light-emitting layers.

[0110] Figure 4B shows an example of a configuration different from those shown in Figures 2B and 4A. The light-emitting device shown in Figure 4B has a configuration in which multiple light-emitting units (EL layer 112G, EL layer 112Ga) are connected in series via an intermediate layer 540, and this configuration is referred to as a tandem structure in this specification. In the tandem structure, the intermediate layer 540 functions as a charge generation layer. By using a tandem structure, a light-emitting device capable of high-brightness light emission can be made. Note that the tandem structure may also be called a stack structure.

[0111] In the EL layer 112Ga, layer 522 may have, for example, an electron injection layer and an electron transport layer. Layer 532 may have, for example, a hole injection layer and a hole transport layer.

[0112] For example, in a light-emitting device where the pixel electrode 111 is the anode and the common electrode 113 is the cathode, layer 532 can be a hole transport layer and layer 522 can be an electron transport layer. Layer 532 may have a stacked structure of a hole injection layer and a hole transport layer on the hole injection layer. Layer 522 may have a stacked structure of an electron injection layer and an electron transport layer on the electron injection layer. Alternatively, layer 530 can be a hole transport layer, layer 520 can be an electron transport layer, and layer 116 can be an electron injection layer. Layer 530 may have a stacked structure of a hole injection layer and a hole transport layer on the hole injection layer.

[0113] For example, in a light-emitting device where the pixel electrode 111 is the cathode and the common electrode 113 is the anode, layer 532 can be an electron transport layer and layer 522 can be a hole transport layer. Layer 532 may have a stacked structure of an electron injection layer and an electron transport layer on top of the electron injection layer. Layer 522 may have a stacked structure of a hole injection layer and a hole transport layer on top of the hole injection layer. Alternatively, layer 530 can be an electron transport layer, layer 520 can be a hole transport layer, and layer 116 can be a hole injection layer. Layer 530 may have a stacked structure of an electron injection layer and an electron transport layer on top of the electron injection layer.

[0114] Light-emitting devices can be broadly classified into single-structure and tandem-structure devices. A single-structure device has one light-emitting unit between a pair of electrodes, and it is preferable that this light-emitting unit includes one or more light-emitting layers. To obtain white light emission, one should select light-emitting layers such that the light emitted from each of the two or more layers is complementary in color. For example, by making the light-emitting color of the first light-emitting layer and the light-emitting color of the second light-emitting layer complementary, a configuration that emits white light as a whole can be obtained. The same applies to light-emitting devices having three or more light-emitting layers.

[0115] A tandem device preferably has two or more light-emitting units between a pair of electrodes, and each light-emitting unit preferably includes one or more light-emitting layers. To obtain white light emission, the device should be configured such that the light from the light-emitting layers of the multiple light-emitting units is combined to produce white light emission. The configuration for obtaining white light emission is the same as that for a single-structure device. In a tandem device, it is preferable to provide an intermediate layer, such as a charge-generating layer, between the multiple light-emitting units.

[0116] When comparing the aforementioned white light-emitting devices (single or tandem structure) with SBS structure light-emitting devices, SBS structure light-emitting devices can consume less power than white light-emitting devices. If you want to keep power consumption low, it is preferable to use an SBS structure light-emitting device. On the other hand, white light-emitting devices are preferable because their manufacturing process is simpler than that of SBS structure light-emitting devices, which can lead to lower manufacturing costs or higher manufacturing yields.

[0117] Although Figures 2A to 4B illustrate the example using the light-emitting device 110G, the configurations of the light-emitting devices 110R and 110B can be similar.

[0118] The light-emitting color of the light-emitting device can be red, green, blue, cyan, magenta, yellow, or white, depending on the material that makes up the EL layer 112. Furthermore, the color purity can be further enhanced by adding a microcavity structure to the light-emitting device.

[0119] A light-emitting device that emits white light preferably has a configuration that includes two or more types of light-emitting materials in its light-emitting layer. To obtain white light emission, it is sufficient to select light-emitting materials such that the light emitted by each of the two or more materials is complementary in color. For example, by making the light-emitting color of the first light-emitting layer and the light-emitting color of the second light-emitting layer complementary, a light-emitting device that emits white light as a whole can be obtained. The same applies to light-emitting devices that have three or more light-emitting layers.

[0120] The light-emitting layer preferably contains two or more light-emitting materials that emit light such as R (red), G (green), B (blue), Y (yellow), and O (orange). Alternatively, it is preferable that the layer contains two or more light-emitting materials, and the light emitted by each light-emitting material contains spectral components of two or more colors from R, G, and B.

[0121] Figure 1C shows a schematic cross-sectional view corresponding to the dashed line B1-B2 in Figure 1A. Figure 1C shows an example in which the EL layer 112G is processed in an island shape. As shown in Figure 1D, the EL layer 112G may also be processed in a strip shape so that the EL layer 112G is continuous in the column direction. By making the EL layer 112G etc. in a strip shape, the space required to separate them is not needed, and the area of ​​the non-emitting region between light-emitting devices can be reduced, thereby increasing the aperture ratio. As shown in Figure 1D, when the EL layer 112G is continuous in the column direction, it is not necessary to provide an insulating layer 133 between the EL layer 112G and the adjacent EL layer 112G.

[0122] Although Figures 1C and 1D show a cross-section of the light-emitting device 110G as an example, the light-emitting devices 110R and 110B can also have similar shapes.

[0123] A protective layer 121 is provided on the common electrode 113, covering the light-emitting devices 110R, 110G, and 110B. The protective layer 121 has the function of preventing impurities such as water from diffusing into each light-emitting device from above. Alternatively, it is preferable that the protective layer 121 includes a layer that has the function of capturing or fixing (also called gettering) at least one of water and oxygen. More preferably, it is preferable to include a layer that has the function of capturing or fixing hydrogen, hydrogen-bonded substances (e.g., water (H2O)), oxygen, and hydrogen, as this makes it possible to adsorb oxygen, hydrogen, etc. that may be contained in each light-emitting device.

[0124] The protective layer 121 can be, for example, a single-layer structure or a multilayer structure including at least an inorganic insulating film. Examples of inorganic insulating films include oxide films or nitride films such as silicon oxide film, silicon oxide nitride film, silicon nitride film, silicon nitride film, aluminum oxide film, aluminum oxide nitride film, and hafnium oxide film. Alternatively, semiconductor materials such as indium gallium oxide and indium gallium zinc oxide may be used as the protective layer 121.

[0125] A laminated film of an inorganic insulating film and an organic insulating film can also be used as the protective layer 121. For example, it is preferable to have a configuration in which an organic insulating film is sandwiched between a pair of inorganic insulating films. Furthermore, it is preferable that the organic insulating film functions as a planarizing film. This makes the upper surface of the organic insulating film flat, thereby improving the coverage of the inorganic insulating film on top of it and enhancing its barrier properties. In addition, since the upper surface of the protective layer 121 is flat, it is preferable because it reduces the influence of uneven shapes caused by the structure below when a structure (e.g., a color filter, touch sensor electrodes, or lens array, etc.) is provided above the protective layer 121.

[0126] Figure 2A and others show an example where the end face of the insulating layer 133 is flat, but the present invention is not limited to this. As shown in Figure 5A, the end face of the insulating layer 133 may be curved. Also, as shown in Figure 5B, the end face of the insulating layer 133 may have a convex shape.

[0127] Furthermore, as shown in Figure 5A, etc., if the width of the insulating layer 133 is not constant, the widest width in the region that is in contact with the side surface of the EL layer 112 and sandwiched between the EL layer 112G and layer 116 may be used as the width 133w of the insulating layer 133. It is preferable that the width 133w of the insulating layer 133 be within the range described above.

[0128] The following describes a configuration example of a display device different from Configuration Example 1. Note that some parts that overlap with Configuration Example 1 may be omitted from the explanation.

[0129] <Configuration Example 2> Figures 6A and 6B show schematic cross-sectional views of a display device 100A according to one embodiment of the present invention. A schematic top view of the display device 100A can be found in Figure 1A. Figure 6A is a schematic cross-sectional view corresponding to the dashed line A1-A2 in Figure 1A. Figure 6B is a schematic cross-sectional view corresponding to the dashed line B1-B2 in Figure 1A. Figure 6C shows an enlarged view of the region Q enclosed by the dashed line in Figure 6A.

[0130] The display device 100A differs from the aforementioned display device 100 in that the thickness of the insulating layer 131 in the region overlapping with the insulating layer 133 is equal to, or approximately equal to, the thickness of the insulating layer 131 in the region overlapping with the EL layer 112G.

[0131] By configuring the display device 100A so that the thickness of the insulating layer 131 in the area overlapping with the insulating layer 133 is equal to, or approximately equal to, the thickness of the insulating layer 131 in the area overlapping with the EL layer 112G, the step difference between the upper surface of the EL layer 112G and the upper surface of the insulating layer 131 is reduced. Therefore, the step coverage of the layer formed on the insulating layer 131 (for example, the insulating layer 133) is improved, and defects such as step breaks and porosity in the layer can be suppressed.

[0132] In addition, in the display device 100A, the EL layer 112G may be processed into a strip shape so that it forms a continuous strip in the column direction, as shown in Figure 1D.

[0133] <Configuration Example 3> Figures 7A and 7B show schematic cross-sectional views of a display device 100B according to one embodiment of the present invention. A schematic top view of the display device 100B can be found in Figure 1A. Figure 7A is a schematic cross-sectional view corresponding to the dashed line A1-A2 in Figure 1A. Figure 7B is a schematic cross-sectional view corresponding to the dashed line B1-B2 in Figure 1A. Figure 7C shows an enlarged view of the region R enclosed by the dashed line in Figure 7A.

[0134] The display device 100B differs from the aforementioned display device 100 mainly in that the height of the end face of the insulating layer 133 in contact with the EL layer 112G is different from the height of the top surface of the EL layer 112G. In the display device 100B, the height of the end face of the insulating layer 133 in contact with the EL layer 112G is lower than the height of the top surface of the EL layer 112G. It can also be said that the end of the insulating layer 133 is in contact with the side surface of the EL layer 112G.

[0135] As shown in Figure 7C, it is preferable that the insulating layer 133 is in contact with at least the side surface of the light-emitting layer 511. By covering the side surface of the light-emitting layer 511 with the insulating layer 133, it is possible to suppress the intrusion of oxygen, moisture, or their constituent elements into the interior from the side surface of the light-emitting layer 511, resulting in a highly reliable display device.

[0136] In addition, in the display device 100B, the EL layer 112G may be processed into a strip shape so that it forms a continuous strip in the column direction, as shown in Figure 1D.

[0137] <Configuration Example 4> Figures 8A and 8B show schematic cross-sectional views of a display device 100C according to one embodiment of the present invention. A schematic top view of the display device 100C can be found in Figure 1A. Figure 8A is a schematic cross-sectional view corresponding to the dashed-dotted line A1-A2 in Figure 1A. Figure 8B is a schematic cross-sectional view corresponding to the dashed-dotted line B1-B2 in Figure 1A. Figure 8C shows an enlarged view of the region S enclosed by the dashed-dotted line in Figure 8A.

[0138] The display device 100C differs from the aforementioned display device 100 mainly in that the height of the end face of the insulating layer 133 in contact with the EL layer 112G is higher than the height of the upper surface of the EL layer 112G.

[0139] As shown in Figure 8C, the insulating layer 133 covers the sides of layer 520, the light-emitting layer 511, and layer 530, thereby suppressing the intrusion of oxygen, moisture, or their constituent elements into the interior from the sides of layer 520, the light-emitting layer 511, and layer 530, resulting in a highly reliable display device.

[0140] In addition, in the display device 100C, the EL layer 112G may be processed into a strip shape so that it forms a continuous strip in the column direction, as shown in Figure 1D.

[0141] <Configuration Example 5> Figures 9A and 9B show schematic cross-sectional views of a display device 100D according to one embodiment of the present invention. A schematic top view of the display device 100D can be found in Figure 1A. Figure 9A is a schematic cross-sectional view corresponding to the dashed line A1-A2 in Figure 1A. Figure 9B is a schematic cross-sectional view corresponding to the dashed line B1-B2 in Figure 1A. Figure 9C shows an enlarged view of the region T enclosed by the dashed line in Figure 9A.

[0142] The display device 100D differs from the aforementioned display device 100 in that layer 116 has a region in contact with the upper surface of the insulating layer 131. Preferably, the insulating layer 133 is in contact with at least the side surface of the light-emitting layer 511. By covering the side surface of the light-emitting layer 511 with the insulating layer 133, it is possible to suppress the intrusion of oxygen, moisture, or their constituent elements into the interior from the side surface of the light-emitting layer 511, resulting in a highly reliable display device.

[0143] In addition, in the display device 100D, the EL layer 112G may be processed into a strip shape so that it forms a continuous strip in the column direction, as shown in Figure 1D.

[0144] <Configuration Example 6> Figures 10A and 10B show schematic cross-sectional views of a display device 100E according to one embodiment of the present invention. A schematic top view of the display device 100E can be found in Figure 1A. Figure 10A is a schematic cross-sectional view corresponding to the dashed-dotted line A1-A2 in Figure 1A. Figure 10B is a schematic cross-sectional view corresponding to the dashed-dotted line B1-B2 in Figure 1A. An enlarged view of Figure 10A is shown in Figure 11.

[0145] The display device 100E differs from the aforementioned display device 100 mainly in that the thickness of the insulating layer 131 varies depending on the light-emitting device.

[0146] Between the light-emitting device 110R and the light-emitting device 110G, the height 131bG of the upper surface of the insulating layer 131 in the region overlapping with the EL layer 112G is lower than the height 131bR of the upper surface of the insulating layer 131 in the region overlapping with the EL layer 112R. The height 131bC of the upper surface of the insulating layer 131 in the region overlapping with the insulating layer 133 is lower than the height 131bG.

[0147] Between the light-emitting device 110G and the light-emitting device 110B, the height 131cB of the upper surface of the insulating layer 131 in the region overlapping with the EL layer 112B is lower than the height 131cG of the upper surface of the insulating layer 131 in the region overlapping with the EL layer 112G. The height 131cC of the upper surface of the insulating layer 131 in the region overlapping with the insulating layer 133 is lower than the height 131cB. Note that the height 131cG is equal to, or approximately equal to, the aforementioned height 131bG.

[0148] Between the light-emitting device 110B and the light-emitting device 110R adjacent to the light-emitting device 110B, the height 131aB of the upper surface of the insulating layer 131 in the region overlapping with the EL layer 112B is lower than the height 131aR of the upper surface of the insulating layer 131 in the region overlapping with the EL layer 112R. The height 131aC of the upper surface of the insulating layer 131 in the region overlapping with the insulating layer 133 is lower than the height 131aB. Note that the height 131aB is equal to or approximately equal to the aforementioned height 131cB. The height 131aR is equal to or approximately equal to the aforementioned height 131bR.

[0149] In this specification, the height of the upper surface of the insulating layer 131 refers to the distance from the substrate 101 to the highest point of the upper surface of the insulating layer 131.

[0150] Figure 11 and others show an example where the heights 131bG and 131cB of the upper surface of the insulating layer 131 in the region overlapping with the EL layer 112G are lower than the heights 131aR and 131bR of the upper surface of the insulating layer 131 in the region overlapping with the EL layer 112R, and the heights 131cB and 131aB of the upper surface of the insulating layer 131 in the region overlapping with the EL layer 112B are lower than the heights 131bG and 131cG of the upper surface of the insulating layer 131 in the region overlapping with the EL layer 112G. However, the present invention is not limited to this example.

[0151] For example, the height of the upper surface of the insulating layer 131 in the region overlapping with the EL layer 112G may be higher than the height of the upper surface of the insulating layer 131 in the region overlapping with the EL layer 112R, and the height of the upper surface of the insulating layer 131 in the region overlapping with the EL layer 112B may be higher than the height of the upper surface of the insulating layer 131 in the region overlapping with the EL layer 112G. The height of the upper surface of the insulating layer 131 in the region overlapping with the EL layer can be made different, for example, depending on the formation order of the light-emitting device 110R, light-emitting device 110G, and light-emitting device 110B.

[0152] The heights 131aC, 131bC, and 131cC of the upper surface of the insulating layer 131 in the region overlapping with the insulating layer 133 are equal, approximately equal, or different from each other.

[0153] The height of the end faces of the insulating layer 133 may differ in the light-emitting device 110. Figure 11 and others show an example where the height of the end face of the insulating layer 133 in contact with the EL layer 112R is lower than the height of the top surface of the EL layer 112R, the height of the end face of the insulating layer 133 in contact with the EL layer 112G is lower than the height of the top surface of the EL layer 112G, and the height of the end face of the insulating layer 133 in contact with the EL layer 112B is equal to the height of the top surface of the EL layer 112B, but the present invention is not limited to this. For example, the height of any of the end faces of the insulating layer 133 may be lower than the height of the EL layer 112.

[0154] In addition, in the display device 100E, the EL layer 112G may be processed into a strip shape so that it forms a continuous strip in the column direction.

[0155] <Configuration Example 7> Figures 12A and 12B show schematic cross-sectional views of a display device 100F according to one embodiment of the present invention. A schematic top view of the display device 100F can be found in Figure 1A. Figure 12A is a schematic cross-sectional view corresponding to the dashed-dotted line A1-A2 in Figure 1A. Figure 12B is a schematic cross-sectional view corresponding to the dashed-dotted line B1-B2 in Figure 1A.

[0156] Display device 100F differs from the aforementioned display device 100 mainly in the configuration of its light-emitting devices. Light-emitting device 110R has an optical adjustment layer 115R between the pixel electrode 111R and the EL layer 112R. Light-emitting device 110G has an optical adjustment layer 115G between the pixel electrode 111G and the EL layer 112G. Light-emitting device 110B has an optical adjustment layer 115B between the pixel electrode 111B and the EL layer 112B.

[0157] Optical adjustment layers 115R, 115G, and 115B are all transparent to visible light. Furthermore, optical adjustment layers 115R, 115G, and 115B have different thicknesses. This allows for different optical path lengths for each light-emitting device.

[0158] Here, a conductive film reflective to visible light is used for the pixel electrodes 111R, 111G, and 111B, and a conductive film reflective and transmittant to visible light is used for the common electrode 113. As a result, each light-emitting device realizes a so-called microcavity structure (micro-resonator structure), and light of a specific wavelength is amplified. This makes it possible to realize a display device with improved color purity.

[0159] Each optical adjustment layer can be made of a conductive material that is transparent to visible light. For example, conductive oxides such as indium oxide, indium tin oxide, indium zinc oxide, zinc oxide, zinc oxide containing gallium, indium tin oxide containing silicon, and indium zinc oxide containing silicon can be used.

[0160] Each optical adjustment layer may use conductive films of different thicknesses, or they may be arranged in a single-layer structure, a two-layer structure, a three-layer structure, and so on, from thinnest to thickest.

[0161] In addition, in the display device 100F, the EL layer 112G may be processed into a strip shape so that it forms a continuous strip in the column direction.

[0162] <Configuration Example 8> Figure 12C shows a schematic cross-sectional view of a display device 100G according to one embodiment of the present invention. A schematic top view of the display device 100G can be found in Figure 1A. Figure 12C is a schematic cross-sectional view corresponding to the dashed line A1-A2 in Figure 1A. A schematic cross-sectional view corresponding to the dashed line B1-B2 in Figure 1A can be found in Figure 1C or Figure 1D.

[0163] The display device 100G shown in Figure 12C differs from the aforementioned display device 100F mainly in that it does not have an optical adjustment layer.

[0164] Display device 100G is an example of realizing a microcavity structure by varying the thickness of the EL layer 112R, EL layer 112G, and EL layer 112B. This configuration eliminates the need for a separate optical adjustment layer, thus simplifying the manufacturing process.

[0165] For example, in the display device 100G, the EL layer 112R of the light-emitting device 110R that emits the longest wavelength light is the thickest, and the EL layer 112B of the light-emitting device 110B that emits the shortest wavelength light is the thinnest. However, this is not limited to this, and the thickness of each EL layer can be adjusted by considering the wavelength of light emitted by each light-emitting device, the optical properties of the layers constituting the light-emitting device, and the electrical properties of the light-emitting device.

[0166] Figure 12C shows an example where the height of the end face of the insulating layer 133 in contact with the EL layer 112R is lower than the height of the upper surface of the EL layer 112R, the height of the end face of the insulating layer 133 in contact with the EL layer 112G is approximately the same as the height of the upper surface of the EL layer 112G, and the height of the end face of the insulating layer 133 in contact with the EL layer 112B is higher than the height of the upper surface of the EL layer 112B. However, the present invention is not limited to this example.

[0167] In addition, in the display device 100G, the EL layer 112G may be processed into a strip shape so that it forms a continuous strip in the column direction.

[0168] <Example of manufacturing method 1> In the following section, an example of a method for manufacturing a display device according to one aspect of the present invention will be described with reference to the drawings. Here, the display device 100E shown in the above configuration example will be used as an example. Figures 13A to 17D are schematic cross-sectional views of each step in the method for manufacturing the display device illustrated below.

[0169] The thin films (insulating films, semiconductor films, conductive films, etc.) that make up the display device can be formed using sputtering, chemical vapor deposition (CVD), vacuum deposition, pulsed laser deposition (PLD), atomic layer deposition (ALD), and other methods. CVD methods include plasma-enhanced CVD (PECVD) and thermal CVD. One type of thermal CVD is metal-organic CVD (MOCVD).

[0170] Thin films (insulating films, semiconductor films, conductive films, etc.) that constitute a display device can be formed by methods such as spin coating, dip coating, spray coating, inkjet printing, dispensing, screen printing, offset printing, doctor knife method, slit coating, roll coating, curtain coating, and knife coating.

[0171] When processing the thin films that constitute the display device, photolithography or the like can be used. In addition, the thin films may be processed by nanoimprint lithography, sandblasting, lift-off lithography, or the like. Furthermore, island-shaped thin films may be directly formed by a film deposition method using a shielding mask such as a metal mask.

[0172] There are two main methods of photolithography. One method involves forming a resist mask on the thin film to be processed, then processing the thin film by etching or other means, and removing the resist mask. The other method involves forming a photosensitive thin film, then exposing and developing it to process the thin film into the desired shape.

[0173] In photolithography, the light used for exposure can be, for example, i-line (wavelength 365 nm), g-line (wavelength 436 nm), h-line (wavelength 405 nm), or a mixture thereof. Other options include ultraviolet light, KrF laser light, or ArF laser light. Exposure may also be performed using immersion lithography. Furthermore, extreme ultraviolet (EUV) light or X-rays may be used as the light source for exposure. An electron beam can also be used instead of the light source. Using extreme ultraviolet light, X-rays, or an electron beam is preferable because it allows for extremely fine processing. Note that a photomask is not required when exposure is performed by scanning a beam such as an electron beam.

[0174] For etching thin films, methods such as dry etching, wet etching, and sandblasting can be used.

[0175] [Preparation of circuit board 101] The substrate 101 can be a substrate with at least sufficient heat resistance to withstand subsequent heat treatment. When an insulating substrate is used as the substrate 101, glass substrates, quartz substrates, sapphire substrates, ceramic substrates, organic resin substrates, etc., can be used. In addition, semiconductor substrates such as single-crystal semiconductor substrates, polycrystalline semiconductor substrates, compound semiconductor substrates such as silicon germanium, and SOI substrates made from silicon or silicon carbide can be used.

[0176] In particular, it is preferable to use a substrate 101 on which a semiconductor circuit including semiconductor elements such as transistors is formed on the semiconductor substrate or insulating substrate. It is preferable that the semiconductor circuit constitutes, for example, a pixel circuit, a gate line driving circuit (gate driver), a source line driving circuit (source driver), etc. In addition to the above, an arithmetic circuit, a memory circuit, etc. may also be configured.

[0177] [Formation of pixel electrode 111R, pixel electrode 111G, and pixel electrode 111B] Next, multiple pixel electrodes 111 are formed on the substrate 101. First, a conductive film to be used as the pixel electrode is deposited, a resist mask is formed by photolithography, and unnecessary parts of the conductive film are removed by etching. After that, the resist mask is removed to form the pixel electrode 111R, pixel electrode 111G, and pixel electrode 111B.

[0178] When using a conductive film that is reflective to visible light as each pixel electrode, it is preferable to use a material (such as silver or aluminum) that has the highest possible reflectivity across the entire wavelength range of visible light. This not only improves the light extraction efficiency of the light-emitting device but also enhances color reproduction.

[0179] Furthermore, as shown in Figures 12A and 12B, when optical adjustment layers 115R, 115G, and 115B are provided, the optical adjustment layers 115R, 115G, and 115B are formed after the pixel electrodes 111R, 111G, and 111B are formed.

[0180] [Formation of insulating layer 131] Next, an insulating layer 131 is formed by covering the ends of the pixel electrodes 111R, 111G, and 111B (Figure 13A). The insulating layer 131 can be an organic insulating film or an inorganic insulating film. The insulating layer 131 is preferably tapered at the ends in order to improve the step coverage of the subsequent EL film. In particular, when using an organic insulating film, it is preferable to use a photosensitive material because it is easier to control the shape of the ends depending on the exposure and development conditions.

[0181] [Formation of EL film 112Rf] Next, an EL film 112Rf, which will later become the EL layer 112R, is deposited on the pixel electrode 111R, pixel electrode 111G, pixel electrode 111B, and insulating layer 131 (Figure 13B).

[0182] The EL film 112Rf has a film containing at least a luminescent compound. In addition, it may have a structure in which one or more films functioning as electron injection layers, electron transport layers, charge generation layers, hole transport layers, or hole injection layers are laminated. The EL film 112Rf can be formed by, for example, vapor deposition, sputtering, or inkjet. However, it is not limited to these, and the above-mentioned film formation methods can be used as appropriate.

[0183] [Formation of sacrificial film 144a] Next, the EL film 112Rf is covered to form a sacrificial film 144a.

[0184] The sacrificial film 144a can be formed by sputtering, ALD (thermal ALD, PEALD), or vacuum deposition. It is preferable to use a method that minimizes damage to the EL film 112Rf when forming the sacrificial film 144a. For example, ALD or vacuum deposition are suitable for forming the sacrificial film 144a. Using aluminum oxide is particularly preferable for the sacrificial film 144a because it reduces manufacturing costs. Furthermore, the ALD method can form the sacrificial film with less damage to the surface to be formed (e.g., the EL film 112Rf) compared to the sputtering method.

[0185] It is preferable to use a sacrificial film 144a that can be removed by a wet etching method. By using a wet etching method, the damage inflicted on the EL film 112Rf during processing of the sacrificial film 144a can be reduced compared to when a dry etching method is used. When using a wet etching method, it is preferable to use a chemical solution containing, for example, a developer, an aqueous solution of tetramethylammonium hydroxide (TMAH), dilute hydrofluoric acid, oxalic acid, phosphoric acid, acetic acid, nitric acid, or a mixture thereof.

[0186] The sacrificial film 144a can be a film with high resistance to etching of each EL film, such as the EL film 112Rf, i.e., a film with a high etching selectivity ratio. Alternatively, the sacrificial film 144a can be a film with a high etching selectivity ratio with a protective film, such as the protective film 146a described later. Furthermore, the sacrificial film 144a can be a film that can be removed by a wet etching method that causes minimal damage to each EL film. The conductivity of the sacrificial film 144a is not particularly limited. The sacrificial film 144a can be at least one of an insulating film, a semiconductor film, and a conductive film.

[0187] The sacrificial film 144a can be an inorganic film such as a metal film, alloy film, metal oxide film, semiconductor film, or inorganic insulating film. Alternatively, the sacrificial film 144a can be an organic film such as polyvinyl alcohol.

[0188] The sacrificial film 144a can be a metallic material such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, titanium, aluminum, yttrium, zirconium, and tantalum, or an alloy material containing such a metallic material. In particular, it is preferable to use a low melting point material such as aluminum or silver.

[0189] The sacrificial film 144a can be a metal oxide such as indium gallium zinc oxide (In-Ga-Zn oxide, also written as IGZO). Furthermore, the sacrificial film 144a can be indium oxide, indium zinc oxide (In-Zn oxide), indium tin 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), etc. Alternatively, the sacrificial film 144a can also be an indium tin oxide containing silicon, etc.

[0190] Furthermore, the above-mentioned method can also be applied when element M (where M is one or more selected from aluminum, silicon, boron, yttrium, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, or magnesium) is used instead of gallium. In particular, it is preferable that M be one or more selected from gallium, aluminum, or yttrium.

[0191] Furthermore, when the above-mentioned In-Ga-Zn oxide is used as the sacrificial film 144a, it can be removed using, for example, oxalic acid, phosphoric acid, acetic acid, nitric acid, or a mixture thereof.

[0192] Alternatively, the sacrificial film 144a may be made of an inorganic insulating material such as aluminum oxide, hafnium oxide, or silicon oxide. In particular, forming the sacrificial film 144a using the ALD method to create an aluminum oxide film is preferable because it can reduce damage to the substrate (especially the EL layer).

[0193] The sacrificial film 144a may be a single-layer structure or a multilayer structure of two or more layers. Typical examples of such multilayer structures include a two-layer structure of In-Ga-Zn oxide formed by sputtering and a silicon nitride film formed by sputtering, a two-layer structure of In-Ga-Zn oxide formed by sputtering and aluminum oxide formed by ALD, or a two-layer structure of aluminum oxide formed by ALD and In-Ga-Zn oxide formed by sputtering.

[0194] Furthermore, when forming the sacrificial film 144a by the ALD method or sputtering method, heat deposition may be used. In addition, it is preferable to use a temperature that does not degrade the substrate (in this case, the EL film 112Rf) when forming the sacrificial film 144a. The substrate temperature when forming the sacrificial film 144a is preferably above room temperature and below 200°C, more preferably between 50°C and 150°C, and more preferably between 70°C and 100°C, and typically around 80°C. If the substrate temperature when forming the sacrificial film 144a is low, the sacrificial film 144a will be a sparse film, and in subsequent processes, the etching rate against the etchant will be faster, which may cause defects such as the disappearance or peeling of the sacrificial film 144a. By using the above temperature, the occurrence of disappearance or peeling can be suppressed, as well as the deterioration of the substrate.

[0195] [Formation of protective film 146a] Next, a protective film 146a is formed on the sacrificial film 144a (Figure 13C).

[0196] The protective film 146a is used as a hard mask when etching the sacrificial film 144a later. Furthermore, the sacrificial film 144a is exposed during the subsequent processing of the protective film 146a. Therefore, a combination of films with a high etching selectivity ratio for each other is selected for the sacrificial film 144a and the protective film 146a. Thus, the film that can be used for the protective film 146a can be selected according to the etching conditions for both the sacrificial film 144a and the protective film 146a.

[0197] For example, when dry etching using a fluorine-containing gas (also called a fluorine-based gas) is used to etch the protective film 146a, silicon, silicon oxide, silicon oxide nitride, silicon oxide nitride, silicon nitride, tungsten, titanium, molybdenum, tantalum, tantalum nitride, an alloy containing molybdenum and niobium, or an alloy containing molybdenum and tungsten can be used for the protective film 146a. Here, metal oxide films such as IGZO and ITO can be used as sacrificial films 144a, as they allow for a higher selectivity ratio for etching (i.e., a slower etching rate) compared to the dry etching using the above-mentioned fluorine-based gas.

[0198] However, the protective film 146a can be selected from a variety of materials depending on the etching conditions of the sacrificial film 144a and the protective film 146a. For example, it can be selected from films that can be used for the sacrificial film 144a.

[0199] The protective film 146a can be, for example, a nitride film. Specifically, silicon nitride, aluminum nitride, hafnium nitride, titanium nitride, tantalum nitride, tungsten nitride, gallium nitride, germanium nitride, etc. The protective film 146a can be, for example, an oxide film. Specifically, silicon oxide, aluminum oxide, hafnium oxide, titanium oxide, tantalum oxide, tungsten oxide, gallium oxide, germanium oxide, etc.

[0200] The protective film 146a may be an organic film that can be used for EL films 112Rf, etc. For example, the same organic film used for EL films 112Rf, EL films 112Gf, or EL films 112Bf can be used for the protective film 146a. Using such an organic film is preferable because it allows the same film deposition equipment to be used for both the EL film 112Rf and the protective film 146a.

[0201] [Formation of resist mask 143a] Next, a resist mask 143a is formed on the protective film 146a at a position overlapping with the pixel electrode 111R (Figure 13D).

[0202] In this case, if a resist mask 143a is formed on the sacrificial film 144a without a protective film 146a, there is a risk that the EL film 112Rf may dissolve due to the solvent of the resist material if there are defects such as pinholes in the sacrificial film 144a. Using a protective film 146a can prevent such problems from occurring.

[0203] The resist mask 143a can use a resist material containing a photosensitive resin, such as a positive-type resist material or a negative-type resist material.

[0204] [Etching of protective film 146a] Next, a portion of the protective film 146a that is not covered by the resist mask 143a is removed by etching to form island-shaped or strip-shaped protective layers 147a (Figure 13E).

[0205] When etching the protective film 146a, it is preferable to use etching conditions with a high selectivity ratio so that the sacrificial film 144a is not removed by the etching. The protective film 146a can be etched using either a wet etching method or a dry etching method. Dry etching is preferably used for etching the protective film 146a, as it can suppress the reduction of the pattern of the protective film 146a.

[0206] [Removal of resist mask 143a] Next, remove the resist mask 143a (Figure 14A).

[0207] The resist mask 143a can be removed by wet etching or dry etching. In particular, it is preferable to remove the resist mask 143a by dry etching (also called plasma ashing) using oxygen gas as the etching gas.

[0208] In this case, the removal of the resist mask 143a is performed while the EL film 112Rf is covered by the sacrificial film 144a, thus suppressing the impact on the EL film 112Rf. In particular, since contact with oxygen can adversely affect the electrical properties of the EL film 112Rf, this method is preferable when etching using oxygen gas, such as plasma ashing, is performed to remove the resist mask 143a.

[0209] [Etching of sacrificial film 144a] Next, using the protective layer 147a as a mask, a portion of the sacrificial film 144a not covered by the protective layer 147a is removed by etching to form island-shaped or strip-shaped sacrificial layers 145a (Figure 14B).

[0210] The sacrificial film 144a can be etched using either a wet etching method or a dry etching method. Dry etching is preferably used for etching the sacrificial film 144a, as it can suppress pattern reduction.

[0211] [Etching of EL film 112Rf] Next, using the protective layer 147a and the sacrificial layer 145a as a mask, a portion of the EL film 112Rf not covered by the protective layer 147a and the sacrificial layer 145a is removed by etching to form island-shaped or strip-shaped EL layers 112R (Figure 14C). This process exposes a portion of the upper surface of the insulating layer 131, the upper surface of the pixel electrode 111G, and the upper surface of the pixel electrode 111B.

[0212] Dry etching is preferred for etching the EL film 112Rf. Dry etching is preferably performed using an etching gas that does not contain oxygen gas. This suppresses deterioration of the EL film 112Rf and enables the realization of a highly reliable display device. As an etching gas that does not contain oxygen gas, one or more selected from CF4, C4F8, SF6, CHF3, Cl2, H2O, BCl3, H2, or noble gases can be used. For example, He can be used as a noble gas. Dry etching using a mixed gas of H2 and Ar is preferably used for etching the EL film 112Rf. Alternatively, a mixed gas of the above gases and an oxygen-free gas can be used as the etching gas.

[0213] During etching of the EL film 112Rf, the thickness of the insulating layer 131 in areas that do not overlap with the protective layer 147a and the sacrificial layer 145a may be reduced. However, by etching the EL film 112Rf in such a way that the thickness of the insulating layer 131 in areas that do not overlap with the protective layer 147a and the sacrificial layer 145a is not reduced, the display device 100A shown in Figure 6A, etc., can be manufactured.

[0214] [Removal of protective layer 147a] Next, the protective layer 147a is removed by etching (Figure 14D).

[0215] The protective layer 147a can be removed by wet etching or dry etching. In this case, it is preferable to use a method that minimizes damage to the EL layer 112R. Dry etching is preferably used for removing the protective layer 147a. For dry etching, it is preferable to use an etching gas that does not contain oxygen. As an etching gas that does not contain oxygen, one or more can be selected from CF4, C4F8, SF6, CHF3, Cl2, H2O, BCl3, H2, or noble gases. For example, He can be used as a noble gas. Alternatively, a mixed gas of the above gases and an oxygen-free gas can be used as the etching gas.

[0216] Furthermore, etching of the EL film 112Rf and removal of the protective layer 147a may be performed using the same process. By using the same process, the process can be simplified, and the manufacturing cost of the display device can be reduced.

[0217] As described above, an EL film 112Rf is formed, and a sacrificial film 144a, a protective film 146a, and a resist mask 143a are formed on the EL film 112Rf in that order. Next, the protective film 146a is etched to form a protective layer 147a, and then the resist mask 143a is removed. Next, the sacrificial film 144a is etched to form a sacrificial layer 145a. After that, the EL film 112Rf is etched to form island-shaped or strip-shaped EL layers 112R. Then, by removing the protective layer 147a, island-shaped EL layers 112R and the sacrificial layer 145a can be formed.

[0218] [Formation of EL film 112Gf] Next, an EL film 112Gf, which will later become the EL layer 112G, is deposited on the sacrificial layer 145a, the insulating layer 131, the pixel electrode 111G, and the pixel electrode 111B (Figure 14E).

[0219] The method for forming the EL film 112Gf can be found in the description of the EL film 112Rf, so a detailed explanation is omitted here.

[0220] [Formation of sacrificial film 144b] Next, a sacrificial film 144b is formed on the EL film 112Gf. The sacrificial film 144b can be formed in the same manner as the sacrificial film 144a. In particular, it is preferable to use the same material for the sacrificial film 144b as for the sacrificial film 144a. A detailed explanation of the sacrificial film 144b can be found in the description of the sacrificial film 144a, so a detailed explanation is omitted here.

[0221] [Formation of protective film 146b] Next, a protective film 146b is formed on the sacrificial film 144b. A detailed explanation of the protective film 146b is omitted as it can be found in the description of protective film 146a.

[0222] [Formation of resist mask 143b] Next, a resist mask 143b is formed on the protective film 146b at a position overlapping with the pixel electrode 111G (Figure 15A).

[0223] Regarding the formation of resist mask 143b, please refer to the description of resist mask 143a, and a detailed explanation will be omitted.

[0224] [Etching of protective film 146b] Next, a portion of the protective film 146b that is not covered by the resist mask 143b is removed by etching to form island-shaped or strip-shaped protective layers 147b (Figure 15B).

[0225] Regarding the etching of protective film 146b, please refer to the description for protective film 146a, and therefore a detailed explanation will be omitted.

[0226] [Removal of resist mask 143b] Next, remove the resist mask 143b.

[0227] Regarding the removal of resist mask 143b, please refer to the description of resist mask 143a; therefore, a detailed explanation will be omitted.

[0228] [Etching of sacrificial film 144b] Next, using the protective layer 147b as a mask, a portion of the sacrificial film 144b not covered by the protective layer 147b is removed by etching to form island-shaped or strip-shaped sacrificial layers 145b.

[0229] Regarding the etching of sacrificial film 144b, please refer to the description for sacrificial film 144a, and a detailed explanation will be omitted.

[0230] [Etching of EL film 112Gf] Next, using the protective layer 147b and the sacrificial layer 145b as a mask, a portion of the EL film 112Gf not covered by the protective layer 147b and the sacrificial layer 145b is removed by etching to form island-shaped or strip-shaped EL layers 112G (Figure 15C). This process exposes a portion of the upper surface of the insulating layer 131 and the upper surface of the pixel electrode 111B.

[0231] Regarding the etching of EL film 112Gf, please refer to the description for EL film 112Rf; therefore, a detailed explanation will be omitted.

[0232] During etching of the EL film 112Gf, the thickness of the insulating layer 131 in the region that does not overlap with the sacrificial layer 145a, and the thickness of the insulating layer 131 in the region that does not overlap with the protective layer 147b and the sacrificial layer 145b may be reduced.

[0233] Furthermore, during etching of the EL film 112Rf, the thickness of the insulating layer 131 in the region that does not overlap with the protective layer 147a and the sacrificial layer 145a may become thinner. Additionally, during etching of the EL film 112Gf, the thickness of the insulating layer 131 in the region that does not overlap with the sacrificial layer 145a, and the thickness of the insulating layer 131 in the region that does not overlap with the protective layer 147b and the sacrificial layer 145b may become thinner. In this case, as shown in Figure 11, the thickness of the insulating layer 131 in the region that overlaps with the EL film 112Gf may be thinner than the thickness of the insulating layer 131 in the region that overlaps with the EL film 112Rf.

[0234] [Removal of protective layer 147b] Next, the protective layer 147b is removed by etching (Figure 15D).

[0235] Regarding the removal of protective layer 147b, please refer to the description for protective layer 147a; therefore, a detailed explanation will be omitted.

[0236] [Formation of EL film 112Bf] Next, an EL film 112Bf, which will later become the EL layer 112B, is deposited on the sacrificial layer 145a, the sacrificial layer 145b, the insulating layer 131, and the pixel electrode 111B.

[0237] The method for forming the EL film 112Bf can be found in the description of the EL film 112Rf above, so a detailed explanation is omitted.

[0238] [Formation of sacrificial film 144c] Next, a sacrificial film 144c is formed on the EL film 112Bf. The sacrificial film 144c can be formed in the same manner as the sacrificial film 144a. In particular, it is preferable to use the same material for the sacrificial film 144c as for the sacrificial film 144a. A detailed explanation of the sacrificial film 144c is omitted here, as it can be found in the description of the sacrificial film 144a.

[0239] [Formation of protective film 146c] Next, a protective film 146c is formed on the sacrificial film 144c. A detailed explanation of the protective film 146c is omitted as it can be found in the description of protective film 146a.

[0240] [Formation of resist mask 143c] Next, a resist mask 143c is formed on the protective film 146c at a position overlapping with the pixel electrode 111B (Figure 16A).

[0241] Regarding the formation of resist mask 143c, please refer to the description of resist mask 143a, and a detailed explanation will be omitted.

[0242] [Etching of protective film 146c] Next, a portion of the protective film 146c that is not covered by the resist mask 143c is removed by etching to form island-shaped or strip-shaped protective layers 147c.

[0243] Regarding the etching of protective film 146c, please refer to the description for protective film 146a, and therefore a detailed explanation will be omitted.

[0244] [Removal of resist mask 143c] Next, remove the resist mask 143c (Figure 16B).

[0245] Regarding the removal of resist mask 143c, please refer to the description of resist mask 143a; therefore, a detailed explanation will be omitted.

[0246] [Etching of sacrificial film 144c] Next, using the protective layer 147c as a mask, a portion of the sacrificial film 144c that is not covered by the protective layer 147c is removed by etching to form island-shaped or strip-shaped sacrificial layers 145c.

[0247] Regarding the etching of sacrificial film 144c, please refer to the description for sacrificial film 144a; therefore, a detailed explanation will be omitted.

[0248] [Etching of EL film 112Bf] Next, using the protective layer 147c and the sacrificial layer 145c as a mask, a portion of the EL film 112Bf not covered by the protective layer 147c and the sacrificial layer 145c is removed by etching to form island-shaped or strip-shaped EL layers 112B (Figure 16C). This process exposes a portion of the upper surface of the insulating layer 131, the upper surface of the sacrificial layer 145a, and the upper surface of the sacrificial layer 145b.

[0249] Regarding the etching of EL film 112Bf, please refer to the description for EL film 112Rf; therefore, a detailed explanation will be omitted.

[0250] During etching of the EL film 112Bf, the thickness of the insulating layer 131 in the region that does not overlap with the sacrificial layer 145a, the insulating layer 131 in the region that does not overlap with the sacrificial layer 145b, and the insulating layer 131 in the region that does not overlap with the protective layer 147c and the sacrificial layer 145c may be reduced.

[0251] Note that when etching the EL film 112Rf, the film thickness of the insulating layer 131 in the region that does not overlap with the protective layer 147a and the sacrificial layer 145a becomes thin. When etching the EL film 112Gf, the film thickness of the insulating layer 131 in the region that does not overlap with the sacrificial layer 145a, and the insulating layer 131 in the region that does not overlap with the protective layer 147b and the sacrificial layer 145b becomes thin. Further, when etching the EL film 112Bf, the film thickness of the insulating layer 131 in the region that does not overlap with the sacrificial layer 145a, the insulating layer 131 in the region that does not overlap with the sacrificial layer 145b, and the insulating layer 131 in the region that does not overlap with the protective layer 147c and the sacrificial layer 145c may become thin. In this case, as shown in FIG. 11, the film thickness of the insulating layer 131 in the region overlapping with the EL film 112Gf may be thinner than the film thickness of the insulating layer 131 in the region overlapping with the EL film 112Rf, and the film thickness of the insulating layer 131 in the region overlapping with the EL film 112Bf may be thinner than the film thickness of the insulating layer 131 in the region overlapping with the EL film 112Gf.

[0252] [Removal of the protective layer 147c] Subsequently, the protective layer 147c is removed by etching (FIG. 16D).

[0253] Regarding the removal of the protective layer 147c, since the description of the protective layer 147a can be referred to, detailed description is omitted.

[0254] In the above steps, three types of EL layers can be separately formed.

[0255] [Formation of the insulating film 133f] Subsequently, an insulating film 133f is formed on the insulating layer 131, the sacrificial layer 145a, the sacrificial layer 145b, and the sacrificial layer 145c (FIG. 17A).

[0256] The insulating film 133f is a film that will later become the insulating layer 133. The insulating film 133f can use, for example, aluminum oxide, magnesium oxide, hafnium oxide, gallium oxide, indium gallium zinc oxide, silicon oxide, silicon oxynitride, silicon nitride, or silicon nitride oxide, etc. The insulating film 133f may be formed by laminating these.

[0257] The insulating film 133f can be formed using sputtering, chemical vapor deposition (CVD), molecular beam epitaxy (MBE), pulsed laser deposition (PLD), atomic layer deposition (ALD), and other methods. The ALD method, which provides good coverage, is preferably used for forming the insulating film 133f.

[0258] [Formation of insulating layer 133] Next, a portion of the insulating film 133f is removed, exposing a portion of the sacrificial layer 145a, a portion of the sacrificial layer 145b, and a portion of the sacrificial layer 145c. This forms an insulating layer 133 that covers the sides of the EL layers 112R, 112G, and 112B, and also forms an insulating layer 133a on the sacrificial layer 145a, a portion of the sacrificial layer 145b, and a portion of the sacrificial layer 145c (Figure 17B). The insulating layer 133 and the insulating layer 133a can be formed using either a wet etching method or a dry etching method. In particular, anisotropic etching using a dry etching method can be preferably used.

[0259] For example, when forming the insulating layer 133, if the insulating film 133f on the sacrificial layer 145a, sacrificial layer 145b, and sacrificial layer 145c is completely removed, that is, if the insulating layer 133a is not formed on any of the sacrificial layers 145a, sacrificial layer 145b, and sacrificial layer 145c, the width 133w of the insulating layer 133 may become smaller. Therefore, by using an etching amount that exposes a portion of the sacrificial layer 145a, a portion of the sacrificial layer 145b, and a portion of the sacrificial layer 145c, and allows the insulating layer 133a to be formed on the sacrificial layer 145a, a portion of the sacrificial layer 145b, and sacrificial layer 145c, it is possible to suppress the reduction in the width 133w of the insulating layer 133.

[0260] Figure 17A shows an example in which the insulating layer 133a is formed on sacrificial layer 145a, sacrificial layer 145b, and sacrificial layer 145c, but the present invention is not limited to this. It is sufficient for the insulating layer 133a to be formed on one or more of the sacrificial layer 145a, sacrificial layer 145b, and sacrificial layer 145c. Furthermore, it is not necessary for the insulating layer 133a to be formed on any of the sacrificial layer 145a, sacrificial layer 145b, and sacrificial layer 145c.

[0261] When forming the insulating layer 133, the height of the end face of the insulating layer 133 can be adjusted by the amount of etching. It is preferable to adjust the amount of etching so that the insulating layer 133 covers the side surface of the EL layer 112. In particular, it is preferable to adjust the amount of etching so that the insulating layer 133 covers the side surface of the light-emitting layer of the EL layer 112. It is also preferable to adjust the amount of etching so that the width 133w of the insulating layer 133 in the region in contact with the side surface of the EL layer 112 falls within the aforementioned range. Furthermore, in conjunction with the amount of etching, the film thickness of the insulating film 133f can be adjusted to achieve the desired height and width 133w of the end face of the insulating layer 133.

[0262] [Removal of the sacrificial layer] Next, sacrificial layers 145a, 145b, and 145c are removed, exposing the upper surfaces of EL layers 112R, 112G, and 112B (Figure 17C). At this time, sacrificial layers 145a, 145b, and 145c are removed, as are the insulating layers 133a on sacrificial layer 145a, 133a on sacrificial layer 145b, and 133a on sacrificial layer 145c.

[0263] The sacrificial layers 145a, 145b, and 145c can be removed by wet etching or dry etching. In this case, it is preferable to use a method that causes as little damage as possible to the EL layers 112R, 112G, and 112B. In particular, it is preferable to use a wet etching method. For example, it is preferable to use a wet etching method using an aqueous solution of tetramethylammonium hydroxide (TMAH), dilute hydrofluoric acid, oxalic acid, phosphoric acid, acetic acid, nitric acid, or a mixture thereof. By using an etchant that dissolves the sacrificial layers 145a, 145b, and 145c, the sacrificial layers 145a, 145b, and 145c are removed, and the insulating layer 133a on the sacrificial layer 145a, the insulating layer 133a on the sacrificial layer 145b, and the insulating layer 133a on the sacrificial layer 145c can also be removed (hereinafter also referred to as lift-off).

[0264] Furthermore, when removing sacrificial layers 145a, 145b, and 145c, a portion of the insulating layer 133 may be removed. For example, when removing sacrificial layers 145a, 145b, and 145c, the height of the end face of the insulating layer 133 may be reduced.

[0265] After removing sacrificial layers 145a, 145b, and 145c, it is preferable to perform a drying treatment to remove water contained inside EL layers 112R, 112G, and 112B, as well as water adsorbed on the surface. For example, it is preferable to perform a heat treatment under an inert gas atmosphere or a reduced pressure atmosphere. The heat treatment can be performed at a substrate temperature of 50°C to 200°C, preferably 60°C to 150°C, and more preferably 70°C to 120°C. A reduced pressure atmosphere is preferable because it allows drying at a lower temperature.

[0266] [Formation of layer 116] Next, layer 116 is formed by covering the insulating layer 133, EL layer 112R, EL layer 112G, and EL layer 112B (Figure 17D). Layer 116 can be formed by, for example, vapor deposition, sputtering, or inkjet. However, it is not limited to these methods, and the above-described film formation methods can be used as appropriate.

[0267] As shown in Figure 3A, when layer 116 has a stacked structure, each of the layers constituting layer 116 is formed. For example, when layer 116a is an electron transport layer and layer 116b is an electron injection layer, an electron transport layer and an electron injection layer on the electron transport layer are formed.

[0268] [Formation of common electrode 113] Next, a common electrode 113 is formed by covering layer 116. The common electrode 113 can be formed by, for example, sputtering or vapor deposition (Figure 17D).

[0269] By following the above steps, light-emitting devices 110R, 110G, and 110B can be manufactured.

[0270] [Formation of protective layer 121] Next, a protective layer 121 is formed on the common electrode 113 (Figure 10A). For forming the inorganic insulating film used in the protective layer 121, sputtering, PECVD, or ALD is preferred. The ALD method is particularly preferred because it offers excellent step coverage and is less prone to defects such as pinholes. Furthermore, for forming the organic insulating film, the inkjet method is preferred because it can form a uniform film in the desired area.

[0271] Based on the above, the display device 100E exemplified in Configuration Example 8 can be manufactured.

[0272] By using the above manufacturing method, it is possible to selectively produce EL layer 112R, EL layer 112G, and EL layer 112B. Furthermore, process damage to EL layer 112R, EL layer 112G, and EL layer 112B can be reduced, thereby enabling the realization of an extremely reliable display device.

[0273] Although a manufacturing method in which EL layers 112R, 112G, and 112B are formed in that order has been shown, the present invention is not limited to this. The formation order of EL layers 112R, 112G, and 112B can be arbitrarily determined. For example, the EL layers that are less susceptible to process damage may be formed first, and the EL layers that are more susceptible to process damage may be formed later. By adopting a formation order that takes process damage into consideration, the reliability of the display device can be further improved.

[0274] <Example of manufacturing method 2> The following describes a manufacturing method example that differs in some respects from the aforementioned manufacturing method example 1. Note that the parts that overlap with manufacturing method example 1 will be omitted from the explanation, and only the differences will be described.

[0275] Similar to Fabrication Method Example 1, the insulating layer 131, sacrificial layer 145a, sacrificial layer 145b, and insulating film 133f on the sacrificial layer 145c are formed (Figure 17A). Since the formation of insulating film 133f can be described in Fabrication Method Example 1, a detailed explanation is omitted.

[0276] [Formation of Insulating Layer 133] Subsequently, a part of the insulating film 133f is removed using anisotropic etching to expose the sacrificial layer 145a, the sacrificial layer 145b, and the sacrificial layer 145c. As a result, an insulating layer 133 covering the side surfaces of the EL layer 112R, the EL layer 112G, and the EL layer 112B is formed (FIG. 18). For anisotropic etching, for example, a dry etching method can be preferably used.

[0277] [Removal of Sacrificial Layer] Subsequently, the sacrificial layer 145a, the sacrificial layer 145b, and the sacrificial layer 145c are removed to expose the upper surfaces of the EL layer 112R, the EL layer 112G, and the EL layer 112B (FIG. 17C). Regarding the removal of the sacrificial layer 145a, the sacrificial layer 145b, and the sacrificial layer 145c, since the description in Preparation Method Example 1 can be referred to, detailed description is omitted.

[0278] After removing the sacrificial layer 145a, the sacrificial layer 145b, and the sacrificial layer 145c, it is preferable to perform a drying process to remove the water contained inside the EL layer 112R, the EL layer 112G, and the EL layer 112B and the water adsorbed on the surface. Regarding the drying process, since the description in Preparation Method Example 1 can be referred to, detailed description is omitted.

[0279] [Formation of Layer 116] Subsequently, the layer 116 is formed (FIG. 17D). After the formation of the layer 116, since the description in the aforementioned Preparation Method Example 1 can be referred to, detailed description is omitted.

[0280] Through the above steps, the display device 100E can be manufactured.

[0281] The above is the description of the example of the manufacturing method of the display device.

[0282] <Configuration Example 9> Hereinafter, an example in the case of using a light-emitting device that exhibits white light emission will be described.

[0283] Figures 19A and 19B show schematic cross-sectional views of a display device 150 according to one embodiment of the present invention. A schematic top view of the display device 150 can be found in Figure 1A. Figure 19A is a schematic cross-sectional view corresponding to the dashed line A1-A2 in Figure 1A. Figure 19B is a schematic cross-sectional view corresponding to the dashed line B1-B2 in Figure 1A.

[0284] The display device 150 includes light-emitting units 120R, 120G, and 120B. Each of the light-emitting units 120R, 120G, and 120B has a light-emitting device 110W. The light-emitting device 110W has a pixel electrode 111, an EL layer 112W, and a common electrode 113. The EL layer 112W and the common electrode 113 are provided in common across multiple pixels. The EL layer 112W has a light-emitting layer that emits white light. The light-emitting device 110W is a light-emitting device that emits white light.

[0285] Each light-emitting unit 120R, light-emitting unit 120G, and light-emitting unit 120B has a colored layer 122R, colored layer 122G, or colored layer 122B on the protective layer 121, respectively. For example, colored layer 122R transmits red light, colored layer 122G transmits green light, and colored layer 122B transmits blue light. This enables the realization of a full-color display device. Furthermore, by forming each colored layer on the protective layer 121, the alignment of each light-emitting device and each colored layer becomes easier compared to the case where the colored layer is formed on a substrate different from the substrate 101 and then the two substrates are bonded together, enabling the realization of an extremely high-definition display device.

[0286] Here, the EL layer 112W is separated between different light-emitting units. This effectively prevents current from flowing through the EL layer 112W between adjacent light-emitting units, which would otherwise result in unintended light emission (also known as crosstalk). As a result, contrast can be enhanced, and a display device with high display quality can be realized.

[0287] As shown in Figure 19C, the EL layer 112W may not be separated between light-emitting units of the same color.

[0288] <Example of manufacturing method 3> The following describes an example of a method for manufacturing the display device 150 illustrated in the above configuration example 9. Note that some parts that overlap with the previously described manufacturing method 1 may be omitted from the explanation.

[0289] First, as shown in Figure 20A, a plurality of pixel electrodes 111 and an insulating layer 131 are formed on the substrate 101. Furthermore, an EL film 112Wf, a sacrificial film 144, and a protective film 146 are formed over them. In addition, a resist mask 143 is formed on the protective film 146 at a position overlapping with the pixel electrodes 111.

[0290] Next, a portion of the protective film 146 that is not covered by the resist mask 143 is removed by etching to form island-shaped or strip-shaped protective layers 147 (Figure 20B).

[0291] Next, remove the resist mask 143 (Figure 20C).

[0292] Next, using the protective layer 147 as a mask, the sacrificial film 144 that is not covered by the protective layer 147 is removed by etching to form the sacrificial layer 145 (Figure 20D).

[0293] Next, using the protective layer 147 as a mask, the EL film 112Wf not covered by the protective layer 147 is removed by etching, separating the EL film 112Wf. This forms multiple strip-shaped EL layers 112W (Figure 21A).

[0294] Next, the protective layer 147 is removed by etching.

[0295] Next, an insulating film 133f is formed on the insulating layer 131 and the sacrificial layer 145 (Figure 21B).

[0296] Next, a portion of the insulating film 133f is removed using anisotropic etching, exposing the sacrificial layer 145. This forms an insulating layer 133 that covers the side surface of the EL layer 112W (Figure 21C). For anisotropic etching, for example, a dry etching method can be suitably used.

[0297] Next, the sacrificial layer 145 on the EL layer 112 is removed, exposing the upper surface of the EL layer 112W (Figure 21D).

[0298] Next, by covering the EL layer 112W and the insulating layer 131 to form layer 116 and the common electrode 113, multiple light-emitting devices 110W can be fabricated.

[0299] Next, a protective layer 121 is formed to cover the common electrode 113 (Figure 21E).

[0300] Next, a colored layer 122R, a colored layer 122G, and a colored layer 122B are formed on the protective layer 121, respectively. The formation of the colored layers 122R, 122G, and 122B can be carried out using photolithography with a photosensitive resin.

[0301] Based on the above, the display device 150 exemplified in Configuration Example 9 can be manufactured.

[0302] <Example of manufacturing method 4> The following describes a manufacturing method example that differs in part from the aforementioned manufacturing method example 3. Note that the parts that overlap with manufacturing method example 3 will be omitted from the explanation, and only the differences will be described.

[0303] Similar to Fabrication Method Example 3, the insulating layer 131 and the insulating film 133f on the sacrificial layer 145 are formed (Figure 21B). Since the formation of the insulating film 133f can be described in Fabrication Method Example 3, a detailed explanation is omitted.

[0304] Next, a portion of the insulating film 133f is removed using anisotropic etching, exposing the sacrificial layer 145. This forms an insulating layer 133 that covers the side surface of the EL layer 112W (Figure 22). For anisotropic etching, for example, a dry etching method can be suitably used.

[0305] Next, the sacrificial layer 145 on the EL layer 112 is removed, exposing the upper surface of the EL layer 112W (Figure 21D). Since the process from the removal of the sacrificial layer 145 onward can be described in the aforementioned example of the manufacturing method 3, a detailed explanation is omitted.

[0306] The display device 150 can be manufactured through the above process.

[0307] This embodiment can be implemented in appropriate combination with other embodiments described herein, at least in part.

[0308] (Embodiment 2) This embodiment describes an example of the configuration of a display device according to one aspect of the present invention.

[0309] The display device of this embodiment can be a high-resolution display device or a large-screen display device. Therefore, the display device of this embodiment can be used in electronic devices with relatively large screens, such as television sets, desktop or notebook personal computers, computer monitors, digital signage, and large game machines such as pachinko machines, as well as in the display units of digital cameras, digital video cameras, digital photo frames, mobile phones, portable game consoles, smartphones, smartwatches, tablet devices, personal digital assistants, and audio playback devices.

[0310] <Display device 400A> Figure 23 shows a perspective view of the display device 400A, and Figure 24A shows a cross-sectional view of the display device 400A.

[0311] The display device 400A has a configuration in which substrate 452 and substrate 451 are bonded together. In Figure 23, substrate 452 is clearly indicated by a dashed line.

[0312] The display device 400A includes a display unit 462, a circuit 464, wiring 465, etc. Figure 23 shows an example in which IC 473 and FPC 472 are mounted on the display device 400A. Therefore, the configuration shown in Figure 23 can also be described as a display module having the display device 400A, an IC (integrated circuit), and an FPC.

[0313] Circuit 464 can, for example, be a scan line drive circuit.

[0314] Wiring 465 has the function of supplying signals and power to the display unit 462 and the circuit 464. These signals and power are input to wiring 465 from an external source via FPC 472 or from IC 473.

[0315] Figure 23 shows an example in which IC 473 is mounted on the substrate 451 using a COG (Chip On Glass) method or COF (Chip On Film) method. IC 473 can be an IC having, for example, a scan line drive circuit or a signal line drive circuit. Note that the display device 400A and the display module may be configured without an IC. Alternatively, the IC may be mounted on an FPC using a COF method or the like.

[0316] Figure 24A shows an example of a cross-section obtained by cutting a portion of the display device 400A, including the FPC 472, a portion of the circuit 464, a portion of the display unit 462, and a portion of the area including the end.

[0317] The display device 400A shown in Figure 24A has a transistor 201, a transistor 205, a light-emitting device 430a that emits red light, a light-emitting device 430b that emits green light, and a light-emitting device 430c that emits blue light, etc., between substrates 451 and 452.

[0318] The light-emitting devices 430a, 430b, and 430c can be the light-emitting devices exemplified in Embodiment 1.

[0319] Here, if the pixels of the display device have three types of subpixels, each having a light-emitting device that emits a different color from the others, examples of these three subpixels include subpixels of three colors: R, G, and B; and subpixels of three colors: yellow (Y), cyan (C), and magenta (M). If there are four such subpixels, examples of these four subpixels include subpixels of four colors: R, G, B, and white (W); and subpixels of four colors: R, G, B, and Y.

[0320] The protective layer 416 and the substrate 452 are bonded together via an adhesive layer 442. For sealing the light-emitting device, a solid sealing structure or a hollow sealing structure can be applied. In Figure 24A, the space 443 surrounded by the substrate 452, the adhesive layer 442, and the substrate 451 is filled with an inert gas (such as nitrogen or argon), demonstrating the application of a hollow sealing structure. The adhesive layer 442 may be provided overlapping the light-emitting device. Alternatively, the space 443 surrounded by the substrate 452, the adhesive layer 442, and the substrate 451 may be filled with a resin different from that of the adhesive layer 442.

[0321] The light-emitting devices 430a, 430b, and 430c have an optical adjustment layer between the pixel electrode and the EL layer. Light-emitting device 430a has an optical adjustment layer 426a, light-emitting device 430b has an optical adjustment layer 426b, and light-emitting device 430c has an optical adjustment layer 426c. Details of the light-emitting devices can be found in Embodiment 1.

[0322] Each of the pixel electrodes 411a, 411b, and 411c is connected to the conductive layer 222b of the transistor 205 through an opening provided in the insulating layer 214.

[0323] The edges of the pixel electrodes and the optical adjustment layer are covered by an insulating layer 421. The pixel electrodes contain a material that reflects visible light, and the counter electrodes contain a material that transmits visible light.

[0324] The light emitted by the light-emitting device is projected onto the substrate 452. It is preferable to use a material with high transparency to visible light for the substrate 452.

[0325] Both transistors 201 and 205 are formed on the substrate 451. These transistors can be manufactured using the same materials and the same process.

[0326] On the substrate 451, insulating layers 211, 213, 215, and 214 are provided in this order. A portion of insulating layer 211 functions as a gate insulating layer for each transistor. A portion of insulating layer 213 functions as a gate insulating layer for each transistor. Insulating layer 215 is provided covering the transistors. Insulating layer 214 is provided covering the transistors and functions as a planarization layer. The number of gate insulating layers and insulating layers covering the transistors are not limited and may be a single layer or two or more layers, respectively.

[0327] It is preferable to use a material that does not easily allow impurities such as water and hydrogen to diffuse into at least one layer of the insulating layer covering the transistor. This allows the insulating layer to function as a barrier layer. With such a configuration, the diffusion of impurities from the outside into the transistor can be effectively suppressed, thereby improving the reliability of the display device.

[0328] Insulating layers 211, 213, and 215 are preferably made of inorganic insulating films. Examples of inorganic insulating films include silicon nitride, silicon oxide nitride, silicon oxide, silicon nitride, aluminum oxide, and aluminum nitride. Alternatively, hafnium oxide, yttrium oxide, zirconium oxide, gallium oxide, tantalum oxide, magnesium oxide, lanthanum oxide, cerium oxide, and neodymium oxide may be used. Furthermore, two or more of the above-mentioned insulating films may be laminated together.

[0329] Here, organic insulating films often have lower barrier properties than inorganic insulating films. Therefore, it is preferable that the organic insulating film has an opening near the edge of the display device 400A. This prevents impurities from entering through the organic insulating film from the edge of the display device 400A. Alternatively, the organic insulating film may be formed so that its edge is inward from the edge of the display device 400A, so that the organic insulating film is not exposed at the edge of the display device 400A.

[0330] An organic insulating film is preferred for the insulating layer 214, which functions as a planarizing layer. Examples of materials that can be used as the organic insulating film include acrylic resins, polyimide resins, epoxy resins, polyamide resins, polyimidoamide resins, siloxane resins, benzocyclobutene resins, phenolic resins, and precursors of these resins.

[0331] In the region 228 shown in Figure 24A, an opening is formed in the insulating layer 214. This prevents impurities from entering the display unit 462 from the outside through the insulating layer 214, even when an organic insulating film is used for the insulating layer 214. Therefore, the reliability of the display device 400A can be improved.

[0332] Transistors 201 and 205 have a conductive layer 221 that functions as a gate, an insulating layer 211 that functions as a gate insulating layer, conductive layers 222a and 222b that function as source and drain, 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. 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.

[0333] The transistor structure of the display device of this embodiment is not particularly limited. For example, planar transistors, staggered transistors, inverse staggered transistors, etc., can be used. Furthermore, either a top-gate or bottom-gate transistor structure may be used. Alternatively, gates may be provided above and below the semiconductor layer in which the channel is formed.

[0334] Transistors 201 and 205 are configured in which a semiconductor layer on which a channel is formed is sandwiched between two gates. The transistors may be driven by connecting the two gates and supplying them with the same signal. Alternatively, the threshold voltage of the transistors may be controlled by applying a potential to control the threshold voltage to one of the two gates and a potential to drive the other gate.

[0335] The crystallinity of the semiconductor material used in the transistor is not particularly limited; amorphous semiconductors, crystalline semiconductors (microcrystalline semiconductors, polycrystalline semiconductors, single-crystal semiconductors, or semiconductors with crystalline regions in part) may be used. Using a crystalline semiconductor is preferable because it can suppress the degradation of transistor characteristics.

[0336] The semiconductor layer of the transistor preferably has a metal oxide (also called an oxide semiconductor). In other words, the display device of this embodiment preferably uses a transistor (hereinafter referred to as an OS transistor) that uses a metal oxide in the channel formation region. Alternatively, the semiconductor layer of the transistor may have silicon. Examples of silicon include amorphous silicon and crystalline silicon (low-temperature polysilicon, single-crystal silicon, etc.).

[0337] The semiconductor layer preferably comprises, for example, indium, element M (where M is one or more selected from gallium, aluminum, silicon, boron, yttrium, tin, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, and magnesium), and zinc. In particular, it is preferable that M is one or more selected from aluminum, gallium, yttrium, and tin.

[0338] In particular, it is preferable to use an oxide (also written as IGZO) containing indium (In), gallium (Ga), and zinc (Zn) as the semiconductor layer.

[0339] When the semiconductor layer is an In-M-Zn oxide, it is preferable that the atomic ratio of In in the In-M-Zn oxide is equal to or greater than the atomic ratio of M. Examples of such In-M-Zn oxide atomic ratios of metal elements include compositions where In:M:Zn=1:1:1 or close to it, In:M:Zn=1:1:1.2 or close to it, In:M:Zn=2:1:3 or close to it, In:M:Zn=3:1:2 or close to it, In:M:Zn=4:2:3 or close to it, In:M:Zn=4:2:4.1 or close to it, In:M:Zn=5:1:3 or close to it, In:M:Zn=5:1:6 or close to it, In:M:Zn=5:1:7 or close to it, In:M:Zn=5:1:8 or close to it, In:M:Zn=6:1:6 or close to it, In:M:Zn=5:2:5 or close to it, and so on. Note that "close to it" compositions include a range of ±30% of the desired atomic ratio.

[0340] For example, when describing a composition with an atomic ratio of In:Ga:Zn = 4:2:3 or a similar ratio, it includes cases where, when the atomic ratio of In is 4, the atomic ratio of Ga is between 1 and 3, and the atomic ratio of Zn is between 2 and 4. Also, when describing a composition with an atomic ratio of In:Ga:Zn = 5:1:6 or a similar ratio, it includes cases where, when the atomic ratio of In is 5, the atomic ratio of Ga is greater than 0.1 and 2 or less, and the atomic ratio of Zn is between 5 and 7. Furthermore, when describing a composition with an atomic ratio of In:Ga:Zn = 1:1:1 or a similar ratio, it includes cases where, when the atomic ratio of In is 1, the atomic ratio of Ga is greater than 0.1 and 2 or less, and the atomic ratio of Zn is greater than 0.1 and 2 or less.

[0341] The transistors in circuit 464 and the transistors in display unit 462 may have the same structure or different structures. The structures of the multiple transistors in circuit 464 may all be the same or there may be two or more different structures. Similarly, the structures of the multiple transistors in display unit 462 may all be the same or there may be two or more different structures.

[0342] A connection portion 204 is provided in the region of substrate 451 where substrate 452 does not overlap. At the connection portion 204, wiring 465 is electrically connected to FPC 472 via conductive layer 466 and connection layer 242. The conductive layer 466 is shown as an example of a laminated structure consisting of a conductive film obtained by processing the same conductive film as the pixel electrode and a conductive film obtained by processing the same conductive film as the optical adjustment layer. The conductive layer 466 is exposed on the upper surface of the connection portion 204. This allows the connection portion 204 and FPC 472 to be electrically connected via the connection layer 242.

[0343] It is preferable to provide a light-shielding layer 417 on the surface of the substrate 452 that faces the substrate 451. Various optical components can also be placed on the outside of the substrate 452. Examples of optical components include polarizing plates, phase difference plates, light diffusion layers (such as diffusion films), anti-reflective layers, and light-collecting films. Furthermore, an antistatic film to suppress the adhesion of dust, a water-repellent film to make it difficult for dirt to adhere, a hard coat film to suppress the occurrence of scratches during use, and an impact-absorbing layer may also be placed on the outside of the substrate 452.

[0344] By providing a protective layer 416 that covers the light-emitting device, it is possible to suppress the ingress of impurities such as water into the light-emitting device and improve the reliability of the light-emitting device.

[0345] In the region 228 near the edge of the display device 400A, it is preferable that the insulating layer 215 and the protective layer 416 are in contact with each other through an opening in the insulating layer 214. In particular, it is preferable that the inorganic insulating film of the insulating layer 215 and the inorganic insulating film of the protective layer 416 are in contact with each other. This makes it possible to suppress the entry of impurities into the display unit 462 from the outside through the organic insulating film. Therefore, the reliability of the display device 400A can be improved.

[0346] Figure 24B shows an example where the protective layer 416 has a three-layer structure. In Figure 24B, the protective layer 416 has an inorganic insulating layer 416a on the light-emitting device 430c, an organic insulating layer 416b on the inorganic insulating layer 416a, and an inorganic insulating layer 416c on the organic insulating layer 416b.

[0347] The edges of the inorganic insulating layer 416a and the inorganic insulating layer 416c extend outward beyond the edge of the organic insulating layer 416b and are in contact with each other. Furthermore, the inorganic insulating layer 416a is in contact with the insulating layer 215 (inorganic insulating layer) through an opening in the insulating layer 214 (organic insulating layer). As a result, the light-emitting device can be surrounded by the insulating layer 215 and the protective layer 416, thereby improving the reliability of the light-emitting device.

[0348] Thus, the protective layer 416 may have a laminated structure of an organic insulating film and an inorganic insulating film. In this case, it is preferable that the edge of the inorganic insulating film extends outward more than the edge of the organic insulating film.

[0349] Substrates 451 and 452 can be made of glass, quartz, ceramic, sapphire, resin, metal, alloy, semiconductor, etc., respectively. The substrate on the side that extracts light from the light-emitting device should be made of a material that transmits the light. Using flexible materials for substrates 451 and 452 can increase the flexibility of the display device. Alternatively, a polarizing plate may be used as substrate 451 or substrate 452.

[0350] Substrates 451 and 452 can be made from polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyacrylonitrile resin, acrylic resin, polyimide resin, polymethyl methacrylate resin, polycarbonate (PC) resin, polyethersulfone (PES) resin, polyamide resin (nylon, aramid, etc.), polysiloxane resin, cycloolefin resin, polystyrene resin, polyamide-imide resin, polyurethane resin, polyvinyl chloride resin, polyvinylidene chloride resin, polypropylene resin, polytetrafluoroethylene (PTFE) resin, ABS resin, cellulose nanofiber, etc. One or both of substrates 451 and 452 may be made of glass of a thickness sufficient to provide flexibility.

[0351] Furthermore, when a circular polarizing plate is superimposed on a display device, it is preferable to use a substrate with high optical isotropy for the substrate of the display device. A substrate with high optical isotropy has low birefringence (or a small amount of birefringence).

[0352] For substrates with high optical isotropy, the absolute value of the retardation (phase difference) is preferably 30 nm or less, more preferably 20 nm or less, and even more preferably 10 nm or less.

[0353] Examples of films with high optical isotropy include triacetylcellulose (TAC, also known as cellulose triacetate) film, cycloolefin polymer (COP) film, cycloolefin copolymer (COC) film, and acrylic film.

[0354] When using a film as a substrate, the film may absorb water, potentially causing wrinkles or other shape changes in the display panel. 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 preferable to use a film with a water absorption rate of 0.1% or less, and even more preferable to use a film with a water absorption rate of 0.01% or less.

[0355] The adhesive layer can be made from various types of curing adhesives, including UV-curing adhesives, reaction-curing adhesives, thermosetting adhesives, and anaerobic adhesives. Examples of these adhesives include epoxy resins, acrylic resins, silicone resins, phenolic resins, polyimide resins, imide resins, PVC (polyvinyl chloride) resins, PVB (polyvinyl butyral) resins, and EVA (ethylene vinyl acetate) resins. Materials with low moisture permeability, such as epoxy resins, are particularly preferred. Two-component mixed resins may also be used. Adhesive sheets may also be used.

[0356] The connecting layer 242 can be made of an anisotropic conductive film (ACF), an anisotropic conductive paste (ACP), or the like.

[0357] Materials that can be used for conductive layers such as the gate, source, and drain of transistors, as well as various wirings and electrodes that constitute display devices, include metals such as aluminum, titanium, chromium, nickel, copper, yttrium, zirconium, molybdenum, silver, tantalum, and tungsten, as well as alloys mainly composed of these metals. Films containing these materials can be used as single layers or in a multilayer structure.

[0358] As a translucent conductive material, conductive oxides such as indium oxide, indium tin oxide, indium zinc oxide, zinc oxide, and zinc oxide containing gallium, or graphene can be used. Alternatively, metallic materials such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, and titanium, or alloy materials containing such metallic materials, can be used. Alternatively, nitrides of such metallic materials (e.g., titanium nitride) may be used. When using metallic materials or alloy materials (or their nitrides), it is preferable to make them thin enough to be translucent. Furthermore, a laminated film of the above materials can be used as a conductive layer. For example, using a laminated film of a silver-magnesium alloy and indium tin oxide is preferable because it can enhance conductivity. These can also be used as conductive layers for various wirings and electrodes constituting display devices, and as conductive layers in light-emitting devices (conductive layers that function as pixel electrodes or common electrodes).

[0359] Examples of insulating materials that can be used for each insulating layer include resins such as acrylic resin and epoxy resin, and inorganic insulating materials such as silicon oxide, silicon oxide nitride, silicon nitride, silicon oxide, and aluminum oxide.

[0360] <Display device 400B> Figure 25A shows a cross-sectional view of the display device 400B. The perspective view of the display device 400B is the same as that of the display device 400A (Figure 23). Figure 25A shows examples of cross-sections of the display device 400B when a portion of the area including the FPC 472, a portion of the circuit 464, and a portion of the display unit 462 are cut. In Figure 25A, an example of a cross-section is shown when a portion of the display unit 462, in particular, including the light-emitting device 430b that emits green light and the light-emitting device 430c that emits blue light, is cut. Note that explanations of parts that are the same as those of the display device 400A may be omitted.

[0361] The display device 400B shown in Figure 25A has transistors 202, 210, light-emitting device 430b, and light-emitting device 430c, etc., between substrates 453 and 454.

[0362] The substrate 454 and the protective layer 416 are bonded together via an adhesive layer 442. The adhesive layer 442 is provided in superimposed on the light-emitting devices 430b and 430c, respectively, and a solid encapsulation structure is applied to the display device 400B.

[0363] The substrate 453 and the insulating layer 212 are bonded together by an adhesive layer 455.

[0364] The method for manufacturing the display device 400B involves first bonding a fabrication substrate, on which an insulating layer 212, transistors, light-emitting devices, etc., are provided, to a substrate 454 on which a light-shielding layer 417 is provided, using an adhesive layer 442. Then, the fabrication substrate is peeled off and a substrate 453 is attached to the exposed surface, thereby transferring the components formed on the fabrication substrate to the substrate 453. It is preferable that both the substrate 453 and the substrate 454 are flexible. This increases the flexibility of the display device 400B.

[0365] The insulating layer 212 can be made of an inorganic insulating film that can be used for insulating layer 211, insulating layer 213, and insulating layer 215, respectively.

[0366] The pixel electrodes are connected to the conductive layer 222b of the transistor 210 through an opening in the insulating layer 214. The conductive layer 222b is connected to the low-resistance region 231n through openings in the insulating layers 215 and 225. The transistor 210 has the function of controlling the driving of the light-emitting device.

[0367] The edges of the pixel electrodes are covered by an insulating layer 421. Additionally, the sides of the EL layer are covered by an insulating layer 433.

[0368] The light emitted by the light-emitting devices 430b and 430c is emitted towards the substrate 454. It is preferable to use a material with high transmittance to visible light for the substrate 454.

[0369] A connection portion 204 is provided in the region of substrate 453 that does not overlap with substrate 454. At the connection portion 204, wiring 465 is electrically connected to FPC 472 via conductive layer 466 and connection layer 242. The conductive layer 466 can be obtained by processing the same conductive film as the pixel electrode. This allows the connection portion 204 and FPC 472 to be electrically connected via the connection layer 242.

[0370] Transistors 202 and 210 each have a conductive layer 221 that functions as a gate, an insulating layer 211 that functions as a gate insulating layer, a semiconductor layer having a channel forming region 231i and a pair of low-resistance regions 231n, a conductive layer 222a connected to one of the pair of low-resistance regions 231n, a conductive layer 222b connected to the other of the pair of low-resistance regions 231n, an insulating layer 225 that functions as a gate insulating layer, a conductive layer 223 that functions as a gate, and an insulating layer 215 covering the conductive layer 223. The insulating layer 211 is located between the conductive layer 221 and the channel forming region 231i. The insulating layer 225 is located between the conductive layer 223 and the channel forming region 231i.

[0371] The conductive layer 222a and the conductive layer 222b are each connected to the low-resistance region 231n via openings provided in the insulating layer 215. Of the conductive layer 222a and the conductive layer 222b, one functions as a source and the other functions as a drain.

[0372] Figure 25A shows an example in which the insulating layer 225 covers the top and sides of the semiconductor layer. The conductive layer 222a and conductive layer 222b are connected to the low-resistance region 231n through openings provided in the insulating layer 225 and insulating layer 215, respectively.

[0373] On the other hand, in the transistor 209 shown in Figure 25B, the insulating layer 225 overlaps with the channel formation region 231i of the semiconductor layer 231, but does not overlap with the low-resistance region 231n. For example, the structure shown in Figure 25B can be fabricated by processing the insulating layer 225 using the conductive layer 223 as a mask. In Figure 25B, an insulating layer 215 is provided covering the insulating layer 225 and the conductive layer 223, and the conductive layers 222a and 222b are connected to the low-resistance region 231n, respectively, through openings in the insulating layer 215. Furthermore, an insulating layer 218 covering the transistor may also be provided.

[0374] The configuration examples illustrated in this embodiment, and the corresponding drawings, etc., can be appropriately combined with other configuration examples or drawings, etc., at least in part.

[0375] (Embodiment 3) In this embodiment, a different configuration example of a display device will be described.

[0376] The display device of this embodiment can be a high-definition display device. Therefore, the display device of this embodiment can be used in the display section of wearable devices that can be worn on the head, such as information terminals (wearable devices) such as wristwatches and bracelets, as well as VR devices such as head-mounted displays and AR devices such as glasses.

[0377] <Display Module> Figure 26A shows a perspective view of the display module 280. The display module 280 includes a display device 400C and an FPC 290. Note that the display device included in the display module 280 is not limited to the display device 400C, but may be the display device 400D or the display device 400E, which will be described later.

[0378] The display module 280 has substrates 291 and 292. The display module 280 has a display unit 281. The display unit 281 is an area in the display module 280 that displays an image, and is an area in which light from each pixel provided in the pixel unit 284, which will be described later, can be seen.

[0379] Figure 26B shows a schematic perspective view illustrating the configuration of the substrate 291. On the substrate 291, a circuit section 282, a pixel circuit section 283 on the circuit section 282, and a pixel section 284 on the pixel circuit section 283 are stacked. In addition, a terminal section 285 for connecting to the FPC 290 is provided in the portion of the substrate 291 that does not overlap with the pixel section 284. The terminal section 285 and the circuit section 282 are electrically connected by a wiring section 286, which is composed of multiple wires.

[0380] The pixel section 284 has multiple pixels 284a arranged periodically. A magnified view of a single pixel 284a is shown on the right side of Figure 26B. Each pixel 284a has light-emitting devices 430a, 430b, and 430c, each with a different emission color. The multiple light-emitting devices may be arranged in a stripe pattern as shown in Figure 26B. Various arrangement methods, such as delta and pentile arrangements, can also be applied.

[0381] The pixel circuit section 283 has a plurality of pixel circuits 283a arranged periodically.

[0382] A single pixel circuit 283a is a circuit that controls the light emission of three light-emitting devices in a single pixel 284a. A single pixel circuit 283a may be configured to have three circuits that control the light emission of one light-emitting device. For example, a pixel circuit 283a can be configured to have at least one selection transistor, one current control transistor (drive transistor), and a capacitive element 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 either the source or the drain. This realizes an active-matrix type display device.

[0383] The circuit section 282 has circuits for driving each pixel circuit 283a of the pixel circuit section 283. For example, it is preferable to have one or both of a gate line drive circuit and a source line drive circuit. In addition, it may have at least one of the following: an arithmetic circuit, a memory circuit, and a power supply circuit.

[0384] The FPC290 functions as wiring for supplying video signals or power potential, etc., to the circuit section 282 from an external source. An IC may also be mounted on the FPC290.

[0385] The display module 280 can be configured such that one or both of the pixel circuit section 283 and the circuit section 282 are stacked on the lower side of the pixel section 284, thereby enabling an extremely high aperture ratio (effective display area ratio) of the display section 281. For example, the aperture ratio of the display section 281 can be 40% or more and less than 100%, preferably 50% or more and 95%, and more preferably 60% or more and 95%. Furthermore, it is possible to arrange the pixels 284a at an extremely high density, enabling an extremely high resolution of the display section 281. For example, it is preferable that the pixels 284a in the display section 281 are arranged with a resolution of 20000 ppi or more, preferably 3000 ppi or more, more preferably 5000 ppi or more, and even more preferably 6000 ppi or more, and with a resolution of 20000 ppi or less, or 30000 ppi or less.

[0386] Because such a display module 280 is extremely high-resolution, it can be suitably used in VR devices such as head-mounted displays, or in glasses-type AR devices. For example, even in a configuration where the display part of the display module 280 is viewed through lenses, the display module 280 has an extremely high-resolution display part 281, so even when the display part is magnified with lenses, pixels are not visible, allowing for a highly immersive display. Furthermore, the display module 280 is not limited to this, and can be suitably used in electronic devices with relatively small display parts. For example, it can be suitably used in the display part of wearable electronic devices such as wristwatches.

[0387] <Display device 400C> The display device 400C shown in Figure 27 comprises a substrate 301, light-emitting devices 430a, 430b, and 430c, a capacitor 240, and a transistor 310.

[0388] Substrate 301 corresponds to substrate 291 in Figures 26A and 26B. The laminated structure 401 from substrate 301 to insulating layer 255 corresponds to the substrate in Embodiment 1.

[0389] The transistor 310 is a transistor having a channel-forming region in the substrate 301. The substrate 301 can be a semiconductor substrate such as a single-crystal silicon substrate. The transistor 310 has a portion of the substrate 301, a conductive layer 311, a low-resistance region 312, an insulating layer 313, and an insulating layer 314. The conductive layer 311 functions as a gate electrode. The insulating layer 313 is located between the substrate 301 and the conductive layer 311 and functions as a gate insulating layer. The low-resistance region 312 is a region of the substrate 301 doped with impurities and functions as either a source or a drain. The insulating layer 314 is provided covering the side surface of the conductive layer 311 and functions as an insulating layer.

[0390] An element isolation layer 315 is provided between two adjacent transistors 310 so as to be embedded in the substrate 301.

[0391] An insulating layer 261 is provided covering the transistor 310, and a capacitance 240 is provided on the insulating layer 261.

[0392] Capacitor 240 has a conductive layer 241, a conductive layer 245, and an insulating layer 243 located between them. 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 the dielectric of the capacitor 240.

[0393] The conductive layer 241 is provided on the insulating layer 261 and embedded in the insulating layer 254. The conductive layer 241 is electrically connected to either the source or drain of the transistor 310 by a plug 271 embedded in the insulating layer 261. The insulating layer 243 is provided covering the conductive layer 241. The conductive layer 245 is provided in the region that overlaps with the conductive layer 241 via the insulating layer 243.

[0394] An insulating layer 255 is provided covering the capacitance 240, and light-emitting devices 430a, 430b, 430c, etc. are provided on the insulating layer 255. A protective layer 416 is provided on the light-emitting devices 430a, 430b, 430c, and a substrate 420 is bonded to the upper surface of the protective layer 416 by a resin layer 419. Substrate 420 corresponds to substrate 292 in Figure 26A.

[0395] The pixel electrodes of the light-emitting device are electrically connected to either the source or drain of the transistor 310 by plugs 256 embedded in the insulating layer 255, a conductive layer 241 embedded in the insulating layer 254, and plugs 271 embedded in the insulating layer 261.

[0396] <Display device 400D> The display device 400D shown in Figure 28 differs from the display device 400C mainly in its transistor configuration. Note that explanations of parts similar to those of the display device 400C may be omitted.

[0397] Transistor 320 is a transistor in which a metal oxide (also called an oxide semiconductor) is applied to the semiconductor layer where the channel is formed.

[0398] The transistor 320 has a semiconductor layer 321, an insulating layer 323, a conductive layer 324, a pair of conductive layers 325, an insulating layer 326, and a conductive layer 327.

[0399] Substrate 331 corresponds to substrate 291 in Figures 26A and 26B. The laminated structure 401 from substrate 331 to insulating layer 255 corresponds to the layer containing the transistor in Embodiment 1. Substrate 331 can be an insulating substrate or a semiconductor substrate.

[0400] An insulating layer 332 is provided on the substrate 331. The insulating layer 332 functions as a barrier layer that prevents impurities such as water or hydrogen from diffusing from the substrate 331 to the transistor 320, and prevents oxygen from detaching from the semiconductor layer 321 to the insulating layer 332. The insulating layer 332 can be made of a film that is less permeable to hydrogen or oxygen than a silicon oxide film, such as an aluminum oxide film, a hafnium oxide film, or a silicon nitride film.

[0401] A conductive layer 327 is provided on an insulating layer 332, and an insulating layer 326 is provided covering the conductive layer 327. The conductive layer 327 functions as the first gate electrode of the transistor 320, and a portion of the insulating layer 326 functions as the first gate insulating layer. It is preferable to use an oxide insulating film, such as a silicon oxide film, for at least the portion of the insulating layer 326 that is in contact with the semiconductor layer 321. It is preferable that the upper surface of the insulating layer 326 is flattened.

[0402] The semiconductor layer 321 is provided on the insulating layer 326. Preferably, the semiconductor layer 321 has a metal oxide (also called an oxide semiconductor) film having semiconductor properties. Details of materials suitable for use in the semiconductor layer 321 will be described later.

[0403] A pair of conductive layers 325 are provided in contact with the semiconductor layer 321 and function as source and drain electrodes.

[0404] An insulating layer 328 is provided covering the top and side surfaces of a pair of conductive layers 325, as well as the side surfaces of the semiconductor layer 321, and an insulating layer 264 is provided on the insulating layer 328. The insulating layer 328 functions as a barrier layer to prevent impurities such as water or hydrogen from diffusing into the semiconductor layer 321 from the insulating layer 264, etc., and to prevent oxygen from detaching from the semiconductor layer 321. The insulating layer 328 can be made of the same insulating film as the insulating layer 332.

[0405] An opening is provided in the insulating layer 328 and the insulating layer 264 that reaches the semiconductor layer 321. Inside this opening, the insulating layer 323 and the conductive layer 324 are embedded, in contact with the sides of the insulating layer 264, the insulating layer 328, and the conductive layer 325, as well as the upper surface of the semiconductor layer 321. The conductive layer 324 functions as a second gate electrode, and the insulating layer 323 functions as a second gate insulating layer.

[0406] The upper surfaces of the conductive layer 324, the insulating layer 323, and the insulating layer 264 are flattened so that their heights are roughly the same, and the insulating layer 329 and insulating layer 265 are provided covering them.

[0407] Insulating layers 264 and 265 function as interlayer insulating layers. Insulating layer 329 functions as a barrier layer to prevent impurities such as water or hydrogen from diffusing from insulating layer 265 to transistor 320. Insulating layer 329 can be an insulating film similar to that used for insulating layers 328 and 332.

[0408] A plug 274, which is electrically connected to one of the pair of conductive layers 325, is provided so as to be embedded in the insulating layers 265, 329, and 264. Here, it is preferable that the plug 274 has a conductive layer 274a that covers the sides of the openings of the insulating layers 265, 329, 264, and 328, and a part of the upper surface of the conductive layer 325, and a conductive layer 274b that is in contact with the upper surface of the conductive layer 274a. In this case, it is preferable to use a conductive material that does not easily allow hydrogen and oxygen to diffuse as the conductive layer 274a.

[0409] The configuration from the insulating layer 254 to the substrate 420 in the display device 400D is the same as that of the display device 400C.

[0410] <Display device 400E> The display device 400E shown in Figure 29 has a configuration in which a transistor 310 with a channel formed on a substrate 301 and a transistor 320 containing a metal oxide in the semiconductor layer where the channel is formed are stacked. Note that explanations of parts that are the same as those of display devices 400C and 400D may be omitted.

[0411] An insulating layer 261 is provided covering the transistor 310, and a conductive layer 251 is provided on the insulating layer 261. An insulating layer 262 is provided covering the conductive layer 251, and a conductive layer 252 is provided on the insulating layer 262. The conductive layers 251 and 252 each function as wiring. An insulating layer 263 and an insulating layer 332 are provided covering the conductive layer 252, and a transistor 320 is provided on the insulating layer 332. An insulating layer 265 is provided covering the transistor 320, and a capacitor 240 is provided on the insulating layer 265. The capacitor 240 and the transistor 320 are electrically connected by a plug 274.

[0412] Transistor 320 can be used as a transistor constituting a pixel circuit. Transistor 310 can also be used as a transistor constituting a pixel circuit, or as a transistor constituting a drive circuit (gate line drive circuit, source line drive circuit) for driving the pixel circuit. Furthermore, transistors 310 and 320 can be used as transistors constituting various circuits such as arithmetic circuits or memory circuits.

[0413] This configuration allows for the formation of not only pixel circuits but also drive circuits directly beneath the light-emitting device, making it possible to miniaturize the display device compared to cases where the drive circuits are located around the display area.

[0414] The configuration examples illustrated in this embodiment, and the corresponding drawings, etc., can be appropriately combined with other configuration examples or drawings, etc., at least in part.

[0415] (Embodiment 4) This embodiment describes metal oxides (also called oxide semiconductors) that can be used in the OS transistor described in the above embodiment.

[0416] The metal oxide preferably contains at least indium or zinc. It is particularly preferable that it contains indium and zinc. In addition, it is preferable that it contains aluminum, gallium, yttrium, tin, etc. It may also contain one or more selected from boron, silicon, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, magnesium, cobalt, etc.

[0417] Metal oxides can be formed by chemical vapor deposition (CVD) methods such as sputtering, metal-organic chemical vapor deposition (MOCVD), or atomic layer deposition (ALD).

[0418] <Classification of crystal structures> Examples of crystalline structures for oxide semiconductors include amorphous (including completely amorphous), CAAC (c-axis-aligned crystalline), nc (nanocrystalline), CAC (cloud-aligned composite), single crystal, and polycrystal.

[0419] The crystal structure of a film or substrate can be evaluated using X-ray diffraction (XRD) spectroscopy. For example, it can be evaluated using the XRD spectrum obtained by GIXD (Grazing-Incidence XRD) measurement. The GIXD method is also known as the thin-film method or the Seemann-Bohlin method.

[0420] For example, in a quartz glass substrate, the peak shape of the XRD spectrum is nearly symmetrical. On the other hand, in an IGZO film with a crystalline structure, the peak shape of the XRD spectrum is asymmetrical. The asymmetrical shape of the XRD spectrum peak clearly indicates the presence of crystals in the film or substrate. In other words, if the peak shape of the XRD spectrum is not symmetrical, the film or substrate cannot be said to be in an amorphous state.

[0421] The crystalline structure of a film or substrate can be evaluated by the diffraction pattern (also called the nano-beam electron diffraction pattern) observed using nano-beam electron diffraction (NBED). For example, a halo is observed in the diffraction pattern of a quartz glass substrate, confirming that the quartz glass is in an amorphous state. However, in the diffraction pattern of an IGZO film deposited at room temperature, a spot-like pattern is observed instead of a halo. Therefore, it is presumed that an IGZO film deposited at room temperature is in an intermediate state, neither crystalline nor amorphous, and cannot be concluded to be in an amorphous state.

[0422] <<Oxide semiconductor structure>> It should be noted that oxide semiconductors may be classified differently from those described above when considering their structure. For example, oxide semiconductors can be divided into single-crystal oxide semiconductors and other non-single-crystal oxide semiconductors. Examples of non-single-crystal oxide semiconductors include the aforementioned CAAC-OS and nc-OS. Furthermore, non-single-crystal oxide semiconductors include polycrystalline oxide semiconductors, pseudo-amorphous oxide semiconductors (a-like OS), and amorphous oxide semiconductors.

[0423] Here, we will explain the details of the CAAC-OS, nc-OS, and a-like OS mentioned above.

[0424] <caac-os> CAAC-OS is an oxide semiconductor having multiple crystalline regions, the c-axis of which is oriented in a specific direction. This specific direction is the thickness direction of the CAAC-OS film, the normal direction to the surface on which the CAAC-OS film is formed, or the normal direction to the surface of the CAAC-OS film. A crystalline region is a region with periodic atomic arrangement. If we consider the atomic arrangement as a lattice arrangement, then a crystalline region is also a region with a aligned lattice arrangement. Furthermore, CAAC-OS has regions where multiple crystalline regions are connected in the ab-plane direction, and these regions may exhibit distortion. Distortion refers to a point in the connected region where the orientation of the lattice arrangement changes between a region with a aligned lattice arrangement and another region with a aligned lattice arrangement. In short, CAAC-OS is an oxide semiconductor that is c-axis oriented and does not exhibit clear orientation in the ab-plane direction.

[0425] Each of the multiple crystalline regions described above is composed of one or more minute crystals (crystals with a maximum diameter of less than 10 nm). When a crystalline region is composed of a single minute crystal, the maximum diameter of that crystalline region is less than 10 nm. When a crystalline region is composed of many minute crystals, the size of that crystalline region may be around several tens of nanometers.

[0426] In In-M-Zn oxide (where element M is one or more elements selected from aluminum, gallium, yttrium, tin, titanium, etc.), CAAC-OS tends to have a layered crystalline structure (also called a layered structure) consisting of layers containing indium (In) and oxygen (hereinafter referred to as the In layer) and layers containing element M, zinc (Zn), and oxygen (hereinafter referred to as the (M,Zn) layer). Indium and element M are mutually substitutable. Therefore, the (M,Zn) layer may contain indium. The In layer may also contain element M. The In layer may also contain Zn. This layered structure can be observed, for example, as a lattice image in high-resolution TEM (Transmission Electron Microscope) images.

[0427] When structural analysis of a CAAC-OS film is performed using an XRD instrument, for example, out-of-plane XRD measurements using θ / 2θ scanning show a peak indicating c-axis orientation at 2θ = 31° or nearby. Note that the position of the c-axis orientation peak (value of 2θ) may vary depending on the type and composition of the metal elements constituting the CAAC-OS.

[0428] For example, multiple bright spots are observed in the electron diffraction pattern of a CAAC-OS film. These spots are observed at point-symmetric positions with respect to the incident electron beam spot (also called the direct spot) that passed through the sample.

[0429] When the crystal region is observed from the specific direction described above, the lattice arrangement within that crystal region is based on a hexagonal lattice, but the unit cell is not necessarily a regular hexagon and may be non-regular hexagonal. Furthermore, the strain may have lattice arrangements such as pentagons or heptagons. Moreover, in CAAC-OS, clear grain boundaries cannot be observed even near the strain. In other words, it can be seen that the formation of grain boundaries is suppressed by the strain in the lattice arrangement. This is thought to be because CAAC-OS can tolerate strain due to the sparse arrangement of oxygen atoms in the ab-plane direction, or because the bond distance between atoms changes due to the substitution of metal atoms.

[0430] A crystal structure in which clear grain boundaries are observed is called a polycrystal. Grain boundaries act as recombination centers, trapping carriers and potentially causing a decrease in transistor on-current and field-effect mobility. Therefore, CAAC-OS, in which clear grain boundaries are not observed, is one of the crystalline oxides with a suitable crystal structure for the semiconductor layer of a transistor. In addition, a structure containing Zn is preferred for the composition of CAAC-OS. For example, In-Zn oxide and In-Ga-Zn oxide are preferred because they suppress the generation of grain boundaries more than In oxide.

[0431] CAAC-OS is an oxide semiconductor with high crystallinity and no clearly defined grain boundaries. Therefore, CAAC-OS is less susceptible to the decrease in electron mobility caused by grain boundaries. Furthermore, since the crystallinity of oxide semiconductors can decrease due to the inclusion of impurities or the generation of defects, CAAC-OS can be said to be an oxide semiconductor with few impurities and defects (such as oxygen vacancies). Consequently, oxide semiconductors containing CAAC-OS have stable physical properties. Therefore, oxide semiconductors containing CAAC-OS are heat-resistant and highly reliable. In addition, CAAC-OS is stable even at high temperatures (so-called thermal budget) during the manufacturing process. Therefore, using CAAC-OS in OS transistors allows for greater flexibility in the manufacturing process.

[0432] <nc-os> nc-OS exhibits periodicity in atomic arrangement in minute regions (e.g., regions between 1 nm and 10 nm, particularly between 1 nm and 3 nm). In other words, nc-OS contains minute crystals. These minute crystals are also called nanocrystals because their size is, for example, between 1 nm and 10 nm, particularly between 1 nm and 3 nm. Furthermore, nc-OS shows no regularity in crystal orientation between different nanocrystals. Therefore, no orientation is observed throughout the film. Consequently, depending on the analytical method, nc-OS may be indistinguishable from a-like OS or amorphous oxide semiconductors. For example, when structural analysis of an nc-OS film is performed using an XRD instrument, no peaks indicating crystallinity are detected in out-of-plane XRD measurements using θ / 2θ scanning. Also, when electron diffraction (also called limited-field electron diffraction) is performed on an nc-OS film using an electron beam with a probe diameter larger than that of the nanocrystals (e.g., 50 nm or larger), a diffraction pattern resembling a halo pattern is observed. On the other hand, when electron diffraction (also called nanobeam electron diffraction) is performed on an nc-OS film using an electron beam with a probe diameter close to or smaller than the size of the nanocrystal (for example, 1 nm to 30 nm), an electron diffraction pattern may be obtained in which multiple spots are observed within a ring-shaped region centered on a direct spot.

[0433] <a-like OS> a-like OS is an oxide semiconductor having a structure between nc-OS and amorphous oxide semiconductors. a-like OS has porous or low-density regions. That is, a-like OS has lower crystallinity compared to nc-OS and CAAC-OS. Also, a-like OS has a higher hydrogen concentration in the film compared to nc-OS and CAAC-OS.

[0434] <<Oxide Semiconductor Composition>> Next, we will explain the details of CAC-OS mentioned above. Note that CAC-OS refers to the material composition.

[0435] <cac-os> CAC-OS is a material composition in which, for example, the elements constituting the metal oxide are unevenly distributed in sizes of 0.5 nm to 10 nm, preferably 1 nm to 3 nm, or close to that size. In the following, a state in which one or more metal elements are unevenly distributed in a metal oxide, and the regions containing these metal elements are mixed in sizes of 0.5 nm to 10 nm, preferably 1 nm to 3 nm, or close to that size, is also referred to as a mosaic or patchy state.

[0436] Furthermore, CAC-OS is a composite metal oxide having a mosaic-like structure formed by the separation of the material into a first region and a second region, with the first region distributed within the film (hereinafter also referred to as a cloud-like structure). In other words, CAC-OS is a composite metal oxide having a structure in which the first region and the second region are mixed.

[0437] Here, the atomic ratios of In, Ga, and Zn to the metal elements constituting CAC-OS in In-Ga-Zn oxide are as follows: <in> 、 <ga>, and <zn>This is how it is written. For example, in CAC-OS in In-Ga-Zn oxide, the first region is, <in>However, in the composition of the CAC-OS film <in>It is a larger region than the first one. Also, the second region is, <ga>However, in the composition of the CAC-OS film <ga>It is a larger region than . Or, for example, the first region is <in>However, in the second domain <in>Larger than, and, <ga>However, in the second domain <ga>It is a smaller region than the first region. Also, the second region is, <ga>However, in the first domain <ga>Larger than, and, <in>However, in the first domain <in>It is a smaller area.

[0438] Specifically, the first region described above is a region whose main components are indium oxide, indium zinc oxide, etc. The second region described above is a region whose main components are gallium oxide, gallium zinc oxide, etc. In other words, the first region can be rephrased as a region whose main component is In. Similarly, the second region can be rephrased as a region whose main component is Ga.

[0439] Furthermore, a clear boundary may not be observed between the first region and the second region described above.

[0440] In in-Ga-Zn oxides, CAC-OS refers to a material composition containing In, Ga, Zn, and O, in which regions with Ga as the main component and regions with In as the main component are arranged in a mosaic-like fashion, with these regions existing randomly. Therefore, it is presumed that CAC-OS has a structure in which the metal elements are unevenly distributed.

[0441] CAC-OS can be formed by sputtering, for example, under conditions where the substrate is not intentionally heated. When forming CAC-OS by sputtering, one or more gases selected from inert gases (typically argon), oxygen gas, and nitrogen gas may be used as the deposition gas. Furthermore, a lower ratio of the oxygen gas flow rate to the total deposition gas flow rate during deposition is preferable. For example, it is preferable that the oxygen gas flow rate ratio to the total deposition gas flow rate during deposition be 0% or more and less than 30%, preferably 0% or more and 10% or less.

[0442] For example, in the case of CAC-OS in In-Ga-Zn oxide, EDX mapping obtained using energy dispersive X-ray spectroscopy (EDX) confirms that it has a structure in which regions mainly composed of In (first region) and regions mainly composed of Ga (second region) are unevenly distributed and mixed.

[0443] Here, the first region is a region with higher conductivity compared to the second region. In other words, the conductivity of the metal oxide is exhibited when carriers flow through the first region. Therefore, a high field-effect mobility (μ) can be achieved when the first region is distributed in a cloud-like manner within the metal oxide.

[0444] On the other hand, the second region is a region with higher insulating properties compared to the first region. In other words, the distribution of the second region within the metal oxide can suppress leakage current.

[0445] Therefore, when CAC-OS is used in a transistor, the conductivity due to the first region and the insulation due to the second region work complementaryly to give CAC-OS a switching function (on / off function). In other words, CAC-OS has conductive function in part of the material, insulating function in part of the material, and semiconductor function as a whole. By separating the conductive function and the insulating function, both functions can be maximized. Therefore, by using CAC-OS in a transistor, a high on-current (I on ), high field-effect mobility (μ), and good switching operation can be achieved.

[0446] Transistors using CAC-OS are highly reliable. Therefore, CAC-OS is ideal for various semiconductor devices, including display devices.

[0447] Oxide semiconductors can take on diverse structures, each possessing different properties. One embodiment of the present invention may include two or more of the following: amorphous oxide semiconductors, polycrystalline oxide semiconductors, a-like OS, CAC-OS, nc-OS, and CAAC-OS.

[0448] <Transistors containing oxide semiconductors> Next, we will explain the case where the above oxide semiconductor is used in a transistor.

[0449] By using the above oxide semiconductor in a transistor, a transistor with high field-effect mobility can be realized. Also, a highly reliable transistor can be realized.

[0450] For the transistor, it is preferable to use an oxide semiconductor with a low carrier concentration. For example, the carrier concentration of the oxide semiconductor is 1×10 17 cm -3 or less, preferably 1×10 15 cm -3 or less, more preferably 1×10 13 cm -3 or less, still more preferably 1×10 11 cm -3 or less, even more preferably 1×10 10 cm -3 less, and 1×10 -9 cm -3 or more. When reducing the carrier concentration of the oxide semiconductor film, the impurity concentration in the oxide semiconductor film may be reduced and the density of defect levels may be reduced. In this specification and the like, a low impurity concentration and a low density of defect levels are referred to as highly pure intrinsic or substantially highly pure intrinsic. In some cases, an oxide semiconductor with a low carrier concentration is referred to as a highly pure intrinsic or substantially highly pure intrinsic oxide semiconductor.

[0451] Since an oxide semiconductor film that is highly pure intrinsic or substantially highly pure intrinsic has a low density of defect levels, the density of trap levels may also be low.

[0452] The charge trapped in the trap levels of the oxide semiconductor takes a long time to disappear and may behave like a fixed charge. Therefore, the electrical characteristics of a transistor in which a channel formation region is formed in an oxide semiconductor with a high trap level density may become unstable.

[0453] Therefore, reducing the impurity concentration in the oxide semiconductor is effective in stabilizing the electrical characteristics of the transistor. Furthermore, in order to reduce the impurity concentration in the oxide semiconductor, it is preferable to also reduce the impurity concentration in adjacent films. Examples of impurities include hydrogen, nitrogen, alkali metals, alkaline earth metals, iron, nickel, and silicon.

[0454] <Impurities> Here, we will explain the effects of various impurities in oxide semiconductors.

[0455] In oxide semiconductors, the presence of silicon or carbon, which are Group 14 elements, leads to the formation of defect levels in the oxide semiconductor. Therefore, the concentration of silicon or carbon in the oxide semiconductor and the concentration of silicon or carbon near the interface with the oxide semiconductor (concentration obtained by secondary ion mass spectrometry (SIMS)) are compared by 2 × 10⁻⁶. 18 atoms / cm 3 The following is preferably 2 × 10 17 atoms / cm 3 The following applies:

[0456] When alkali metals or alkaline earth metals are present in oxide semiconductors, they can form defect levels and generate carriers. Therefore, transistors using oxide semiconductors containing alkali metals or alkaline earth metals tend to exhibit normally-on characteristics. For this reason, the concentration of alkali metals or alkaline earth metals in the oxide semiconductor obtained by SIMS should be set to 1 × 10⁻⁶. 18 atoms / cm 3 The following is preferably 2 × 10 16 atoms / cm 3 Do the following:

[0457] In oxide semiconductors, the presence of nitrogen generates electrons, which act as carriers, increasing the carrier concentration and making it easier for the semiconductor to become n-type. As a result, transistors using oxide semiconductors containing nitrogen tend to exhibit normally-on characteristics. Alternatively, the presence of nitrogen in oxide semiconductors can lead to the formation of trap levels. This can result in unstable electrical properties of the transistor. Therefore, the nitrogen concentration in oxide semiconductors obtained by SIMS should be set to 5 × 10⁻¹⁰. 19 atoms / cm 3 Less than 5 × 10 18 atoms / cm 3 More preferably 1 × 10 18 atoms / cm 3 More preferably 5 × 10 17 atoms / cm 3 Do the following:

[0458] Hydrogen contained in oxide semiconductors can react with oxygen bonded to metal atoms to form water, potentially creating oxygen vacancies. When hydrogen fills these vacancies, electrons, which act as carriers, can be generated. Furthermore, some of the hydrogen can combine with oxygen bonded to metal atoms to generate electrons. Therefore, transistors using oxide semiconductors containing hydrogen tend to exhibit normally-on characteristics. For this reason, it is preferable to reduce the hydrogen content in oxide semiconductors as much as possible. Specifically, in oxide semiconductors, the hydrogen concentration obtained by SIMS should be 1 × 10⁻⁶. 20 atoms / cm 3 Less than 1 × 10 19 atoms / cm 3 Less than 5x10 18 atoms / cm 3 Less than 1 × 10 18 atoms / cm 3 Make it less than.

[0459] By using an oxide semiconductor with sufficiently reduced impurities in the channel formation region of a transistor, stable electrical characteristics can be imparted.

[0460] This embodiment can be implemented in appropriate combination with other embodiments described herein, at least in part.

[0461] (Embodiment 5) In this embodiment, an electronic device according to one aspect of the present invention will be described with reference to Figures 30 to 33.

[0462] The electronic device of this embodiment has a display device according to one aspect of the present invention. The display device according to one aspect of the present invention is easily made high-definition, high-resolution, and large-scale. Therefore, the display device according to one aspect of the present invention can be used in the display units of various electronic devices.

[0463] A display device according to one aspect of the present invention can be manufactured at a low cost, thereby reducing the manufacturing cost of electronic devices.

[0464] Examples of electronic devices include television sets, desktop or notebook personal computers, computer monitors, digital signage, and large game machines such as pachinko machines, as well as other electronic devices with relatively large screens, digital cameras, digital video cameras, digital photo frames, mobile phones, portable game consoles, personal digital assistants, and audio playback devices.

[0465] In particular, a display device according to one aspect of the present invention can be used suitably in electronic devices having a relatively small display area because it can increase resolution. Examples of such electronic devices include information terminals (wearable devices) such as wristwatches and bracelets, as well as wearable devices that can be worn on the head, such as VR devices such as head-mounted displays and AR devices such as glasses. Wearable devices can also include devices for SR and MR.

[0466] A display device according to one aspect of the present invention preferably has an extremely high resolution such as HD (1280 x 720 pixels), FHD (1920 x 1080 pixels), WQHD (2560 x 1440 pixels), WQXGA (2560 x 1600 pixels), 4K2K (3840 x 2160 pixels), or 8K4K (7680 x 4320 pixels). In particular, a resolution of 4K2K, 8K4K, or higher is preferred. Furthermore, the pixel density (resolution) of the display device according to one aspect of the present invention is preferably 300 ppi or more, more preferably 500 ppi or more, more preferably 1000 ppi or more, more preferably 2000 ppi or more, more preferably 3000 ppi or more, more preferably 5000 ppi or more, and even more preferably 7000 ppi or more. By using display devices with such high resolution or high detail, it becomes possible to enhance the sense of presence and depth in personal electronic devices such as portable or home-use devices.

[0467] The electronic device of this embodiment can be incorporated along the curved surfaces of the interior or exterior walls of a house or building, or the interior or exterior of an automobile.

[0468] The electronic device in this embodiment may have an antenna. By receiving signals with the antenna, the display unit can display images and information. Furthermore, if the electronic device has an antenna and a secondary battery, the antenna may be used for contactless power transmission.

[0469] The electronic device of this embodiment may have sensors (including those with the function of measuring force, displacement, position, velocity, acceleration, angular velocity, rotational speed, distance, light, liquid, magnetism, temperature, chemical substances, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor, or infrared radiation).

[0470] The electronic device of this embodiment can have a variety of functions. For example, it can have a function to display various information (still images, videos, text images, etc.) on the display unit, a touch panel function, a function to display a calendar, date or time, a function to execute various software (programs), a wireless communication function, a function to read programs or data recorded on a recording medium, and so on.

[0471] The electronic device 6500 shown in Figure 30A is a portable information terminal that can be used as a smartphone.

[0472] The electronic device 6500 includes a housing 6501, a display unit 6502, a power button 6503, a button 6504, a speaker 6505, a microphone 6506, a camera 6507, and a light source 6508, etc. The display unit 6502 has a touch panel function.

[0473] A display device according to one aspect of the present invention can be applied to the display unit 6502.

[0474] Figure 30B is a schematic cross-sectional view of the housing 6501, including the end on the microphone 6506 side.

[0475] A light-transmitting protective member 6510 is provided on the display side of the housing 6501, and the display panel 6511, optical member 6512, touch sensor panel 6513, printed circuit board 6517, battery 6518, etc. are arranged in the space enclosed by the housing 6501 and the protective member 6510.

[0476] The protective member 6510 is fixed to the display panel 6511, the optical member 6512, and the touch sensor panel 6513 by an adhesive layer (not shown).

[0477] In the area outside the display unit 6502, a portion of the display panel 6511 is folded back, and the FPC 6515 is connected to this folded portion. IC 6516 is mounted on the FPC 6515. The FPC 6515 is connected to terminals provided on the printed circuit board 6517.

[0478] A flexible display (a display device with flexibility) according to one embodiment of the present invention can be applied to the display panel 6511. As a result, an extremely lightweight electronic device can be realized. Furthermore, because the display panel 6511 is extremely thin, a large-capacity battery 6518 can be installed while keeping the thickness of the electronic device low. In addition, by folding back a part of the display panel 6511 and placing the connection part with the FPC 6515 on the back of the pixel area, an electronic device with a narrow bezel can be realized.

[0479] Figure 31A shows an example of a television system. The television system 7100 has a display unit 7000 incorporated into a housing 7101. Here, the housing 7101 is shown supported by a stand 7103.

[0480] A display device according to one embodiment of the present invention can be applied to the display unit 7000.

[0481] The television device 7100 shown in Figure 31A can be operated using the operation switches on the housing 7101 and a separate remote control unit 7111. Alternatively, the display unit 7000 may be equipped with a touch sensor, and the television device 7100 can be operated by touching the display unit 7000 with a finger or the like. The remote control unit 7111 may have a display unit that displays information output from the remote control unit 7111. Channels and volume can be controlled and the image displayed on the display unit 7000 can be controlled using the operation keys or touch panel on the remote control unit 7111.

[0482] The television system 7100 is configured to include a receiver and a modem. The receiver can receive general television broadcasts. Furthermore, by connecting to a wired or wireless communication network via the modem, it is possible to perform one-way (from sender to receiver) or two-way (between sender and receiver, or between receivers, etc.) information communication.

[0483] Figure 31B shows an example of a notebook personal computer. The notebook personal computer 7200 has a casing 7211, a keyboard 7212, a pointing device 7213, an external connection port 7214, etc. A display unit 7000 is incorporated into the casing 7211.

[0484] A display device according to one embodiment of the present invention can be applied to the display unit 7000.

[0485] Figures 31C and 31D show examples of digital signage.

[0486] The digital signage 7300 shown in Figure 31C includes a housing 7301, a display unit 7000, and a speaker 7303, etc. Furthermore, it may include LED lamps, operation keys (including a power switch or operation switch), connection terminals, various sensors, a microphone, etc.

[0487] Figure 31D shows a digital signage 7400 mounted on a cylindrical column 7401. The digital signage 7400 has a display unit 7000 that is provided along the curved surface of the column 7401.

[0488] In Figures 31C and 31D, a display device according to one embodiment of the present invention can be applied to the display unit 7000.

[0489] The larger the display area 7000, the more information can be provided at once. Furthermore, a larger display area 7000 is more eye-catching, which can, for example, enhance the effectiveness of advertising.

[0490] Applying a touch panel to the display unit 7000 is preferable because it not only allows images or videos to be displayed on the display unit 7000, but also enables intuitive operation by the user. Furthermore, when used for purposes such as providing route information or traffic information, intuitive operation can enhance usability.

[0491] As shown in Figures 31C and 31D, it is preferable that the digital signage 7300 or digital signage 7400 can be linked wirelessly with an information terminal 7311 or information terminal 7411, such as a smartphone, owned by the user. For example, the advertising information displayed on the display unit 7000 can be displayed on the screen of the information terminal 7311 or information terminal 7411. In addition, the display on the display unit 7000 can be switched by operating the information terminal 7311 or information terminal 7411.

[0492] The digital signage 7300 or digital signage 7400 can also be used to run games using the screen of the information terminal 7311 or information terminal 7411 as the control device (controller). This allows a large number of users to participate in and enjoy the game simultaneously.

[0493] Figure 32A shows the external appearance of the camera 8000 with the viewfinder 8100 attached.

[0494] The camera 8000 includes a housing 8001, a display unit 8002, operation buttons 8003, a shutter button 8004, etc. A detachable lens 8006 is also attached to the camera 8000. The lens 8006 and the housing of the camera 8000 may be integrated into a single unit.

[0495] Camera 8000 can take an image by pressing the shutter button 8004 or by touching the display unit 8002, which functions as a touch panel.

[0496] The housing 8001 has a mount with electrodes, and in addition to the viewfinder 8100, a strobe device and the like can be connected to it.

[0497] The viewfinder 8100 includes a housing 8101, a display unit 8102, buttons 8103, etc.

[0498] The housing 8101 is attached to the camera 8000 by a mount that engages with the camera 8000's mount. The viewfinder 8100 can display images and other data received from the camera 8000 on the display unit 8102.

[0499] Button 8103 functions as a power button, etc.

[0500] A display device according to one embodiment of the present invention can be applied to the display unit 8002 of the camera 8000 and the display unit 8102 of the viewfinder 8100. The camera 8000 may also have a built-in viewfinder.

[0501] Figure 32B shows the external appearance of the head-mounted display 8200.

[0502] The head-mounted display 8200 includes a mounting section 8201, lenses 8202, a main unit 8203, a display unit 8204, a cable 8205, etc. The mounting section 8201 also has a built-in battery 8206.

[0503] Cable 8205 supplies power from battery 8206 to main unit 8203. Main unit 8203 is equipped with a wireless receiver and can display received video information on display unit 8204. In addition, main unit 8203 is equipped with a camera and can use information about the user's eyeball or eyelid movements as an input means.

[0504] The attachment unit 8201 may have a function to recognize gaze, provided with multiple electrodes at a position that touches the user and capable of detecting the current flowing in accordance with the user's eye movements. It may also have a function to monitor the user's pulse based on the current flowing through the electrodes. Furthermore, the attachment unit 8201 may have various sensors such as a temperature sensor, a pressure sensor, and an acceleration sensor, and may have a function to display the user's biometric information on the display unit 8204, or a function to change the image displayed on the display unit 8204 in accordance with the user's head movements.

[0505] A display device according to one aspect of the present invention can be applied to the display unit 8204.

[0506] Figures 32C to 32E show the external appearance of the head-mounted display 8300. The head-mounted display 8300 includes a housing 8301, a display unit 8302, a band-shaped fixing device 8304, and a pair of lenses 8305.

[0507] The user can view the display on the display unit 8302 through the lens 8305. It is preferable to position the display unit 8302 in a curved shape, as this allows the user to experience a greater sense of presence. Furthermore, by viewing different images displayed in different areas of the display unit 8302 through the lens 8305, three-dimensional display using parallax can be performed. Note that the configuration is not limited to a single display unit 8302; two display units 8302 may be provided, with one display unit for each of the user's eyes.

[0508] A display device according to one embodiment of the present invention can be applied to the display unit 8302. The display device according to one embodiment of the present invention can also achieve extremely high resolution. For example, even when the display is magnified and viewed using the lens 8305 as shown in Figure 32E, the pixels are difficult for the user to see. In other words, the display unit 8302 can be used to allow the user to view highly realistic images.

[0509] Figure 32F shows the external appearance of a goggle-type head-mounted display 8400. The head-mounted display 8400 has a pair of housings 8401, a mounting part 8402, and a cushioning member 8403. A display unit 8404 and a lens 8405 are provided inside each of the pair of housings 8401. By displaying different images on the pair of display units 8404, a three-dimensional display using parallax can be achieved.

[0510] The user can view the display unit 8404 through the lens 8405. The lens 8405 has a focus adjustment mechanism and its position can be adjusted according to the user's eyesight. The display unit 8404 is preferably a square or a horizontally elongated rectangle. This can enhance the sense of realism.

[0511] The mounting portion 8402 is preferably adjustable to the size of the user's face and has plasticity and elasticity to prevent it from slipping off. Furthermore, it is preferable that a part of the mounting portion 8402 has a vibration mechanism that functions as a bone conduction earphone. This eliminates the need for separate audio equipment such as earphones or speakers, allowing users to enjoy video and audio simply by wearing the device. The housing 8401 may also have a function to output audio data via wireless communication.

[0512] The mounting portion 8402 and the cushioning member 8403 are parts that come into contact with the user's face (forehead, cheeks, etc.). By ensuring that the cushioning member 8403 is in close contact with the user's face, light leakage can be prevented, thereby enhancing the sense of immersion. It is preferable to use a soft material for the cushioning member 8403 so that it adheres closely to the user's face when the user wears the head-mounted display 8400. For example, materials such as rubber, silicone rubber, urethane, and sponge can be used. Furthermore, if the surface of a sponge or similar material is covered with cloth, leather (genuine leather or synthetic leather), gaps are less likely to form between the user's face and the cushioning member 8403, effectively preventing light leakage. In addition, using such materials is preferable because it feels good against the skin and does not make the user feel cold when worn in cold seasons. It is preferable that the components that come into contact with the user's skin, such as the cushioning member 8403 or the mounting portion 8402, are removable, as this makes cleaning or replacement easier.

[0513] The electronic equipment shown in Figures 33A to 33F includes a housing 9000, a display unit 9001, a speaker 9003, operation keys 9005 (including a power switch or operation switch), connection terminals 9006, sensors 9007 (including functions for measuring force, displacement, position, velocity, acceleration, angular velocity, rotational speed, distance, light, liquid, magnetism, temperature, chemical substances, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor, or infrared radiation), a microphone 9008, etc.

[0514] The electronic devices shown in Figures 33A to 33F have various functions. For example, they may have functions to display various information (still images, videos, text images, etc.) on a display unit, a touch panel function, a function to display a calendar, date or time, a function to control processing by various software (programs), a wireless communication function, a function to read and process programs or data recorded on a recording medium, etc. However, the functions of electronic devices are not limited to these and can have various functions. Electronic devices may have multiple display units. Furthermore, electronic devices may be equipped with a camera, etc., and have functions to capture still images or videos and save them to a recording medium (external or built into the camera), a function to display the captured images on a display unit, etc.

[0515] A display device according to one embodiment of the present invention can be applied to the display unit 9001.

[0516] Details of the electronic equipment shown in Figures 33A to 33F will be explained below.

[0517] Figure 33A is a perspective view showing a personal digital assistant (PDA) 9101. The PDA 9101 can be used, for example, as a smartphone. The PDA 9101 may also be equipped with a speaker 9003, connection terminals 9006, sensors 9007, etc. The PDA 9101 can also display text and image information on multiple surfaces. Figure 33A shows an example where three icons 9050 are displayed. Information 9051, indicated by a dashed rectangle, can also be displayed on other surfaces of the display unit 9001. Examples of information 9051 include notifications of incoming emails, SNS messages, and phone calls, the subject of emails and SNS messages, the sender's name, date and time, battery level, and antenna signal strength. Alternatively, icons 9050 or the like may be displayed in the location where the information 9051 is displayed.

[0518] Figure 33B is a perspective view showing the personal digital assistant (PDA) 9102. The PDA 9102 has the function of displaying information on three or more sides of the display unit 9001. Here, an example is shown in which information 9052, information 9053, and information 9054 are displayed on different sides. For example, a user can check information 9053, which is displayed in a position that can be observed from above the PDA 9102, while the PDA 9102 is stored in the breast pocket of their clothing. The user can check the display without taking the PDA 9102 out of their pocket and decide, for example, whether or not to answer a call.

[0519] Figure 33C is a perspective view showing a wristwatch-type personal information terminal 9200. The personal information terminal 9200 can be used, for example, as a smartwatch (registered trademark). The display unit 9001 has a curved display surface, allowing it to display information along the curved surface. The personal information terminal 9200 can also be used for hands-free calls by communicating with, for example, a wireless communication headset. Furthermore, the personal information terminal 9200 can transmit data to other information terminals and be charged via a connection terminal 9006. Charging may be performed by wireless power supply.

[0520] Figures 33D to 33F are perspective views showing a foldable personal information terminal 9201. Figure 33D shows the personal information terminal 9201 in an unfolded state, Figure 33F shows it in a folded state, and Figure 33E shows a perspective view of the transition between Figures 33D and 33F. The personal information terminal 9201 offers excellent portability in its folded state and excellent readability of the display due to its seamless, wide display area in its unfolded state. The display unit 9001 of the personal information terminal 9201 is supported by three housings 9000 connected by a hinge 9055. For example, the display unit 9001 can be bent with a radius of curvature of 0.1 mm to 150 mm.

[0521] The configuration examples illustrated in this embodiment, and the corresponding drawings, etc., can be appropriately combined with other configuration examples or drawings, etc., at least in part. [Explanation of Symbols]

[0522] 100A: Display device, 100B: Display device, 100C: Display device, 100D: Display device, 100E: Display device, 100F: Display device, 100G: Display device, 100: Display device, 101: Substrate, 110B: Light-emitting device, 110G: Light-emitting device, 110R: Light-emitting device, 110W: Light-emitting device, 110: Light-emitting device, 111B: Pixel electrode, 111G: Pixel electrode, 111R: Pixel electrode, 111: Pixel electrode, 112B: EL layer, 112Bf: EL film, 112G: EL layer, 112Ga: EL layer, 112Gf: EL film, 112R: EL layer, 112Rf: EL Film, 112W: EL layer, 112Wf: EL film, 112: EL layer, 113: common electrode, 115B: optical adjustment layer, 115G: optical adjustment layer, 115R: optical adjustment layer, 116a: layer, 116b: layer, 116: layer, 120B: light-emitting unit, 120G: light-emitting unit, 120R: light-emitting unit, 121: protective layer, 122B: colored layer, 122G: colored layer, 122R: colored layer, 131aB: height, 131aC: height, 131aR: height, 131bC: height, 131bG: height, 131bR: height, 131cB: height, 131cC: height, 131cG: height, 131: insulating layer , 133a: insulating layer, 133f: insulating film, 133w: width, 133: insulating layer, 143a: resist mask, 143b: resist mask, 143c: resist mask, 143: resist mask, 144a: sacrificial film, 144b: sacrificial film, 144c: sacrificial film, 144: sacrificial film, 145a: sacrificial layer, 145b: sacrificial layer, 145c: sacrificial layer, 145: sacrificial layer, 146a: protective film, 146b: protective film, 146c: protective film, 146: protective film, 147a: protective layer, 147b: protective layer, 147c: protective layer, 147: protective layer, 150: display device, 201: transistor, 202: Transistor, 204: Connector, 205: Transistor, 209: Transistor, 210: Transistor, 211: Insulating layer, 212: Insulating layer, 213: Insulating layer, 214: Insulating layer, 215: Insulating layer, 218: Insulating layer, 221: Conductive layer, 222a: Conductive layer, 222b: Conductive layer, 223: Conductive layer, 225: Insulating layer, 228: Region, 231i: Channel formation region, 231n: Low resistance region, 231: Semiconductor layer, 240: Capacitance, 241: Conductive layer, 242: Connector layer, 243: Insulating layer, 245: Conductive layer, 251: Conductive layer, 252: Conductive layer, 254: Insulating layer, 255: Insulating layer,256: Plug, 261: Insulating layer, 262: Insulating layer, 263: Insulating layer, 264: Insulating layer, 265: Insulating layer, 271: Plug, 274a: Conductive layer, 274b: Conductive layer, 274: Plug, 280: Display module, 281: Display section, 282: Circuit section, 283a: Pixel circuit, 283: Pixel circuit section, 284a: Pixel, 284: Pixel section, 285: Terminal section, 286: Wiring section, 290: FPC, 291: Substrate, 292: Substrate, 301: Substrate, 310: Transistor, 311: Conductive layer, 312: Low resistance region, 313: Insulating layer, 314: Insulating layer, 315: Element isolation layer, 3 20: Transistor, 321: Semiconductor layer, 323: Insulating layer, 324: Conductive layer, 325: Conductive layer, 326: Insulating layer, 327: Conductive layer, 328: Insulating layer, 329: Insulating layer, 331: Substrate, 332: Insulating layer, 400A: Display device, 400B: Display device, 400C: Display device, 400D: Display device, 400E: Display device, 401: Laminated structure, 411a: Pixel electrode, 411b: Pixel electrode, 411c: Pixel electrode, 416a: Inorganic insulating layer, 416b: Organic insulating layer, 416c: Inorganic insulating layer, 416: Protective layer, 417: Light-shielding layer, 419: Resin layer, 420: Substrate, 421: Insulating layer, 426a: Optical adjustment layer, 426b: Optical adjustment layer, 426c: Optical adjustment layer, 430a: Light-emitting device, 430b: Light-emitting device, 430c: Light-emitting device, 433: Insulating layer, 442: Adhesive layer, 443: Space, 451: Substrate, 452: Substrate, 453: Substrate, 454: Substrate, 455: Adhesive layer, 462: Display unit, 464: Circuit, 465: Wiring, 466: Conductive layer, 472: FPC, 473: IC, 511: Light-emitting layer, 512: Light-emitting layer, 513: Light-emitting layer, 520: Layer, 522: Layer, 530: Layer, 532: Layer, 540: Intermediate layer, 6500: Electronic equipment, 6501 : Enclosure, 6502: Display unit, 6503: Power button, 6504: Button, 6505: Speaker, 6506: Microphone, 6507: Camera, 6508: Light source, 6510: Protective component, 6511: Display panel, 6512: Optical component, 6513: Touch sensor panel, 6515: FPC, 6516: IC, 6517: Printed circuit board, 6518: Battery, 7000: Display unit, 7100: Television equipment, 7101: Enclosure, 7103: Stand, 7111: Remote control unit, 7200: Notebook personal computer, 7211: Enclosure, 7212: Keyboard,7213: Pointing device, 7214: External connection port, 7300: Digital signage, 7301: Housing, 7303: Speaker, 7311: Information terminal, 7400: Digital signage, 7401: Pillar, 7411: Information terminal, 8000: Camera, 8001: Housing, 8002: Display unit, 8003: Operation buttons, 8004: Shutter button, 8006: Lens, 8100: Viewfinder, 8101: Housing, 8102: Display unit, 8103: Buttons, 8200: Head-mounted display, 8201: Mounting unit, 8202: Lens, 8203: Main unit, 8204: Display unit, 8205: Cable, 8206: Battery, 830 0: Head-mounted display, 8301: Housing, 8302: Display unit, 8304: Fixing device, 8305: Lens, 8400: Head-mounted display, 8401: Housing, 8402: Mounting part, 8403: Cushioning material, 8404: Display unit, 8405: Lens, 9000: Housing, 9001: Display unit, 9003: Speaker, 9005: Operation keys, 9006: Connection terminal, 9007: Sensor, 9008: Microphone, 9050: Icon, 9051: Information, 9052: Information, 9053: Information, 9054: Information, 9055: Hinge, 9101: Personal digital assistant, 9102: Personal digital assistant, 9200: Personal digital assistant, 9201: Personal digital assistant,< / in> < / in> < / ga> < / ga> < / ga> < / ga> < / in> < / in> < / ga> < / ga> < / in> < / in> < / zn> < / ga> < / in>

Claims

1. A first step of forming a first pixel electrode and a second pixel electrode, A second step of forming a first EL film on the first pixel electrode and the second pixel electrode, A third step of forming a first sacrificial film that covers the first EL film, A fourth step involves etching the first sacrificial film to form a first sacrificial layer having a region that overlaps with the first pixel electrode, A fifth step involves etching the first EL film to form a first EL layer having a region that overlaps with the first sacrificial layer, and exposing the second pixel electrode. A sixth step involves forming a second EL film on the first sacrificial layer and the second pixel electrode, A seventh step of forming a second sacrificial film that covers the second EL film, An eighth step of etching the second sacrificial film to form a second sacrificial layer having a region that overlaps with the second pixel electrode, A ninth step involves etching the second EL film to form a second EL layer having a region that overlaps with the second sacrificial layer, A tenth step of forming an insulating film that covers the upper and side surfaces of the first sacrificial layer, the side surfaces of the first EL layer, the upper and side surfaces of the second sacrificial layer, and the side surfaces of the second EL layer, An eleventh step of etching the insulating film to form a first insulating layer having a region in contact with the side surface of the first EL layer and a region in contact with the side surface of the second EL layer, and exposing the first sacrificial layer and the second sacrificial layer, A method for manufacturing a display device, comprising a twelfth step of removing the first sacrificial layer and the second sacrificial layer.

2. A first step of forming a first pixel electrode and a second pixel electrode, A second step of forming a first EL film on the first pixel electrode and the second pixel electrode, A third step of forming a first sacrificial film that covers the first EL film, A fourth step involves etching the first sacrificial film to form a first sacrificial layer having a region that overlaps with the first pixel electrode, A fifth step involves etching the first EL film to form a first EL layer having a region that overlaps with the first sacrificial layer, and exposing the second pixel electrode. A sixth step involves forming a second EL film on the first sacrificial layer and the second pixel electrode, A seventh step of forming a second sacrificial film that covers the second EL film, An eighth step of etching the second sacrificial film to form a second sacrificial layer having a region that overlaps with the second pixel electrode, A ninth step involves etching the second EL film to form a second EL layer having a region that overlaps with the second sacrificial layer, A tenth step of forming an insulating film that covers the upper and side surfaces of the first sacrificial layer, the side surfaces of the first EL layer, the upper and side surfaces of the second sacrificial layer, and the side surfaces of the second EL layer, An eleventh step of etching the insulating film to form a first insulating layer having a region in contact with the side surface of the first EL layer and a region in contact with the side surface of the second EL layer, and forming a second insulating layer on the first sacrificial layer and a third insulating layer on the second sacrificial layer, A method for manufacturing a display device, comprising a twelfth step of removing the first sacrificial layer and the second sacrificial layer, as well as removing the second insulating layer and the third insulating layer.

3. In claim 1 or claim 2, The first sacrificial film comprises one or more of a metal film, an alloy film, a metal oxide film, a semiconductor film, or an inorganic insulating film. In the fifth step, the etching of the first EL film is performed using dry etching with an etching gas that does not contain oxygen gas, in a method for manufacturing a display device.

4. In claim 3, The etching gas不含 oxygen gas is CF ４ , C ４ F ８ , SF ６ , CHF ３ , Cl ２ , H ２ O, BCl ３ , H ２ , or one or more selected from noble gases, is a method for manufacturing a display device.

5. In any one of claims 1 to 4, Between the third step and the fourth step, there is a step of forming a first protective layer having a region that overlaps with the first pixel electrode. A method for manufacturing a display device, wherein in the fourth step, the first protective layer is used as a mask to etch the first sacrificial film to form the first sacrificial layer.

6. In claim 5, A method for manufacturing a display device, comprising the step of removing the first protective layer between the fifth step and the sixth step.

7. In any one of claims 1 to 6, A method for manufacturing a display device, comprising a thirteenth step of forming a common electrode that covers the upper surface of the first EL layer, the upper surface of the second EL layer, and the upper and side surfaces of the first insulating layer, after the twelfth step.

8. In claim 7, Between the 12th step and the 13th step, there is a step of forming a layer that covers the upper surface of the first EL layer, the upper surface of the second EL layer, and the upper surface and side surface of the first insulating layer. A method for manufacturing a display device, wherein the layer is a layer containing a material with high electron injection properties.

9. In claim 7, Between the 12th step and the 13th step, there is a step of forming a layer that covers the upper surface of the first EL layer, the upper surface of the second EL layer, and the upper surface and side surface of the first insulating layer. A method for manufacturing a display device having a laminated structure comprising a first layer containing a material with high electron transport properties and a second layer on the first layer containing a material with high electron injection properties.

10. In claim 7, Between the 12th step and the 13th step, there is a step of forming a layer that covers the upper surface of the first EL layer, the upper surface of the second EL layer, and the upper surface and side surface of the first insulating layer. A method for manufacturing a display device, wherein the layer is a layer containing a substance with high hole injection properties.

11. In claim 7, Between the 12th step and the 13th step, there is a step of forming a layer that covers the upper surface of the first EL layer, the upper surface of the second EL layer, and the upper surface and side surface of the first insulating layer. A method for manufacturing a display device having a laminated structure comprising a first layer containing a material with high hole transport properties and a second layer on the first layer containing a material with high hole injection properties.

12. A first step of forming a first pixel electrode and a second pixel electrode, A second step involves forming an EL film on the first pixel electrode and the second pixel electrode, A third step of forming a sacrificial film that covers the EL film, A fourth step involves etching the sacrificial film to form a first sacrificial layer having a region overlapping with the first pixel electrode and a second sacrificial layer having a region overlapping with the second pixel electrode. A fifth step involves etching the EL film to form a first EL layer having a region overlapping with the first sacrificial layer and a second EL layer having a region overlapping with the second sacrificial layer. A sixth step of forming an insulating film that covers the upper and side surfaces of the first sacrificial layer, the side surfaces of the first EL layer, the upper and side surfaces of the second sacrificial layer, and the side surfaces of the second EL layer, A seventh step involves etching the insulating film to form a first insulating layer having a region in contact with the side surface of the first EL layer and a region in contact with the side surface of the second EL layer, and exposing the first sacrificial layer and the second sacrificial layer. The process includes an eighth step of removing the first sacrificial layer and the second sacrificial layer, The EL film is a method for manufacturing a display device having a light-emitting layer that emits white light.

13. A first step of forming a first pixel electrode and a second pixel electrode, A second step involves forming an EL film on the first pixel electrode and the second pixel electrode, A third step of forming a sacrificial film that covers the EL film, A fourth step involves etching the sacrificial film to form a first sacrificial layer having a region overlapping with the first pixel electrode and a second sacrificial layer having a region overlapping with the second pixel electrode. A fifth step involves etching the EL film to form a first EL layer having a region overlapping with the first sacrificial layer and a second EL layer having a region overlapping with the second sacrificial layer. A sixth step of forming an insulating film that covers the upper and side surfaces of the first sacrificial layer, the side surfaces of the first EL layer, the upper and side surfaces of the second sacrificial layer, and the side surfaces of the second EL layer, A seventh step involves etching the insulating film to form a first insulating layer having a region in contact with the side surface of the first EL layer and a region in contact with the side surface of the second EL layer, and forming a second insulating layer on the first sacrificial layer and a third insulating layer on the second sacrificial layer. The process includes an eighth step of removing the first sacrificial layer and the second sacrificial layer, as well as removing the second insulating layer and the third insulating layer. The EL film is a method for manufacturing a display device having a light-emitting layer that emits white light.

Images