Display device

Abstract

Provided is a display device having high display quality. The display device includes a pixel portion, a dummy pixel portion, and a peripheral region. The pixel comprises a first pixel electrode, a first layer on the first pixel electrode and a common electrode, the first layer comprises a light-emitting layer, the dummy pixel comprises a second pixel electrode, a second layer on the second pixel electrode and a common electrode, the peripheral area comprises a third layer, and the second layer and the third layer are made of the same material as the light-emitting layer. The first insulating layer has a region in contact with a side surface of the first layer, a region in contact with a side surface of the second layer, and a region covering the third layer, the common electrode is provided so as to cover the first insulating layer, and the first opening of the first insulating layer is provided in a region overlapping the first pixel electrode. The second opening is provided in a region overlapping the second pixel electrode.

Description

Technical Field

[0001] One embodiment of the present invention relates to a display device.

[0002] Note that one embodiment of the present invention is not limited to the aforementioned technical fields. Examples of the technical fields of one embodiment of the present invention disclosed in this specification and other related disclosures include semiconductor devices, display devices, light-emitting devices, power storage devices, memory devices, electronic devices, lighting devices, input devices, input / output devices, and methods for driving or manufacturing the same. A semiconductor device refers to any device that can operate using semiconductor properties. Background Art

[0003] In recent years, high-definition display panels have become increasingly popular. Examples of devices requiring high-definition display panels include smartphones, tablet computers, and laptop computers. Furthermore, fixed display devices such as televisions and monitors are also being required to achieve higher resolutions as resolution increases. Devices that require the highest resolution include those used in virtual reality (VR) and augmented reality (AR).

[0004] Typical display devices applicable to display panels include liquid crystal display devices, light-emitting devices including light-emitting elements such as organic EL (Electro Luminescence) elements and light-emitting diodes (LEDs), and electronic paper that displays using electrophoresis or the like.

[0005] For example, the basic structure of an organic EL element is a layer containing a light-emitting organic compound sandwiched between a pair of electrodes. By applying a voltage to the element, light from the light-emitting organic compound can be obtained. Because display devices using these organic EL elements do not require the backlight required by liquid crystal displays, they can achieve thin, lightweight, high-contrast, and low-power display devices. For example, Patent Document 1 discloses an example of a display device using an organic EL element.

[0006] Patent Document 2 discloses a display device for VR application using an organic EL device.

[0007] As image processing software, for example, ImageJ (Non-Patent Documents 1 to 3) and Fiji (Non-Patent Documents 4 and 5) are known. By using these software, analysis of brightness distribution and the like can be performed.

[0008] [Prior technical literature]

[0009] [Patent Document]

[0010] [Patent Document 1] Japanese Patent Application Publication No. 2002-324673

[0011] [Patent Document 2] International Patent Application Publication No. 2018 / 087625

[0012] [Non-patent literature]

[0013] [Non-patent document 1] Rasband, WS, ImageJ, USNational Institutes of Health, Bethesda, Maryland, USA, http: / / rsb.info.nih.gov / ij / , 1997-2012.

[0014] [Non-patent document 2] Schneider, CA, Rasband, WS, Eliceiri, KW. “NIH Image to ImageJ: 25 years of image analysis.” Nature Methods 9, 671-675, 2012.

[0015] [Non-patent document 3] Abramoff, MD, Magelhaes, PJ, Ram, SJ "Image Processing with ImageJ". Biophotonics International, volume 11, issue 7, pp. 36-42, 2004.

[0016] [Non-Patent Document 4] Fiji, https: / / fiji.sc /

[0017] [Non-patent document 5] Schindelin, J., Arganda-Carreras, I., Frise, E. et al. Fiji: an open-source platform for biological-image analysis. Nature Methods 9, 676-682 (2012). Summary of the Invention

[0018] Technical problem to be solved by the invention

[0019] One object of one embodiment of the present invention is to provide a display device with high display quality. Another object of one embodiment of the present invention is to provide a display device with high reliability. Another object of one embodiment of the present invention is to provide a display device that can easily achieve high definition. Another object of one embodiment of the present invention is to provide a display device that has both high display quality and high definition. Another object of one embodiment of the present invention is to provide a display device with low power consumption.

[0020] One object of one embodiment of the present invention is to provide a display device having a novel structure or a method for manufacturing a display device. Another object of one embodiment of the present invention is to provide a method for manufacturing the display device with a high yield. Another object of one embodiment of the present invention is to at least alleviate at least one of the problems of the prior art.

[0021] Note that the inclusion of these objectives does not preclude the existence of other objectives. Note that one embodiment of the present invention does not necessarily achieve all of the above objectives. Note that objectives other than those listed above can be extracted from the description of the specification, drawings, claims, etc.

[0022] Means of solving technical problems

[0023] One embodiment of the present invention is a display device, which includes a pixel portion, a dummy pixel portion and a peripheral area, wherein the dummy pixel portion and the peripheral area are areas that do not contribute to display, and when viewed from above, the dummy pixel portion is arranged between the pixel portion and the peripheral area, the pixel portion includes a plurality of pixels, each of the plurality of pixels includes a first pixel electrode, a first layer on the first pixel electrode and a common electrode on the first layer, the common electrode is arranged in a manner spanning the pixel portion, the dummy pixel portion and the peripheral area, the first layer includes a light-emitting layer, the dummy pixel portion includes a plurality of dummy pixels, each of the plurality of dummy pixels includes a second pixel electrode, a second layer on the second pixel electrode and a common electrode on the second layer, the second layer includes the same material as the light-emitting layer, and the peripheral area includes a third layer, and the third layer includes a plurality of dummy pixels. The layer contains the same material as the light-emitting layer, the pixel portion, the pseudo-pixel portion and the peripheral area include a first insulating layer, the first insulating layer has an area in contact with the side of the first layer of each of the multiple pixels, an area in contact with the side of the second layer of each of the multiple pseudo-pixels, an area in contact with the top surface of the third layer and an area in contact with the side of the third layer, the common electrode is arranged in the pixel portion, the pseudo-pixel portion and the peripheral area in a manner covering the first insulating layer, the first insulating layer includes a plurality of first openings and a plurality of second openings, each of the plurality of first openings is arranged in an area overlapping with each of the first pixel electrodes included in the multiple pixels, and each of the plurality of second openings is arranged in an area overlapping with each of the second pixel electrodes included in the multiple pseudo-pixels.

[0024] In the above structure, the first insulating layer preferably contains an organic material.

[0025] In the above structure, the first insulating layer is preferably a stacked layer of a layer containing an inorganic material and a layer containing an organic material located on the layer containing the inorganic material.

[0026] In the above structure, the intervals between the plurality of first openings are preferably substantially the same as the intervals between the plurality of second openings.

[0027] In the above structure, the area of ​​the first opening when viewed from a planar perspective is preferably substantially identical to the area of ​​the second opening when viewed from a planar perspective.

[0028] In addition, one embodiment of the present invention is a display device, which includes a pixel electrode, a first layer on the pixel electrode, a protective layer on the first layer, a common layer on the protective layer, a common electrode on the common layer, and a first insulating layer, wherein the first layer includes a light-emitting layer, the first insulating layer has an area in contact with the side of the first layer, the first insulating layer includes an opening arranged in an area overlapping with the pixel electrode, the protective layer is arranged in a manner covering the first insulating layer, and the protective layer contacts the top surface of the first layer in the opening.

[0029] In the above structure, preferably, the first layer includes a hole injection layer, a hole transport layer, and an electron transport layer, the common layer includes an electron injection layer, and the protective layer is an inorganic insulating layer.

[0030] Effects of the Invention

[0031] According to one embodiment of the present invention, a display device with high display quality can be provided. According to one embodiment of the present invention, a display device with high reliability can be provided. According to one embodiment of the present invention, a display device that can easily achieve high definition can be provided. According to one embodiment of the present invention, a display device with both high display quality and high definition can be provided. According to one embodiment of the present invention, a display device with low power consumption can be provided.

[0032] According to one embodiment of the present invention, a display device having a novel structure or a method for manufacturing a display device can be provided. According to one embodiment of the present invention, a method for manufacturing the display device with a high yield can be provided. According to one embodiment of the present invention, at least one of the problems of the prior art can be improved.

[0033] Note that the description of these effects does not preclude the existence of other effects. Note that one embodiment of the present invention does not necessarily have all of the above effects. Note that effects other than the above can be extracted from the description of the specification, drawings, claims, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1A It is a plan view showing an example of a display device. Figure 1BIt is a plan view showing an example of a pixel portion. Figure 1C is a plan view showing an example of a pixel. Figure 1D It is a plan view showing an example of a display device.

[0035] Figure 2A and Figure 2B is a plan view showing an example of a pixel. Figure 2C and Figure 2D is a cross-sectional view showing an example of a pixel.

[0036] Figure 3A FIG. 1 is a plan view showing an example of a dummy pixel. Figure 3B It is a plan view showing an example of a display device. Figure 3C is a cross-sectional view showing an example of a dummy pixel. Figure 3D is a cross-sectional view showing an example of a display device.

[0037] Figures 4A to 4D is a cross-sectional view showing an example of a display device.

[0038] Figure 5A is a cross-sectional view showing an example of a dummy pixel. Figure 5B It is a plan view showing an example of a display device. Figure 5C is a cross-sectional view showing an example of a dummy pixel.

[0039] Figure 6A and Figure 6B It is a plan view showing an example of a display device.

[0040] Figure 7A and Figure 7B It is a plan view showing an example of a display device.

[0041] Figure 8A and Figure 8B It is a plan view showing an example of a display device.

[0042] Figure 9 It is a plan view showing an example of a display device.

[0043] Figure 10A It is a plan view showing an example of a display device. Figure 10B is a cross-sectional view showing an example of a display device.

[0044] Figure 11A and Figure 11B is a cross-sectional view showing an example of a pixel.

[0045] 12A to 12C This is a cross-sectional view illustrating an example of a method for manufacturing a display device.

[0046] 13A to 13C This is a cross-sectional view illustrating an example of a method for manufacturing a display device.

[0047] 14A to 14C This is a cross-sectional view illustrating an example of a method for manufacturing a display device.

[0048] Figures 15A to 15C This is a cross-sectional view illustrating an example of a method for manufacturing a display device.

[0049] 16A to 16C This is a cross-sectional view illustrating an example of a method for manufacturing a display device.

[0050] 17A to 17C This is a cross-sectional view illustrating an example of a method for manufacturing a display device.

[0051] 18A to 18C This is a cross-sectional view illustrating an example of a method for manufacturing a display device.

[0052] Figures 19A to 19F is a plan view showing an example of a pixel.

[0053] 20A to 20H is a plan view showing an example of a pixel.

[0054] Figures 21A to 21J is a plan view showing an example of a pixel.

[0055] 22A to 22D is a plan view showing an example of a pixel. Figures 22E to 22G is a cross-sectional view showing an example of a display device.

[0056] Figure 23A and Figure 23B It is a perspective view showing an example of a display device.

[0057] Figure 24A and Figure 24B is a cross-sectional view showing an example of a display device.

[0058] Figure 25 is a cross-sectional view showing an example of a display device.

[0059] Figure 26 is a cross-sectional view showing an example of a display device.

[0060] Figure 27 is a cross-sectional view showing an example of a display device.

[0061] Figure 28 is a cross-sectional view showing an example of a display device.

[0062] Figure 29is a cross-sectional view showing an example of a display device.

[0063] Figure 30 It is a perspective view showing an example of a display device.

[0064] Figure 31A is a cross-sectional view showing an example of a display device. Figure 31B and Figure 31C is a cross-sectional view showing an example of a transistor. Figure 31D is a cross-sectional view showing an example of a display device.

[0065] Figure 32A is a block diagram showing an example of a display device. Figures 32B to 32D is a diagram showing an example of a pixel circuit.

[0066] Figures 33A to 33C is a diagram showing an example of a transistor.

[0067] Figure 34A and Figure 34B is a diagram showing an example of a transistor.

[0068] Figures 35A to 35I is a diagram showing a structural example of a light emitting device.

[0069] Figures 36A to 36D is a diagram illustrating an example of an electronic device.

[0070] Figures 37A to 37F is a diagram illustrating an example of an electronic device.

[0071] Figures 38A to 38G is a diagram illustrating an example of an electronic device.

[0072] Figures 39A to 39E An optical microscope photograph of the display device is shown.

[0073] Figures 40A to 40E An optical microscope photograph of the display device is shown.

[0074] Figure 41A and Figure 41B The relationship between the normalized luminescent area and the storage time is shown.

[0075] Figure 42 The relationship between the normalized luminescent area and the storage time is shown.

[0076] Figure 43 The normalized driving voltage of the light emitting device is shown.

[0077] Figure 44 The normalized brightness of the light emitting device is shown.

[0078] Figure 45 The normalized LT95 values ​​of the light-emitting devices are shown.

[0079] Figure 46A and Figure 46B The voltage-current density characteristics are shown.

[0080] Figure 47A and Figure 47B The voltage-current density characteristics are shown.

[0081] Figure 48A and Figure 48B Current density-luminance characteristics are shown.

[0082] Figure 49A and Figure 49B Shows chromaticity.

[0083] Figure 50A and Figure 50B The time dependence of the normalized luminescence intensity is shown.

[0084] Figure 51 The time dependence of the normalized luminescence intensity is shown.

[0085] Figure 52A and Figure 52B It is a diagram illustrating the measurement area.

[0086] Figure 53 The results of ToF-SIMS analysis are shown.

[0087] Figure 54 The results of ToF-SIMS analysis are shown.

[0088] Figure 55 The results of ToF-SIMS analysis are shown.

[0089] Figure 56 The results of the etching rate are shown.

[0090] Figure 57 The results of the etching rate are shown.

[0091] Figure 58A is the time dependence of the normalized driving voltage. Figure 58B The voltage-current density characteristics are shown.

[0092] Figure 59A and Figure 59B The voltage-current density characteristics are shown.

[0093] Figure 60A The time dependence of the normalized luminescence brightness is shown. Figure 60B Current density-luminance characteristics are shown.

[0094] Figure 61A and Figure 61B Current density-luminance characteristics are shown.

[0095] Figure 62A and Figure 62B The temporal dependence of chromaticity is shown.

[0096] Figure 63A and Figure 63B The temporal dependence of chromaticity is shown.

[0097] Figure 64A and Figure 64B is a top view of the sample.

[0098] Figure 65A The normalized driving voltage of the light emitting device is shown. Figure 65B The normalized brightness of the light emitting device is shown. Figure 65C The normalized LT95 values ​​of the light-emitting devices are shown.

[0099] Figure 66A and Figure 66B The voltage-current density characteristics are shown.

[0100] Figure 67A and Figure 67B The voltage-current density characteristics are shown.

[0101] Figure 68A and Figure 68B Current density-luminance characteristics are shown.

[0102] Figure 69A and Figure 69B Shows chromaticity.

[0103] Figure 70A and Figure 70B The time dependence of the normalized luminescence intensity is shown.

[0104] Figure 71 The time dependence of the normalized luminescence intensity is shown.

[0105] Figure 72A and Figure 72B The voltage-current density characteristics are shown.

[0106] Figure 73A and Figure 73B The voltage-current density characteristics are shown.

[0107] Figure 74A and Figure 74B The voltage-current density characteristics are shown.

[0108] Figure 75A and Figure 75B Current density-luminance characteristics are shown.

[0109] Figure 76A and Figure 76B Current density-luminance characteristics are shown.

[0110] Figure 77A and Figure 77B Current density-luminance characteristics are shown.

[0111] Figure 78A The normalized driving voltage of the light emitting device is shown. Figure 78B The normalized brightness of the light emitting device is shown.

[0112] Figure 79 This is a microscope photograph of the display device.

[0113] Figures 80A to 80C This is a microscope photograph of the display device.

[0114] Figures 81A to 81C This is a microscope photograph of the display device.

[0115] Figure 82A and Figure 82B is a SEM image of a cross section of a light-emitting device.

[0116] Figure 83A and Figure 83B is a SEM image of a cross section of a light-emitting device.

[0117] Figure 84A The normalized driving voltage of the light emitting device is shown. Figure 84B The normalized brightness of the light emitting device is shown. Figure 84C The normalized LT95 values ​​of the light-emitting devices are shown.

[0118] Figure 85A and Figure 85B The voltage-current density characteristics are shown.

[0119] Figure 86A Current density-luminance characteristics are shown. Figure 86B Shows chromaticity.

[0120] Figure 87A and Figure 87B The time dependence of the normalized luminescence intensity is shown.

[0121] Figure 88A The normalized driving voltage of the light emitting device is shown. Figure 88B The normalized brightness of the light emitting device is shown. Figure 88C The normalized LT95 values ​​of the light-emitting devices are shown.

[0122] Figure 89A and Figure 89B The voltage-current density characteristics are shown.

[0123] Figure 90A and Figure 90BThe voltage-current density characteristics are shown.

[0124] Figure 91A and Figure 91B Current density-luminance characteristics are shown.

[0125] Figure 92A and Figure 92B Shows chromaticity.

[0126] Figure 93A and Figure 93B The time dependence of the normalized luminescence intensity is shown.

[0127] Figure 94A The normalized LT95 values ​​of the light-emitting devices are shown. Figure 94B The time dependence of the normalized luminous intensity of the light emitting device is shown.

[0128] Figure 95A The voltage-current density characteristics are shown. Figure 95B Current density-luminance characteristics are shown.

[0129] Figure 96 The emission spectrum is shown.

[0130] Figure 97A The normalized driving voltage of the light emitting device is shown. Figure 97B The normalized brightness of the light emitting device is shown.

[0131] Figure 98A The voltage-current density characteristics are shown. Figure 98B Current density-luminance characteristics are shown.

[0132] Figure 99 The emission spectrum is shown.

[0133] Figure 100A The normalized driving voltage of the light emitting device is shown. Figure 100B The normalized brightness of the light emitting device is shown.

[0134] Figure 101A The voltage-current density characteristics are shown. Figure 101B Current density-luminance characteristics are shown.

[0135] Figure 102 The emission spectrum is shown.

[0136] Figure 103A The normalized driving voltage of the light emitting device is shown. Figure 103B The normalized brightness of the light emitting device is shown.

[0137] Figures 104A to 104C This is a microscope photograph of the display device.

[0138] Figure 105A and Figure 105B It is a plan view showing an example of a display device. Figure 105C is a plan view showing an example of a pixel.

[0139] Figure 106 This is a microscope photograph of the display device.

[0140] Figure 107A This is a microscope photograph of the display device. Figure 107B The time dependence of the normalized luminous intensity of the light emitting device is shown.

[0141] Figure 108 This is a microscope photograph of the display device.

[0142] Figure 109A and Figure 109B The time dependence of the normalized luminous intensity of the light emitting device is shown.

[0143] Figure 110 This is a microscope photograph of the display device.

[0144] Figure 111A and Figure 111B OBIRCH analysis results are shown.

[0145] Figure 112A It is a plan view showing an example of a display device. Figure 112B is a plan view showing an example of a pixel. DETAILED DESCRIPTION

[0146] The following describes the embodiments with reference to the accompanying drawings. Note that the embodiments can be implemented in a variety of different ways, and those skilled in the art will readily appreciate that the methods and details can be modified in various ways without departing from the spirit and scope of the present invention. Therefore, the present invention should not be construed as being limited solely to the following embodiments.

[0147] Note that in the inventive structure described below, the same reference numerals are used in common in different drawings to indicate the same parts or parts having the same function, and repeated descriptions are omitted. In addition, when parts having the same function are shown, the same hatching is sometimes used without adding a special reference numeral.

[0148] Note that in the drawings described in this specification, the size of each component, the thickness of a layer, or the region may be exaggerated for clarity. Therefore, the present invention is not limited to the dimensions shown in the drawings.

[0149] The ordinal numbers such as “first” and “second” used in this specification and the like are provided to avoid confusion among constituent elements and are not intended to limit the number of constituent elements.

[0150] In this specification and other documents, the display device may be referred to as an electronic device.

[0151] In this specification, etc., a display device as one embodiment of a display device has a function of displaying (outputting) an image on a display surface. Therefore, a display device is one embodiment of an output device.

[0152] In this specification and other documents, a display device substrate with a connector such as an FPC (Flexible Printed Circuit) or TCP (Tape Carrier Package) mounted on it, or a display device substrate with an IC mounted using a COG (Chip On Glass) method, may be referred to as a display module. In this specification and other documents, a display device may also be referred to as a display panel.

[0153] In this specification, "film" and "layer" may be interchanged. For example, "conductive layer" or "insulating layer" may be replaced with "conductive film" or "insulating film," respectively.

[0154] Note that in this specification, an EL layer is provided between a pair of electrodes in a light-emitting device (also referred to as a light-emitting element) and refers to a layer containing at least a light-emitting substance (also referred to as a light-emitting layer) or a stacked structure including a light-emitting layer.

[0155] In this specification, devices manufactured using a metal mask or FMM (Fine Metal Mask) are sometimes referred to as devices having an MM (Metal Mask) structure. Furthermore, devices manufactured without using a metal mask or FMM are sometimes referred to as devices having an MML (Metal Mask Less) structure.

[0156] In this specification, holes or electrons are sometimes referred to as "carriers." Specifically, a hole injection layer or electron injection layer, a hole transport layer or electron transport layer, and a hole blocking layer or electron blocking layer are sometimes referred to as a "carrier injection layer," a "carrier transport layer," and a "carrier blocking layer," respectively. Note that depending on the cross-sectional shape or characteristics, the above-mentioned carrier injection layer, carrier transport layer, and carrier blocking layer may not be clearly distinguished. In addition, a single layer may sometimes function as two or three of the following: a carrier injection layer, a carrier transport layer, and a carrier blocking layer.

[0157] (Implementation Method 1)

[0158] In this embodiment, a display device which is one embodiment of the present invention is described.

[0159] One embodiment of the present invention is a display device including a display unit capable of full-color display. The display unit includes a first sub-pixel and a second sub-pixel that emit light of different colors. The first sub-pixel includes a first light-emitting device that emits light of a first color, and the second sub-pixel includes a second light-emitting device that emits light of a different color from the first light-emitting device. The first and second light-emitting devices include at least one material that differs from each other, for example, different luminescent substances. In other words, the display device according to one embodiment of the present invention uses light-emitting devices manufactured separately for each luminescent color.

[0160] A structure in which separate light-emitting layers are formed or applied to light-emitting devices for each color (for example, blue (B), green (G), and red (R)) is sometimes referred to as a side-by-side (SBS) structure. The SBS structure allows for optimization of materials and structures for each light-emitting device, increasing the freedom of material and structure selection and facilitating improvements in brightness and reliability.

[0161] When manufacturing a display device that includes light-emitting devices that emit different colors, it is necessary to form the light-emitting layers of different colors into island shapes. Note that in this specification, "island shape" refers to a state in which two or more layers, formed in the same process and using the same material, are physically separated. For example, an island-shaped light-emitting layer refers to a state in which the light-emitting layer is physically separated from adjacent light-emitting layers.

[0162] For example, island-shaped light-emitting layers can be deposited by vacuum evaporation using a metal mask (also called a shadow mask). However, this method is affected by various factors, such as the accuracy of the metal mask, the misalignment between the metal mask and the substrate, the deflection of the metal mask, and the enlargement of the outline of the deposited film caused by vapor scattering. As a result, the shape and position of the island-shaped light-emitting layer deviate from the designed shape and position, making it difficult to achieve high definition and high aperture ratio of the display device. In addition, during evaporation, the outline of the layer is sometimes blurred and the thickness of the end is thinner. In other words, the thickness of the island-shaped light-emitting layer formed using the metal mask sometimes varies depending on the position. In addition, when manufacturing large-scale, high-resolution or high-definition display devices, there is a concern that the manufacturing yield will decrease due to deformation caused by low dimensional accuracy of the metal mask, heat, etc.

[0163] In a method for manufacturing a display device according to one embodiment of the present invention, a first layer (also referred to as an EL layer or a portion of the EL layer) including a light-emitting layer that emits light of a first color is formed entirely on a surface. A first mask layer is then formed on the first layer. A first resist mask is then formed on the first mask layer, and the first layer and the first mask layer are processed using the first resist mask to form the first layer in an island shape. Next, a second layer (also referred to as an EL layer or a portion of the EL layer) including a light-emitting layer that emits light of a second color is formed in an island shape using a second mask layer and the second resist mask, similarly to the first layer.

[0164] Note that in this specification and other documents, a mask layer is located at least above the light-emitting layer (more specifically, a layer processed into an island shape among the layers constituting the EL layer) and has a function of protecting the light-emitting layer during the manufacturing process.

[0165] Note that when a layer including at least a portion of the above-mentioned EL layer is processed into an island shape, a method of processing it using photolithography right above the light-emitting layer can be conceived. When this method is adopted, damage to the light-emitting layer (damage caused by processing, etc.) may sometimes be caused and reliability may be seriously impaired. Therefore, when manufacturing a display device of one embodiment of the present invention, it is preferred to use a method of forming a mask layer or the like on a layer above the light-emitting layer (for example, a carrier transport layer, a carrier blocking layer or a carrier injection layer, more specifically an electron transport layer, a hole blocking layer or an electron injection layer, etc.) and processing the light-emitting layer into an island shape. By adopting this method, a display device with high reliability can be provided.

[0166] In this way, the island-shaped EL layer or the island-shaped layer consisting of a portion of the EL layer manufactured by the manufacturing method of a display device according to one embodiment of the present invention can be formed by depositing a film that will become the EL layer or a film that will become a portion of the EL layer on the entire surface and then processing it. As a result, a display device with higher definition and a display device with a higher aperture ratio can be achieved compared to the case where a metal mask with a fine pattern is used. In addition, since the island-shaped EL layer of each color or the island-shaped layer consisting of a portion of the EL layer can be formed separately, a display device with extremely clear, high contrast and high display quality can be achieved. In addition, by providing a mask layer on the island-shaped EL layer or the island-shaped layer consisting of a portion of the EL layer, damage to the island-shaped EL layer or the island-shaped layer consisting of a portion of the EL layer during the manufacturing process of the display device can be reduced, thereby improving the reliability of the light-emitting device.

[0167] [Configuration Example of Display Device]

[0168] A display device according to one embodiment of the present invention will be described with reference to FIG. 1 to FIG. 11 and the like. FIG.

[0169] Figure 1A1 is an example of a plan view of the display device 100 . The display device 100 includes a pixel portion 284 in which a plurality of pixels 110 are arranged, a dummy pixel portion 294 outside the pixel portion 284 , and a peripheral region 297 outside the dummy pixel portion 294 .

[0170] Figure 1B 2 is an example of a plan view of the pixel portion 284. In the pixel portion 284, a plurality of pixels 110 are arranged in a matrix.

[0171] In this specification, the row direction is sometimes referred to as the X direction and the column direction is sometimes referred to as the Y direction. The X direction intersects the Y direction. Figure 1B In the figure, the X direction is perpendicular to the Y direction. Note that the angle formed by the straight line along the X direction and the straight line along the Y direction may be smaller than 90°.

[0172] Pixel 110 may also have a structure including multiple sub-pixels. As an example, pixel 110 includes multiple sub-pixels corresponding to different colors. In addition, pixel 110 may also include two or more sub-pixels corresponding to the same color of light. For example, pixel 110 may also include four sub-pixels and have a structure in which a first sub-pixel corresponds to a first color, a second sub-pixel corresponds to a second color, and a third sub-pixel and a fourth sub-pixel correspond to a third color.

[0173] Figure 1C 1 is an example of a top view of the pixel 110 . Figure 1C The pixel 110 shown is composed of three pixels: a sub-pixel 110a, a sub-pixel 110b, and a sub-pixel 110c. The sub-pixels 110a, 110b, and 110c correspond to light of different colors, for example. Figure 2A The illustrated pixel 110 is arranged in two rows and two columns, with one subpixel (subpixel 110c) in the left column (first column) and two subpixels (subpixel 110a and subpixel 110b) in the right column (second column). In other words, the pixel 110 includes two subpixels (subpixel 110c and subpixel 110a) in the upper row (first row), two subpixels (subpixel 110c and subpixel 110b) in the lower row (second row), and the subpixel 110c is included across both rows.

[0174] Examples of the sub-pixels 110a, 110b, and 110c include sub-pixels corresponding to the three colors of red (R), green (G), and blue (B), and sub-pixels corresponding to the three colors of yellow (Y), cyan (C), and magenta (M). Furthermore, the number of sub-pixels is not limited to three, and four or more sub-pixels may be used. Examples of the four sub-pixels include sub-pixels corresponding to the four colors of R, G, B, and white (W), sub-pixels corresponding to the four colors of R, G, B, and Y, and four sub-pixels corresponding to R, G, B, and infrared light (IR).

[0175] In addition, the arrangement of sub-pixels in the pixel 110 is not limited to Figure 1C For example, the sub-pixels 110a, 110b, and 110c included in the pixel 110 may also be arranged in stripes.

[0176] Figure 2A Yes Figure 1C The pixel 110 shown is a top view of additional components. Figure 2C It is along Figure 2A An example of a cross-sectional view taken along the dotted line X1-X2 is shown. Figure 2B The abstract shows Figure 2A Insulating layer 127 is shown among the components.

[0177] Sub-pixel 110a includes a pixel electrode 111a and an island layer 113a thereon. Sub-pixel 110b includes a pixel electrode 111b and an island layer 113b thereon. Sub-pixel 110c includes a pixel electrode 111c and an island layer 113c thereon.

[0178] exist Figure 2A The description thereof is omitted, and a common layer 114 and a common electrode 115 are provided to cover the layers 113a, 113b, and 113c. The layers 113a, 113b, and 113c are all island layers, which include at least a portion of the EL layer, preferably a light-emitting layer.

[0179] The pixel electrode, common electrode, and EL layer sandwiched between the pixel electrode and the common electrode included in the sub-pixel can constitute a light-emitting device. The light-emitting device includes an EL layer between a pair of electrodes. The EL layer includes at least a light-emitting layer. In this specification, one of the pair of electrodes is sometimes referred to as the pixel electrode and the other as the common electrode. In the pair of electrodes included in the light-emitting device, one electrode is used as an anode and the other electrode is used as a cathode. The following description sometimes uses the case where the pixel electrode is used as an anode and the common electrode is used as a cathode as an example.

[0180] In subpixel 110a, pixel electrode 111a, common electrode 115, layer 113a, and common layer 114 constitute light-emitting device 130a. Layer 113a and common layer 114 may be collectively referred to as an EL layer. In subpixel 110b, pixel electrode 111b, common electrode 115, layer 113b, and common layer 114 constitute light-emitting device 130b. Layer 113b and common layer 114 may be collectively referred to as an EL layer. In subpixel 110c, pixel electrode 111c, common electrode 115, layer 113c, and common layer 114 constitute light-emitting device 130c. Layer 113c and common layer 114 may be collectively referred to as an EL layer.

[0181] In a display device according to one embodiment of the present invention, films to become layers 113a, 113b, and 113c (films 113af, 113bf, and 113cf, described later) are deposited over the entire surface and then processed using photolithography or other methods. This allows for a high-definition display device and a display device with a high aperture ratio. Furthermore, by providing a mask layer over layers 113a, 113b, and 113c during processing, damage can be reduced, thereby improving the reliability of the light-emitting device. Note that a mask layer is sometimes referred to as a sacrificial layer.

[0182] In addition, the light-emitting device 130 a , the light-emitting device 130 b , and the light-emitting device 130 c may not include the common layer 114 .

[0183] By providing the insulating layer 127 so as to fill recesses or steps between light-emitting devices included in adjacent sub-pixels, it is possible to improve coverage with the common electrode 115. As the insulating layer 127, an insulating layer made of an organic material can be preferably used.

[0184] The insulating layer 127 is provided to cover the ends of the layers 113a, 113b, and 113c. The insulating layer 127 includes openings 139a, 139b, and 139c in regions overlapping the pixel electrodes 111a, 111b, and 111c, respectively.

[0185] Alternatively, the insulating layer 125 may be provided so as to cover each end portion of the layer 113a, the layer 113b, and the layer 113c. In this case, for example, the insulating layer 127 may be provided on the insulating layer 125. The insulating layer 125 may be an insulating layer made of an inorganic material. Alternatively, a mask layer 118 may be provided between the top surface of the layer 113a, the top surface of the layer 113b, and the top surface of the layer 113c and the insulating layer 125 or the insulating layer 127. Note that each mask layer 118 provided on the layer 113a, the layer 113b, and the layer 113c may be provided by a different process, and thus each mask layer may be referred to as the mask layer 118a, the mask layer 118b, and the mask layer 118c.

[0186] An opening is provided in the insulating layer 125 using the insulating layer 127 as a mask. An opening is provided in the mask layer 118 using the insulating layer 127 or the insulating layer 125 as a mask.

[0187] exist Figure 2C In the structure shown, light emitting devices 130a, 130b, and 130c are provided on the layer 101 having transistors. An insulating layer 255 is an insulating layer on the transistors.

[0188] The insulating layer 125 and the insulating layer 127 are preferably provided so as to fill the recesses between adjacent light-emitting devices. By providing the insulating layer 125 and the insulating layer 127, the coverage of the common electrode 115, the common layer 114, and the protective layer 131 can be improved. In addition, by providing the insulating layer 125 and the insulating layer 127, a short circuit between the pixel electrode and the common electrode can sometimes be suppressed. In addition, in the display device 100, the insulating layer 125 and the insulating layer 127 may be provided with an opening in the region overlapping with the pixel electrode. By providing the opening in the insulating layer 125 and the insulating layer 127, a layer above the light-emitting device, such as the common layer 114, can be provided in the opening so as to contact the island EL layer or the island layer consisting of a portion of the EL layer.

[0189] Each light-emitting region of the light-emitting device 130 a , the light-emitting device 130 b , and the light-emitting device 130 c is, for example, a region overlapping with the openings of the insulating layer 125 and the insulating layer 127 .

[0190] In a display device according to one embodiment of the present invention, no insulating layer (sometimes referred to as a partition wall, dam, bank, spacer, etc.) is provided between the pixel electrode 111a and the layer 113a, between the pixel electrode 111b and the layer 113b, and between the pixel electrode 111c and the layer 113c to cover the top surface ends of the pixel electrodes 111a, 111b, and 111c, respectively. Therefore, the intervals between adjacent light-emitting devices can be made extremely narrow. Therefore, a high-definition or high-resolution display device can be realized.

[0191] In the display device of this embodiment, for example, the distance between light-emitting devices, the distance between layers 113, or the distance between pixel electrodes can be set to less than 10 μm, less than 8 μm, less than 5 μm, less than 3 μm, less than 2 μm, less than 1 μm, less than 500 nm, less than 200 nm, less than 100 nm, less than 90 nm, less than 70 nm, less than 50 nm, less than 30 nm, less than 20 nm, less than 15 nm, or less than 10 nm. In other words, the display device of this embodiment has a region where the interval between two adjacent island layers 113 is less than 1 μm, preferably has a region where the interval is less than 0.5 μm (500 nm), and more preferably has a region where the interval is less than 100 nm. In addition, for example, by using an exposure device for LSI, the interval between adjacent light-emitting devices can be reduced to less than 500 nm, less than 200 nm, less than 100 nm, or even less than 50 nm. As a result, the area of ​​the non-luminous region that can exist between two light-emitting devices can be greatly reduced, and the aperture ratio can be made close to 100%. For example, an aperture ratio of 50% or more, 60% or more, 70% or more, 80% or more, or even 90% or more and less than 100% may be achieved.

[0192] Note that a display device of one embodiment of the present invention may also adopt any one of the following structures: a top-surface emission structure (top emission structure) that emits light in a direction opposite to the substrate on which the light-emitting device is formed, a bottom-surface emission structure (bottom emission structure) that emits light to one side of the substrate on which the light-emitting device is formed, or a dual-surface emission structure (dual emission) that emits light to both sides.

[0193] Figure 1D yes Figure 1A 1 is an enlarged view of a region A surrounded by a dotted line in FIG. In region A, the pixel portion 284 , the dummy pixel portion 294 , and the peripheral region 297 are arranged in this order in the X direction.

[0194] The dummy pixel portion 294 includes a plurality of dummy pixels 51. For example, the dummy pixel 51 may have the same structure as the pixel 110, or may have a structure in which some components of the pixel 110 are omitted.

[0195] The display device 100 includes a display portion. The display portion is an area where an image is displayed, and is also an area where light emitted by each pixel provided in the pixel portion 284 can be seen. The pseudo pixel portion 294 is, for example, an area that does not contribute to the display of an image (also referred to as a non-display area). Thus, for example, in the case where the pseudo pixel 51 has the same structure as that used for a light-emitting device, such as a structure in which an EL layer is sandwiched between a pixel electrode and a common electrode, a potential difference that causes the structure to emit light is not supplied between the pixel electrode and the common electrode. As an example, sometimes the pixel electrodes included in the pseudo pixel 51 (the pixel electrode 111e, the pixel electrode 111f, and the pixel electrode 111g to be described later) are not electrically connected to the wiring and circuits included in the display device.

[0196] Alternatively, for example, when the dummy pixel 51 has a function of emitting light, the light is shielded. For example, a light shielding portion may be provided so as to overlap with the dummy pixel portion to shield the light.

[0197] Sometimes the dummy pixel 51 does not include an EL layer. Furthermore, sometimes the dummy pixel 51 does not include a layer having a light-emitting layer. For example, sometimes the dummy pixel 51 does not include layers formed by processing a film to become the layer 113a, a film to become the layer 113b, and a film to become the layer 113c (films 113af, 113bf, and 113cf described later).

[0198] The dummy pixels 51 are preferably arranged along the rows or columns in which the pixels 110 are arranged. In addition, it can be said that the pixels 110 and the dummy pixels 51 are arranged in a matrix in the pixel portion 284 and the dummy pixel portion 294 .

[0199] The arrangement interval of the plurality of dummy pixels 51 included in the dummy pixel portion 294 is preferably substantially the same as the arrangement interval of the pixels 110 included in the pixel portion 284. For example, the arrangement interval of the dummy pixels 51 is not less than 0.8 times and not more than 1.2 times the arrangement interval of the pixels 110. More specifically, the arrangement interval of the plurality of dummy pixels 51 arranged in the row direction in the dummy pixel portion 294 is preferably substantially the same as the arrangement interval of the plurality of pixels 110 arranged in the row direction in the pixel portion 284. Furthermore, the arrangement interval of the plurality of dummy pixels 51 arranged in the column direction in the dummy pixel portion 294 is preferably substantially the same as the arrangement interval of the plurality of pixels 110 arranged in the column direction in the pixel portion 284.

[0200] Furthermore, the interval between a dummy pixel adjacent to a pixel 110 of the pixel section 284 in the dummy pixel section 294 and the adjacent pixel 110 is preferably substantially the same as the interval between pixels 110 in the pixel section 284. More specifically, the interval between a dummy pixel 51 adjacent to a pixel 110 of the pixel section 284 in the row direction in the dummy pixel section 294 and the adjacent pixel 110 is preferably substantially the same as the interval between pixels 110 adjacent to the pixel section 284 in the row direction. Furthermore, the interval between a dummy pixel 51 adjacent to a pixel 110 of the pixel section 284 in the column direction in the dummy pixel section 294 and the adjacent pixel 110 is preferably substantially the same as the interval between pixels 110 adjacent to the pixel section 284 in the column direction.

[0201] The dummy pixel portion 294 includes a plurality of dummy pixels 51 arranged in a matrix. Figure 1D In the example of the dummy pixel portion 294 shown, three columns of dummy pixels 51 are arranged in the X direction. However, the dummy pixels 51 included in the dummy pixel portion 294 in the region A are not limited to three columns. The dummy pixels 51 are preferably arranged in one or more columns, but may also be arranged in four or more columns, for example, in a range of one or more columns and five or less, or in a range of one or more columns and three or less.

[0202] By disposing dummy pixels 51 in dummy pixel sections 294 surrounding pixel sections 284 and arranging the pixels 110 and dummy pixels 51 so that they are continuous, the influence of the surrounding area on pixel sections 284 is suppressed, and the unevenness in the characteristics of the light-emitting devices provided in each pixel can be reduced. Furthermore, the reliability of the light-emitting devices can be improved, thereby enhancing the display quality of display device 100.

[0203] When an organic insulating layer is used as the insulating layer 127, gas may be released from the organic insulating layer. In the display device according to one embodiment of the present invention, although the display device can improve resolution by utilizing photolithography or the like, the pixel area decreases when the resolution is high. Therefore, even a very small amount of released gas may affect the characteristics and reliability of the light-emitting device.

[0204] The opening of the insulating layer 127 is provided so as to overlap with the pixel electrode of the light-emitting device, and, for example, the region of the light-emitting device that overlaps with the opening becomes the light-emitting region. Furthermore, in regions where no light-emitting device is provided, such as the peripheral region of the pixel portion 284, the insulating layer 127 may not have an opening. The area of ​​the insulating layer 127 varies in regions where no opening is provided, and the amount of gas released from the insulating layer 127 depends on the area of ​​the insulating layer 127. Therefore, the amount of gas released from the insulating layer 127 may differ between regions where an opening is provided and regions where no opening is provided. Similarly, in a dummy pixel portion where no light-emitting device is provided, for example, by making the area of ​​the opening of the insulating layer 127 consistent with that of the pixel portion 284, the influence of the insulating layer 127 can be made substantially the same between pixels 110 located near the dummy pixel portion and pixels 110 located inside the dummy pixel portion in the pixel portion 284, thereby reducing variations in the characteristics and reliability of the light-emitting device included in each pixel 110 among the plurality of pixels 110.

[0205] In the dummy pixel 51, the insulating layer 127 preferably includes one or more openings. In a plan view, the ratio of the total area of ​​the openings included in the dummy pixel 51 by the insulating layer 127 to the total area of ​​the pixel 110 is denoted as R51, and the ratio of the total area of ​​the openings included in the pixel 110 by the insulating layer 127 to the total area of ​​the pixel 110 is denoted as R51. Figure 2B The ratio of the total area of ​​the openings 139a, 139b, and 139c in the image is denoted as R110. Preferably, the values ​​of R51 and R110 are equal or close to each other. For example, R51 is 0.8 times or more and 1.2 times or less of R110.

[0206] Figure 3A is an example of a top view of a pseudo pixel 51. Figure 3C It is along Figure 3A An example of a cross-sectional view taken along the dashed line Y1-Y2 is shown.

[0207] Figure 3A The pseudo pixel 51 shown includes a pseudo sub-pixel 51a, a pseudo sub-pixel 51b, and a pseudo sub-pixel 51c. The pseudo sub-pixel 51a includes a pixel electrode 111e and a layer 113e on the pixel electrode 111e, the pseudo sub-pixel 51b includes a pixel electrode 111f and a layer 113f on the pixel electrode 111f, and the pseudo sub-pixel 51c includes a pixel electrode 111g and a layer 113g on the pixel electrode 111g. Figure 3A Although description thereof is omitted, a common layer 114 and a common electrode 115 are provided so as to cover the layer 113e, the layer 113f, and the layer 113g.

[0208] When viewed from above, the shape and area of ​​the pixel 110 are preferably substantially identical to those of the dummy pixel 51. Furthermore, the top surface shapes and configurations of the pixel electrodes 111a, 111b, and 111c in the pixel 110 can be substantially identical to the configurations of the pixel electrodes 111e, 111f, and 111g in the dummy pixel 51, respectively.

[0209] The layers 113 e , 113 f , and 113 g may have top surface shapes substantially identical to those of the layers 113 a , 113 b , and 113 c , respectively.

[0210] exist Figure 3A In the structure shown, the insulating layer 127 is provided to cover each of the end portions of the layers 113e, 113f, and 113g, and the insulating layer 127 includes an opening in a region overlapping each of the pixel electrodes 111e, 111f, and 111g.

[0211] When viewed from above, the shapes and areas of the opening of the insulating layer 127 in the area overlapping with the pixel electrode 111e, the opening of the insulating layer 127 in the area overlapping with the pixel electrode 111f, and the opening of the insulating layer 127 in the area overlapping with the pixel electrode 111g can be roughly consistent with the shapes and areas of the opening 139a, the opening 139a, and the opening 139a, respectively.

[0212] The pixel electrodes 111e and 111a are formed by processing the same conductive film, for example. The pixel electrodes 111f and 111b are formed by processing the same conductive film, for example. The pixel electrodes 111g and 111c are formed by processing the same conductive film, for example.

[0213] The thickness of the pixel electrodes obtained by processing the same conductive film is preferably substantially the same. The difference in thickness between the two pixel electrodes obtained by processing the same conductive film is preferably less than 30% of the thickness of one pixel electrode, more preferably less than 20%, and even more preferably less than 10%.

[0214] The layer 113e and the layer 113a, the layer 113f and the layer 113b, and the layer 113g and the layer 113c can be formed by processing the same film.

[0215] Furthermore, the layers 113e, 113f, 113g, and 113a can be formed by processing the same film. The layers 113e, 113f, 113g, and 113b can also be formed by processing the same film. The layers 113e, 113f, 113g, and 113c can also be formed by processing the same film.

[0216] Figure 3BYes Figure 1D The region 61 shown is a top view with additional components. The region 61 is a part of the peripheral region 297. Figure 3D Shown along Figure 3B An example of a cross-sectional view along the dashed line Z1-Z2 is shown.

[0217] The peripheral region 297 includes, for example, the layer 113 h on the insulating layer 255 and the insulating layer 127 on the insulating layer 255 and the layer 113 h .

[0218] In the manufacturing process of the display device according to one embodiment of the present invention, layers 113a, 113b, and 113c can be processed without using a metal mask. Meanwhile, during the deposition of the films that will become layers 113a, 113b, and 113c (films 113af, 113bf, and 113cf described later), a mask (hereinafter referred to as a range mask, sometimes also referred to as a rough metal mask) is used to define the deposition area.

[0219] Preferably, the films 113af, 113bf, and 113cf formed using the range mask are all formed, for example, outside the dummy pixel portion 294, and their ends are located in the peripheral region 297. In other words, the ends of the films 113af, 113bf, and 113cf are preferably not located outside the peripheral region 297.

[0220] When depositing films 113af, 113bf, and 113cf using a range mask, the thickness of the films around them may gradually decrease toward the ends. In areas where the film thickness gradually decreases, the thickness of the EL layer may not match the desired value, potentially causing uneven characteristics of the light-emitting device. Therefore, it is preferable not to place a light-emitting device in such areas.

[0221] In addition, in the region where the film is gradually thinned, the time required to etch the film 113af, the film 113bf, the film 113cf, etc. is short when processing the layer 113a, the layer 113b, the layer 113c, etc., so the etching may be excessive and the insulating layer 255 under it may also be etched. Figure 3D In the illustrated structural example, patterning of the films 113af, 113bf, and 113cf is not performed in regions where the film thickness gradually decreases, and the layer 113h is formed as a layer that is not patterned.

[0222] Figure 3DThe illustrated layer 113h is formed from any one of the films 113af, 113bf, and 113cf. Alternatively, the layer 113h may be formed from a stack of two or more films selected from the films 113af, 113bf, and 113cf. The layer 113h gradually becomes thinner toward the end of the peripheral region 297.

[0223] Note that in patterns with a larger area than layers 113a, 113b, and 113c, such as layer 113h, layer 113h may be more easily delaminated from insulating layer 255. Appropriately covering layer 113h with insulating layer 127 can sometimes suppress film delamination of layer 113h. It is preferable that at least the side surfaces and ends of layer 113h be covered with insulating layer 127. Stress may cause film separation at the ends of layer 113h. When the ends of layer 113h are exposed, etching gas, etchant, or the like may enter the bottom surface of layer 113h during the manufacturing process of layer 113h and the layers above it. Covering the side surfaces and ends of layer 113h with insulating layer 127 can sometimes suppress film delamination of layer 113h from insulating layer 255.

[0224] like Figure 4A As shown, the following structure can also be adopted in the peripheral region 297: a conductive layer 111h is provided on the insulating layer 255, and a layer 113h is provided on the conductive layer 111h. For example, the shape, arrangement interval, and area of ​​the conductive layer 111h and the pixel electrode 111e can be the same or different.

[0225] The top surface shape, size, pattern spacing, etc. of the conductive layer 111h can refer to the pixel electrodes 111e, 111f, and 111g. Furthermore, the shape, size, pattern spacing, etc. of the conductive layer 111h can be different from those of the pixel electrodes 111e, 111f, and 111g.

[0226] When an island-shaped conductive layer is provided on the insulating layer 255 as the conductive layer 111h, sometimes in the manufacturing process of the display device, the adhesion of the formed surface of the layer above the conductive layer 111h, such as the film which will become the layer 113h, the common layer 114, the common electrode 115, etc., is improved, and the stability of the manufacturing process is improved.

[0227] exist Figure 3D and Figure 4A In the embodiment, the insulating layer 127 covers the top surface, side surfaces, and ends of the layer 113 h , and no opening is provided in the insulating layer 127 .

[0228] like Figure 4B and Figure 4CAs shown, an opening may be provided in the insulating layer 127. Note that when an opening is provided in the insulating layer 127, the opening preferably does not overlap with an end portion of the layer 113h. Figure 4B Shown in Figure 3D The example of the structure shown in which the opening is provided in the insulating layer 127 is shown in FIG. Figure 4C Shown in Figure 4A The structure shown is an example in which an opening is provided in the insulating layer 127 .

[0229] also, Figure 4A The layer 113h is shown as an example of a large pattern, but as Figure 4D As shown, in region 61, layer 113h (hereinafter, layer 113h_1) covering the first conductive layer 111h near the Z1 side may be processed into an island shape similar to layer 113e, and layer 113h (hereinafter, layer 113h_2) covering the second and subsequent conductive layers 111h near the Z1 side may not be formed into an island shape but into a single large pattern. Alternatively, in region 61, each of layers 113h (hereinafter, layer 113h_1) covering the first to p-th (p is an integer greater than or equal to 2) conductive layers 111h near the Z1 side may be processed into an island shape similar to layer 113e, and layer 113h (hereinafter, layer 113h_2) covering the (p+1)-th and subsequent conductive layers 111h near the Z1 side may not be formed into an island shape but into a single large pattern.

[0230] By providing the openings in the insulating layer 127, the total area of ​​the insulating layer 127 can be reduced. Thus, the amount of gas released from the insulating layer 127 can be reduced.

[0231] exist Figure 5A In, as Figure 3C A modified example of the dummy pixel 51 shown is a dummy pixel 51_2 .

[0232] Figure 5A The pseudo pixel 51_2 shown is Figure 3C The difference between the dummy pixel 51 shown is that it includes layer 113x instead of layers 113e, 113f, and 113g. Note that layers 113e, 113f, and 113g are all formed as islands, while layer 113x is provided across a large area within pixel electrodes 111e, 111f, and 111g. Layers 113e, 113f, and 113g differ from layer 113x in this respect. For example, layer 113x is formed by processing a stack of one or more layers of a film to become layer 113e, a film to become layer 113f, a film to become layer 113g, and a mask film used in the manufacturing process of each layer.

[0233] Figure 5B ShowFigure 1D The example of the variation of the structure of the region A shown in FIG. Figure 5B In the dummy pixel portion 294, the dummy pixel 51_2 is used to replace a portion of the dummy pixel 51. Specifically, in the dummy pixel portion 294, the dummy pixel 51_2 is used to replace the dummy pixel adjacent to the peripheral area 297 and the dummy pixel in the vicinity thereof.

[0234] In the dummy pixel 51, an opening is provided in the insulating layer 127. However, for example, a dummy pixel having a structure in which no opening is provided in the insulating layer 127 may be provided instead of a part of the plurality of dummy pixels 51. Specifically, for example, Figure 5C A pseudo pixel 52 is shown. Figure 5C The pseudo pixel 52 shown is Figure 3C The dummy pixel 51 shown is different in that no opening is provided in the insulating layer 127 .

[0235] Note that the dummy pixels 51 are preferably arranged along the rows or columns in which the pixels 110 are arranged, but may also be arranged at positions slightly offset from the rows or columns. In this case, for example, the spacing in the X direction and the spacing in the Y direction of the arranged plurality of dummy pixels 51 are made substantially equal to the spacing in the X direction and the spacing in the Y direction of the arranged plurality of pixels 110.

[0236] Figure 6A 2 shows the region adjacent to the pixel portion 284 in the X direction in the pixel portion 284 and the dummy pixel portion 294. Figure 6B Only excerpts are shown Figure 6A The insulating layer 127 is one of the components shown. The insulating layer 127 is continuously provided in two regions, and a plurality of openings are provided in each of the two regions.

[0237] Figure 7A yes Figure 1A An enlarged view of the region B surrounded by a dotted line in FIG. In the region B, the pixel portion 284, the dummy pixel portion 294, and the peripheral region 297 are sequentially arranged in the Y direction. Figure 7A In the example of the dummy pixel portion 294 shown, three rows of dummy pixels 51 are arranged in the Y direction. However, the number of rows of dummy pixels 51 included in the dummy pixel portion 294 in the region B is not limited to three rows. Preferably, there is one or more rows, and four or more rows may be used, for example, one or more rows and five or less, or one or more rows and three or less.

[0238] Figure 7B Yes Figure 7A The region 62 shown is a top view with additional components. The region 62 is a part of the peripheral region 297. Figure 7B The cross section along the dotted line Z1-Z2 shown can be referred to Figure 3D 、 Figure 4A 、 Figure 4B 、 Figure 4C wait.

[0239] Figure 8A yes Figure 1A 1 is an enlarged view of a region C surrounded by a dotted line in FIG. The region C includes the pixel portion 284 , a dummy pixel portion 294 located around the pixel portion 284 , and a peripheral region 297 located outside the dummy pixel portion 294 . Figure 8A The dummy pixel portion 294 shown in the figure shows an example in which the dummy pixels 51 are arranged in three circles. However, the dummy pixels 51 included in the dummy pixel portion 294 in the region B are not limited to three circles. Preferably, the dummy pixels 51 are arranged in a circle of one or more, and may be arranged in a circle of four or more, for example, one or more and five or less, or one or more and three or less.

[0240] Figure 8B Yes Figure 8A The region 63 shown is a top view with additional components. The region 63 is a part of the peripheral region 297. Figure 8B The cross section along the dotted line Z1-Z2 shown can be referred to Figure 3D 、 Figure 4A 、 Figure 4B 、 Figure 4C wait.

[0241] Figure 9 FIG. 1 shows an example in which the display device 100 includes a connection portion 140 surrounding four sides of the display portion. Figure 9 In the embodiment, the connection portion 140 is arranged outside the peripheral region 297. The connection portion 140 is sometimes referred to as a cathode contact portion.

[0242] Figure 10A yes Figure 9 An enlarged view of the area D surrounded by a dotted line in FIG. Figure 10B Shown along Figure 10A An example of a cross-sectional view taken along the dashed line W1 - W2 is shown.

[0243] The connection portion 140 includes a conductive layer 123 and a common electrode 115. In the connection portion 140, the common electrode 115 and the conductive layer 123 are electrically connected.

[0244] exist Figure 10AIn the illustrated structural example, the outer side of peripheral region 297 includes an area where insulating layer 127 is not provided, and insulating layer 127 is provided in connection portion 140 outside this area. Furthermore, insulating layer 127 has an opening in the area overlapping conductive layer 123. Furthermore, mask layer 118 may be provided between the top surface of conductive layer 123 and insulating layer 125, or between the top surface of conductive layer 123 and insulating layer 127. Note that mask layer 118 provided on conductive layer 123 may sometimes be referred to as mask layer 118j in the following description of the manufacturing method.

[0245] When the common layer 114 in the connection portion 140 has low conductivity, a structure in which the common layer 114 is not provided in the connection portion 140 may be adopted. In addition, the conductive layer 123 included in the connection portion 140 may be formed using the same material and process as at least one of the pixel electrodes 111a, 111b, and 111c.

[0246] Note that in Figure 9 , the example in which the connection portion 140 is arranged so as to surround the four sides of the display portion when viewed from above is shown, but there is no particular limitation. The connection portion 140 can be arranged in at least one of the upper side, right side, left side, and lower side of the display portion when viewed from above. For example, the connection portion 140 can also be arranged along three sides. The top surface shape of the connection portion 140 can be, for example, a strip shape, an L shape, a U shape, or a frame shape. In addition, the connection portion 140 can also be one or more.

[0247] <Light-emitting device>

[0248] As the light-emitting device 130a, the light-emitting device 130b, and the light-emitting device 130c, for example, OLED (Organic Light Emitting Diode) and QLED (Quantum-dot Light Emitting Diode) can be cited. As the light-emitting substance contained in the light-emitting device, a substance that emits fluorescence (fluorescent material), a substance that emits phosphorescence (phosphorescent material), a substance that exhibits thermally activated delayed fluorescence (thermally activated delayed fluorescence (TADF) material) can be cited. Note that as a TADF material, a material that is in thermal equilibrium between a singlet excited state and a triplet excited state can also be used. Since this TADF material has a short luminescence lifetime (excitation lifetime), it can suppress the reduction in efficiency in the high brightness area of ​​the light-emitting device. As the light-emitting substance contained in the EL element, in addition to organic compounds, inorganic compounds (quantum dot materials, etc.) can also be used.

[0249] There is no particular limitation on the structure of the light-emitting device of this embodiment, and a single structure or a tandem structure may be employed.

[0250] Note that in the following description of the contents common to light-emitting devices 130a, 130b, and 130c, the symbols may be omitted and the components may be referred to as light-emitting devices 130. Similarly, layers 113a, 113b, and 113c may be referred to as layers 113. Similarly, pixel electrodes 111a, 111b, and 111c may be referred to as pixel electrodes 111.

[0251] In this embodiment, the island-shaped layers provided for each light-emitting device in the EL layer included in the light-emitting device are referred to as layers 113a, 113b, and 113c, and the layer included in common by multiple light-emitting devices is referred to as a common layer 114. Note that in this specification and other documents, the layers 113a, 113b, and 113c excluding the common layer 114 may be referred to as EL layers.

[0252] Layer 113a, layer 113b, and layer 113c preferably include at least a light-emitting layer. For example, layer 113a, layer 113b, and layer 113c preferably include a light-emitting layer emitting red light, a light-emitting layer emitting green light, and a light-emitting layer emitting blue light, respectively.

[0253] In addition, each of the layer 113a, the layer 113b, and the layer 113c may include one or more of a hole injection layer, a hole transport layer, a hole blocking layer, a charge generation layer, an electron blocking layer, an electron transport layer, and an electron injection layer.

[0254] For example, layer 113a, layer 113b, and layer 113c may include a hole injection layer, a hole transport layer, a light-emitting layer, and an electron transport layer. Furthermore, an electron blocking layer may be included between the hole transport layer and the light-emitting layer. Furthermore, an electron injection layer may be included on the electron transport layer.

[0255] For example, layer 113a, layer 113b, and layer 113c may include an electron injection layer, an electron transport layer, a light-emitting layer, and a hole transport layer in that order. Furthermore, a hole blocking layer may be included between the electron transport layer and the light-emitting layer. Furthermore, a hole injection layer may be included on the hole transport layer.

[0256] Layers 113a, 113b, and 113c preferably include a light-emitting layer and a carrier transport layer (electron transport layer or hole transport layer) on the light-emitting layer. Because the surfaces of layers 113a, 113b, and 113c are exposed during the display device manufacturing process, providing a carrier transport layer on the light-emitting layer can prevent the light-emitting layer from being exposed to the outermost surface, thereby reducing damage to the light-emitting layer. This can improve the reliability of the light-emitting device.

[0257] Layer 113a, layer 113b, and layer 113c each include, for example, a first light-emitting unit, a charge generation layer, and a second light-emitting unit. For example, preferably, layer 113a includes two or more light-emitting units that emit red light, layer 113b includes two or more light-emitting units that emit green light, and layer 113c includes two or more light-emitting units that emit blue light.

[0258] The second light-emitting unit preferably includes a light-emitting layer and a carrier transport layer (electron transport layer or hole transport layer) on the light-emitting layer. Because the surface of the second light-emitting unit is exposed during the manufacturing process of the display device, providing a carrier transport layer on the light-emitting layer can prevent the light-emitting layer from being exposed to the outermost surface, thereby reducing damage to the light-emitting layer. This can improve the reliability of the light-emitting device.

[0259] The common layer 114 may include, for example, an electron injection layer or a hole injection layer. Alternatively, the common layer 114 may include a stack of an electron transport layer and an electron injection layer, or a stack of a hole transport layer and a hole injection layer. The light-emitting devices 130a, 130b, and 130c may all include the common layer 114.

[0260] Here, between the layer 113 and the common layer 114, sometimes Figure 2D As shown, a protective layer 116 is provided. The protective layer 116 is preferably formed thin enough not to hinder the function of the light emitting device. In addition, the protective layer 116 may be formed in an island shape rather than a layer shape.

[0261] For example, in a light-emitting device of one embodiment of the present invention, as an example, when the light-emitting device includes a hole transport layer, a hole injection layer, a light-emitting layer, an electron transport layer and an electron injection layer, layer 113 includes a hole transport layer, a hole injection layer, a light-emitting layer and an electron transport layer, and the common layer 114 includes an electron injection layer, a protective layer 116 is sometimes arranged between the electron transport layer included in layer 113 and the electron injection layer included in the common layer.

[0262] Providing the protective layer 116 can reduce surface damage to the layer 113 and suppress degradation of the layer 113 when the layer 113 is exposed to the atmosphere, for example, from the processing of the insulating film 125A using the insulating layer 127 as a mask and the processing of the mask layer 118 until the formation of the common layer 114, while the protective layer 116 is formed. Furthermore, surface degradation and the formation of another layer on the surface caused by exposure to the atmosphere can be suppressed, thereby reducing the driving voltage of the light-emitting device. Furthermore, the reliability of the light-emitting device can be improved.

[0263] As the protective layer 116 , for example, a material that can be used as the protective layer 131 described later can be used.

[0264] If the protective layer 116 is too thick, the driving voltage of the light-emitting device may increase. Therefore, for example, the thickness of the protective layer 116 is preferably 2 nm or less. For example, an aluminum oxide film with a thickness of 2 nm or less can be used as the protective layer 116.

[0265] In addition, the mask layer 118 removed by etching may remain between the electron transport layer included in the layer 113 and the electron injection layer included in the common layer, and the mask layer 118 may be used as the protective layer 116 .

[0266] Note that the protective layer 116 is provided on the layer 113 so as to cover the insulating layer 127. Thus, when a material having a barrier property against a gas such as oxygen is used as the protective layer 116, upward release of the gas from the insulating layer 127 can be suppressed.

[0267] In the light-receiving device described later, the active layer of the photoelectric conversion device is used as the layer 113 , and a protective layer 116 is provided on the layer 113 . This may improve the reliability of the light-receiving device.

[0268] A display device according to one embodiment of the present invention can have layers 113a through 113c with varying thicknesses. The thicknesses can be set based on the optical path length that enhances the light emitted by each layer 113a through 113c. This allows for a microcavity structure to be implemented, improving the color purity of each light-emitting device.

[0269] The thickness of the layer 113 and the like may be set so that the optical path length relative to the wavelength λ of light obtained from the light-emitting layer of the light-emitting device is mλ / 2 (m is a natural number) or in the vicinity thereof.

[0270] When the light emitting device 130a is red, the light emitting device 130b is green, and the light emitting device 130c is blue, and m in mλ / 2 is the same, for example, the layer 113a emitting light with the longest wavelength is the thickest, and the layer 113c emitting light with the shortest wavelength is the thinnest. Figure 7A An example is shown in which, among the layers 113 a to 113 c , the layer 113 a is the thickest, the layer 113 c is the thinnest, and the layer 113 b is thinner than the layer 113 a and thicker than the layer 113 c .

[0271] On the other hand, when the value of m is different in each light-emitting device, the present invention is not limited to this. For example, the layer 113c included in the light-emitting device that emits blue may be the thickest.

[0272] Note that the present invention is not limited thereto, and the thickness of each layer may be adjusted in consideration of the wavelength of light emitted by each light-emitting device, the optical characteristics of the layers constituting the light-emitting device, the electrical characteristics of the light-emitting device, and the like.

[0273] Note that the optical path length in the light-emitting device can be adjusted not only by varying the thicknesses of layers 113a and 113c but also by varying the thicknesses of pixel electrodes 111a and 111c. Specifically, for example, when pixel electrode 111 is a reflective electrode comprising a stacked structure of a reflective conductive material (reflective conductive film) and a translucent conductive material (transparent conductive film), varying the thickness of the transparent conductive film between light-emitting devices of different colors allows for an optical path length suitable for each color.

[0274] When layers 113a to 113c include a white light-emitting layer, they can be formed by, for example, processing the same layer. Layers 113a to 113c formed by processing the same film can have, for example, substantially the same thickness. In this case, the optical path length is preferably adjusted by adjusting the thickness of the transparent conductive film included in the pixel electrode. Figure 8A An example is shown in which the pixel electrode 111 a is the thickest, the pixel electrode 111 c is the thinnest, and the pixel electrode 111 b is thinner than the pixel electrode 111 a and thicker than the pixel electrode 111 c .

[0275] The optical path length in the light emitting device depends on, for example, the total thickness of the transparent conductive film, the layer 113 , and the common layer 114 included in the pixel electrode 111 .

[0276] For the sake of simplicity, the drawings in this specification sometimes do not show that the thickness of the layer 113 and the pixel electrode 111 of each light-emitting device is clearly different, but it is preferable to appropriately adjust the thickness in each light-emitting device and enhance the light of the wavelength corresponding to each light-emitting device.

[0277] <Detailed Description of Components of Display Device>

[0278] The top surface of the insulating layer 127 is preferably as flat as possible, but may have a gently curved surface. For example, the top surface of the insulating layer 127 may be convex, concave, or flat.

[0279] like Figure 2C As shown in FIG. 1 , the insulating layer 125 and the insulating layer 127 preferably cover a portion of the top surface of the island-shaped layer 113a, layer 113b, or layer 113c. Covering the side surfaces and top surface of the island-shaped layer 113a, layer 113b, or layer 113c with the insulating layer 125 and the insulating layer 127 further prevents film peeling of the layer 113a, layer 113b, or layer 113c, thereby improving the reliability of the light-emitting device. Furthermore, the manufacturing yield of the light-emitting device can be further improved.

[0280] The insulating layer 127 is provided on the insulating layer 125 so as to fill the recess formed in the insulating layer 125. The insulating layer 127 can have a structure overlapping with a portion of the top surfaces and side surfaces of the layers 113a, 113b, and 113c with the insulating layer 125 interposed therebetween.

[0281] By providing the insulating layers 125 and 127, the gaps between adjacent island layers can be filled. This can reduce the unevenness of the formed surface of layers (e.g., the carrier injection layer and the common electrode) disposed on the island layers, thereby further flattening the surface. This improves the coverage of the carrier injection layer and the common electrode, thereby preventing disconnection of the common electrode.

[0282] Next, examples of materials and formation methods of the insulating layer 125 and the insulating layer 127 are described.

[0283] The insulating layer 125 may be an insulating layer composed of an inorganic material. For example, an inorganic insulating film such as an oxide insulating film, a nitride insulating film, an oxynitride insulating film, or a nitride oxide insulating film can be used as the insulating layer 125. The insulating layer 125 may have a single-layer structure or a stacked-layer structure. Examples of oxide insulating films include silicon oxide films, aluminum oxide films, magnesium oxide films, indium gallium zinc oxide films, gallium oxide films, germanium oxide films, yttrium oxide films, zirconium oxide films, lanthanum oxide films, neodymium oxide films, hafnium oxide films, and tantalum oxide films. Examples of nitride insulating films include silicon nitride films and aluminum nitride films. Examples of oxynitride insulating films include silicon oxynitride films and aluminum oxynitride films. Examples of nitride oxide insulating films include silicon oxynitride films and aluminum oxynitride films. Aluminum oxide is particularly preferred because it has a high selectivity with respect to the layer 113 during etching and functions as a protective layer 113 in the formation of the insulating layer 127 described later. In particular, by using an inorganic insulating film such as an aluminum oxide film, a hafnium oxide film, or a silicon oxide film formed by ALD as the insulating layer 125, it is possible to form an insulating layer 125 with few pinholes and a good function as the protective layer 113. Alternatively, the insulating layer 125 may have a stacked structure of a film formed by ALD and a film formed by sputtering. For example, the insulating layer 125 may have a stacked structure of an aluminum oxide film formed by ALD and a silicon nitride film formed by sputtering.

[0284] The insulating layer 125 preferably functions as a barrier insulating layer against at least one of water and oxygen. Furthermore, the insulating layer 125 preferably functions to suppress the diffusion of at least one of water and oxygen. Furthermore, the insulating layer 125 preferably functions to capture or immobilize (also known as gettering) at least one of water and oxygen.

[0285] When the insulating layer 125 has a barrier insulating layer function or a gettering function, it can have a structure that suppresses the entry of impurities (typically, at least one of water and oxygen) that might diffuse from the outside into each light-emitting device. This structure can provide a highly reliable light-emitting device and a highly reliable display device.

[0286] Furthermore, the impurity concentration of insulating layer 125 is preferably low. This can prevent impurities from entering layer 113 from insulating layer 125 and causing degradation of layer 113. Furthermore, by reducing the impurity concentration in insulating layer 125, the barrier properties against at least one of water and oxygen can be improved. For example, it is preferable that either the hydrogen concentration or the carbon concentration in insulating layer 125 be sufficiently low, and preferably both the hydrogen concentration and the carbon concentration be sufficiently low.

[0287] Examples of a method for forming the insulating layer 125 include sputtering, CVD, pulsed laser deposition (PLD), and ALD. The insulating layer 125 is preferably formed by ALD, which has good coverage.

[0288] By increasing the substrate temperature during deposition of insulating layer 125, it is possible to form insulating layer 125 that is thin, has a low impurity concentration, and exhibits high barrier properties against at least one of water and oxygen. Therefore, the substrate temperature is preferably 60°C or higher, more preferably 80°C or higher, even more preferably 100°C or higher, and even more preferably 120°C or higher. Meanwhile, insulating layer 125 is deposited after formation of island layer 113, so it is preferably formed at a temperature lower than the heat resistance temperature of layer 113. Therefore, the substrate temperature is preferably 200°C or lower, more preferably 180°C or lower, even more preferably 160°C or lower, even more preferably 150°C or lower, and even more preferably 140°C or lower.

[0289] Indicators of heat resistance include, for example, glass transition point, softening point, melting point, thermal decomposition temperature, and 5% weight loss temperature. The heat resistance temperature of layer 113 may be any of the above temperatures, but the lowest temperature among the above temperatures is preferably used.

[0290] The insulating layer 125 is preferably formed to have a thickness of, for example, 3 nm or more, 5 nm or more, or 10 nm or more and 200 nm or less, 150 nm or less, 100 nm or less, or 50 nm or less.

[0291] The insulating layer 127 provided on the insulating layer 125 has the function of flattening the large unevenness of the insulating layer 125 formed between adjacent light-emitting devices. In other words, the inclusion of the insulating layer 127 improves the flatness of the surface on which the common electrode 115 is formed.

[0292] An insulating layer composed of an organic material can be suitably used as insulating layer 127. A photosensitive organic resin, such as a photosensitive acrylic resin, is preferably used as the organic material. The viscosity of the material of insulating layer 127 can be from 1 cP to 1500 cP, preferably from 1 cP to 12 cP. By setting the viscosity of the material of insulating layer 127 within the above range, the tapered shape of insulating layer 127, described later, can be easily formed. Note that in this specification, etc., the term "acrylic resin" refers not only to polymethacrylate or methacrylic resin but also to acrylic polymers in a broader sense.

[0293] Note that the insulating layer 127 only needs to have a tapered shape on the side described later, and the organic material that can be used for the insulating layer 127 is not limited to the above-mentioned materials. For example, acrylic resin, polyimide resin, epoxy resin, imide resin, polyamide resin, polyimide amide resin, silicone resin, siloxane resin, benzocyclobutene resin, phenolic resin and precursors of the above resins can sometimes be used as the insulating layer 127. For example, organic materials such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinyl pyrrolidone, polyethylene glycol, polyglycerol, pullulan, water-soluble cellulose or alcohol-soluble polyamide resin can sometimes be used as the insulating layer 127. Photoresist can sometimes be used as the photosensitive resin. Positive or negative materials can sometimes be used as the photosensitive resin.

[0294] A material that absorbs visible light can also be used as the insulating layer 127. By absorbing the light emitted by the light-emitting device, the insulating layer 127 can suppress light leakage from the light-emitting device to adjacent light-emitting devices through the insulating layer 127 (stray light). This improves the display quality of the display device. Furthermore, even without using a polarizing plate in the display device, the display quality can be improved, thereby achieving a lighter and thinner display device.

[0295] Examples of materials that absorb visible light include materials containing pigments such as black, materials containing dyes, resin materials with light absorption properties (e.g., polyimide), and resin materials that can be used for color filters (color filter materials). In particular, the use of resin materials formed by laminating or mixing two or more color filter materials is preferred because it can enhance the visible light shielding effect. In particular, by mixing three or more color filter materials, a black or nearly black resin layer can be achieved.

[0296] The insulating layer 127 can be formed by a wet deposition method such as spin coating, dipping, spray coating, inkjet coating, dispenser coating, screen printing, offset printing, doctor blade coating, slit coating, roll coating, curtain coating, or blade coating, as appropriate. In particular, the organic insulating film to be the insulating layer 127 is preferably formed by spin coating.

[0297] The insulating layer 127 is formed at a temperature lower than the heat resistance temperature of the layer 113. The substrate temperature during formation of the insulating layer 127 is typically 200° C. or lower, preferably 180° C. or lower, more preferably 160° C. or lower, further preferably 150° C. or lower, and even more preferably 140° C. or lower.

[0298] A conductive film that transmits visible light is used as the electrode on the light-extracting side of the pixel electrode and the common electrode. Alternatively, a conductive film that reflects visible light is preferably used as the electrode on the side that does not extract light. Furthermore, when the display device includes a light-emitting device that emits infrared light, it is preferable to use a conductive film that transmits visible and infrared light as the electrode on the light-extracting side, and a conductive film that reflects visible and infrared light as the electrode on the side that does not extract light.

[0299] Alternatively, a conductive film that transmits visible light can be used as the electrode on the side that does not extract light. In this case, it is preferably placed between the reflective layer and the EL layer. In other words, the light emitted by the EL layer can also be reflected by the reflective layer and extracted from the display device.

[0300] Light-emitting devices preferably employ an optical microcavity resonator (microcavity) structure. Therefore, one of a pair of electrodes included in the light-emitting device is preferably an electrode that is both transmissive and reflective to visible light (a transflective electrode), while the other is preferably an electrode that is reflective to visible light (a reflective electrode). When a light-emitting device has a microcavity structure, the light emitted from the light-emitting layer can resonate between the two electrodes, thereby enhancing the light emitted from the light-emitting device.

[0301] Note that the transflective electrode may have a stacked-layer structure of a reflective electrode and an electrode transmissive to visible light (also referred to as a transparent electrode).

[0302] The light transmittance of the transparent electrode is set to 40% or more. For example, it is preferred to use an electrode with a transmittance of visible light (light with a wavelength of 400 nm or more and less than 750 nm) of 40% or more for a light-emitting device. The visible light reflectance of the transflective electrode is set to 10% or more and 95% or less, preferably 30% or more and 80% or less. The visible light reflectance of the reflective electrode is set to 40% or more and 100% or less, preferably 70% or more and 100% or less. In addition, the resistivity of the above-mentioned electrode is preferably 1×10 -2 Ωcm or less.

[0303] As the pixel electrode 111, for example, a metal material such as aluminum, magnesium, titanium, gold, platinum, silver, nickel, tungsten, chromium, manganese, molybdenum, iron, cobalt, copper, gallium, zinc, indium, tin, tantalum, palladium, yttrium or neodymium, or an alloy containing the above metal materials can be used. Copper is preferred because it has a high reflectivity for visible light. In addition, when aluminum is used, it is easy to etch the electrode and easy to process, and it has a high reflectivity for visible light and near-infrared light, so it is preferred. In addition, lanthanum, neodymium or germanium can be added to the above metal materials and alloys. In addition, an alloy containing aluminum (aluminum alloy) can also be used. For example, an alloy containing one or more selected from titanium, nickel and neodymium and aluminum (aluminum alloy), an alloy of aluminum, nickel and lanthanum (Al-Ni-La), etc. can be used. In addition, an alloy containing silver can also be used, such as an alloy of silver and magnesium, an alloy of silver, palladium and copper (Ag-Pd-Cu, also denoted as APC), an alloy containing copper, palladium, magnesium and silver, etc. An alloy containing silver and copper is preferred because of its high heat resistance.

[0304] In addition, for example, indium oxide, indium tin oxide (In-Sn oxide, also called ITO), In-Si-Sn oxide (also called ITSO. Or sometimes also called indium tin oxide containing silicon oxide), indium zinc oxide (In-Zn oxide), zinc oxide, zinc oxide added with gallium, and In-W-Zn oxide can be used to form the pixel electrode 111. In addition, it is also possible to use metal materials such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium or titanium, alloys containing these metal materials, or nitrides of these metal materials (for example, titanium nitride) that are thinned to a degree that they are light-transmitting. In addition, a multilayer film of the above materials can be used as a conductive layer. As an example, when a multilayer film of an alloy of silver, palladium and copper and In-Si-Sn oxide or a multilayer film of an alloy of silver and magnesium and indium tin oxide is used, the conductivity can be improved, so it is preferred. In addition, elements belonging to Group 1 or Group 2 of the periodic table (e.g., lithium, cesium, calcium, strontium), rare earth metals such as europium and ytterbium, and alloys of appropriately combined elements may also be used. Graphene may also be used.

[0305] As the pixel electrode 111 , a film containing the above-mentioned materials can be used in a single-layer or stacked-layer structure.

[0306] In addition, the pixel electrode 111 may also have a structure in which a conductive metal oxide film is stacked on a conductive film that reflects visible light. By adopting this structure, oxidation and corrosion of the conductive film that reflects visible light can be suppressed. For example, by stacking a metal film or a metal oxide film in contact with an aluminum film or an aluminum alloy film, oxidation can be suppressed. Examples of materials for such a metal film or metal oxide film include titanium or titanium oxide. In addition, the conductive film that transmits visible light may be stacked with a film made of a metal material. For example, a laminated film of silver and indium tin oxide, a laminated film of a silver and magnesium alloy and indium tin oxide, etc. may be used.

[0307] Each end of the pixel electrode 111a, the pixel electrode 111b, and the pixel electrode 111c preferably has a tapered shape. When the ends of these pixel electrodes have a tapered shape, the layers 113a, 113b, and 113c provided along the side surfaces of the pixel electrodes have inclined portions. By having the side surfaces of the pixel electrodes have a tapered shape, the coverage of at least a portion of the EL layer provided along the side surfaces of the pixel electrodes can be improved. In addition, by having the side surfaces of the pixel electrodes have a tapered shape, foreign matter (e.g., also referred to as dust or particles) in the manufacturing process can be easily removed by treatments such as washing, which is preferred.

[0308] In this specification, a tapered shape refers to a shape in which at least a portion of a side surface of a component is inclined relative to the substrate surface. For example, a region in which the angle formed by the inclined side surface and the substrate surface (also called a taper angle) is less than 90° is preferably included.

[0309] As the layer 101 having transistors, for example, a stacked structure may be used, wherein a plurality of transistors are provided on a substrate and an insulating layer is provided to cover these transistors. The insulating layer on the transistor may have either a single-layer structure or a stacked-layer structure. Figure 2C In FIG. 2 , an insulating layer 255 is shown as an insulating layer over the transistor.

[0310] A structural example of a layer including a transistor will be described in the following embodiment.

[0311] In at least a portion of the light-emitting region of the light-emitting device 130a, the pixel electrode 111a is in contact with, for example, the top surface of the insulating layer 255. Furthermore, in at least a portion of the light-emitting region of the light-emitting device 130b, the pixel electrode 111b is in contact with, for example, the top surface of the insulating layer 255. Furthermore, in at least a portion of the light-emitting region of the light-emitting device 130c, the pixel electrode 111c is in contact with, for example, the top surface of the insulating layer 255c.

[0312] The insulating layer 255 may also have a recess between adjacent light emitting devices. In addition, the insulating layer 255 may also be a single layer or a stacked structure of two or more layers.

[0313] As the insulating layer 255 , various inorganic insulating films such as an oxide insulating film, a nitride insulating film, an oxynitride insulating film, and a nitride oxide insulating film can be used as appropriate.

[0314] When the insulating layer 255 has a three-layer stacked structure, it is preferable to use an oxide insulating film or an oxynitride insulating film such as a silicon oxide film, a silicon oxynitride film, or an aluminum oxide film as the lower and upper layers, respectively, and to use a nitride insulating film or an oxynitride insulating film such as a silicon nitride film or a silicon oxynitride film as the layer interposed between the lower and upper layers. More specifically, it is preferable to use a silicon oxide film as the lower and upper layers, and to use a silicon nitride film as the layer interposed between the lower and upper layers.

[0315] In this specification, etc., "oxynitride" refers to a material containing more oxygen than nitrogen in its composition, and "oxynitride" refers to a material containing more nitrogen than oxygen in its composition. For example, "silicon oxynitride" refers to a material containing more oxygen than nitrogen in its composition, while "silicon oxynitride" refers to a material containing more nitrogen than oxygen in its composition.

[0316] exist Figure 2C In the embodiment of the present invention, a mask layer 118 is provided on the layer 113 included in the light emitting device 130a. The mask layer 118 is a remaining portion of the mask layer provided in contact with the top surface of the layer 113 when the layer 113 is processed.

[0317] As the mask layer, for example, one or more of a metal film, an alloy film, a metal oxide film, a semiconductor film, an inorganic insulating film, and an organic insulating film can be used.

[0318] Examples of metal films and alloy films that can be used include gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, titanium, aluminum, yttrium, zirconium, and tantalum, or alloys containing these metals. Low-melting-point materials such as aluminum and silver are particularly preferred. Using a metal material that blocks ultraviolet light as the mask layer 118 is preferred because it prevents ultraviolet light from reaching the EL layer and thus reduces degradation of the EL layer.

[0319] As the metal oxide film, for example, In-Ga-Zn oxide, indium oxide, In-Zn oxide, In-Sn oxide, indium titanium oxide (In-Ti oxide), indium tin zinc oxide (In-Sn-Zn oxide), indium titanium zinc oxide (In-Ti-Zn oxide), indium gallium tin zinc oxide (In-Ga-Sn-Zn oxide), etc. can be used. In addition, indium tin oxide containing silicon, etc. can be used.

[0320] Note that element M (M is one or more of aluminum, silicon, boron, yttrium, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, and magnesium) may be used instead of gallium.

[0321] As the inorganic insulating film, for example, the inorganic material described in the insulating layer 125 can be used. For example, aluminum oxide, hafnium oxide, silicon oxide, or the like can be used.

[0322] Furthermore, a structure in which two or more films selected from the above-mentioned films are stacked may be used as the mask layer. For example, two or more different types of films selected from metal films, alloy films, metal oxide films, semiconductor films, inorganic insulating films, and organic insulating films may be stacked. For example, an inorganic insulating film and a metal film may be stacked. Alternatively, films of the same type but different materials may be stacked. For example, two or more different types of inorganic insulating films may be stacked.

[0323] As a mask layer, for example, a stacked structure of aluminum oxide and a metal film on the aluminum oxide can be suitably used. The metal film can be, for example, molybdenum, tungsten, or the like. Aluminum oxide is preferably used due to its high adhesion to layer 113. Note that to minimize the effect of the light-shielding properties of the metal film on the characteristics of the light-emitting or light-receiving device, the metal film can be used as a hard mask during the manufacturing process and then removed.

[0324] As the mask layer, for example, a stacked structure of aluminum oxide and a metal oxide film on the aluminum oxide can be suitably used. As the metal oxide film, for example, In—Ga—Zn oxide can be used.

[0325] Alternatively, a water-soluble material may be used as the mask layer. In other words, a material that dissolves in a solvent including water may be used as the mask layer. Specifically, a material having a higher water solubility than the layer 113 may be used as the mask layer.

[0326] <Light-receiving device>

[0327] The display device according to one embodiment of the present invention may include a light-receiving device in each pixel. For example, a structure may be adopted in which one or more of the plurality of sub-pixels included in a pixel is a light-emitting device and one or more is a light-receiving device.

[0328] As a light-receiving device, for example, a pn-type or pin-type photodiode can be used. A light-receiving device is used as a photoelectric conversion device (also called a photoelectric conversion element) that detects light incident on the light-receiving device and generates charge. The amount of charge generated by the light-receiving device is determined by the amount of light incident on the light-receiving device.

[0329] In particular, organic photodiodes having a layer containing an organic compound are preferably used as light-receiving devices. Organic photodiodes are easy to make thinner, lighter, and larger in size, and have a high degree of freedom in shape and design, making them applicable to various display devices.

[0330] In one embodiment of the present invention, an organic EL device can be used as a light-emitting device, and an organic photodiode can be used as a light-receiving device. The organic EL device and the organic photodiode can be formed on the same substrate. Therefore, an organic photodiode can be built into a display device using an organic EL device.

[0331] The light-receiving device includes at least an active layer serving as a photoelectric conversion layer between a pair of electrodes. In this specification, one of the pair of electrodes may be referred to as a pixel electrode and the other as a common electrode.

[0332] In a pair of electrodes included in a light-receiving device, one electrode is used as an anode and the other electrode is used as a cathode. The following is an example of a case where a pixel electrode is used as an anode and a common electrode is used as a cathode. By applying a reverse bias voltage between the pixel electrode and the common electrode to drive the light-receiving device, it is possible to detect light incident on the light-receiving device to generate charge, which can be extracted as current. Alternatively, the pixel electrode can be used as a cathode and the common electrode can be used as an anode.

[0333] In the light-emitting device 130 , by replacing the layer 113 with an active layer of a photoelectric conversion device (also referred to as a photoelectric conversion layer), it can be used as a light-receiving device.

[0334] Light-receiving devices can also be manufactured using the same manufacturing methods as light-emitting devices. The island-shaped active layer included in the light-receiving device is not formed using a high-definition metal mask, but rather by depositing the film that will become the active layer over the entire surface and then processing it. This allows the island-shaped active layer to be formed with a uniform thickness. Furthermore, by providing a mask layer over the active layer, damage to the active layer during the display device manufacturing process can be reduced, thereby improving the reliability of the light-receiving device.

[0335] Here, the layer commonly included in the light-receiving device and the light-emitting device sometimes has a different function in the light-emitting device and the light-receiving device. In this specification, the constituent elements are sometimes referred to according to the function of the light-emitting device. For example, the hole injection layer is used as a hole injection layer in the light-emitting device and as a hole transport layer in the light-receiving device. Similarly, the electron injection layer is used as an electron injection layer in the light-emitting device and as an electron transport layer in the light-receiving device. In addition, the layer commonly included in the light-receiving device and the light-emitting device sometimes has the same function in the light-emitting device and the light-receiving device. The hole transport layer is used as a hole transport layer in both the light-emitting device and the light-receiving device, and the electron transport layer is used as an electron transport layer in both the light-emitting device and the light-receiving device.

[0336] Because pixels in a display device that include both light-emitting and light-receiving devices have a light-receiving function, it is possible to detect the contact or proximity of an object while simultaneously displaying an image. For example, rather than using all sub-pixels in the display device to display an image, a portion of the sub-pixels can be used as light sources to emit light, another portion of the sub-pixels can be used for light detection, and the remaining sub-pixels can be used to display the image.

[0337] In the display portion of a display device according to one embodiment of the present invention, light-emitting devices are arranged in a matrix, so that an image can be displayed on the display portion. In addition, in the display portion, light-receiving devices are arranged in a matrix, so that the display portion has one or both of a camera function and a sensing function in addition to the image display function. The display portion can be used for an image sensor or a touch sensor. That is, by detecting light by the display portion, an image can be captured or the approach or contact of an object (a finger, a hand, a pen, etc.) can be detected. In addition, a display device according to one embodiment of the present invention can use a light-emitting device as a light source for a sensor. Therefore, there is no need to set up a light-receiving portion and a light source separately from the display device, and the number of components of the electronic device can be reduced. For example, there is no need to set up a fingerprint recognition device included in the electronic device or an electrostatic capacitive touch panel for scrolling, etc.

[0338] In a display device of one embodiment of the present invention, since the light receiving device can detect the reflected light (or scattered light) when the light emitted by the light-emitting device included in the display portion is reflected (or scattered) by an object, video recording or touch detection can be performed even in a dark place.

[0339] When a light-receiving device is used as an image sensor, the display device can capture an image using the light-receiving device. For example, the display device of this embodiment can be used as a scanner.

[0340] For example, image sensors can be used to acquire data based on biometric information such as fingerprints and palm prints. In other words, a biometric sensor can be incorporated into the display device. By incorporating a biometric sensor into the display device, the number of components in the electronic device can be reduced compared to separately incorporating the display device and biometric sensor, thereby achieving miniaturization and weight reduction.

[0341] Furthermore, when a light-receiving device is used for the touch sensor, the display device detects the approach or contact of an object using the light-receiving device.

[0342] The display device according to one embodiment of the present invention has one or both of an imaging function and a sensing function in addition to the image display function. Thus, it can be said that the display device according to one embodiment of the present invention has a structure that is highly compatible with functions other than the display function.

[0343] [Configuration Example 2 of Display Device]

[0344] In the display device according to one embodiment of the present invention, a protective layer 131 is preferably provided on the common electrode 115. Figure 11A In the display device 100 shown, a protective layer 131 is provided on the common electrode 115. Furthermore, a substrate 120 is bonded to the protective layer 131 via a resin layer 122.

[0345] The reliability of the light emitting device can be improved by providing the protective layer 131. The protective layer 131 can be a single layer structure or a stacked layer structure of two or more layers.

[0346] There is no limitation on the conductivity of the protective layer 131. As the protective layer 131, at least one of an insulating film, a semiconductor film, and a conductive film can be used.

[0347] As the protective layer 131 , an organic film, an inorganic film, or the like can be used.

[0348] As the protective layer 131, a layer that can be used as the layer 113 or the common layer 114 can be appropriately used. Alternatively, as the protective layer 131, for example, an organic insulating material that can be used for the insulating layer 127 can be used.

[0349] In addition, when the protective layer 131 includes an inorganic film, degradation of the light-emitting device can be suppressed, such as preventing oxidation of the common electrode 115 and suppressing impurities (such as moisture and oxygen) from entering the light-emitting device, thereby improving the reliability of the display device.

[0350] As the protective layer 131, for example, an inorganic insulating film such as an oxide insulating film, a nitride insulating film, an oxynitride insulating film, and a nitride oxide insulating film can be used. Examples of the oxide insulating film include a silicon oxide film, an aluminum oxide film, a magnesium oxide film, an indium gallium zinc oxide (In-Ga-Zn oxide, also referred to as IGZO) film, a gallium oxide film, a germanium oxide film, an yttrium oxide film, a zirconium oxide film, a lanthanum oxide film, a neodymium oxide film, a hafnium oxide film, and a tantalum oxide film. Examples of the nitride insulating film include a silicon nitride film and an aluminum nitride film. Examples of the oxynitride insulating film include an oxynitride silicon film and an oxynitride aluminum film. Examples of the nitride oxide insulating film include a silicon nitride oxide film and an aluminum nitride oxide film. In particular, the protective layer 131 preferably includes a nitride insulating film or an oxynitride insulating film, and more preferably includes a nitride insulating film.

[0351] Alternatively, an inorganic film containing In-Sn oxide (also referred to as ITO), In-Zn oxide, Ga-Zn oxide, or Al-Zn oxide may be used for the protective layer 131. The inorganic film preferably has a high resistance, and more specifically, preferably has a resistance higher than that of the common electrode 115. The inorganic film may further contain nitrogen.

[0352] When light emitted from the light emitting device is extracted through the protective layer 131, the protective layer 131 preferably has high visible light transmittance. For example, ITO, IGZO, and alumina are inorganic materials with high visible light transmittance and are therefore preferred.

[0353] The protective layer 131 may include, for example, a stacked structure of an aluminum oxide film and a silicon nitride film thereon, or a stacked structure of an aluminum oxide film and an IGZO film thereon. This stacked structure can suppress the intrusion of impurities (such as water and oxygen) into the EL layer.

[0354] Alternatively, a stacked structure of an organic film and an inorganic film may be used as the protective layer 131 .

[0355] The protective layer 131 may also have a two-layer structure formed using different deposition methods. Specifically, the first layer of the protective layer 131 may be formed using ALD and the second layer may be formed using sputtering.

[0356] [Configuration Example 3 of Display Device]

[0357] In a display device according to one embodiment of the present invention, Figure 11B As shown, it may also have the following structure: an insulating layer 162 is provided on the protective layer 131, an insulating layer 163 is provided on the insulating layer 162, and a coloring layer 165R overlapping the light-emitting device 130a, a coloring layer 165G overlapping the light-emitting device 130b, and a coloring layer 165B overlapping the light-emitting device 130c are provided on the insulating layer 163.

[0358] A highly translucent organic insulating film can be used for insulating layer 162. Using an organic insulating film for insulating layer 162 mitigates the effects of the uneven shape on the lower side of insulating layer 162, resulting in a smoother surface for insulating layer 163. This reduces the likelihood of defects such as pinholes forming in insulating layer 163, further improving the moisture permeability of insulating layer 163.

[0359] Note that the material and structure that can be used for the insulating layer 163 may refer to those of the protective layer 131 .

[0360] Note that the structure of the protective layer covering the light emitting device 130 is not limited thereto, and may be a single-layer or two-layer structure or a stacked-layer structure of four or more layers.

[0361] For example, colored layer 165R transmits red light, colored layer 165G transmits green light, and colored layer 165B transmits blue light. This improves the color purity of light from each light-emitting element, thereby achieving a display device with higher display quality.

[0362] Alternatively, the colored layers may be formed on substrate 120 and bonded to substrate 120 via an adhesive layer. Forming the colored layers on substrate 120 simplifies the structure of layer 101 having transistors. Furthermore, forming each colored layer on insulating layer 163 makes it easier to align the positions of each light-emitting unit with each colored layer compared to forming the colored layers on substrate 120, thereby achieving an extremely high-definition display device.

[0363] Note that since the pixels included in the dummy pixel portion may not have a light-emitting function, a coloring layer may not be provided in the dummy pixel portion. Alternatively, a coloring layer may be provided in the dummy pixel portion.

[0364] A light shielding layer may also be provided on the surface of the resin layer 122 of the substrate 120. The light shielding layer may be provided, for example, so as to overlap the region between each light-emitting region of adjacent light-emitting devices. Furthermore, for example, the light shielding layer may be provided so as to overlap the dummy pixel portion. Specifically, for example, the entire dummy pixel portion may be provided so as to overlap the light shielding layer. Alternatively, a portion of the dummy sub-pixels included in the dummy pixel portion may be provided so as to overlap the light shielding layer.

[0365] In addition, various optical components can be configured on the outside of the substrate 120. As optical components, polarizers, phase difference plates, light diffusion layers (diffusion films, etc.), anti-reflection layers, and condensing films can be used. In addition, surface protective layers such as antistatic films that inhibit the adhesion of dust, water-repellent films that are not easily soiled, hard coatings or buffer layers that inhibit damage during use can also be configured on the outside of the substrate 120. For example, by providing a glass layer or a silicon dioxide layer (SiO x Layer), which can prevent the surface from being soiled or damaged, is preferred. In addition, DLC (diamond-like carbon), aluminum oxide (AlO x ), polyester materials or polycarbonate materials, etc. In addition, as the surface protection layer, preferably a material with high transmittance to visible light is used. In addition, the surface protection layer preferably uses a material with high hardness.

[0366] Substrate 120 can be made of glass, quartz, ceramic, sapphire, resin, metal, alloy, semiconductor, or the like. The substrate on the side that extracts light from the light-emitting device is made of a material that transmits this light. Using a flexible material for substrate 120 can enhance the flexibility of the display device. A polarizing plate can also be used as substrate 120.

[0367] The substrate 120 may be made of polyester resins such as polyethylene terephthalate (PET) or polyethylene naphthalate (PEN), polyacrylonitrile resins, acrylic resins, polyimide resins, polymethyl methacrylate resins, polycarbonate (PC) resins, polyethersulfone (PES) resins, polyamide resins (such as nylon and aramid), polysiloxane resins, cycloolefin resins, polystyrene resins, polyamide-imide resins, polyurethane resins, polyvinyl chloride resins, polyvinylidene chloride resins, polypropylene resins, polytetrafluoroethylene (PTFE) resins, ABS resins, and cellulose nanofibers. Furthermore, glass having a thickness sufficient to provide flexibility may also be used as the substrate 120.

[0368] When a circular polarizing plate is stacked on a display device, it is preferable to use a substrate having high optical isotropy as the substrate included in the display device. A substrate having high optical isotropy has low birefringence (or a small amount of birefringence).

[0369] The absolute value of the retardation value of the substrate having high optical isotropy is preferably 30 nm or less, more preferably 20 nm or less, and further preferably 10 nm or less.

[0370] Examples of films having high optical isotropy include cellulose triacetate (also referred to as TAC or Cellulose triacetate) films, cycloolefin polymer (COP) films, cycloolefin copolymer (COC) films, and acrylic films.

[0371] When a film is used as a substrate, water absorption by the film may cause the display device to wrinkle or change shape. Therefore, a film with low water absorption is preferably used as the substrate. For example, a film with a water absorption of 1% or less is preferred, 0.1% or less is more preferred, and 0.01% or less is even more preferred.

[0372] As the resin layer 122, various curing adhesives such as light-curing adhesives such as ultraviolet curing adhesives, reaction-curing adhesives, heat-curing adhesives, and anaerobic adhesives can be used. 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. In particular, materials with low moisture permeability such as epoxy resins are preferably used. In addition, two-liquid mixed resins can also be used. In addition, adhesive sheets can also be used.

[0373] [Example of a method for manufacturing a display device]

[0374] Next, refer to Figures 12A to 18C An example of a method for manufacturing the display device 100 will be described. Note that A in each drawing corresponds to Figure 2C The manufacturing method of the pixel 110 shown in FIG. 1 corresponds to Figure 3C The manufacturing method of the pseudo pixel 51 shown in FIG. C corresponds to Figure 4A The manufacturing method of the region 61 is shown.

[0375] Thin films (insulating films, semiconductor films, conductive films, etc.) that constitute display devices can be formed using methods such as sputtering, chemical vapor deposition (CVD), vacuum evaporation, pulsed laser deposition (PLD), and ALD. CVD methods include plasma-enhanced chemical vapor deposition (PECVD) and thermal CVD. Furthermore, one thermal CVD method is metal organic chemical vapor deposition (MOCVD).

[0376] In addition, thin films (insulating films, semiconductor films, and conductive films, etc.) that constitute the display device can be formed using methods such as spin coating, dipping, spraying, inkjet, dispenser, screen printing, offset printing, doctor knife, slit coating, roller coating, curtain coating, and doctor blade coating.

[0377] In particular, when manufacturing a light-emitting device, a vacuum process such as an evaporation method and a solution process such as a spin coating method and an inkjet method can be used. As the evaporation method, physical evaporation methods (PVD methods) such as sputtering, ion plating, ion beam evaporation, molecular beam evaporation, and vacuum evaporation methods and chemical evaporation methods (CVD methods) can be cited. In particular, the functional layers (hole injection layer, hole transport layer, light-emitting layer, electron transport layer, electron injection layer, etc.) included in the EL layer can be formed by methods such as evaporation (vacuum evaporation), coating (dip coating, dye coating, rod coating, spin coating, spray coating), printing (inkjet, screen printing (porcelain printing) method, offset printing (lithography) method, flexographic printing (letterpress printing) method, gravure printing or microcontact printing method) and the like.

[0378] Furthermore, when processing thin films constituting the display device, photolithography or the like can be used. Alternatively, thin films can be processed using nanoimprinting, sandblasting, lift-off, or the like. Furthermore, island-shaped thin films can be directly formed using a deposition method using a shadow mask such as a metal mask.

[0379] Photolithography typically involves two methods: one involves forming a resist mask on the film to be processed, processing the film through etching or other methods, and then removing the resist mask. The other involves depositing a photosensitive film, then performing exposure and development to shape the film into the desired shape.

[0380] In the photolithography method, as the light used for exposure, for example, i-line (wavelength 365nm), g-line (wavelength 436nm), h-line (wavelength 405nm) or a mixture of these lights can be used. In addition, ultraviolet light, KrF laser or ArF laser, etc. can also be used. In addition, exposure can also be performed using liquid immersion exposure technology. In addition, as the light used for exposure, extreme ultraviolet (EUV: Extreme Ultra-violet) light or X-rays can also be used. In addition, an electron beam can also be used instead of the light used for exposure. When extreme ultraviolet light, X-rays or electron beams are used, extremely fine processing can be performed, so it is preferred. In addition, when exposure is performed by scanning with a light beam such as an electron beam, there is no need to use a photomask.

[0381] For etching of the thin film, dry etching, wet etching, sand blasting, or the like can be used.

[0382] First, an insulating layer 255 ( 12A to 12C Here, an example is shown in which the insulating layer 255 has a three-layer structure including an insulating layer 255a, an insulating layer 255b on the insulating layer 255a, and an insulating layer 255c on the insulating layer 255b.

[0383] Next, a conductive film to be a pixel electrode is formed on the insulating layer 255c. Next, a portion of the conductive film is removed using a mask such as a resist mask to form pixel electrodes 111a, 111b, 111c, 111e, 111f, 111g, and a conductive layer 111h ( 12A to 12C ).

[0384] Note that by also disposing a conductive layer having the same pattern as that of the pixel portion 284 in the peripheral region 297 , adhesion to the formed surface can be made uniform in a subsequent deposition step of the film 113 cf .

[0385] The pixel electrode preferably has a tapered shape, thereby improving the coverage of the layer formed on the pixel electrode, thereby improving the manufacturing yield of the light-emitting device.

[0386] Next, a film 113cf is formed on the pixel electrodes 111a, 111b, 111c, 111e, 111f, 111g, and the conductive layer 111h. Next, a mask film 118cf is formed on the film 113cf, and a mask film 119cf is formed on the mask film 118cf. 12A to 12C ).

[0387] The film 113cf will later become the layer 113c. Therefore, the structure that can be used for the layer 113c can be adopted. The film 113cf can be formed by a method such as evaporation (including vacuum evaporation), transfer, printing, inkjet, coating, etc. The film 113cf is preferably formed by evaporation. Premixed materials can also be used for deposition using the evaporation method. Note that in this specification, etc., premixed materials refer to composite materials prepared or mixed in advance.

[0388] The mask films 118cf and 119cf are films that are highly resistant to processing conditions of the film 113cf and the films 113bf and 113af to be formed in subsequent steps. Specifically, films having a high etching selectivity with various EL layers are used.

[0389] The mask film 118cf and the mask film 119cf can be formed, for example, by sputtering, ALD (thermal ALD, PEALD), CVD, or vacuum evaporation. Note that the mask film 118cf formed in contact with the EL layer is preferably formed by a formation method that causes less damage to the EL layer than the mask film 119cf. For example, it is preferable to form the mask film 118cf by ALD or vacuum evaporation rather than sputtering. In addition, the mask film 118cf and the mask film 119cf are formed at a temperature lower than the heat resistance temperature of the EL layer. The substrate temperature when forming the mask film 118cf and the mask film 119cf is typically below 200°C, preferably below 150°C, more preferably below 120°C, further preferably below 100°C, and even more preferably below 80°C.

[0390] Mask films 118cf and 119cf are preferably films that can be removed by wet etching. Wet etching can reduce damage to film 113cf during processing of mask films 118cf and 119cf compared to dry etching.

[0391] The mask film 118cf is preferably a film having a high etching selectivity ratio with the mask film 119cf.

[0392] In the manufacturing process of the display device of this embodiment, it is preferable that the layers constituting the EL layer (such as the hole injection layer, hole transport layer, light-emitting layer, and electron transport layer) are not easily processed during the processing of the layers constituting the EL layer. It is preferable that the material and processing method of the mask layer and the processing method of the EL layer be selected in consideration of these conditions.

[0393] Note that mask film 118cf is a film that will later become mask layer 118c on layer 113c. Furthermore, mask film 119cf is a film that will become mask layer 119c formed on mask layer 118c. Although this embodiment shows an example in which the mask layer is formed from a two-layer structure of a first mask layer and a second mask layer, the mask layer may also have a single-layer structure or a stacked structure of three or more layers.

[0394] As the mask film 118 cf and the mask film 119 cf , for example, an inorganic film such as a metal film, an alloy film, a metal oxide film, a semiconductor film, or an inorganic insulating film can be used.

[0395] Mask films 118cf and 119cf can be made of, for example, metal materials such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, titanium, aluminum, yttrium, zirconium, and tantalum, or alloys containing these metal materials. Using a metal material capable of shielding ultraviolet light as one or both of mask films 118cf and 119cf is preferred because it is possible to suppress ultraviolet light from reaching the EL layer and thus suppress degradation of the EL layer.

[0396] Alternatively, metal oxides such as In-Ga-Zn oxide can be used for mask films 118cf and 119cf. For example, an In-Ga-Zn oxide film can be formed by sputtering as mask films 118cf and 119cf. Furthermore, indium oxide, In-Zn oxide, In-Sn oxide, indium titanium oxide (In-Ti oxide), indium tin zinc oxide (In-Sn-Zn oxide), indium titanium zinc oxide (In-Ti-Zn oxide), indium gallium tin zinc oxide (In-Ga-Sn-Zn oxide), and the like can be used. Alternatively, indium tin oxide containing silicon can be used.

[0397] Note that an element M (M is one or more of aluminum, silicon, boron, yttrium, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, and magnesium) may be used instead of the gallium described above. In particular, M is preferably one or more selected from gallium, aluminum, and yttrium.

[0398] In addition, various inorganic insulating films that can be used for the protective layer 131 can be used as the mask films 118cf and 119cf. In particular, oxide insulating films are preferred because they have higher adhesion to the EL layer than nitride insulating films. For example, inorganic insulating materials such as aluminum oxide, hafnium oxide, and silicon oxide can be used for the mask films 118cf and 119cf. For example, an aluminum oxide film can be formed using the ALD method as the mask films 118cf and 119cf. The ALD method is preferred because it can reduce damage to the substrate (especially the EL layer, etc.).

[0399] Here, as an example, an inorganic insulating film (e.g., an aluminum oxide film) formed by ALD can be used as the mask film 118cf, and a metal film (e.g., a molybdenum film, a tungsten film, or an aluminum film) formed by sputtering can be used as the mask film 119cf. Alternatively, a metal oxide film (e.g., an In—Ga—Zn oxide film) formed by sputtering can be used as the mask film 119cf.

[0400] Note that the same inorganic insulating film can be used for both the mask film 118cf and the insulating layer 125 to be formed later. For example, an aluminum oxide film formed using ALD can be used for both the mask film 118cf and the insulating layer 125. The mask film 118cf and the insulating layer 125 can also be deposited under the same deposition conditions. For example, by depositing the mask film 118cf under the same conditions as the insulating layer 125, the mask film 118cf can be formed as an insulating layer with high barrier properties against at least one of water and oxygen. Note that this is not limiting; the mask film 118cf and the insulating layer 125 can also be deposited under different deposition conditions.

[0401] For either or both of mask film 118cf and mask film 119cf, a material soluble in a solvent that is chemically stable at least to the film located on the uppermost portion of film 113cf may be used. When depositing such a material, it is preferable to apply it using a wet deposition method while dissolved in a solvent, followed by a heat treatment to evaporate the solvent. In this case, heat treatment under a reduced pressure atmosphere is preferred because it allows for quick removal of the solvent at a low temperature, thereby minimizing thermal damage to the EL layer.

[0402] Mask film 118cf can be made of a material having a higher water solubility than film 113cf. For example, a material soluble in an aqueous solution containing hydrofluoric acid (HF) can be used for layer SCRA2. Alternatively, a material soluble in an aqueous solution containing tetramethylammonium hydroxide (TMAH) can be used for layer SCRA2.

[0403] Specifically, metal complexes such as tris(8-hydroxyquinoline)aluminum(III) (abbreviated as: Alq3), bis(10-hydroxybenzo[h]quinoline)beryllium(II) (abbreviated as: BeBq2), bis(2-methyl-8-hydroxyquinoline)(4-phenylphenol)aluminum(III) (abbreviated as: BAlq), bis(8-hydroxyquinoline)zinc(II) (abbreviated as: Znq), bis[2-(2-benzoxazolyl)phenol]zinc(II) (abbreviated as: ZnPBO), and bis[2-(2-benzothiazolyl)phenol]zinc(II) (abbreviated as: ZnBTZ) can be used for the mask film 118cf.

[0404] In addition, as the mask film 118cf, for example, a stacked structure of a water-soluble material and an inorganic film thereon can be used.

[0405] By forming a layer containing a water-soluble material as a mask layer on layer 113c, even if the shape of mask layer 118c changes during the manufacturing process, for example, mask layer 118c on layer 113c can be removed to form light-emitting device 130c. Furthermore, mask layer 118c, which has been exposed to plasma or the like during the manufacturing process, can be removed. Mask layer 118c can reduce the effects of plasma or the like on components located closer to layer 101 than mask layer 118c during the manufacturing process. Furthermore, layer 113c can be protected from damage during the manufacturing process. As a result, a novel display device with excellent convenience, practicality, and reliability can be provided.

[0406] As the mask film 118cf, a material soluble in alcohol may be used.

[0407] Mask film 118cf and mask film 119cf can also be appropriately formed using wet deposition methods such as spin coating, dipping, spraying, inkjet, dispenser, screen printing, offset printing, scraper, slit coating, roller coating, curtain coating, and scraper coating.

[0408] Mask films 118cf and 119cf may be made of organic materials such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinyl pyrrolidone, polyethylene glycol, polyglycerol, pullulan, water-soluble cellulose, or alcohol-soluble polyamide resin.

[0409] Next, a resist mask 190a is formed on the mask film 119cf. The resist mask can be formed by applying a photosensitive resin (photoresist), exposing it to light, and developing it. By using a metal film as the mask film 119cf, for example, ultraviolet light, etc., used for exposure, can be prevented from reaching the region of the film 113cf that will become the layer 113c.

[0410] The resist mask can also be manufactured using a positive resist material or a negative resist material.

[0411] The resist mask 190a is provided at a position overlapping the pixel electrode 111c and at a position overlapping the pixel electrode 111g. The resist mask 190a preferably covers at least the area near the dummy pixel portion 294 in the peripheral region 297.

[0412] In the pixel portion 284, the resist mask 190a is preferably provided with an island pattern for each sub-pixel 110c or each light-emitting device 130c. Furthermore, in the dummy pixel portion 294, an island pattern is preferably provided for each dummy sub-pixel 51c. Alternatively, the resist mask 190a may be provided with a stripe pattern for a plurality of sub-pixels 110c arranged in a column (e.g., arranged in the Y direction). Alternatively, the resist mask 190a may be provided with a stripe pattern for a plurality of dummy sub-pixels 51c arranged in a column.

[0413] Here, when the resist mask 190a is formed so that the end of the resist mask 190a is located outside the end of the pixel electrode 111c, the end of the layer 113c formed later can be located outside the end of the pixel electrode 111c. By positioning the end of the layer 113c outside the end of the pixel electrode 111c, the aperture ratio of the pixel can be increased.

[0414] Furthermore, when the resist mask 190a is formed so that the end of the resist mask 190a is located outside the pixel electrode 111g, the end of the layer 113g formed later can be provided outside the end of the pixel electrode 111g.

[0415] Next, a portion of the mask film 119cf is removed using the resist mask 190a to form a mask layer 119c, a mask layer 119g, and a mask layer 119h ( 13A to 13C ). Mask layer 119c remains on pixel electrode 111c, and mask layer 119g remains on pixel electrode 111g. Mask layer 119h remains in the area near at least the dummy pixel portion 294 of the peripheral region 297 and covers layer 113h. In addition, at this time, a mask layer (herein referred to as mask layer 119j, but not shown) can also be provided on the conductive layer 123 included in the connecting portion 140 by processing the mask film 119cf. The conditions for etching the mask film 119cf will be described later.

[0416] Then, the resist mask 190a is removed. For example, the resist mask 190a can be removed by ashing using oxygen plasma. Alternatively, oxygen gas and a noble gas (also known as a rare gas) such as CF4, C4F8, SF6, CHF3, Cl2, H2O, BCl3, or He can be used. Alternatively, the resist mask 190a can be removed by wet etching. In this case, the mask film 118cf is located at the outermost surface and the film 113cf is not exposed, so damage to the film 113cf can be suppressed during the removal process of the resist mask 190a. In addition, the range of options for the removal method of the resist mask 190a can be expanded.

[0417] Here, when removing the resist mask 190 a , a tetramethylammonium hydroxide (TMAH) aqueous solution is used.

[0418] In addition, while resist mask 190a is being removed, mask film 118cf may be half-etched using mask layer 119c as a hard mask. For example, an aluminum oxide film may be used as mask film 118cf, and mask film 118cf may be half-etched using a TMAH aqueous solution. In addition, while resist mask 190a is being removed, mask film 118cf may be etched using mask layer 119c as a hard mask to form mask layer 118c.

[0419] Next, the mask layer 119c is used as a mask (also referred to as a hard mask) to remove a portion of the mask film 118cf to form a mask layer 118c ( Figure 14A ). Mask layer 119g is used as a mask to form mask layer 118g ( Figure 14B ). Mask layer 119h is used as a mask to form mask layer 118h ( Figure 14C ). In addition, at this time, in the connection portion 140, the mask layer 119j (not shown. As described above, the mask layer 119j is a layer formed on the conductive layer 123 by processing the mask film 119cf) is used as a mask to process the mask film 118cf, thereby providing a mask layer 118j on the conductive layer 123.

[0420] The mask films 118cf and 119cf can be processed by wet etching or dry etching, respectively. The mask films 118cf and 119cf are preferably processed by anisotropic etching.

[0421] By utilizing a wet etching method, the damage to the film 113cf during processing of the mask film 118cf and the mask film 119cf can be reduced compared to the case of utilizing a dry etching method. In the case of utilizing a wet etching method, for example, it is preferred to use a developer, a tetramethylammonium hydroxide (TMAH) aqueous solution, a dilute hydrofluoric acid, oxalic acid, phosphoric acid, acetic acid, nitric acid, or a mixed liquid thereof. Specifically, for example, a mixed liquid containing phosphoric acid can be used. As a mixed liquid containing phosphoric acid, for example, a mixed liquid of phosphoric acid, acetic acid, nitric acid, and water can be used. In addition, the mask film can also be etched by dissolving in a solvent such as water or alcohol. As alcohols, ethyl alcohol, methyl alcohol, isopropyl alcohol (IPA), or glycerol can be cited.

[0422] On the other hand, when wet etching is used, the etchant may enter between the film 113cf and the mask layer 118c, causing the end of the mask layer 118c to peel off from the film 113cf. By using dry etching, such film peeling may be suppressed.

[0423] When dry etching is used, for example, a halogen-containing gas can be used. For example, a halogen-containing gas and a noble gas (also referred to as a rare gas) such as He can be used. Examples of the halogen include fluorine. For example, a gas containing a noble gas such as CF4, C4F8, SF6, CHF3, Cl2, H2O, BCl3, or He is preferably used as the etching gas.

[0424] For example, when an aluminum oxide film formed by an ALD method is used as the mask film 118cf, the mask film 118cf can be processed by a dry etching method using CHF3 and He.

[0425] Furthermore, during the etching of mask film 119cf, mask film 118cf covers film 113cf, thus suppressing degradation of film 113cf even when a gas containing oxygen is used as the etching gas. For example, a halogen-containing gas and an oxygen gas can be used. Furthermore, a halogen-containing gas, a noble gas (also known as a rare gas) such as He, and an oxygen gas can be used. Examples of halogens include fluorine.

[0426] When a molybdenum film formed by sputtering is used as the mask film 119cf, the mask film 119cf can be processed by dry etching using CF4, O2, and He, or SF6 and O2. In addition, when a tungsten film formed by sputtering is used as the mask film 119cf, the mask film 119cf can be processed by dry etching using CF4 and O2, CF6 and O2, CF4, Cl2 and O2, or CF6, Cl2 and O2. In the case of using an In-Ga-Zn oxide film, the mask film 119cf can be processed by wet etching using dilute phosphoric acid. Alternatively, it can be processed by dry etching using CH4 and Ar or CF4, O2, and He. In addition, when molybdenum is used as the mask film, the mask film 119cf can be processed by wet etching using, for example, a solution containing phosphoric acid, hydrofluoric acid, water, or the like. Alternatively, a solution containing phosphoric acid, hydrofluoric acid, water, nitric acid, or the like can be used.

[0427] When etching mask film 119cf, it is preferable to use etching conditions with a high selectivity ratio to prevent mask film 118cf from being removed. Furthermore, since the EL layer is not exposed during processing of mask film 119cf, a wider range of processing methods is available compared to processing of mask film 118cf. Specifically, when processing mask film 119cf, even using an oxygen-containing etching gas can further suppress degradation of the EL layer.

[0428] As an etching method, both dry etching and wet etching can be combined. For example, wet etching can be performed after dry etching. In addition, dry etching can be performed after wet etching.

[0429] Next, an etching process is performed using the mask layer 119c and the mask layer 118c as a hard mask to remove a portion of the film 113cf and form the layer 113c ( Figure 14A ). In addition, by performing etching processing using the mask layer 119g and the mask layer 118g as a hard mask, the layer 113g ( Figure 14B By performing etching processing using the mask layer 119h and the mask layer 118h as a hard mask, a layer 113h ( Figure 14C ).

[0430] As a result, the stacked structure of layer 113c, mask layer 118c, and mask layer 119c remains on pixel electrode 111c. The stacked structure of layer 113g, mask layer 118g, and mask layer 119g remains on pixel electrode 111g. Furthermore, the stacked structure of layer 113h, mask layer 118h, and mask layer 119h remains on conductive layer 111h. Furthermore, in the region corresponding to connection portion 140, the stacked structure of mask layer 118c and mask layer 119c remains on conductive layer 123.

[0431] Because layer 113c covers the top and side surfaces of pixel electrode 111c, subsequent processes can be performed without exposing pixel electrode 111c. Similarly, because layer 113g covers the top and side surfaces of pixel electrode 111g, subsequent processes can be performed without exposing pixel electrode 111g. When the ends of pixel electrode 111c and the like are exposed, corrosion may occur during etching processes. The products produced by corrosion of pixel electrode 111c and the like are sometimes unstable. For example, they may dissolve in the solution during wet etching or disperse into the atmosphere during dry etching. Dissolving in the solution or dispersing into the atmosphere may cause the products to adhere to the processed surface or the side surfaces of layer 113c and the like, negatively impacting the characteristics of the light-emitting device or creating leakage paths between multiple light-emitting devices. Furthermore, in areas where the ends of pixel electrode 111c and the like are exposed, the adhesion of contacting layers may be reduced, making it more likely that film separation of layer 113c and the like or pixel electrode 111c and the like may occur.

[0432] By having a structure in which the top surface and the side surfaces of the pixel electrode 111 c are covered by the layer 113 c , for example, the yield of the light-emitting device can be improved, and the display quality of the light-emitting device can be improved.

[0433] Note that, even if the resist mask 190a is not removed after the mask layer 119c is formed, a portion of the film 113cf may be removed using the resist mask 190a.

[0434] Note that the etching process may sometimes form recessed portions in regions of the insulating layer 255c that do not overlap with the layer 113c. Providing dummy pixel portions around the pixel portion 284 can suppress overetching of the insulating layer 255c and reduce the depth of the recessed portions. This can stabilize the characteristics of the display device and improve the characteristics of the display device 100.

[0435] The film 113cf is preferably processed by anisotropic etching. Anisotropic dry etching is particularly preferred. Alternatively, wet etching may be used.

[0436] By using a gas containing O2 as the etching gas for dry etching, the etching rate can be increased. Therefore, etching can be performed at low power while maintaining a sufficient etching rate. This reduces damage to the film 113cf and prevents defects such as adhesion of reaction products during etching.

[0437] In addition, by using an etching gas that does not contain O 2 , degradation of the film 113 cf can sometimes be further suppressed.

[0438] As an etching gas for the dry etching method, for example, O2 gas can be used. Alternatively, a gas containing O2 can also be used. For example, the following gas can be used: a gas containing O2 gas and one or more of H2, CF4, C4F8, SF6, CHF3, Cl2, H2O, BCl3, and noble gases such as He and Ar (also referred to as rare gases). Alternatively, for example, the following gas can be used: a gas containing O2 gas, one or more of H2, CF4, C4F8, SF6, CHF3, Cl2, H2O, and BCl3, and one or more of noble gases such as He and Ar (also referred to as rare gases). Specifically, for example, a gas containing O2, CF4, and He can be used as an etching gas.

[0439] Alternatively, as an etching gas for the dry etching method, an etching gas containing one or more of H2, CF4, C4F8, SF6, CHF3, Cl2, H2O, BCl3, and noble gases (also called rare gases) such as He and Ar can be used. Specifically, for example, a gas containing H2 and Ar or a gas containing CF4 and He can be used as the etching gas.

[0440] Through the above steps, the regions of the film 113cf, the mask film 118cf, and the mask film 119cf that do not overlap with the resist mask 190a can be removed.

[0441] Next, a film 113bf (not shown) is formed on the mask layer 119c, the pixel electrode 111b, the pixel electrode 111a, the mask layer 119g, the pixel electrode 111f and the pixel electrode 111e, a mask film 118bf (not shown) is formed on the film 113bf, and a mask film 119bf (not shown) is formed on the mask film 118bf.

[0442] Film 113bf is a layer that will later become layer 113b. Layer 113b emits light of a different color from layer 113c. The structure and materials that can be used for layer 113b are the same as those for layer 113c. Film 113bf can be deposited using the same method as film 113cf.

[0443] By arranging patterns having the same structure in the pixel portion 284 and the dummy pixel portion 294 , it is possible to make the adhesion to the formed surface uniform during the deposition step of the film 113 bf.

[0444] The mask film 118bf can be formed using a material that can be used for the mask film 118cf. The mask film 119bf can be formed using a material that can be used for the mask film 119cf.

[0445] Next, a resist mask is formed on the mask film 119bf. The resist mask is provided at a position overlapping with the pixel electrode 111b and at a position overlapping with the pixel electrode 111f.

[0446] Next, by performing the same process as that described in the production of the layer 113c, the mask layer 118c, and the mask layer 119c, the regions of the film 113bf, the mask film 118bf, and the mask film 119bf that do not overlap with the resist mask are removed. As a result, the stacked structure of the layer 113b, the mask layer 118b, and the mask layer 119b remains on the pixel electrode 111b ( Figure 15A ), a stacked structure of a residual layer 113f, a mask layer 118f, and a mask layer 119f is formed on the pixel electrode 111f ( Figure 15B ).

[0447] Next, a film 113af is formed on the mask layer 119c, the mask layer 119b, the pixel electrode 111a, the mask layer 119g, the mask layer 119f, the pixel electrode 111e, and the mask layer 119h. A mask film 118af is formed on the film 113af. A mask film 119af is formed on the mask film 118af. Figures 15A to 15C ).

[0448] Film 113af is the film that will later become layer 113a. Layer 113a emits light of a different color from layers 113c and 113b. The structure and materials that can be used for layer 113a are the same as those for layer 113c. Layer 113af can be deposited using the same method as film 113cf.

[0449] The mask film 118af can be formed using a material that can be used for the mask film 118cf. The mask film 119af can be formed using a material that can be used for the mask film 119cf.

[0450] Next, a resist mask 190c ( Figures 15A to 15C ). The resist mask 190c is provided at a position overlapping with the pixel electrode 111a and at a position overlapping with the pixel electrode 111e.

[0451] Next, mask film 119af, mask film 118af, and film 113af are processed using the same steps as those used to form layers 113c and 113b. This results in a stacked structure of a mask layer (hereinafter referred to as mask layer 119a; mask layer 119a is not shown) formed by leaving processed layer 113a, mask layer 118a, and mask film 119af on pixel electrode 111a, and a stacked structure of a mask layer (hereinafter referred to as mask layer 119e; mask layer 119e is not shown) formed by leaving processed layer 113e, mask layer 118e, and mask film 119af on pixel electrode 111e.

[0452] As described above, by processing the EL layers using photolithography, the distance between pixels can be reduced to less than 8 μm, less than 5 μm, less than 3 μm, less than 2 μm, or less than 1 μm. For example, the distance between adjacent opposing ends of layers 113a, 113b, and 113c can be used to determine the distance between pixels. By reducing the distance between pixels, a display device with high resolution and a large aperture ratio can be provided.

[0453] Next, mask layers 119a, 119b, 119c, 119e, 119f, and 119g are removed. Thus, mask layers 118a, 118b, 118c, 118e, 118f, and 118g are exposed. A stacked structure of layer 113a and mask layer 118a remains on pixel electrode 111a, a stacked structure of layer 113b and mask layer 118b remains on pixel electrode 111b, and a stacked structure of layer 113c and mask layer 118c remains on pixel electrode 111c ( Figure 16A ). A stacked structure of a residual layer 113e and a mask layer 118e is formed on the pixel electrode 111e, a stacked structure of a residual layer 113f and a mask layer 118f is formed on the pixel electrode 111f, and a stacked structure of a residual layer 113g and a mask layer 118g is formed on the pixel electrode 111g ( Figure 16B ). A stacked structure of a residual layer 113h and a mask layer 118h is formed on the conductive layer 111h ( Figure 16C ) In addition, in the connection portion 140 , when the mask layer 118 j and the mask layer 119 j are provided on the conductive layer 123 , the mask layer 118 j is exposed in the connection portion 140 by removing the mask layer 119 j .

[0454] Note that the mask layer 119a, the mask layer 119b, the mask layer 119c, and the like do not need to be removed during the step of forming the insulating film 125A.

[0455] When a light-shielding metal film is used as the mask layer 119 , light is shielded around the light-emitting region of the light-emitting device or the light-receiving region of the light-receiving device while the mask layer 119 remains, thereby improving resolution.

[0456] Next, a description will be given of a case where the mask layer 119 is removed. Note that when the mask layer 119 remains, the mask layer 118 may be replaced with a stacked-layer structure of the mask layer 118 and the mask layer 119 in the following description.

[0457] The mask layer 119 removal step can use the same method as the mask layer 119 processing step. Alternatively, the mask layer 119 processing step and the mask layer 119 removal step can use different methods. Since the side surfaces of the layers 113a, 113b, and 113c are exposed when the mask layer 119 is removed, it is preferable to use a method that can minimize damage to these surfaces. Furthermore, it is preferable to use a method that can suppress the adhesion of impurities to the side surfaces of the layers 113a, 113b, and 113c.

[0458] Adhesion may be improved by using dry etching compared to wet etching in the removal step of mask layer 119. When wet etching is used, adhesion may be reduced due to the etchant entering between mask layer 118 and layer 113 or between layer 113 and insulating layer 255c. However, using dry etching can suppress the reduction in adhesion.

[0459] In addition, when wet etching is used, damage to the layer 113 a , the layer 113 b , the layer 113 c , and the like when the mask layer 119 is removed can sometimes be reduced compared to the case of dry etching.

[0460] In both the case of dry etching and the case of wet etching as the etching method, it is preferable to suppress impurities remaining on the side surfaces of the layer 113 a , the layer 113 b , and the layer 113 c after etching.

[0461] Remaining impurities may be removed by performing a treatment using a solution or water (wet treatment) after etching, or by performing a plasma treatment after etching.

[0462] As an etching method, both dry etching and wet etching can be combined. For example, wet etching can be performed after dry etching. In addition, dry etching can be performed after wet etching.

[0463] When a layer formed by processing a molybdenum film is used as mask layer 119, dry etching can be performed using, for example, an etching gas containing CF4, O2, and He as dry etching conditions. Dry etching is preferred because it can suppress a decrease in adhesion during etching. Furthermore, when using a gas containing CF4, O2, and He as an etching gas, wet treatment using a TMAH aqueous solution as post-treatment after dry etching can remove surface impurities, thereby achieving a suitable state of the surface to be formed when depositing insulating films 125A and 127A.

[0464] Alternatively, when a layer formed by processing a molybdenum film is used as the mask layer 119, for example, dry etching can be performed using an etching gas containing SF6 and O2 as a condition for dry etching. By utilizing dry etching, the decrease in adhesion during etching can be suppressed, so it is preferred. In addition, when a gas containing CF4, O2, and He is used as the etching gas, by performing oxygen plasma treatment as a post-treatment after dry etching, impurities on the surface can be removed, thereby obtaining a suitable state of the formed surface when depositing the insulating film 125A and the insulating film 127A. In addition, when oxygen plasma treatment is performed as a post-treatment, there is an advantage that wet treatment is not required in the removal and post-treatment of the mask layer 119. By using a gas that does not contain carbon, such as SF6 gas, the reaction products during etching can be suppressed, thereby reducing the reaction products deposited on the surface of the mask layer 118 after etching, and the mask layer 118 can be properly etched.

[0465] After removing the mask layer, a drying treatment may be performed to remove water contained in the EL layer and water adhering to the surface of the EL layer. For example, heat treatment is preferably performed in an inert gas atmosphere or a reduced pressure atmosphere. 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. Using a reduced pressure atmosphere is preferred because it allows drying at a lower temperature.

[0466] Next, an insulating film 125A is formed to cover the layers 113a, 113b, 113c, 113e, 113f, 113g, 113h, and the mask layers 118a, 118b, 118c, 118e, 118f, 118g, and 118h. 16A to 16C ).

[0467] The insulating film 125A is a layer that will later become the insulating layer 125. Therefore, the insulating film 125A can use a material that can be used for the insulating layer 125. The thickness of the insulating film 125A is preferably 3 nm or more, 5 nm or more, or 10 nm or more and 200 nm or less, 150 nm or less, 100 nm or less, or 50 nm or less.

[0468] Since the insulating film 125A is formed in contact with the side surfaces of the EL layer, it is preferably deposited using a method that minimizes damage to the EL layer. Furthermore, the insulating film 125A is formed at a temperature below the heat resistance temperature of the EL layer. The substrate temperature during formation of the insulating film 125A and the insulating layer 127 is typically 200°C or lower, preferably 180°C or lower, more preferably 160°C or lower, even more preferably 150°C or lower, and even more preferably 140°C or lower.

[0469] For example, an aluminum oxide film is preferably formed by ALD as the insulating film 125A. ALD is preferred because it reduces deposition damage and allows for the deposition of films with high coverage. The insulating film 125A can be deposited using the same material and method as the mask layers 118a, 118b, 118c, etc. However, the boundary between the insulating film 125A and the mask layers 118a, 118b, 118c, etc. may be unclear.

[0470] Next, an insulating film 127A ( 16A to 16C ).

[0471] Insulating film 127A will become insulating layer 127 in a later step. The aforementioned organic material can be used for insulating film 127A. A photosensitive organic resin, such as a photosensitive acrylic resin, is preferably used as the organic material. The viscosity of the material for insulating film 127A can be between 1 cP and 1500 cP, preferably between 1 cP and 12 cP. Setting the viscosity of the material for insulating film 127A within this range facilitates the formation of the tapered insulating layer 127, described later.

[0472] The method for forming the insulating film 127A is not particularly limited. For example, a wet deposition method such as spin coating, dipping, spray coating, inkjet coating, dispenser coating, screen printing, offset printing, doctor blade coating, slit coating, roll coating, curtain coating, or blade coating can be used as appropriate. In particular, the organic insulating film to be the insulating film 127A is preferably formed by spin coating.

[0473] After the insulating film 127A is applied, heat treatment is preferably performed. This heat treatment is performed at a temperature lower than the heat resistance temperature of the EL layer. The substrate temperature during the heat treatment is preferably 50°C to 200°C, preferably 60°C to 150°C, and more preferably 70°C to 120°C. This removes the solvent from the insulating film 127A.

[0474] Next, exposure is performed to expose a portion of the insulating film 127A to visible light or ultraviolet light. When a positive-type acrylic resin is used for the insulating film 127A, visible light or ultraviolet light can be irradiated through a mask onto the area where the insulating layer 127 will not be formed in a subsequent step. When visible light is used for exposure, it preferably includes i-rays (wavelength 365 nm). Alternatively, visible light including g-rays (wavelength 436 nm) or h-rays (wavelength 405 nm) can be used.

[0475] Note that a negative-type photosensitive organic resin may be used for the insulating film 127A. In this case, the region where the insulating layer 127 is to be formed may be irradiated with visible light or ultraviolet light.

[0476] Next, the exposed region of the insulating film 127A is removed by development to form the insulating layer 127 ( 17A to 17C When an acrylic resin is used for the insulating film 127A, an alkaline solution is preferably used as a developer, for example, a tetramethylammonium hydroxide (TMAH) aqueous solution can be used.

[0477] Alternatively, the entire substrate may be exposed to visible light or ultraviolet light after development. Furthermore, a heat treatment may be performed after development or after development and exposure.

[0478] Next, etching is performed using the insulating layer 127 as a mask to form the insulating layer 125 ( 18A to 18C ). The above etching process can be performed by dry etching or wet etching.

[0479] When the insulating film 125A is made of the same material as that used for the mask film 118 af and the like, the etching conditions for the mask film 118 af and the like can be adopted as the etching conditions for the insulating film 125A.

[0480] In addition, as the etching conditions for the insulating film 125A using the insulating layer 127 as a mask, and the etching conditions for the mask layer 118a, the mask layer 118b, and the mask layer 118c performed after the etching of the insulating film 125A to be described later, it is preferable to adopt conditions with a high selectivity ratio with the insulating layer 127, that is, conditions where the etching rate of the insulating layer 127 is sufficiently lower than the etching rates of the insulating film 125A and the mask layer 118.

[0481] When an organic resin is used for the insulating layer 127, it may be difficult to sufficiently reduce the etching rate during dry etching. In this case, wet etching is preferably used to etch the insulating film 125A, the mask layers 118a, 118b, and 118c.

[0482] If the temperature of the post-development heat treatment is low, the resin used as the insulating film 127A may not be sufficiently cured. On the other hand, by lowering the temperature of the post-development heat treatment, damage to the layer 113 can be reduced, thereby further improving reliability.

[0483] Depending on the degree of curing (extent of curing) of the resin used as the insulating film 127A, the insulating layer 127 may be easily dissolved in an alkaline solution. In this case, for example, when wet etching is performed, it is preferable to use an acidic solution.

[0484] For example, the etching of the insulating film 125A using the insulating layer 127 as a mask and the subsequent etching of the mask layer 118a, the mask layer 118b and the mask layer 118c can utilize wet etching, and a chemical solution containing dilute hydrofluoric acid, oxalic acid, phosphoric acid, acetic acid, nitric acid or a mixed liquid thereof can be used.

[0485] Here, as an example, a chemical solution containing phosphoric acid, hydrofluoric acid, and water is used.

[0486] Next, etching is performed using the insulating layer 127 as a mask to remove portions of the mask layers 118a, 118b, and 118c ( 18A to 18C ).

[0487] When the insulating film 125A is made of the same material as that used for the mask film 118af and the like, portions of the mask layers 118a, 118b, and 118c can be removed under the same conditions after etching the insulating film 125A.

[0488] In addition, when the light-emitting devices 130a, 130b, and 130c can be used as light-emitting devices, parts of the mask layers 118a, 118b, and 118c may remain after etching.

[0489] Next, a common layer 114, a common electrode 115 ( 18A to 18C ).

[0490] The materials that can be used for the common layer 114 are as described above. The common layer 114 can be formed by evaporation (including vacuum evaporation), transfer, printing, inkjet, coating, etc. Alternatively, the common layer 114 can be formed using premixed materials.

[0491] The common layer 114 is provided so as to cover the top surfaces of the layers 113a, 113b, and 113c, as well as the top and side surfaces of the insulating layer 127. When the common layer 114 has high conductivity, the light-emitting device may short-circuit due to the side surfaces of any of the pixel electrodes 111a, 111b, and 111c, the layers 113a, 113b, and 113c contacting the common layer 114. However, in a display device according to one embodiment of the present invention, the insulating layers 125 and 127 cover the side surfaces of the layers 113a, 113b, and 113c, and the layers 113a, 113b, and 113c cover the side surfaces of the corresponding pixel electrodes 111a, 111b, and 111c. This prevents the highly conductive common layer 114 from contacting the side surfaces of these layers, thereby preventing the light-emitting device from short-circuiting. This improves the reliability of the light-emitting device.

[0492] Since the insulating layers 125 and 127 are filled between the layers 113a and 113b and between the layers 113b and 113c, the surface of the common layer 114 is flatter with less steps than when the insulating layers 125 and 127 are not provided. This improves the coverage of the common layer 114.

[0493] A range mask may be used when depositing the common electrode 115. Alternatively, the common electrode 115 may be deposited without using the range mask and processed using a resist mask or the like after the common electrode 115 is deposited.

[0494] The materials that can be used as the common electrode 115 are the materials described above. The common electrode 115 can be formed, for example, by sputtering or vacuum evaporation. Alternatively, a film formed by evaporation and a film formed by sputtering can be stacked. By the above process, a film including Figure 2C The pixel 110 shown, Figure 3C The pseudo pixel 51 and Figure 4A The display device 100 includes the area 61 and the like shown.

[0495] This embodiment mode can be combined with other embodiment modes as appropriate.

[0496] (Implementation Method 2)

[0497] In this embodiment, a display device according to one embodiment of the present invention is described with reference to FIG. 19 to FIG. 22 .

[0498] [Pixel layout]

[0499] This embodiment mainly describes a pixel layout different from that in FIG1 . There are no particular limitations on the arrangement of subpixels, and various methods can be used. Examples of subpixel arrangements include stripe, S-stripe, matrix, delta, Bayer, and PenTile arrangements.

[0500] Examples of the top surface shape of the sub-pixel include a triangle, a quadrangle (including a rectangle and a square), a pentagon, and other polygonal shapes, shapes with rounded corners, an ellipse, or a circle. Here, the top surface shape of the sub-pixel corresponds to the top surface shape of the light-emitting region of the light-emitting device.

[0501] Furthermore, the circuit layout of the subpixels is not limited to the subpixels shown in the drawings and can also be arranged outside of them. For example, the transistors included in subpixel 110a can be located within the subpixel 110b shown in the drawings, or some or all of them can be located outside of subpixel 110a.

[0502] Figure 19A The pixels 110 are shown arranged in an S-stripe pattern. Figure 19A The pixel 110 shown is composed of three sub-pixels 110a, 110b, and 110c. Figure 21A As shown, the sub-pixel 110a may also be a blue sub-pixel B, the sub-pixel 110b may also be a red sub-pixel R, and the sub-pixel 110c may also be a green sub-pixel G.

[0503] Figure 19B The pixel 110 shown includes a sub-pixel 110a having a top surface shape that is approximately triangular with rounded corners, a sub-pixel 110b having a top surface shape that is approximately triangular with rounded corners, and a sub-pixel 110c having a top surface shape that is approximately quadrilateral or approximately hexagonal with rounded corners. In addition, the light-emitting area of ​​the sub-pixel 110a is larger than that of the sub-pixel 110b. In this way, the shape and size of each sub-pixel can be determined independently. For example, the sub-pixel including the light-emitting device with higher reliability can be made smaller in size. For example, as Figure 21B As shown, the sub-pixel 110a may also be a green sub-pixel G, the sub-pixel 110b may also be a red sub-pixel R, and the sub-pixel 110c may also be a blue sub-pixel B.

[0504] Figure 19C The pixels 124a and 124b shown are arranged in a PenTile pattern. Figure 19C 1 and 2 show an example in which a pixel 124a including sub-pixels 110a and 110b and a pixel 124b including sub-pixels 110b and 110c are alternately arranged. Figure 21CAs shown, the sub-pixel 110a may also be a red sub-pixel R, the sub-pixel 110b may also be a green sub-pixel G, and the sub-pixel 110c may also be a blue sub-pixel B.

[0505] Figure 19D and Figure 19E Pixels 124a and 124b are shown in a delta arrangement. Pixel 124a includes two sub-pixels (sub-pixels 110a and 110b) in the upper row (first row) and one sub-pixel (sub-pixel 110c) in the lower row (second row). Pixel 124b includes one sub-pixel (sub-pixel 110c) in the upper row (first row) and two sub-pixels (sub-pixels 110a and 110b) in the lower row (second row). For example, Figure 21D As shown, the sub-pixel 110a may also be a red sub-pixel R, the sub-pixel 110b may also be a green sub-pixel G, and the sub-pixel 110c may also be a blue sub-pixel B.

[0506] Figure 19D An example is shown in which each sub-pixel has a top surface shape that is approximately quadrangular with rounded corners. Figure 19E An example is shown in which each sub-pixel has a circular top surface shape.

[0507] Figure 19F 10. The example of sub-pixels of each color arranged in a zigzag shape is shown. Specifically, in the top view, the positions of the top edges of two sub-pixels arranged in the row direction (for example, sub-pixel 110a and sub-pixel 110b or sub-pixel 110b and sub-pixel 110c) are not consistent. For example, Figure 21E As shown, the sub-pixel 110a may also be a red sub-pixel R, the sub-pixel 110b may also be a green sub-pixel G, and the sub-pixel 110c may also be a blue sub-pixel B.

[0508] In photolithography, the finer the pattern being processed, the more important the effect of light diffraction is. This leads to a loss of reproducibility when transferring the photomask pattern through exposure, making it difficult to process the resist mask into the desired shape. Consequently, even if the photomask pattern is rectangular, it can easily result in a pattern with rounded corners. Consequently, the top surface shape of the subpixel may be polygonal with rounded corners, elliptical, or circular.

[0509] Furthermore, in a method for manufacturing a display device according to one embodiment of the present invention, an EL layer or an island layer comprising a portion of the EL layer is processed into an island shape using a resist mask. The resist film formed on the EL layer or the island layer comprising a portion of the EL layer needs to be cured at a temperature lower than the heat resistance temperature of the EL layer or the island layer comprising a portion of the EL layer. Therefore, depending on the heat resistance temperature of the material of the EL layer or the island layer comprising a portion of the EL layer and the curing temperature of the resist material, the resist film may not cure sufficiently. An insufficiently cured resist film may have a shape different from the desired shape during processing. As a result, the top surface of the EL layer or the island layer comprising a portion of the EL layer may have a polygonal shape with rounded corners, an elliptical shape, or a circular shape. For example, when a resist mask with a square top surface is intended, a resist mask with a circular top surface may be formed, resulting in the top surface of the EL layer or the island layer comprising a portion of the EL layer having a circular shape.

[0510] Note that in order to achieve the desired top surface shape of the EL layer or an island-shaped layer formed from a portion of the EL layer, a technique (OPC (Optical Proximity Correction)) for pre-correcting the mask pattern so that the design pattern and the transferred pattern match can also be used. Specifically, in OPC, correction patterns are added to, for example, the corners of the pattern on the mask pattern.

[0511] Note that in the pixel 110 adopting the stripe arrangement shown in FIG. 4 , for example, Figure 21F As shown, the sub-pixel 110a may be a red sub-pixel R, the sub-pixel 110b may be a green sub-pixel G, and the sub-pixel 110c may be a blue sub-pixel B.

[0512] like 20A to 20H As shown, a pixel may include four types of sub-pixels.

[0513] 20A to 20C The pixels 110 are shown arranged in a stripe pattern.

[0514] Figure 20A An example is shown in which each sub-pixel has a rectangular top surface shape. Figure 20B An example is shown in which each sub-pixel has a top surface shape formed by connecting two semicircles and a rectangle. Figure 20C An example is shown in which each sub-pixel has an elliptical top surface shape.

[0515] Figures 20D to 20F The pixels 110 are shown arranged in a matrix.

[0516] Figure 20D An example is shown in which each sub-pixel has a square top surface shape. Figure 20EAn example is shown in which each sub-pixel has a top surface shape that is approximately square with rounded corners. Figure 20F An example is shown in which each sub-pixel has a circular top surface shape.

[0517] Figure 20G and Figure 20H An example is shown in which one pixel 110 is configured in two rows and three columns.

[0518] Figure 20G The pixel 110 shown includes three sub-pixels (sub-pixels 110a, 110b, 110c) on the upper row (first row) and one sub-pixel (sub-pixel 110d) on the lower row (second row). In other words, the pixel 110 includes sub-pixel 110a on the left column (first column), sub-pixel 110b on the center column (second column), sub-pixel 110c on the right column (third column), and sub-pixel 110d across the three columns.

[0519] Figure 20H The pixel 110 shown includes three sub-pixels (sub-pixels 110a, 110b, 110c) on the upper row (first row) and three sub-pixels 110d on the lower row (second row). In other words, the pixel 110 includes sub-pixels 110a and 110d on the left column (first column), sub-pixels 110b and 110d on the center column (second column), and sub-pixels 110c and 110d on the right column (third column). Figure 20H As shown, by aligning the arrangement of sub-pixels in the upper and lower rows, dust and the like generated during the manufacturing process can be efficiently removed. This makes it possible to provide a display device with high display quality.

[0520] 20A to 20H The pixel 110 shown is composed of four sub-pixels, 110a, 110b, 110c, and 110d. Each of the sub-pixels 110a, 110b, 110c, and 110d includes a light-emitting device that emits light of a different color. As the sub-pixels 110a, 110b, 110c, and 110d, there can be exemplified: sub-pixels of four colors, R, G, B, and white (W); sub-pixels of four colors, R, G, B, and Y; or sub-pixels of R, G, B, and infrared light (IR); and the like. For example, Figures 21G to 21J As shown, the sub-pixels 110a, 110b, 110c, and 110d may be red, green, blue, and white sub-pixels, respectively.

[0521] In the display device according to one embodiment of the present invention, the pixel may include a light-receiving device (also referred to as a light-receiving element).

[0522] In addition, you can also use Figures 21G to 21JThe illustrated pixel 110 includes four sub-pixels, three of which include structures of light-emitting devices and the remaining one includes a structure of a light-receiving device.

[0523] For example, the sub-pixels 110 a , 110 b , and 110 c are sub-pixels of three colors, R, G, and B, and the sub-pixel 110 d may also be a sub-pixel including a light-receiving device.

[0524] Figure 22A and Figure 22B The pixel shown includes sub-pixel G, sub-pixel B, sub-pixel R, and sub-pixel PS. Note that the order of the sub-pixels is not limited to the structure shown in the figure and can be determined appropriately. For example, the positions of sub-pixel G and sub-pixel R can also be swapped.

[0525] Figure 22A The pixels are shown arranged in stripes. Figure 22B The pixels shown are arranged in a matrix.

[0526] Sub-pixel R includes a light-emitting device that emits red light, sub-pixel G includes a light-emitting device that emits green light, and sub-pixel B includes a light-emitting device that emits blue light.

[0527] The sub-pixel PS includes a light-receiving device. There is no particular limitation on the wavelength of light detected by the sub-pixel PS. The sub-pixel PS can detect one or both of visible light and infrared light.

[0528] Figure 22C and Figure 22D The pixel shown includes sub-pixel G, sub-pixel B, sub-pixel R, sub-pixel X1, and sub-pixel X2. Note that the order of the sub-pixels is not limited to the structure shown in the figure and can be determined as appropriate. For example, the positions of sub-pixel G and sub-pixel R can also be swapped.

[0529] Figure 22C An example is shown in which one pixel is arranged in two rows and three columns. Three sub-pixels (sub-pixel G, sub-pixel B, and sub-pixel R) are arranged in the upper row (first row). Figure 22C In FIG, two sub-pixels (sub-pixel X1 and sub-pixel X2) are provided in the lower row (the second row).

[0530] Figure 22D An example in which one pixel is arranged in three rows and two columns is shown. Figure 22D In FIG, the first row includes sub-pixels G, the second row includes sub-pixels R, and the first and second rows include sub-pixels B. In addition, the third row includes two sub-pixels (sub-pixel X1 and sub-pixel X2). In other words, Figure 22D The pixel shown includes three subpixels (subpixel G, subpixel R, and subpixel X2) on the left column (first column) and two subpixels (subpixel B and subpixel X1) on the right column (second column).

[0531] Figure 22C The layout of the sub-pixels R, G, and B shown is a stripe arrangement. Figure 22D The layout of the sub-pixels R, G, and B shown is a so-called S-stripe arrangement, which can achieve high display quality.

[0532] At least one of the sub-pixel X1 and the sub-pixel X2 preferably includes a light-receiving device (also referred to as a sub-pixel PS).

[0533] Note that the layout of pixels including sub-pixels PS is not limited to 22A to 22D The structure described.

[0534] Subpixel X1 or subpixel X2 may, for example, use a structure including a light-emitting device that emits infrared light (IR). In this case, subpixel PS preferably detects infrared light. For example, while subpixels R, G, and B are used to display an image, one of subpixel X1 and subpixel X2 may be used as a light source, and the other may be configured to detect reflected light from the light source.

[0535] Both sub-pixel X1 and sub-pixel X2 may include a light-receiving device. In this case, the wavelength ranges of light detected by sub-pixel X1 and sub-pixel X2 may be the same, different, or partially the same. For example, one of sub-pixel X1 and sub-pixel X2 may primarily detect visible light, while the other may primarily detect infrared light.

[0536] The light-receiving area of ​​sub-pixel X1 is smaller than that of sub-pixel X2. The smaller the light-receiving area, the narrower the imaging range, which can reduce blur and improve resolution in the captured image. Therefore, by using sub-pixel X1, higher-definition or higher-resolution images can be achieved compared to using the light-receiving device included in sub-pixel X2. For example, sub-pixel X1 can be used for imaging for personal identification using fingerprints, palm prints, irises, vein patterns (including vein patterns and artery patterns), or faces.

[0537] Preferably, the light receiving device included in the sub-pixel PS detects visible light and detects one or more colors of blue, purple, blue-purple, green, yellow-green, yellow, orange, red, etc. In addition, the light receiving device included in the sub-pixel PS can also detect infrared light.

[0538] When subpixel X2 includes a light-receiving device, it can be used as a touch sensor (also known as a direct touch sensor) or a near-touch sensor (also known as a hovering sensor, a floating touch sensor, a non-contact sensor, or a non-touch sensor). Subpixel X2 can appropriately determine the wavelength of light it detects depending on its intended use. For example, subpixel X2 preferably detects infrared light. This allows touch detection even in darkness.

[0539] Here, the touch sensor or the proximity touch sensor can detect the approach or contact of an object (a finger, a hand, a pen, etc.).

[0540] When the display device is in direct contact with the object, the touch sensor can detect the object. In addition, the approximate touch sensor can detect the object even if the object is not in contact with the display device. For example, it is preferred to adopt the following structure: the display device can detect the object within a range of 0.1 mm to 300 mm, preferably 3 mm to 50 mm, between the display device and the object. By adopting this structure, the object can be operated in a manner that is not in direct contact with the display device, in other words, the display device can be operated in a non-contact (non-touch) manner. By adopting the above structure, the risk of the display device being soiled or damaged can be reduced, or the display device can be operated in a manner that the object is not in direct contact with stains (for example, garbage or viruses, etc.) attached to the display device.

[0541] A display device according to one embodiment of the present invention can have a variable refresh rate. For example, the refresh rate can be adjusted according to the content displayed on the display device (for example, within a range of 1 Hz to 240 Hz) to reduce power consumption. In addition, the driving frequency of the touch sensor or the near-touch sensor can also be changed according to the refresh rate. For example, when the refresh rate of the display device is 120 Hz, the driving frequency of the touch sensor or the near-touch sensor can be set to a frequency higher than 120 Hz (typically 240 Hz). By adopting this structure, low power consumption can be achieved and the response speed of the touch sensor or the near-touch sensor can be improved.

[0542] Figures 22E to 22G The display device 100 shown includes a layer 353 having a light-receiving device, a functional layer 355 , and a layer 357 having a light-emitting device between a substrate 351 and a substrate 359 .

[0543] The functional layer 355 includes a circuit for driving the light-receiving device and a circuit for driving the light-emitting device. Switches, transistors, capacitors, resistors, wiring, terminals, and the like may be provided in the functional layer 355. Note that switches and transistors may not be provided when driving the light-emitting and light-receiving devices in a passive matrix manner.

[0544] For example, Figure 22E As shown, light emitted by the light-emitting devices in the layer 357 having light-emitting devices is reflected by the finger 352 in contact with the display device 100, and the light-receiving devices in the layer 353 having light-receiving devices detect the reflected light. Thus, the finger 352 in contact with the display device 100 can be detected.

[0545] In addition, if Figure 22F and Figure 22G As shown, it may also have a function of detecting or photographing an object approaching (not in contact with) the display device. Figure 22F An example of detecting a person's finger is shown. Figure 22G An example of detecting information about the periphery, surface, or interior of a human eye (number of blinks, movement of the eyeball, movement of the eyelid, etc.) is shown.

[0546] In the display device of this embodiment, a light receiving device can be used to capture the periphery of the eye, the surface of the eye, or the inside of the eye (fundus, etc.) of the user of the wearable device. Therefore, the wearable device can have the function of detecting any one or more selected from the user's blinking, black eye movement, and eyelid movement.

[0547] As described above, in a display device according to one embodiment of the present invention, various layouts can be adopted for pixels composed of sub-pixels including light-emitting devices. Furthermore, a display device according to one embodiment of the present invention can employ a structure in which pixels include both light-emitting devices and light-receiving devices. In this case, various layouts can also be adopted.

[0548] This embodiment mode can be combined with other embodiment modes as appropriate.

[0549] (Implementation 3)

[0550] In this embodiment, a display device according to one embodiment of the present invention is described with reference to FIG. 23 to FIG. 31 .

[0551] The display device of this embodiment can be a high-definition display device. Therefore, for example, the display device of this embodiment can be used as the display portion of information terminal devices (wearable devices) such as watches and bracelets, as well as the display portion of wearable devices such as head-mounted displays for VR devices and glasses-type AR devices that can be worn on the head.

[0552] Furthermore, the display device of this embodiment can be a high-resolution display device or a large display device. Therefore, for example, the display device of this embodiment can be used as a display portion of electronic devices with large screens, such as televisions, desktop or notebook personal computers, monitors for computers, digital signage, large-scale game consoles such as pinball machines, etc.; digital cameras; digital video cameras; digital photo frames; mobile phones; portable game consoles; portable information terminals; and audio reproduction devices.

[0553] [Display module]

[0554] Figure 23A 2 shows a perspective view of a display module 280. The display module 280 includes a display device 100A and an FPC 290. Note that the display device included in the display module 280 is not limited to the display device 100A, and may be any of the display devices 100B to 100F described later.

[0555] The display module 280 includes a substrate 291 and a substrate 292. The display module 280 includes a display portion 281. The display portion 281 is an image display region in the display module 280, and allows light from each pixel provided in a pixel portion 284 described below to be viewed.

[0556] Figure 23B A perspective schematic diagram shows the structure of one side of a substrate 291. A circuit portion 282, a pixel circuit portion 283 on the circuit portion 282, a pixel portion 284 on the pixel circuit portion 283, and a dummy pixel portion 294 are stacked on the substrate 291. Furthermore, a terminal portion 285 for connecting to an FPC 290 is provided on a portion of the substrate 291 that does not overlap with the pixel portion 284. The terminal portion 285 is electrically connected to the circuit portion 282 via a wiring portion 286 composed of a plurality of wiring lines.

[0557] The pixel portion 284 includes a plurality of pixels 284 a arranged periodically. Figure 23B The right side of FIG shows an enlarged view of a pixel 284a. Pixel 284a includes a light-emitting device 130a, a light-emitting device 130b, and a light-emitting device 130c. Light-emitting device 130a, for example, emits red light. Light-emitting device 130b, for example, emits green light. Light-emitting device 130c, for example, emits blue light.

[0558] The pixel circuit portion 283 includes a plurality of pixel circuits 283 a arranged periodically.

[0559] One pixel circuit 283a controls the emission of three light-emitting devices included in one pixel 284a. A pixel circuit 283a can also be configured with three circuits for controlling the emission of one light-emitting device. For example, the pixel circuit 283a can include at least one selection transistor, one current control transistor (drive transistor), and a capacitor for each light-emitting device. In this case, a gate signal is input to the gate of the selection transistor, and a source signal is input to the source. This implements an active matrix display device.

[0560] The circuit unit 282 includes a circuit for driving each pixel circuit 283a of the pixel circuit unit 283. For example, it preferably includes one or both of a gate line driver circuit and a source line driver circuit. In addition, it may include at least one of a calculation circuit, a storage circuit, and a power supply circuit.

[0561] The FPC 290 is used as wiring for supplying video signals, power supply potential, and the like from the outside to the circuit portion 282. Alternatively, an IC may be mounted on the FPC 290.

[0562] Dummy pixel portion 294 includes a plurality of dummy pixels. In some cases, each dummy pixel included in dummy pixel portion 294 is not electrically connected to circuit portion 282. Alternatively, a configuration may be employed in which some of the dummy pixels included in dummy pixel portion 294 are electrically connected to circuit portion 282, while others are not.

[0563] When each dummy pixel included in the dummy pixel portion 294 is not electrically connected to the circuit portion 282, sometimes the plug 256b, plug 256c, etc. (hereinafter collectively referred to as the plug 256) described later are not provided under the pixel electrode included in the dummy pixel.

[0564] Alternatively, when each dummy pixel included in the dummy pixel portion 294 is not electrically connected to the circuit portion 282, a plug 256, described later, may be provided under the pixel electrode included in the dummy pixel. When the plug 256 is provided, the plug 256 may not be electrically connected to the transistor 310. Alternatively, the provided plug 256 may be electrically connected to the transistor 310.

[0565] Each dummy pixel included in the dummy pixel portion 294 includes, for example, a pixel electrode and an EL layer. Each dummy pixel included in the dummy pixel portion 294 may have the same structure as the pixel 284a.

[0566] Each dummy pixel included in the dummy pixel portion 294 can adopt a structure such as the dummy pixel 51 described in the above embodiment.

[0567] A peripheral region 297 is provided around the dummy pixel portion 294 .

[0568] The display module 280 can adopt a structure in which one or both of the pixel circuit unit 283 and the circuit unit 282 are overlapped on the lower side of the pixel unit 284, so that the display unit 281 can have an extremely high aperture ratio (effective display area ratio). For example, the aperture ratio of the display unit 281 can be greater than 40% and less than 100%, preferably greater than 50% and less than 95%, and more preferably greater than 60% and less than 95%. In addition, the pixels 284a can be arranged at an extremely high density, thereby making the display unit 281 have an extremely high definition. For example, the display unit 281 preferably configures the pixels 284a with a definition of greater than 2000ppi, more preferably greater than 3000ppi, further preferably greater than 5000ppi, and even more preferably greater than 6000ppi and less than 20,000ppi or less than 30,000ppi.

[0569] This display module 280 is very clear and is therefore suitable for use in VR devices such as head-mounted displays or glasses-type AR devices. For example, because the display module 280 has a display portion 281 with extremely high clarity, in a structure where the display portion of the display module 280 is viewed through a lens, even if the display portion is magnified using the lens, the user cannot see the pixels, thereby achieving a highly immersive display. In addition, the display module 280 is not limited to this and can also be suitable for use in electronic devices with smaller display portions. For example, it is suitable for use in the display portion of wearable electronic devices such as watch-type devices.

[0570] [Display device 100A]

[0571] Figure 24A The display device 100A shown includes a substrate 301, a light-emitting device 130b and a light-emitting device 130c, a capacitor 240, and a transistor 310. The light-emitting device 130b and the light-emitting device 130c are light-emitting devices included in the pixel 284a. The display device 100A includes a structure 58a as a component of the dummy pixel included in the dummy pixel portion. The structure 58a has a structure in which a pixel electrode 111e, a layer 113e, a common layer 114, and a common electrode 115 are stacked. In addition, although not shown in the figure, the display device 100A includes, for example, a structure 58b in which a light-emitting device 130a, a pixel electrode 111f, a layer 113f, a common layer 114, and a common electrode 115 are stacked on the substrate 301, and a structure 58c in which a pixel electrode 111g, a layer 113g, a common layer 114, and a common electrode 115 are stacked.

[0572] Substrate 301 is equivalent to Figure 23A and Figure 23B The stacked-layer structure from the substrate 301 to the insulating layer 255c can adopt the structure described in Embodiment 1, in which the layer 101 including the transistor and the insulating layers 255a, 255b, and 255c thereover are provided.

[0573] Transistor 310 is a transistor having a channel formation region in substrate 301. As substrate 301, a semiconductor substrate such as a single crystal silicon substrate can be used, for example. Transistor 310 includes a portion of substrate 301, a conductive layer 311, a low-resistance region 312, an insulating layer 313, and an insulating layer 314. Conductive layer 311 serves as a gate electrode. Insulating layer 313 is located between substrate 301 and conductive layer 311 and serves as a gate insulating layer. Low-resistance region 312 is a region in substrate 301 doped with impurities and serves as either a source or a drain. Insulating layer 314 covers the side surfaces of conductive layer 311.

[0574] Furthermore, an element isolation layer 315 is provided between two adjacent transistors 310 so as to be embedded in the substrate 301 .

[0575] Furthermore, an insulating layer 261 is provided to cover the transistor 310 , and the capacitor 240 is provided over the insulating layer 261 .

[0576] Capacitor 240 includes conductive layer 241, conductive layer 245, and insulating layer 243 therebetween. Conductive layer 241 serves as one electrode of capacitor 240, conductive layer 245 serves as the other electrode of capacitor 240, and insulating layer 243 serves as a dielectric of capacitor 240.

[0577] Conductive layer 241 is provided on insulating layer 261 and embedded in insulating layer 254. Conductive layer 241 is electrically connected to one of the source and drain of transistor 310 via plug 271 embedded in insulating layer 261. Insulating layer 243 is provided to cover conductive layer 241. Conductive layer 245 is provided in a region overlapping conductive layer 241 with insulating layer 243 interposed therebetween.

[0578] The capacitor 240 is covered with an insulating layer 255 a , an insulating layer 255 b is provided on the insulating layer 255 a , and an insulating layer 255 c is provided on the insulating layer 255 b .

[0579] exist Figure 24A In the embodiment, the light emitting device 130b, the light emitting device 130c and the structure 58a are provided on the insulating layer 255c.

[0580] Since the layers 113b and 113c are separated and isolated from each other in the display device 100A, crosstalk between adjacent sub-pixels can be suppressed even in a high-definition display device, thereby achieving a display device with high definition and high display quality.

[0581] An insulator is provided in the region between adjacent light emitting devices. Figure 24AIn the embodiment, an insulating layer 125 and an insulating layer 127 on the insulating layer 125 are provided in this region.

[0582] The mask layer 118b is located on the layer 113b included in the light emitting device 130b, and the mask layer 118c is located on the layer 113c included in the light emitting device 130c.

[0583] Pixel electrodes 111b and 111c of the light-emitting device are electrically connected to one of the source and drain electrodes of transistor 310 via plugs such as plugs 256b and 256c embedded in insulating layers 255a, 255b, and 255c, a conductive layer 241 embedded in insulating layer 254, and a plug 271 embedded in insulating layer 261. The top surface of insulating layer 255c is the same or substantially the same height as the top surfaces of plugs such as plugs 256b and 256c. Various conductive materials can be used for the plugs.

[0584] On the other hand, structure 58a has the same structure as light-emitting device 130, but preferably does not have a light-emitting function. Therefore, for example, a structure can be adopted in which a plug embedded in insulating layers 255a, 255b, and 255c is not provided below structure 58a, and the pixel electrode 111e is not connected to the transistor provided in layer 101 via a plug.

[0585] A protective layer 131 is provided on the light emitting device 130b, the light emitting device 130c and the structure 58a. The substrate 120 is bonded to the protective layer 131 via a resin layer 122. The details of the components from the light emitting device to the substrate 120 can be referred to in Embodiment 1. The substrate 120 is equivalent to Figure 23A The substrate 292 in FIG.

[0586] Examples of materials that can be used for plugs such as plug 271, plug 256b, and plug 256c include metals such as aluminum, titanium, chromium, nickel, copper, yttrium, zirconium, molybdenum, gold, silver, platinum, magnesium, iron, cobalt, palladium, tantalum, or tungsten, alloys containing these metals, or nitrides of these metals. Furthermore, films containing these materials can be used as plugs in single-layer or multi-layer structures. Examples include single-layer structures of an aluminum film containing silicon, two-layer structures of an aluminum film stacked on a titanium film, two-layer structures of an aluminum film stacked on a tungsten film, two-layer structures of a copper film stacked on a copper-magnesium-aluminum alloy film, two-layer structures of a copper film stacked on a titanium film, two-layer structures of a copper film stacked on a tungsten film, three-layer structures of a titanium film or titanium nitride film, an aluminum film or copper film, and a titanium film or titanium nitride film stacked in this order, and three-layer structures of a molybdenum film or molybdenum nitride film, an aluminum film or copper film, and a molybdenum film or molybdenum nitride film stacked in this order. Alternatively, oxides such as indium oxide, tin oxide, and zinc oxide may be used. Furthermore, the use of copper containing manganese is preferred because it improves the controllability of the shape during etching.

[0587] No insulating layer covering the top end of pixel electrode 111b is provided between pixel electrode 111b and layer 113b. Furthermore, no insulating layer covering the top end of pixel electrode 111c is provided between pixel electrode 111c and layer 113c. Therefore, the spacing between adjacent light-emitting devices can be extremely narrow. Consequently, a high-definition or high-resolution display device can be realized.

[0588] Although the display device 100A includes the light-emitting device 130 b and the light-emitting device 130 c , the display device of this embodiment may further include a light-receiving device.

[0589] Figure 24B The display device shown is an example including a light-emitting device 130b, a light-receiving device 150, and a structure 58a. Light-receiving device 150 is composed of a stack of pixel electrodes 111d, a layer 113d, a common layer 114, and a common electrode 115. Layer 113d is preferably used as an active layer. Details of the components of light-receiving device 150 can be found in Embodiment 1.

[0590] [Display device 100B]

[0591] Figure 25 The display device 100B shown has a structure in which a transistor 310A and a transistor 310B are stacked, each of which forms a channel in a semiconductor substrate. Note that in the description of the display device described later, description of parts similar to those of the display device described previously may be omitted.

[0592] The display device 100B has a structure in which a substrate 301B provided with a transistor 310B, a capacitor 240 , and a light-emitting device is bonded to a substrate 301A provided with a transistor 310A.

[0593] Here, an insulating layer 345 is preferably provided on the bottom surface of the substrate 301B. Furthermore, an insulating layer 346 is preferably provided on the insulating layer 261 provided on the substrate 301A. The insulating layers 345 and 346 function as protective layers and can suppress the diffusion of impurities into the substrates 301B and 301A. Inorganic insulating films that can be used for the protective layer 131 or the insulating layer 332 can be used as the insulating layers 345 and 346.

[0594] Substrate 301B is provided with a plug 343 that penetrates substrate 301B and insulating layer 345. Preferably, insulating layer 344 is provided to cover the side surfaces of plug 343. Insulating layer 344 serves as a protective layer and can suppress diffusion of impurities into substrate 301B. An inorganic insulating film that can be used for protective layer 131 can be used as insulating layer 344.

[0595] A conductive layer 342 is provided on the back surface (the surface opposite to the substrate 120) of the substrate 301B, below the insulating layer 345. The conductive layer 342 is preferably provided so as to be embedded in the insulating layer 335. Furthermore, the bottom surfaces of the conductive layer 342 and the insulating layer 335 are preferably flattened. The conductive layer 342 is electrically connected to the plug 343.

[0596] On the other hand, the substrate 301A includes a conductive layer 341 provided over the insulating layer 346. The conductive layer 341 is preferably provided so as to be embedded in the insulating layer 336. Furthermore, the top surfaces of the conductive layer 341 and the insulating layer 336 are preferably planarized.

[0597] The substrate 301A and the substrate 301B are electrically connected by bonding the conductive layer 341 and the conductive layer 342. Here, by improving the flatness of the surface formed by the conductive layer 342 and the insulating layer 335 and the surface formed by the conductive layer 341 and the insulating layer 336, the conductive layer 341 and the conductive layer 342 can be well bonded.

[0598] The conductive layers 341 and 342 are preferably made of the same conductive material. For example, a metal film containing an element selected from Al, Cr, Cu, Ta, Ti, Mo, and W, or a metal nitride film containing these elements (such as a titanium nitride film, a molybdenum nitride film, or a tungsten nitride film) can be used. It is particularly preferred that copper be used for the conductive layers 341 and 342. This allows for the use of Cu-Cu (copper-copper) direct bonding technology (a technology that achieves electrical continuity by connecting Cu (copper) pads to each other).

[0599] [Display device 100C]

[0600] Figure 26 The display device 100C shown has a structure in which a conductive layer 341 and a conductive layer 342 are connected via a bump 347 .

[0601] like Figure 26 As shown, by providing a bump 347 between conductive layer 341 and conductive layer 342, conductive layer 341 and conductive layer 342 can be electrically connected. Bump 347 can be formed using a conductive material such as gold (Au), nickel (Ni), indium (In), or tin (Sn). For example, solder is sometimes used as bump 347. Furthermore, an adhesive layer 348 may be provided between insulating layer 345 and insulating layer 346. Furthermore, when providing bump 347, insulating layer 335 and insulating layer 336 may not be provided.

[0602] [Display device 100D]

[0603] Figure 27 The main difference between the display device 100D shown and the display device 100A is the structure of the transistors.

[0604] The transistor 320 is a transistor (OS transistor) in which a metal oxide (also referred to as an oxide semiconductor) is used in a semiconductor layer forming a channel.

[0605] The transistor 320 includes a semiconductor layer 321 , an insulating layer 323 , a conductive layer 324 , a pair of conductive layers 325 , an insulating layer 326 , and a conductive layer 327 .

[0606] Substrate 331 is equivalent to Figure 23A and Figure 23B The stacked-layer structure from the substrate 331 to the insulating layer 255b corresponds to the layer 101 including the transistor in Embodiment 1. As the substrate 331, an insulating substrate or a semiconductor substrate can be used.

[0607] An insulating layer 332 is provided over the substrate 331. The insulating layer 332 functions as a barrier layer that prevents impurities such as water and hydrogen from diffusing from the substrate 331 to the transistor 320 and prevents oxygen from escaping from the semiconductor layer 321 toward the insulating layer 332. For example, a film into which hydrogen and oxygen are less likely to diffuse than a silicon oxide film, such as an aluminum oxide film, a hafnium oxide film, or a silicon nitride film, can be used as the insulating layer 332.

[0608] A conductive layer 327 is provided over the insulating layer 332, and an insulating layer 326 is provided to cover the conductive layer 327. The conductive layer 327 serves as the first gate electrode of the transistor 320, and a portion of the insulating layer 326 serves as a first gate insulating layer. An oxide insulating film such as a silicon oxide film is preferably used for at least the portion of the insulating layer 326 that contacts the semiconductor layer 321. The top surface of the insulating layer 326 is preferably planarized.

[0609] The semiconductor layer 321 is provided on the insulating layer 326. The semiconductor layer 321 preferably includes a metal oxide (also referred to as an oxide semiconductor) film having semiconductor characteristics. A pair of conductive layers 325 are in contact with the semiconductor layer 321 and function as a source electrode and a drain electrode.

[0610] An insulating layer 328 is provided to cover the top and side surfaces of the pair of conductive layers 325 and the side surfaces of the semiconductor layer 321. The insulating layer 264 is provided on the insulating layer 328. The insulating layer 328 serves as a barrier layer that prevents impurities such as water and hydrogen from diffusing from the insulating layer 264 into the semiconductor layer 321 and prevents oxygen from escaping from the semiconductor layer 321. As the insulating layer 328, an insulating film similar to the insulating layer 332 described above can be used.

[0611] Insulating layer 328 and insulating layer 264 have openings that reach semiconductor layer 321. Embedded within these openings are insulating layer 323 and conductive layer 324, which contact the side surfaces of insulating layer 264, insulating layer 328, and conductive layer 325, and the top surface of semiconductor layer 321. Conductive layer 324 serves as a second gate electrode, and insulating layer 323 serves as a second gate insulating layer.

[0612] The top surfaces of the conductive layer 324 , the insulating layer 323 , and the insulating layer 264 are planarized so that their heights are uniform or substantially uniform, and the insulating layer 329 and the insulating layer 265 are provided to cover them.

[0613] The insulating layer 264 and the insulating layer 265 serve as interlayer insulating layers. The insulating layer 329 serves as a barrier layer that prevents impurities such as water and hydrogen from diffusing from the insulating layer 265 and the like into the transistor 320. The insulating layer 329 can be an insulating film similar to the insulating layer 328 and the insulating layer 332 described above.

[0614] Plug 274, electrically connected to one of the pair of conductive layers 325, is embedded in insulating layer 265, insulating layer 329, and insulating layer 264. Plug 274 preferably includes a conductive layer 274a that covers the side surfaces of the openings in insulating layers 265, 329, 264, and 328, and a portion of the top surface of conductive layer 325, and a conductive layer 274b that contacts the top surface of conductive layer 274a. A conductive material that is not easily diffused by hydrogen and oxygen is preferably used for conductive layer 274a.

[0615] [Display device 100E]

[0616] Figure 28 The display device 100E shown has a structure in which a transistor 320A and a transistor 320B, each of which includes an oxide semiconductor in a semiconductor forming a channel, are stacked.

[0617] The structures of the transistor 320A, the transistor 320B and their peripheries may refer to the above-mentioned display device 100D.

[0618] Note that although two transistors including oxide semiconductors are stacked here, the present invention is not limited to this structure and may have a structure in which three or more transistors are stacked.

[0619] [Display device 100F]

[0620] Figure 29 The display device 100F shown includes a transistor 310 having a channel formed in a substrate 301 and a transistor 320 having a semiconductor layer including a metal oxide and forming the channel.

[0621] An insulating layer 261 is provided to cover transistor 310, and a conductive layer 251 is provided over insulating layer 261. Furthermore, an insulating layer 262 is provided to cover conductive layer 251, and conductive layer 252 is provided over insulating layer 262. Both conductive layer 251 and conductive layer 252 function as wiring. Furthermore, an insulating layer 263 and an insulating layer 332 are provided to cover conductive layer 252, and transistor 320 is provided over insulating layer 332. Furthermore, an insulating layer 265 is provided to cover transistor 320, and capacitor 240 is provided over insulating layer 265. Capacitor 240 is electrically connected to transistor 320 via plug 274.

[0622] Transistor 320 can be used as a transistor constituting a pixel circuit. In addition, transistor 310 can be used as a transistor constituting a pixel circuit or a transistor constituting a driver circuit (gate line driver circuit, source line driver circuit) for driving the pixel circuit. In addition, transistors 310 and 320 can be used as transistors constituting various circuits such as arithmetic circuits and memory circuits.

[0623] With this structure, not only the pixel circuit but also the driver circuit can be formed directly under the light-emitting device, so the display device can be miniaturized compared to the case where the driver circuit is provided around the display area.

[0624] [Display device 100G]

[0625] Figure 30 A perspective view showing a display device 100G is shown. Figure 31A A cross-sectional view of the display device 100G is shown.

[0626] The display device 100G has a structure in which a substrate 152 and a substrate 151 are bonded together. Figure 30 , the substrate 152 is indicated by a dotted line.

[0627] The display device 100G includes a display portion 167 , a connection portion 140 , a circuit 164 , a wiring 165 , and the like. Figure 30 FIG. 1 shows an example in which the IC 173 and the FPC 172 are mounted on the display device 100G. Figure 30 The structure shown is called a display module including a display device 100G, an IC (integrated circuit), and an FPC.

[0628] The connection portion 140 is provided on the outer side of the display portion 167. The connection portion 140 may be provided along one side or multiple sides of the display portion 167. The number of the connection portions 140 may also be one or more. Figure 30In the example shown, the connection portion 140 is provided so as to surround the four sides of the display portion. In the connection portion 140, the common electrode of the light emitting device is electrically connected to the conductive layer, and a potential can be supplied to the common electrode.

[0629] As the circuit 164 , for example, a scan line driver circuit can be used.

[0630] The wiring 165 has a function of supplying signals and power to the display portion 167 and the circuit 164. The signals and power are input to the wiring 165 from the outside through the FPC 172 or from the IC 173.

[0631] Figure 30 The following illustrates an example in which an IC 173 is provided on a substrate 151 using a COG (Chip On Glass) method or a COF (Chip On Film) method. For example, an IC including a scan line driver circuit or a signal line driver circuit can be used as the IC 173. Note that the display device 100G and the display module may also have a structure without an IC. Alternatively, the IC may be mounted on an FPC using a COF method or the like.

[0632] Figure 31A An example of a cross section of the display device 100G including a portion of the region including the FPC 172 , a portion of the circuit 164 , a portion of the display portion 167 , a portion of the connection portion 140 , and a portion of the region including the end portion is shown.

[0633] Figure 31A The display device 100G shown includes a transistor 201, a transistor 205, a light-emitting device 130b, and a light-emitting device 130a between a substrate 151 and a substrate 152. The light-emitting device 130a is, for example, a light-emitting device that emits red light. In addition, the light-emitting device 130b is, for example, a light-emitting device that emits green light. As a constituent element of the pseudo pixel included in the pseudo pixel portion, the display device 100G includes a structure 58c. The structure 58c has a structure in which a conductive layer (a stack of a conductive layer 112g, a conductive layer 126g, and a conductive layer 129g to be described later) is stacked, a layer 113g, a common layer 114, and a common electrode 115. Although not shown, the display device 100G includes, between the substrates 151 and 152, a structure 58a including a stacked structure of a light-emitting device 130c, a conductive layer, a layer 113e, a common layer 114, and a common electrode 115; and a structure 58b including a stacked structure of a conductive layer, a layer 113f, a common layer 114, and a common electrode 115. The light-emitting device 130c is, for example, a light-emitting device that emits blue light.

[0634] The light emitting device 130a and the light emitting device 130b have the same structure except for the difference in the structure of the pixel electrode. Figure 2CThe structure 58c has the same structure as the stacked structure shown in FIG. Figure 3C The stacked structure shown in FIG. 1 is similar in structure to the stacked structure shown in FIG. Detailed description of the light emitting device can be found in Embodiment 1. The light emitting device 130 a , the light emitting device 130 b , and the structure 58 c are provided on the insulating layer 214 .

[0635] Since the layers 113a, 113b, and 113c are separated and isolated from each other in the display device 100G, crosstalk between adjacent sub-pixels can be suppressed even in a high-definition display device. Therefore, a display device with high definition and high display quality can be realized.

[0636] The light emitting device 130a includes a conductive layer 112a, a conductive layer 126a on the conductive layer 112a, and a conductive layer 129a on the conductive layer 126a. The conductive layers 112a, 126a, and 129a may all be referred to as pixel electrodes, or a portion thereof may be referred to as pixel electrodes.

[0637] The light emitting device 130b includes a conductive layer 112b, a conductive layer 126b on the conductive layer 112b, and a conductive layer 129b on the conductive layer 126b.

[0638] The structural body 58c includes a conductive layer 112g, a conductive layer 126g on the conductive layer 112g, and a conductive layer 129g on the conductive layer 126g.

[0639] The conductive layer 112a is connected to the conductive layer 222b included in the transistor 205 through an opening provided in the insulating layer 214. The end of the conductive layer 126a is located outside the end of the conductive layer 112a. The end of the conductive layer 126a is aligned or substantially aligned with the end of the conductive layer 129a. For example, a conductive layer that functions as a reflective electrode may be used as the conductive layer 112a and the conductive layer 126a, and a conductive layer that functions as a transparent electrode may be used as the conductive layer 129a.

[0640] Conductive layer 112b is connected to conductive layer 222b included in transistor 205 via an opening provided in insulating layer 214. An end portion of conductive layer 126b is located outside an end portion of conductive layer 112b. The end portion of conductive layer 126b is aligned or substantially aligned with an end portion of conductive layer 129b. For example, conductive layers 112b and 126b may be reflective electrodes, and conductive layer 129b may be a transparent electrode.

[0641] Conductive layer 112g is connected to conductive layer 222b included in transistor 205 through an opening provided in insulating layer 214. An end portion of conductive layer 126g is located outside an end portion of conductive layer 112g. The end portion of conductive layer 126g is aligned or substantially aligned with an end portion of conductive layer 129g. For example, conductive layers 112g and 126g may be reflective electrodes, and conductive layer 129g may be a transparent electrode.

[0642] Recesses are formed in conductive layers 112a, 112b, and 112g so as to cover openings provided in insulating layer 214. Layer 128 is filled in these recesses.

[0643] Layer 128 flattens the concave portions of conductive layers 112a, 112b, and 112g. Conductive layers 126a, 126b, and 126g are provided on conductive layers 112a, 112b, and 112g and layer 128, and are electrically connected to conductive layers 112a, 112b, and 112g. Therefore, the areas overlapping the concave portions of conductive layers 112a, 112b, and 112g can also be used as light-emitting areas, thereby increasing the pixel aperture ratio.

[0644] Layer 128 may be an insulating layer or a conductive layer. Various inorganic insulating materials, organic insulating materials, and conductive materials can be used as appropriate for layer 128. In particular, layer 128 is preferably formed using an insulating material.

[0645] An insulating layer composed of an organic material can be suitably used as layer 128. For example, acrylic resin, polyimide resin, epoxy resin, polyamide resin, polyimideamide resin, siloxane resin, benzocyclobutene resin, phenolic resin, and precursors of these resins can be used as layer 128. Alternatively, a photosensitive resin can be used as layer 128. Either a positive-type material or a negative-type material can be used for the photosensitive resin.

[0646] By using a photosensitive resin, layer 128 can be formed only through exposure and development steps, which can reduce the effects on the surfaces of conductive layers 112a, 112b, and 112g caused by dry etching or wet etching. In addition, by using a negative photosensitive resin to form layer 128, the same photomask (exposure mask) as that used to form the openings in insulating layer 214 can be used to form layer 128.

[0647] The top and side surfaces of conductive layer 126a and the top and side surfaces of conductive layer 129a are covered by layer 113a. Similarly, the top and side surfaces of conductive layer 126b and the top and side surfaces of conductive layer 129b are covered by layer 113b. Furthermore, the top and side surfaces of conductive layer 126g and the top and side surfaces of conductive layer 129g are covered by layer 113c. Therefore, since the entire area provided with conductive layers 126a, 126b, and 126g can be used as the light-emitting area of ​​light-emitting devices 130a, 130b, and 130c, the aperture ratio of the pixel can be increased.

[0648] The sides of layers 113a, 113b, and 113g are covered by insulating layers 125 and 127. Mask layer 118a is located between layer 113a and insulating layer 125. Furthermore, mask layer 118b is located between layer 113b and insulating layer 125, and mask layer 118g is located between layer 113g and insulating layer 125. Common layer 114 is provided on layers 113a, 113b, and insulating layers 125 and 127, and common electrode 115 is provided on common layer 114. Common layer 114 and common electrode 115 are both continuous films commonly provided in multiple light-emitting devices.

[0649] A protective layer 131 is provided on each of the light emitting devices 130a, 130b, and the structure 58c. By forming the protective layer 131 covering the light emitting devices, impurities such as water can be prevented from entering the light emitting devices, thereby improving the reliability of the light emitting devices.

[0650] The protective layer 131 and the substrate 152 are bonded by the adhesive layer 142. The sealing of the light emitting device can adopt a solid sealing structure or a hollow sealing structure. Figure 31A In the embodiment, the space between substrate 152 and substrate 151 is filled with adhesive layer 142, i.e., a solid sealing structure is adopted. Alternatively, the space can be filled with an inert gas (such as nitrogen or argon), i.e., a hollow sealing structure can also be adopted. In this case, adhesive layer 142 can also be arranged so as not to overlap with the light-emitting device. In addition, a resin different from the adhesive layer 142 arranged in a frame shape can also be used to fill the space.

[0651] In the connection portion 140, a conductive layer 123 is provided on the insulating layer 214. The conductive layer 123 shows an example of a stacked structure comprising a conductive film processed from the same conductive film as the conductive layers 112a, 112b, and 112g, a conductive film processed from the same conductive film as the conductive layers 126a, 126b, and 126g, and a conductive film processed from the same conductive film as the conductive layers 129a, 129b, and 129g. The ends of the conductive layer 123 are covered by a mask layer 118a, an insulating layer 125, and an insulating layer 127. Furthermore, a common layer 114 is provided on the conductive layer 123, and a common electrode 115 is provided on the common layer 114. The conductive layer 123 and the common electrode 115 are electrically connected via the common layer 114. Alternatively, the common layer 114 may not be formed on the connection portion 140. In this case, the conductive layer 123 and the common electrode 115 are in direct contact and electrically connected.

[0652] The display device 100G adopts a top emission structure. The light-emitting device emits light toward the substrate 152. The substrate 152 is preferably made of a material that is highly transparent to visible light. The pixel electrode is made of a material that reflects visible light, while the counter electrode (common electrode 115) is made of a material that transmits visible light.

[0653] The stacked-layer structure from the substrate 151 to the insulating layer 214 corresponds to the layer 101 including the transistor in the first embodiment.

[0654] The transistor 201 and the transistor 205 are both provided over the substrate 151. These transistors can be formed using the same material and the same process.

[0655] Insulating layer 211, insulating layer 213, insulating layer 215, and insulating layer 214 are sequentially provided on substrate 151. A portion of insulating layer 211 serves as a gate insulating layer for each transistor. A portion of insulating layer 213 serves as a gate insulating layer for each transistor. Insulating layer 215 is provided to cover the transistors. Insulating layer 214 is provided to cover the transistors and serves as a planarization layer. There are no particular restrictions on the number of gate insulating layers or insulating layers covering transistors; they can be one or two or more.

[0656] Preferably, at least one of the insulating layers covering the transistor is made of a material that is less susceptible to diffusion of impurities such as water and hydrogen. This allows the insulating layer to function as a barrier layer. This structure effectively suppresses the diffusion of impurities from the outside into the transistor, thereby improving the reliability of the display device.

[0657] Inorganic insulating films are preferably used as the insulating layer 211, the insulating layer 213, and the insulating layer 215. Examples of the inorganic insulating film include a silicon nitride film, a silicon oxynitride film, a silicon oxide film, a silicon nitride oxide film, an aluminum oxide film, and an aluminum nitride film. Alternatively, a hafnium oxide film, an yttrium oxide film, a zirconium oxide film, a gallium oxide film, a tantalum oxide film, a magnesium oxide film, a lanthanum oxide film, a cerium oxide film, and a neodymium oxide film may be used. Furthermore, two or more of the above insulating films may be stacked.

[0658] The insulating layer 214 used as a planarizing layer is preferably an organic insulating layer. Examples of materials that can be used for the organic insulating layer include acrylic resins, polyimide resins, epoxy resins, polyamide resins, polyimideamide resins, siloxane resins, benzocyclobutene resins, phenolic resins, and precursors of the above resins. In addition, the insulating layer 214 may also have a stacked structure of an organic insulating layer and an inorganic insulating layer. The outermost surface layer of the insulating layer 214 is preferably used as an etching protection layer. As a result, when processing the conductive layer 112a, the conductive layer 126a, or the conductive layer 129a, etc., it is possible to suppress the formation of recesses in the insulating layer 214. Alternatively, a recess may be provided in the insulating layer 214 when processing the conductive layer 112a, the conductive layer 126a, or the conductive layer 129a.

[0659] Transistor 201 and transistor 205 include a conductive layer 221 serving as a gate electrode; an insulating layer 211 serving as a gate insulator; conductive layers 222a and 222b serving as a source and drain electrode; a semiconductor layer 231; an insulating layer 213 serving as a gate insulator; and a conductive layer 223 serving as a gate electrode. Multiple layers formed by processing the same conductive film are shaded identically. 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.

[0660] There are no particular limitations on the structure of the transistors included in the display device of this embodiment. For example, planar transistors, staggered transistors, or inversely staggered transistors may be used. Furthermore, top-gate or bottom-gate transistor structures may be employed. Alternatively, gate electrodes may be provided above and below the semiconductor layer forming the channel.

[0661] Transistor 201 and transistor 205 employ a structure in which a semiconductor layer forming a channel is sandwiched between two gates. Alternatively, the two gates may be connected and the same signal supplied to both gates to drive the transistor. Alternatively, the threshold voltage of the transistor may be controlled by applying a potential for controlling the threshold voltage to one of the two gates and a potential for driving the other.

[0662] There are no particular restrictions on the crystallinity of the semiconductor material used for the transistor. Amorphous semiconductors, single crystal semiconductors, or semiconductors other than single crystal semiconductors with crystallinity (microcrystalline semiconductors, polycrystalline semiconductors, or semiconductors having a crystalline region in part thereof) can be used. Using a single crystal semiconductor or a crystalline semiconductor is preferred because it can suppress degradation of transistor characteristics.

[0663] A metal oxide (also referred to as an oxide semiconductor) is preferably used for the semiconductor layer of the transistor. That is, the display device of this embodiment preferably uses a transistor (hereinafter referred to as an OS transistor) using a metal oxide for the channel formation region.

[0664] Examples of crystalline oxide semiconductors include CAAC (c-axis-aligned crystalline)-OS and nc (nanocrystalline)-OS.

[0665] Alternatively, a transistor using silicon for the channel formation region (Si transistor) may be used. Examples of silicon include single crystal silicon, polycrystalline silicon, and amorphous silicon. In particular, a transistor containing low temperature polycrystalline silicon (LTPS (Low Temperature Poly Silicon)) in the semiconductor layer (hereinafter also referred to as an LTPS transistor) may be used. LTPS transistors have high field effect mobility and good frequency characteristics.

[0666] By using Si transistors such as LTPS transistors, circuits requiring high-frequency drive (e.g., source driver circuits) and the display unit can be formed on the same substrate. This simplifies the external circuitry incorporated into the display device, reducing component and installation costs.

[0667] Compared to transistors using amorphous silicon, OS transistors have significantly higher field-effect mobility. Furthermore, when an OS transistor is off, the source-drain leakage current (hereinafter also referred to as off-state current) is extremely low, allowing the charge stored in the capacitor connected in series with the transistor to be retained for a long period of time. Furthermore, the use of OS transistors can reduce power consumption in display devices.

[0668] In addition, the off-state current value of the OS transistor with a channel width of 1 μm at room temperature can be 1 aA (1×10 -18 A) or less, 1zA(1×10 -21 A) or less or 1yA(1×10 -24 Note that the off-state current of a Si transistor with a channel width of 1 μm at room temperature is 1 fA (1×10 -15 A) and above 1pA(1×10 -12Therefore, it can be said that the off-state current of the OS transistor is about 10 digits lower than that of the Si transistor.

[0669] Furthermore, to increase the brightness of the light-emitting device included in the pixel circuit, it is necessary to increase the current flowing through the light-emitting device. To achieve this, it is necessary to increase the source-drain voltage of the driver transistor included in the pixel circuit. Because the source-drain withstand voltage of an OS transistor is higher than that of a Si transistor, a high voltage can be applied between the source and drain of the OS transistor. Therefore, by using an OS transistor as the driver transistor included in the pixel circuit, the current flowing through the light-emitting device can be increased, thereby improving the brightness of the light-emitting device.

[0670] Furthermore, when operating in the saturation region, OS transistors can minimize changes in source-drain current in response to changes in gate-source voltage compared to Si transistors. Therefore, by using OS transistors as driver transistors in pixel circuits, the current flowing between the source and drain can be precisely determined based on changes in gate-source voltage, allowing the amount of current flowing through the light-emitting device to be controlled. This increases the number of grayscales in the pixel circuit.

[0671] Furthermore, regarding the saturation characteristics of the current flowing through a transistor when operating in its saturation region, compared to Si transistors, OS transistors can allow a stable current (saturation current) to flow even when the source-drain voltage is gradually increased. Therefore, by using an OS transistor as a driver transistor, a stable current can flow through the light-emitting device even if, for example, the current-voltage characteristics of an EL device are uneven. In other words, when an OS transistor operates in its saturation region, even when the source-drain voltage is increased, the source-drain current remains virtually unchanged, thereby stabilizing the luminous brightness of the light-emitting device.

[0672] As described above, by using an OS transistor as a driving transistor included in a pixel circuit, it is possible to achieve "suppression of black blur," "increase in emission brightness," "multi-gradation," "suppression of unevenness in light-emitting devices," and the like.

[0673] For example, the semiconductor layer preferably contains indium, M (M is one or more selected from gallium, aluminum, silicon, boron, yttrium, tin, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten and magnesium) and zinc. In particular, M is preferably one or more selected from aluminum, gallium, yttrium and tin.

[0674] In particular, as the semiconductor layer, an oxide containing indium (In), gallium (Ga), and zinc (Zn) (also referred to as IGZO) is preferably used. Alternatively, an oxide containing indium, tin, and zinc is preferably used. Alternatively, an oxide containing indium, gallium, tin, and zinc is preferably used. Alternatively, an oxide containing indium (In), aluminum (Al), and zinc (Zn) (also referred to as IAZO) is preferably used. Alternatively, an oxide containing indium (In), aluminum (Al), gallium (Ga), and zinc (Zn) (also referred to as IAGZO) is preferably used.

[0675] When an In-M-Zn oxide is used as the semiconductor layer, the atomic ratio of In in the In-M-Zn oxide is preferably equal to or greater than the atomic ratio of M. Examples of the atomic ratio of the metal elements in the In-M-Zn oxide include: a composition of In:M:Zn=1:1:1 or in the vicinity thereof, a composition of In:M:Zn=1:1:1.2 or in the vicinity thereof, a composition of In:M:Zn=1:3:2 or in the vicinity thereof, a composition of In:M:Zn=1:3:4 or in the vicinity thereof, a composition of In:M:Zn=2:1:3 or in the vicinity thereof, a composition of In:M:Zn=3:1:2 or in the vicinity thereof, and a composition of In:M:Zn=1:3:4 or in the vicinity thereof. Compositions of n=4:2:3 or in the vicinity thereof, compositions of In:M:Zn=4:2:4.1 or in the vicinity thereof, compositions of In:M:Zn=5:1:3 or in the vicinity thereof, compositions of In:M:Zn=5:1:6 or in the vicinity thereof, compositions of In:M:Zn=5:1:7 or in the vicinity thereof, compositions of In:M:Zn=5:1:8 or in the vicinity thereof, compositions of In:M:Zn=6:1:6 or in the vicinity thereof, compositions of In:M:Zn=5:2:5 or in the vicinity thereof, etc. Note that the near compositions include a range of ±30% of the desired atomic ratio.

[0676] For example, a composition described as having an atomic ratio of In:Ga:Zn = 4:2:3 or thereabouts includes the following: when In is 4, Ga is 1 or more and 3 or less, and Zn is 2 or more and 4 or less. Furthermore, a composition described as having an atomic ratio of In:Ga:Zn = 5:1:6 or thereabouts includes the following: when In is 5, Ga is greater than 0.1 and 2 or less, and Zn is 5 or more and 7 or less. Furthermore, a composition described as having an atomic ratio of In:Ga:Zn = 1:1:1 or thereabouts includes the following: when In is 1, Ga is greater than 0.1 and 2 or less, and Zn is greater than 0.1 and 2 or less.

[0677] The transistors included in the circuit 164 and the transistors included in the display portion 167 may have the same structure or different structures. The multiple transistors included in the circuit 164 may have the same structure or two or more structures. Similarly, the multiple transistors included in the display portion 167 may have the same structure or two or more structures.

[0678] All transistors included in the display portion 167 may be OS transistors, all transistors included in the display portion 167 may be Si transistors, or some transistors included in the display portion 167 may be OS transistors and the remaining transistors may be Si transistors.

[0679] For example, by using both LTPS transistors and OS transistors in the display portion 167, a display device with low power consumption and high driving capability can be realized. A structure combining LTPS transistors and OS transistors is sometimes referred to as LTPO. A more preferred example is a structure in which an OS transistor is used as a transistor for controlling conduction and non-conduction between wirings, and an LTPS transistor is used as a transistor for controlling current flow.

[0680] For example, one of the transistors included in the display portion 167 is used as a transistor for controlling the current flowing through the light-emitting device and may also be referred to as a drive transistor. One of the source and drain of the drive transistor is electrically connected to the pixel electrode of the light-emitting device. An LTPS transistor is preferably used as the drive transistor. Therefore, the current flowing through the light-emitting device in the pixel circuit can be increased.

[0681] On the other hand, one of the other transistors included in the display unit 167 is used as a switch function for controlling the selection and non-selection of pixels, and may also be referred to as a selection transistor. The gate of the selection transistor is electrically connected to the gate line, and one of the source and drain is electrically connected to the source line (signal line). An OS transistor is preferably used as the selection transistor. Therefore, even if the frame rate is significantly reduced (for example, below 1 fps), the grayscale of the pixel can be maintained, thereby reducing power consumption by stopping the driver when displaying a static image.

[0682] In this manner, the display device according to one embodiment of the present invention can achieve high aperture ratio, high definition, high display quality, and low power consumption.

[0683] A display device according to one embodiment of the present invention has a structure including an OS transistor and a light-emitting device having an MML structure. By adopting this structure, the leakage current that can flow through the transistor and the leakage current that can flow between adjacent light-emitting devices (also known as lateral leakage current, side leakage current, etc.) can be made extremely low. In addition, by adopting the above-mentioned structure, when an image is displayed on the display device, the viewer can observe any one or more of the image's sharpness, image sharpness, high color saturation, and high contrast. In addition, by adopting a structure in which the leakage current that can flow through the transistor and the lateral leakage current between the light-emitting devices are extremely low, a display with minimal light leakage, which can occur when displaying black, can be achieved.

[0684] Figure 31D The structure shown is that an opening is provided in the insulating layer 214 in the region surrounding the pixel portion, such as the circuit 164, and the insulating layer 215 is in contact with the protective layer 131. By using an inorganic insulating film for both the insulating layer 215 and the protective layer 131, the pixel portion can be sealed by the inorganic insulating film, thereby further improving the effect of suppressing the entry of impurities (such as moisture and oxygen) into the light-emitting device.

[0685] Figure 31B and Figure 31C Other structural examples of transistors are shown.

[0686] The transistor 209 and the transistor 210 include: a conductive layer 221 serving as a gate; an insulating layer 211 serving as a gate insulating layer; a semiconductor layer 231 including a channel formation region 231i and a pair of low-resistance regions 231n; a conductive layer 222a connected to one of the pair of low-resistance regions 231n; a conductive layer 222b connected to the other of the pair of low-resistance regions 231n; an insulating layer 225 serving as a gate insulating layer; a conductive layer 223 serving 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 formation region 231i. The insulating layer 225 is located at least between the conductive layer 223 and the channel formation region 231i. Furthermore, an insulating layer 218 covering the transistors may be provided.

[0687] exist Figure 31B In the illustrated example, in the transistor 209, the insulating layer 225 covers the top and side surfaces of the semiconductor layer 231. The conductive layers 222a and 222b are connected to the low-resistance region 231n via openings provided in the insulating layer 225 and the insulating layer 215. One of the conductive layers 222a and 222b functions as a source, and the other functions as a drain.

[0688] On the other hand, Figure 31CIn the transistor 210 shown in FIG. 1 , 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, by processing the insulating layer 225 using the conductive layer 223 as a mask, a Figure 31C The structure shown. Figure 31C In the embodiment, the insulating layer 215 covers the insulating layer 225 and the conductive layer 223 , and the conductive layer 222 a and the conductive layer 222 b are connected to the low resistance region 231 n through the openings of the insulating layer 215 .

[0689] Connecting portion 204 is provided in a region where substrates 151 and 152 do not overlap. In connecting portion 204, wiring 165 is electrically connected to FPC 172 via conductive layer 166 and connecting layer 242. Conductive layer 166 illustrates an example of a laminated structure comprising a conductive film processed from the same conductive film as conductive layers 112a, 112b, and 112g, a conductive film processed from the same conductive film as conductive layers 126a, 126b, and 126g, and a conductive film processed from the same conductive film as conductive layers 129a, 129b, and 129g. Conductive layer 166 is exposed on the top surface of connecting portion 204. Therefore, connecting portion 204 and FPC 172 can be electrically connected via connecting layer 242.

[0690] A light-shielding layer 117 is preferably provided on the surface of substrate 152 on the substrate 151 side. Light-shielding layer 117 can be provided between adjacent light-emitting elements, in connector 140, circuit 164, and the like. Furthermore, various optical components can be disposed outside substrate 152. FIG. 31 shows an example structure in which structure 58c is covered by a light-shielding layer. Note that structure 58c does not need to be covered by a light-shielding layer, for example, if structure 58c does not have a light-emitting function.

[0691] The substrate 151 and the substrate 152 may both be made of the same material as that used for the substrate 120 .

[0692] As the adhesive layer 142 , a material that can be used for the resin layer 122 can be used.

[0693] As the connection layer 242 , an anisotropic conductive film (ACF), anisotropic conductive paste (ACP), or the like can be used.

[0694] This embodiment mode can be combined with other embodiment modes as appropriate.

[0695] (Implementation 4)

[0696] This embodiment describes a structural example of a transistor that can be used in a display device according to one embodiment of the present invention. In particular, the description will focus on a case where a transistor containing silicon is used as a semiconductor for forming a channel.

[0697] One embodiment of the present invention is a display device including a light-emitting device and a pixel circuit. For example, a display device including three light-emitting devices emitting red (R), green (G), or blue (B) light can realize a full-color display device.

[0698] All transistors included in the pixel circuit that drives the light-emitting device are preferably transistors containing silicon in the semiconductor layer in which the channel is formed. Examples of silicon include single crystal silicon, polycrystalline silicon, amorphous silicon, and the like. In particular, transistors containing low-temperature polycrystalline silicon (LTPS (Low Temperature Poly Silicon)) in the semiconductor layer are preferably used (hereinafter also referred to as LTPS transistors). LTPS transistors have high field-effect mobility and good frequency characteristics.

[0699] By using silicon transistors such as LTPS transistors, circuits requiring high-frequency drive (e.g., source driver circuits) and the display unit can be formed on the same substrate. This simplifies the external circuitry incorporated into the display device, reducing component and installation costs.

[0700] In addition, it is preferred that a transistor (hereinafter also referred to as an OS transistor) containing a metal oxide (hereinafter also referred to as an oxide semiconductor) in the semiconductor forming the channel is used for at least one of the transistors included in the pixel circuit. Compared with transistors using amorphous silicon, the field effect mobility of the OS transistor is very high. In addition, the leakage current between the source and the drain in the off state of the OS transistor (hereinafter also referred to as the off-state current) is extremely low, and the charge stored in the capacitor connected in series with the transistor can be maintained for a long period of time. In addition, by using an OS transistor, the power consumption of the display device can be reduced.

[0701] By using LTPS transistors for some of the transistors included in the pixel circuit and OS transistors for the other transistors, a display device with low power consumption and high driving capability can be realized. As a more preferred example, it is preferable to use OS transistors for transistors that function as switches controlling conduction and non-conduction between wirings, and to use LTPS transistors for transistors that control current flow.

[0702] For example, one of the transistors provided in the pixel circuit is used as a transistor for controlling the current flowing through the light-emitting device, and may also be referred to as a drive transistor. One of the source and drain electrodes of the drive transistor is electrically connected to the pixel electrode of the light-emitting device. An LTPS transistor is preferably used as the drive transistor. Therefore, the current flowing through the light-emitting device in the pixel circuit can be increased.

[0703] On the other hand, another of the transistors provided in the pixel circuit is used as a switch for controlling the selection and non-selection of the pixel, and may also be referred to as a selection transistor. The gate of the selection transistor is electrically connected to the gate line, and one of the source and drain is electrically connected to the source line (signal line). An OS transistor is preferably used as the selection transistor. Therefore, even if the frame rate is significantly reduced (for example, below 1fps), the grayscale of the pixel can be maintained, thereby reducing power consumption by stopping the driver when displaying a static image.

[0704] Next, a more specific configuration example will be described with reference to the drawings.

[0705] [Configuration Example of Display Device]

[0706] Figure 32A 4 is a block diagram of a display device 400. The display device 400 includes a display portion 404, a driver circuit portion 402, a driver circuit portion 403, and the like.

[0707] The display unit 404 includes a plurality of pixels 430 arranged in a matrix. The pixel 430 includes a sub-pixel 405R, a sub-pixel 405G, and a sub-pixel 405B. Each of the sub-pixel 405R, the sub-pixel 405G, and the sub-pixel 405B includes a light-emitting device serving as a display device.

[0708] Pixel 430 is electrically connected to wiring GL, wiring SLR, wiring SLG, and wiring SLB. Wiring SLR, wiring SLG, and wiring SLB are each electrically connected to driver circuit section 402. Wiring GL is electrically connected to driver circuit section 403. Driver circuit section 402 functions as a source line driver circuit (also called a source driver), while driver circuit section 403 functions as a gate line driver circuit (also called a gate driver). Wiring GL functions as a gate line, and wiring SLR, wiring SLG, and wiring SLB each function as a source line.

[0709] Sub-pixel 405R includes a light-emitting device that emits red light. Sub-pixel 405G includes a light-emitting device that emits green light. Sub-pixel 405B includes a light-emitting device that emits blue light. Therefore, display device 400 is capable of full-color display. Note that pixel 430 may also include sub-pixels having light-emitting devices that emit other colors. For example, in addition to the three sub-pixels described above, pixel 430 may also include a sub-pixel having a light-emitting device that emits white light or a sub-pixel having a light-emitting device that emits yellow light.

[0710] The wiring GL is electrically connected to the sub-pixels 405R, 405G, and 405B arranged in the row direction (the direction in which the wiring GL extends). The wiring SLR, wiring SLG, and wiring SLB are electrically connected to the sub-pixels 405R, 405G, or 405B (not shown) arranged in the column direction (the direction in which the wiring SLR and the like extend).

[0711] [Structural Example of Pixel Circuit]

[0712] Figure 32B An example of a circuit diagram of a pixel 405 that can be used for the above-mentioned sub-pixel 405R, sub-pixel 405G, and sub-pixel 405B is shown. The pixel 405 includes a transistor M1, a transistor M2, a transistor M3, a capacitor C1, and a light-emitting device EL. In addition, a wiring GL and a wiring SL are electrically connected to the pixel 405. The wiring SL corresponds to Figure 32A Any one of the wiring SLR, wiring SLG, and wiring SLB shown in .

[0713] Transistor M1 has a gate electrically connected to wiring GL, one of its source and drain electrically connected to wiring SL, and the other of its source and drain electrically connected to one electrode of capacitor C1 and the gate of transistor M2. Transistor M2 has one of its source and drain electrically connected to wiring AL, and the other of its source and drain electrically connected to one electrode of light-emitting device EL, the other electrode of capacitor C1, and one of the source and drain of transistor M3. Transistor M3 has a gate electrically connected to wiring GL, and the other of its source and drain electrically connected to wiring RL. The other electrode of light-emitting device EL is electrically connected to wiring CL.

[0714] The wiring SL is supplied with a data potential D. The wiring GL is supplied with a selection signal. The selection signal includes a potential for turning on the transistor and a potential for turning off the transistor.

[0715] A reset potential is supplied to wiring RL. An anode potential is supplied to wiring AL. A cathode potential is supplied to wiring CL. In pixel 405, the anode potential is higher than the cathode potential. Furthermore, the reset potential supplied to wiring RL may be such that the potential difference between the reset potential and the cathode potential is less than the threshold voltage of light-emitting device EL. The reset potential may be higher than the cathode potential, the same as the cathode potential, or lower than the cathode potential.

[0716] The transistors M1 and M3 function as switches. The transistor M2 functions as a transistor for controlling the current flowing through the light emitting device EL. For example, the transistor M1 functions as a selection transistor, and the transistor M2 functions as a drive transistor.

[0717] Here, it is preferable to use LTPS transistors for all of the transistors M1 to M3 . Alternatively, it is preferable to use OS transistors for the transistors M1 and M3 and use an LTPS transistor for the transistor M2 .

[0718] Alternatively, transistors M1 to M3 may all be OS transistors. In this case, one or more of the multiple transistors included in the driver circuit portion 402 and the multiple transistors included in the driver circuit portion 403 may be LTPS transistors, and the other transistors may be OS transistors. For example, the transistors provided in the display portion 404 may be OS transistors, and the transistors provided in the driver circuit portion 402 and the driver circuit portion 403 may be LTPS transistors.

[0719] As an OS transistor, a transistor using an oxide semiconductor for a semiconductor layer in which a channel is formed can be used. For example, the semiconductor layer preferably contains indium, M (M is one or more selected from gallium, aluminum, silicon, boron, yttrium, tin, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten and magnesium) and zinc. In particular, M is preferably selected from one or more of aluminum, gallium, yttrium and tin. In particular, as the semiconductor layer of the OS transistor, an oxide containing indium, gallium and zinc (also described as IGZO) is preferably used. Alternatively, an oxide containing indium, tin and zinc is preferably used. Alternatively, an oxide containing indium, gallium, tin and zinc is preferably used.

[0720] A transistor using an oxide semiconductor having a wider band gap than silicon and a low carrier density can achieve an extremely low off-state current. Due to its low off-state current, the charge stored in the capacitor connected in series with the transistor can be maintained for a long period of time. Therefore, in particular, the transistor M1 and the transistor M3 connected in series with the capacitor C1 preferably use transistors containing oxide semiconductors. By using transistors containing oxide semiconductors as the transistor M1 and the transistor M3, the charge maintained in the capacitor C1 can be prevented from leaking through the transistor M1 or the transistor M3. In addition, the charge stored in the capacitor C1 can be maintained for a long period of time, so a static image can be displayed for a long period of time without rewriting the data of the pixel 405.

[0721] Note that in Figure 32B In the embodiment, the transistors are n-channel transistors, but p-channel transistors can also be used.

[0722] In addition, the transistors included in the pixel 405 are preferably arranged and formed over the same substrate.

[0723] As the transistor included in the pixel 405 , a transistor including a pair of gate electrodes overlapping with each other via a semiconductor layer can be used.

[0724] When a transistor including a pair of gates has a structure in which the gates are electrically connected to each other and supplied with the same potential, there are advantages such as increased on-state current and improved saturation characteristics of the transistor. In addition, a potential that controls the threshold voltage of the transistor can be supplied to one of the pair of gates. In addition, by supplying a constant potential to one of the pair of gates, the stability of the electrical characteristics of the transistor can be improved. For example, one gate of the transistor can be electrically connected to a wiring supplied with a constant potential, or one gate of the transistor can be electrically connected to the source or drain of the transistor itself.

[0725] Figure 32C The pixel 405 shown is an example of a case where a transistor including a pair of gate electrodes is used for transistor M1 and transistor M3. In each of transistor M1 and transistor M3, the pair of gate electrodes are electrically connected to each other. By adopting this structure, the data writing period for pixel 405 can be shortened.

[0726] Figure 32D The pixel 405 shown is an example of a case where a transistor having a pair of gate electrodes is used not only for transistors M1 and M3 but also for transistor M2. The pair of gate electrodes of transistor M2 are electrically connected to each other. Using such a transistor for transistor M2 improves saturation characteristics, thereby facilitating control of the luminance of the light-emitting device EL and improving display quality.

[0727] [Structure example of transistor]

[0728] An example of a cross-sectional structure of a transistor that can be used in the above-described display device will be described below.

[0729] [Structure Example 1]

[0730] Figure 33A is a cross-sectional view including the transistor 410 .

[0731] The transistor 410 is a transistor provided on the substrate 401 and using polysilicon in the semiconductor layer. For example, the transistor 410 corresponds to the transistor M2 of the pixel 405. That is, Figure 33A This is an example in which one of the source and the drain of the transistor 410 is electrically connected to the conductive layer 431 of the light-emitting device.

[0732] Transistor 410 includes a semiconductor layer 411, an insulating layer 412, a conductive layer 413, and the like. Semiconductor layer 411 includes a channel formation region 411i and a low-resistance region 411n. Semiconductor layer 411 comprises silicon. Preferably, semiconductor layer 411 comprises polycrystalline silicon. A portion of insulating layer 412 serves as a gate insulating layer. A portion of conductive layer 413 serves as a gate electrode.

[0733] Note that the semiconductor layer 411 may include a metal oxide having semiconductor characteristics (also referred to as an oxide semiconductor). In this case, the transistor 410 may be referred to as an OS transistor.

[0734] The low-resistance region 411n is a region containing impurity elements. For example, if the transistor 410 is an n-channel transistor, phosphorus, arsenic, or the like can be added to the low-resistance region 411n. On the other hand, if the transistor 410 is a p-channel transistor, boron, aluminum, or the like can be added to the low-resistance region 411n. Furthermore, to control the threshold voltage of the transistor 410, the aforementioned impurities can also be added to the channel formation region 411i.

[0735] An insulating layer 421 is provided on the substrate 401. The semiconductor layer 411 is provided on the insulating layer 421. The insulating layer 412 is provided to cover the semiconductor layer 411 and the insulating layer 421. The conductive layer 413 is provided on the insulating layer 412 at a position overlapping with the semiconductor layer 411.

[0736] Insulating layer 422 is provided to cover conductive layer 413 and insulating layer 412. Conductive layer 414a and conductive layer 414b are provided on insulating layer 422. Conductive layer 414a and conductive layer 414b are electrically connected to low-resistance region 411n through openings provided in insulating layer 422 and insulating layer 412. A portion of conductive layer 414a functions as one of a source electrode and a drain electrode, while a portion of conductive layer 414b functions as the other of the source electrode and the drain electrode. Insulating layer 423 is provided to cover conductive layer 414a, conductive layer 414b, and insulating layer 422.

[0737] A conductive layer 431 serving as a pixel electrode is provided over the insulating layer 423. The conductive layer 431 is provided over the insulating layer 423 and is electrically connected to the conductive layer 414b through an opening provided in the insulating layer 423. Although omitted here, an EL layer and a common electrode may be stacked over the conductive layer 431.

[0738] like Figure 33B As shown, the source electrode and the drain electrode can be formed using the same conductive film as the conductive layer 413. In this case, for example, the conductive layer 414a and the conductive layer 414b are electrically connected to the low-resistance region 411n in the opening provided in the insulating layer 412.

[0739] [Structure Example 2]

[0740] Figure 33C Transistor 410a is shown including a pair of gate electrodes. Figure 33C The transistor 410a is shown with Figure 33A The main difference is that the former includes a conductive layer 415 and an insulating layer 416.

[0741] The conductive layer 415 is provided on the insulating layer 421. The insulating layer 416 is provided to cover the conductive layer 415 and the insulating layer 421. The semiconductor layer 411 is provided so that at least the channel formation region 411i overlaps with the conductive layer 415 with the insulating layer 416 interposed therebetween.

[0742] exist Figure 33C In the transistor 410a shown, part of the conductive layer 413 serves as a first gate electrode, and part of the conductive layer 415 serves as a second gate electrode. In this case, part of the insulating layer 412 serves as a first gate insulating layer, and part of the insulating layer 416 serves as a second gate insulating layer.

[0743] Here, when electrically connecting the first gate electrode and the second gate electrode, the conductive layer 413 and the conductive layer 415 may be electrically connected in a region not shown through openings provided in the insulating layer 412 and the insulating layer 416. Alternatively, when electrically connecting the second gate electrode and the source or drain, the conductive layer 414 a or the conductive layer 414 b may be electrically connected to the conductive layer 415 in a region not shown through openings provided in the insulating layer 422, the insulating layer 412, and the insulating layer 416.

[0744] When LTPS transistors are used for all transistors constituting the pixel 405, Figure 33A The transistor 410 shown, Figure 33B The transistor 410 or Figure 33C In this case, the transistor 410a may be used for all transistors constituting the pixel 405, the transistor 410 may be used for all transistors, or the transistor 410a and the transistor 410 may be used in combination.

[0745] [Structure Example 3]

[0746] Hereinafter, structural examples including a transistor using silicon for a semiconductor layer and a transistor using a metal oxide for a semiconductor layer will be described.

[0747] Figure 34A is a schematic cross-sectional view including the transistor 410 a and the transistor 450 .

[0748] The transistor 410a can refer to the above-described structural example 1. Note that although the example using the transistor 410a is shown here, a structure including the transistor 410 and the transistor 450 or a structure including all of the transistors 410, 410a, and 450 may also be employed.

[0749] The transistor 450 is a transistor using metal oxide in a semiconductor layer. Figure 34AThe structure shown is an example in which the transistor 450 corresponds to the transistor M1 of the pixel 405 and the transistor 410a corresponds to the transistor M2. That is, Figure 34A This is an example in which one of the source and the drain of the transistor 410 a is electrically connected to the conductive layer 431 .

[0750] Figure 34A An example is shown in which the transistor 450 includes a pair of gates.

[0751] The transistor 450 includes a conductive layer 455, an insulating layer 422, a semiconductor layer 451, an insulating layer 452, a conductive layer 453, and the like. A portion of the conductive layer 453 serves as a first gate of the transistor 450, and a portion of the conductive layer 455 serves as a second gate of the transistor 450. In this case, a portion of the insulating layer 452 serves as a first gate insulating layer of the transistor 450, and a portion of the insulating layer 422 serves as a second gate insulating layer of the transistor 450.

[0752] The conductive layer 455 is provided on the insulating layer 412. The insulating layer 422 is provided so as to cover the conductive layer 455. The semiconductor layer 451 is provided on the insulating layer 422. The insulating layer 452 is provided so as to cover the semiconductor layer 451 and the insulating layer 422. The conductive layer 453 is provided on the insulating layer 452 and has a region overlapping with the semiconductor layer 451 and the conductive layer 455.

[0753] Insulating layer 426 is provided to cover insulating layer 452 and conductive layer 453. Conductive layer 454a and conductive layer 454b are provided over insulating layer 426. Conductive layer 454a and conductive layer 454b are electrically connected to semiconductor layer 451 through openings provided in insulating layer 426 and insulating layer 452. Part of conductive layer 454a functions as one of a source electrode and a drain electrode, and part of conductive layer 454b functions as the other of the source electrode and the drain electrode. Insulating layer 423 is provided to cover conductive layer 454a, conductive layer 454b, and insulating layer 426.

[0754] Here, the conductive layer 414a and the conductive layer 414b electrically connected to the transistor 410a and the conductive layer 454a and the conductive layer 454b are preferably formed by processing the same conductive film. Figure 34A 4 shows a structure in which conductive layers 414a, 414b, 454a, and 454b are formed on the same surface (i.e., in contact with the top surface of insulating layer 426) and contain the same metal element. In this case, conductive layers 414a and 414b are electrically connected to low-resistance region 411n via openings provided in insulating layers 426, 452, 422, and 412. This is preferred because it simplifies the manufacturing process.

[0755] Note that the conductive layer 413 serving as the first gate electrode of the transistor 410a and the conductive layer 455 serving as the second gate electrode of the transistor 450 are preferably formed by processing the same conductive film. Figure 34A 4 shows a structure in which the conductive layer 413 and the conductive layer 455 are formed on the same surface (that is, in contact with the top surface of the insulating layer 412) and contain the same metal element. This is preferred because it can simplify the manufacturing process.

[0756] exist Figure 34A In the embodiment, the insulating layer 452 used as the first gate insulating layer of the transistor 450 covers the end portion of the semiconductor layer 451, but as shown in FIG. Figure 34B As in the transistor 450 a shown in the figure, the insulating layer 452 can be processed so that the top surface shape thereof is consistent with or substantially consistent with the top surface shape of the conductive layer 453 .

[0757] In this specification, etc., the phrase "top surface shapes are substantially identical" means that at least a portion of the edges of each layer in the stack overlap. For example, this refers to the case where the upper and lower layers are processed using the same mask pattern or a portion of the same mask pattern. However, strictly speaking, the "top surface shapes are substantially identical" can also be considered to exist when the edges do not overlap and the upper layer is positioned inside or outside the lower layer.

[0758] Note that although the example in which transistor 410a corresponds to transistor M2 and is electrically connected to the pixel electrode is shown here, the present invention is not limited thereto. For example, transistor 450 or transistor 450a may also correspond to transistor M2. In this case, transistor 410a corresponds to transistor M1, transistor M3, or another transistor.

[0759] This embodiment mode can be combined with other embodiment modes as appropriate.

[0760] (Implementation 5)

[0761] In this embodiment, a light-emitting device that can be used in a display device that is one embodiment of the present invention is described.

[0762] like Figure 35A As shown, the light-emitting device includes an EL layer 763 between a pair of electrodes (a lower electrode 761 and an upper electrode 762). The EL layer 763 can be composed of a plurality of layers such as a layer 780, a light-emitting layer 771, and a layer 790.

[0763] The light-emitting layer 771 contains at least a light-emitting substance (also referred to as a light-emitting material).

[0764] When the lower electrode 761 and the upper electrode 762 are respectively the anode and the cathode, the layer 780 includes one or more of a layer containing a substance with high hole injection properties (hole injection layer), a layer containing a substance with high hole transport properties (hole transport layer), and a layer containing a substance with high electron blocking properties (electron blocking layer). In addition, the layer 790 includes one or more of a layer containing a substance with high electron injection properties (electron injection layer), a layer containing a substance with high electron transport properties (electron transport layer), and a layer containing a substance with high hole blocking properties (hole blocking layer). When the lower electrode 761 and the upper electrode 762 are respectively the cathode and the anode, the structures of the layers 780 and 790 are reversed from the above.

[0765] The structure including the layer 780, the light-emitting layer 771, and the layer 790 disposed between a pair of electrodes can be used as a single light-emitting unit. Figure 35A The structure is called a simple structure.

[0766] in addition, Figure 35B Show Figure 35A The light-emitting device shown in FIG. 7 is a modified example of the EL layer 763 included in the light-emitting device. Specifically, Figure 35B The light-emitting device shown includes layer 781 on lower electrode 761, layer 782 on layer 781, light-emitting layer 771 on layer 782, layer 791 on light-emitting layer 771, layer 792 on layer 791, and upper electrode 762 on layer 792.

[0767] In the case where the lower electrode 761 and the upper electrode 762 are respectively an anode and a cathode, for example, the layers 781, 782, 791, and 792 may be a hole injection layer, a hole transport layer, an electron transport layer, and an electron injection layer, respectively. Alternatively, in the case where the lower electrode 761 and the upper electrode 762 are respectively a cathode and an anode, the layers 781, 782, 791, and 792 may be an electron injection layer, an electron transport layer, a hole transport layer, and a hole injection layer, respectively. By adopting the above-described layer structure, carriers can be efficiently injected into the light-emitting layer 771, thereby improving the efficiency of carrier recombination within the light-emitting layer 771.

[0768] In addition, if Figure 35C and Figure 35D As shown in FIG, a structure in which a plurality of light-emitting layers (light-emitting layers 771, 772, 773) are provided between layer 780 and layer 790 is also a modified example of a single structure. Figure 35C and Figure 35D Although an example including three light-emitting layers is shown, a light-emitting device having a single structure may have two light-emitting layers or four or more light-emitting layers. In addition, a light-emitting device having a single structure may include a buffer layer between two light-emitting layers.

[0769] like Figure 35E and Figure 35F As shown, in this specification, a structure in which multiple light-emitting units (light-emitting unit 763a and light-emitting unit 763b) are connected in series via a charge generation layer 785 (also referred to as an intermediate layer) is referred to as a series structure. In addition, a series structure can also be referred to as a stacked structure. By adopting a series structure, a light-emitting device capable of emitting light with high brightness can be realized. In addition, the series structure can reduce the current required to obtain the same brightness compared to a single structure, thereby improving reliability.

[0770] Figure 35D and Figure 35F An example is shown in which the display device includes a layer 764 overlapping the light-emitting device. Figure 35D Layer 764 is shown overlapping Figure 35C Examples of light emitting devices shown, Figure 35F Layer 764 is shown overlapping Figure 35E An example of a light emitting device is shown. Figure 35D and Figure 35F In the embodiment, the upper electrode 762 uses a conductive film that transmits visible light to extract light to the upper electrode 762 side.

[0771] As the layer 764 , one or both of a color conversion layer and a color filter (coloring layer) can be used.

[0772] exist Figure 35C and Figure 35D In the embodiment, luminescent materials emitting light of the same color, or even the same luminescent material, may be used for the luminescent layers 771, 772, and 773. For example, a luminescent material emitting blue light may be used for the luminescent layers 771, 772, and 773. In the sub-pixel that emits blue light, the blue light emitted by the light-emitting device can be extracted. In addition, by using the same luminescent material as the light-emitting material in the sub-pixel that emits red light and the sub-pixel that emits green light, the blue light emitted by the light-emitting device can be extracted. Figure 35D Layer 764, shown as a color conversion layer, converts the blue light emitted by the light-emitting device into longer-wavelength light, extracting it as red or green light. Preferably, both a color conversion layer and a coloring layer are used as layer 764. Some light emitted by the light-emitting device may pass through the color conversion layer without being converted. By extracting the light that has passed through the color conversion layer through the coloring layer, the coloring layer absorbs light other than the desired color, thereby improving the color purity of the light emitted by the sub-pixel.

[0773] exist Figure 35C and Figure 35DIn the embodiment of the present invention, light-emitting materials that emit light of different colors may be used for the light-emitting layer 771, the light-emitting layer 772, and the light-emitting layer 773. When the light emitted by the light-emitting layer 771, the light-emitting layer 772, and the light-emitting layer 773 is of complementary colors, white light emission can be obtained. For example, a light-emitting device having a single structure preferably includes a light-emitting layer containing a light-emitting material that emits blue light and a light-emitting layer containing a light-emitting material that emits visible light with a wavelength longer than blue.

[0774] As Figure 35D The layer 764 shown may also be provided with a color filter. By passing white light through the color filter, light of a desired color can be obtained.

[0775] For example, in a light-emitting device having a single structure and including three light-emitting layers, it is preferred that the light-emitting layer include a light-emitting layer containing a light-emitting substance that emits red (R), a light-emitting layer containing a light-emitting substance that emits green (G), and a light-emitting layer containing a light-emitting substance that emits blue (B). The order in which the light-emitting layers are stacked can be R, G, and B, or R, B, and G, in this order from the anode side. In this case, a buffer layer may be provided between R and G or B.

[0776] For example, when a light-emitting device having a single structure includes two light-emitting layers, it is preferable to adopt a structure including a light-emitting layer containing a light-emitting substance that emits blue (B) light and a light-emitting layer containing a light-emitting substance that emits yellow (Y) light. This structure is sometimes called a BY single structure.

[0777] Light-emitting devices that emit white light preferably contain two or more luminescent materials. To achieve white light, two or more luminescent materials can be selected whose emission colors are complementary. For example, by aligning the emission colors of the first and second luminescent layers, a light-emitting device can be made to emit white light as a whole. The same applies to light-emitting devices with three or more luminescent layers.

[0778] Notice, Figure 35C and Figure 35D Layer 780 and layer 790 can also be used independently. Figure 35B The laminated structure shown is composed of two or more layers.

[0779] exist Figure 35E and Figure 35FIn the embodiment, a luminescent material emitting light of the same color, or even the same luminescent material, may be used for the luminescent layer 771 and the luminescent layer 772. For example, in the luminescent device included in the sub-pixel presenting light of each color, a luminescent material emitting blue light may be used for the luminescent layer 771 and the luminescent layer 772. In the sub-pixel presenting blue light, the blue light emitted by the luminescent device can be extracted. In addition, by using the luminescent material as a light emitting material in the sub-pixel presenting red light and the sub-pixel presenting green light, Figure 35F The layer 764 shown is provided with a color conversion layer, which can convert the blue light emitted by the light-emitting device into light with a longer wavelength and extract it as red or green light. In addition, it is preferable to use both a color conversion layer and a coloring layer as the layer 764.

[0780] In addition, Figure 35E or Figure 35F When the light-emitting device of the structure shown is used to present sub-pixels of each color, different light-emitting materials can be used according to the sub-pixels. Specifically, in the light-emitting device included in the sub-pixel that presents red light, a light-emitting material that emits red light can be used for the light-emitting layer 771 and the light-emitting layer 772. Similarly, in the light-emitting device included in the sub-pixel that presents green light, a light-emitting material that emits green light can be used for the light-emitting layer 771 and the light-emitting layer 772. In the light-emitting device included in the sub-pixel that presents blue light, a light-emitting material that emits blue light can be used for the light-emitting layer 771 and the light-emitting layer 772. It can be said that a display device with such a structure uses a light-emitting device with a tandem structure and has an SBS structure. Thus, it can have the advantages of both the tandem structure and the SBS structure. Thus, a light-emitting device that can emit light with high brightness and high reliability can be realized.

[0781] exist Figure 35E and Figure 35F In the embodiment, luminescent materials that emit light of different colors may be used for the luminescent layer 771 and the luminescent layer 772. When the light emitted by the luminescent layer 771 and the light emitted by the luminescent layer 772 are in a complementary color relationship, white light emission can be obtained. Figure 35F The layer 764 shown may also be provided with a color filter. By passing white light through the color filter, light of a desired color may be obtained.

[0782] Note that although Figure 35E and Figure 35F The light-emitting unit 763a includes one light-emitting layer 771 and the light-emitting unit 763b includes one light-emitting layer 772. However, the present invention is not limited thereto. Each of the light-emitting unit 763a and the light-emitting unit 763b may include two or more light-emitting layers.

[0783] In addition, although Figure 35E and Figure 35FThe example of a light-emitting device including two light-emitting units is shown, but the present invention is not limited thereto. A light-emitting device may also include three or more light-emitting units. In addition, a structure including two light-emitting units and a structure including three light-emitting units may also be referred to as a two-stage series structure and a three-stage series structure, respectively.

[0784] In addition, Figure 35E and Figure 35F In the embodiment, the light emitting unit 763a includes a layer 780a, a light emitting layer 771, and a layer 790a, and the light emitting unit 763b includes a layer 780b, a light emitting layer 772, and a layer 790b.

[0785] When the lower electrode 761 and the upper electrode 762 serve as the anode and cathode, respectively, layers 780a and 780b each comprise one or more of a hole injection layer, a hole transport layer, and an electron blocking layer. Furthermore, layers 790a and 790b each comprise one or more of an electron injection layer, an electron transport layer, and a hole blocking layer. When the lower electrode 761 and the upper electrode 762 serve as the cathode and anode, respectively, the structures of layers 780a and 790a are reversed, and the structures of layers 780b and 790b are also reversed.

[0786] In the case where the lower electrode 761 and the upper electrode 762 are the anode and the cathode, respectively, for example, the layer 780a includes a hole injection layer and a hole transport layer on the hole injection layer, and may further include an electron blocking layer on the hole transport layer. In addition, the layer 790a includes an electron transport layer and may further include a hole blocking layer between the light-emitting layer 771 and the electron transport layer. In addition, the layer 780b includes a hole transport layer and may further include an electron blocking layer on the hole transport layer. In addition, the layer 790b includes an electron transport layer and an electron injection layer on the electron transport layer, and may further include a hole blocking layer between the light-emitting layer 772 and the electron transport layer. In the case where the lower electrode 761 and the upper electrode 762 are the cathode and the anode, respectively, for example, the layer 780a includes an electron injection layer and an electron transport layer on the electron injection layer, and may further include a hole blocking layer on the electron transport layer. In addition, the layer 790a includes a hole transport layer and may further include an electron blocking layer between the light-emitting layer 771 and the hole transport layer. Layer 780b includes an electron transport layer and a hole blocking layer on the electron transport layer. Layer 790b includes a hole transport layer and a hole injection layer on the hole transport layer and an electron blocking layer between the light emitting layer 772 and the hole transport layer.

[0787] When manufacturing a light-emitting device having a tandem structure, two light-emitting units are stacked with a charge generation layer 785 interposed therebetween. The charge generation layer 785 includes at least a charge generation region. When a voltage is applied between a pair of electrodes, the charge generation layer 785 injects electrons into one of the two light-emitting units and injects holes into the other.

[0788] As an example of a light emitting device having a tandem structure, there is Figures 35G to 35I The structure shown.

[0789] Figure 35G A structure with three light-emitting units is shown. Figure 35G The plurality of light-emitting units (light-emitting unit 763a, light-emitting unit 763b, and light-emitting unit 763c) are connected in series via a charge generation layer 785. Furthermore, light-emitting unit 763a includes layer 780a, light-emitting layer 771, and layer 790a; light-emitting unit 763b includes layer 780b, light-emitting layer 772, and layer 790b; and light-emitting unit 763c includes layer 780c, light-emitting layer 773, and layer 790c. Layer 780c can employ a structure applicable to layers 780a and 780b, and layer 790c can employ a structure applicable to layers 790a and 790b.

[0790] exist Figure 35G In the embodiment, the light-emitting layer 771, the light-emitting layer 772, and the light-emitting layer 773 preferably contain light-emitting substances that emit light of the same color. Specifically, the following structures can be adopted: a structure in which the light-emitting layer 771, the light-emitting layer 772, and the light-emitting layer 773 all contain a red (R) light-emitting substance (so-called R\R\R three-stage tandem structure); a structure in which the light-emitting layer 771, the light-emitting layer 772, and the light-emitting layer 773 all contain a green (G) light-emitting substance (so-called G\G\G three-stage tandem structure); or a structure in which the light-emitting layer 771, the light-emitting layer 772, and the light-emitting layer 773 all contain a blue (B) light-emitting substance (so-called B\B\B three-stage tandem structure). Note that "a\b" means that a light-emitting unit containing a light-emitting substance emitting light a is provided with a light-emitting unit containing a light-emitting substance emitting light b via a charge generation layer, and a and b represent colors.

[0791] exist Figure 35G In the embodiment, light-emitting materials that emit light of different colors may be used for part or all of the light-emitting layer 771, the light-emitting layer 772, and the light-emitting layer 773. Examples of combinations of light-emitting colors of the light-emitting layers 771, 772, and 773 include a structure in which any two emit blue (B) and the remaining one emits yellow (Y); and a structure in which any one emits red (R), another emits green (G), and the remaining one emits blue (B).

[0792] Note that the luminescent materials that emit light of the same color are not limited to the above structures. Figure 35H As shown, a tandem light-emitting device in which light-emitting units including a plurality of light-emitting layers are stacked may also be used. Figure 35H The structure shown is a structure in which two light-emitting units (light-emitting unit 763a and light-emitting unit 763b) are connected in series via a charge generation layer 785. In addition, light-emitting unit 763a includes layer 780a, light-emitting layer 771a, light-emitting layer 771b, light-emitting layer 771c, and layer 790a, and light-emitting unit 763b includes layer 780b, light-emitting layer 772a, light-emitting layer 772b, light-emitting layer 772c, and layer 790b.

[0793] exist Figure 35H In the embodiment, the luminescent materials of the luminescent layers 771a, 771b, and 771c are selected to have complementary colors, so that the luminescent unit 763a has a structure capable of achieving white light emission (W). In addition, the luminescent materials of the luminescent layers 772a, 772b, and 772c are also selected to have complementary colors, so that the luminescent unit 763b has a structure capable of achieving white light emission (W). In other words, Figure 35H The structure shown is a two-stage W\W tandem structure. Note that there are no particular restrictions on the order in which the complementary luminescent materials are stacked. The user can select the most appropriate stacking order. Although not shown, a three-stage W\W\W tandem structure or a tandem structure with four or more stages is also possible.

[0794] When using a light-emitting device with a series structure, the following structures can be cited: a B\Y or Y\B two-stage series structure including a light-emitting unit emitting yellow (Y) light and a light-emitting unit emitting blue (B) light; an R·G\B or B\R·G two-stage series structure including a light-emitting unit emitting red (R) light and green (G) light and a light-emitting unit emitting blue (B) light; a B\Y\B three-stage series structure including a light-emitting unit emitting blue (B) light, a light-emitting unit emitting yellow (Y) light and a light-emitting unit emitting blue (B) light in sequence; a B\YG\B three-stage series structure including a light-emitting unit emitting blue (B) light, a light-emitting unit emitting yellow-green (YG) light and a light-emitting unit emitting blue (B) light in sequence; and a B\G\B three-stage series structure including a light-emitting unit emitting blue (B) light, a light-emitting unit emitting green (G) light and a light-emitting unit emitting blue (B) light, etc. Note that “a·b” means that one light-emitting unit includes a light-emitting substance that emits light of a and a light-emitting substance that emits light of b.

[0795] In addition, if Figure 35I As shown, a light-emitting unit including one light-emitting layer and a light-emitting unit including a plurality of light-emitting layers may be combined.

[0796] Specifically, in Figure 35I In the illustrated structure, a plurality of light-emitting units (light-emitting unit 763a, light-emitting unit 763b, and light-emitting unit 763c) are connected in series via a charge generation layer 785. Furthermore, light-emitting unit 763a includes layer 780a, light-emitting layer 771, and layer 790a; light-emitting unit 763b includes layer 780b, light-emitting layer 772a, light-emitting layer 772b, light-emitting layer 772c, and layer 790b; and light-emitting unit 763c includes layer 780c, light-emitting layer 773, and layer 790c.

[0797] For example, in Figure 35I The structure shown can adopt a B\R·G·YG\B three-stage series structure, etc., wherein the light-emitting unit 763a is a light-emitting unit that emits blue (B) light, the light-emitting unit 763b is a light-emitting unit that emits red (R) light, green (G) light and yellow-green (YG) light, and the light-emitting unit 763c is a light-emitting unit that emits blue (B) light.

[0798] For example, examples of the number of layers stacked and the color sequence of the light-emitting unit include a two-stage structure in which B and Y are stacked from the anode side, a two-stage structure in which B and the light-emitting unit X are stacked, a three-stage structure in which B, Y, and B are stacked, and a three-stage structure in which B, X, and B are stacked. Examples of the number of layers stacked and the color sequence of the light-emitting layer in the light-emitting unit X include a two-stage structure in which R and Y are stacked from the anode side, a two-stage structure in which R and G are stacked, a two-stage structure in which G and R are stacked, a three-stage structure in which G, R, and G are stacked, and a three-stage structure in which R, G, and R are stacked. Furthermore, other layers may be provided between the two light-emitting layers.

[0799] Next, materials that can be used for the light-emitting device are described.

[0800] A conductive film that transmits visible light is used as the electrode on the light-extracting side of the lower electrode 761 and the upper electrode 762. Alternatively, a conductive film that reflects visible light is preferably used as the electrode on the side that does not extract light. Furthermore, when the display device includes a light-emitting device that emits infrared light, it is preferable to use a conductive film that transmits visible and infrared light as the electrode on the light-extracting side, and a conductive film that reflects visible and infrared light as the electrode on the side that does not extract light.

[0801] Alternatively, a conductive film that transmits visible light may be used as the electrode on the side that does not extract light. In this case, the electrode is preferably disposed between the reflective layer and the EL layer 763. In other words, light emitted from the EL layer 763 can also be reflected by the reflective layer and extracted from the display device.

[0802] As the material for forming a pair of electrodes (pixel electrode and common electrode) of the light-emitting device, metals, alloys, conductive compounds and mixtures thereof can be appropriately used. As the material, specifically, metals such as aluminum, magnesium, titanium, chromium, manganese, iron, cobalt, nickel, copper, gallium, zinc, indium, tin, molybdenum, tantalum, tungsten, palladium, gold, platinum, silver, yttrium, neodymium and alloys of the above metals can be cited as appropriate. In addition, as the material, indium tin oxide (In-Sn oxide, also known as ITO), In-Si-Sn oxide (also known as ITSO), indium zinc oxide (In-Zn oxide), In-W-Zn oxide, indium oxide, zinc oxide added with gallium, etc. can also be cited. In addition, as the material, alloys (aluminum alloys) containing aluminum can be cited. For example, alloys (aluminum alloys) containing one or more selected from titanium, nickel and neodymium and aluminum, alloys (Al-Ni-La) of aluminum, nickel and lanthanum, etc. can be us...

Claims

1. A display device comprising pixel unit; a dummy pixel portion; and surrounding areas, in, The dummy pixel portion and the surrounding area are areas that do not contribute to display. In a plan view, the dummy pixel portion is provided between the pixel portion and the peripheral region. The pixel portion includes a plurality of pixels, Each of the plurality of pixels includes a first pixel electrode, a first layer on the first pixel electrode, and a common electrode on the first layer. The common electrode is provided so as to span the pixel portion, the dummy pixel portion, and the peripheral region. The first layer includes a light-emitting layer, The dummy pixel portion includes a plurality of dummy pixels, Each of the plurality of dummy pixels includes a second pixel electrode, a second layer on the second pixel electrode, and the common electrode on the second layer. The second layer comprises the same material as the light-emitting layer, The peripheral area includes a third layer, The third layer comprises the same material as the light-emitting layer, The pixel portion, the dummy pixel portion, and the peripheral region include a first insulating layer. The first insulating layer has a region contacting a side surface of the first layer of each of the plurality of pixels, a region contacting a side surface of the second layer of each of the plurality of dummy pixels, a region contacting a top surface of the third layer, and a region contacting a side surface of the third layer. The common electrode is provided in the pixel portion, the dummy pixel portion, and the peripheral region in a manner of covering the first insulating layer. The first insulating layer includes a plurality of first openings and a plurality of second openings, Each of the plurality of first openings is provided in a region overlapping with each of the first pixel electrodes included in the plurality of pixels. Furthermore, each of the plurality of second openings is provided in a region overlapping with each of the second pixel electrodes included in the plurality of dummy pixels.

2. The display device according to claim 1, The first insulating layer comprises an organic material.

3. The display device according to claim 1, The first insulating layer is a stack of a layer containing an inorganic material and a layer containing an organic material located on the layer containing the inorganic material.

4. The display device according to claim 1, The intervals between the plurality of first openings are substantially consistent with the intervals between the plurality of second openings.

5. The display device according to claim 1, The area of ​​the first opening when viewed from a plane is substantially consistent with the area of ​​the second opening when viewed from a plane.

6. A display device comprising pixel electrode; a first layer on the pixel electrode; a protective layer on the first layer; a common layer on the protective layer; A common electrode on the common layer; and The first insulating layer, in, The first layer includes a light-emitting layer, The first insulating layer has a region in contact with a side surface of the first layer, The first insulating layer includes an opening provided in a region overlapping with the pixel electrode, The protective layer is provided in a manner of covering the first insulating layer, And the protection layer contacts the top surface of the first layer in the opening.

7. The display device according to claim 6, The first layer includes a hole injection layer, a hole transport layer and an electron transport layer, The common layer includes an electron injection layer, and the protective layer is an inorganic insulating layer.

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