Display device

Abstract

A display device with high display quality is provided. A display device with high reliability is provided. A display device with low power consumption is provided. A display device with high definition is provided. A display device with high contrast is provided. The display device includes a plurality of pixels on a first insulating layer, wherein each of the plurality of pixels includes a first conductive layer disposed along an opening of the first insulating layer, a second insulating layer on the first conductive layer, an EL layer on the first conductive layer and the second insulating layer, and a common electrode on the EL layer. The second insulating layer is on the first conductive layer and in contact with the first conductive layer, and is disposed below the EL layer. The first conductive layers of adjacent pixels are separated by a third insulating layer containing an inorganic material and a fourth insulating layer containing an organic material. The side surfaces of the first conductive layer and the side surfaces of the EL layer have areas in contact with the third insulating layer. The fourth insulating layer is on the third insulating layer and in contact with the third insulating layer, and is disposed below the common electrode.

Description

Technical Field

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

[0002] Note that one embodiment of the present invention is not limited to the above-described technical fields. Examples of technical fields within the scope of one embodiment of the present invention disclosed in this specification include semiconductor devices, display devices, light-emitting devices, energy storage devices, memory devices, electronic devices, lighting equipment, input devices, input / output devices, methods for driving these devices, and methods for manufacturing these devices. A semiconductor device refers to any device capable of operating by utilizing the characteristics of semiconductors. Prior Technology

[0003] In recent years, there has been a demand for high-definition display panels. Devices requiring high-definition display panels include smartphones, tablets, and laptops. Additionally, fixed display devices such as televisions and surveillance equipment are also demanding higher resolution. Among the devices with the greatest need for high definition are those used in virtual reality (VR) or augmented reality (AR) applications.

[0004] In addition, typical examples of display devices that can be applied to display panels include liquid crystal displays, light-emitting devices that have light-emitting elements such as organic EL (Electro Luminescence) elements or light-emitting diodes (LEDs), and electronic paper that displays by electrophoresis or the like.

[0005] For example, the basic structure of an organic EL element is a structure in which a layer containing a luminescent organic compound is sandwiched between a pair of electrodes. By applying a voltage to the element, light emission from the luminescent organic compound can be obtained. Since display devices using the above-mentioned organic EL elements do not require a backlight source as needed for liquid crystal displays, thin, lightweight, high-contrast, and low-power display devices can be realized. 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 that uses organic EL devices.

[0007] [Patent Document 1] Japanese Patent Application Publication No. 2002-324673 [Patent Document 2] International Patent Application Publication No. 2018 / 087625 Summary of the Invention

[0008] One objective of one embodiment of the present invention is to provide a display device with high display quality. Another objective of one embodiment of the present invention is to provide a display device with high reliability. Another objective of one embodiment of the present invention is to provide a display device with low power consumption. Another objective of one embodiment of the present invention is to provide a display device that easily achieves high definition. Another objective of one embodiment of the present invention is to provide a display device that combines high display quality and high definition. Another objective of one embodiment of the present invention is to provide a display device with high contrast.

[0009] One objective of one embodiment of the present invention is to provide a display device or a method for manufacturing a display device having a novel structure. Another objective of one embodiment of the present invention is to provide a method for manufacturing the aforementioned display device with high yield. Finally, another objective of one embodiment of the present invention is to improve at least one of the problems of the prior art.

[0010] Note that the description of these objectives does not preclude the existence of other objectives. Also note that one embodiment of the present invention does not need to achieve all of the above objectives. Furthermore, objectives other than those described above can be derived from the description in the specification, drawings, claims, etc.

[0011] One embodiment of the present invention is a display device including a plurality of pixels on a first insulating layer, wherein each of the plurality of pixels includes a first conductive layer disposed along an opening of the first insulating layer, a second insulating layer disposed on the first conductive layer, an EL layer disposed on the first conductive layer and the second insulating layer, and a common electrode disposed on the EL layer. The common electrode among the plurality of pixels is shared. The second insulating layer is disposed on and in contact with the first conductive layer on the first conductive layer and is disposed below the EL layer. The first conductive layers of adjacent pixels among the plurality of pixels are separated by a third insulating layer containing an inorganic material and a fourth insulating layer containing an organic material. The side surfaces of the first conductive layer and the side surfaces of the EL layer have areas in contact with the third insulating layer. The fourth insulating layer is disposed on and in contact with the third insulating layer on the third insulating layer and is disposed below the common electrode.

[0012] In the above structure, the third insulating layer preferably comprises aluminum and oxygen. Preferably, the second insulating layer is formed by an ALD process at a temperature of 60°C or higher and 150°C or lower. The alumina formed by the ALD process sometimes contains carbon.

[0013] One embodiment of the present invention is a display device including a first pixel on a first insulating layer and a second pixel disposed adjacent to the first pixel. The first pixel includes a first light-emitting element, which includes a first conductive layer disposed along a first opening of the first insulating layer, a second insulating layer on the first conductive layer, a first EL layer on the first conductive layer and the second insulating layer, and a common electrode on the first EL layer. The second pixel includes a second light-emitting element, which includes a second conductive layer disposed along a second opening of the first insulating layer, a third insulating layer on the second conductive layer, and a second EL layer on the second conductive layer and the third insulating layer. The common electrode on the second EL layer includes a fourth insulating layer, the side surface of the first conductive layer, the side surface of the first EL layer, the side surface of the second conductive layer and the side surface of the second EL layer having a region in contact with the fourth insulating layer, including a fifth insulating layer, the fifth insulating layer being disposed on and in contact with the fourth insulating layer and disposed below the common electrode, the second insulating layer being on and in contact with the first conductive layer and disposed below the first EL layer, the third insulating layer being on and in contact with the second conductive layer and disposed below the second EL layer, the fourth insulating layer comprising an inorganic material, and the fifth insulating layer comprising an organic material.

[0014] In the above structure, the fourth insulating layer is formed by the ALD method, and the temperature at which the fourth insulating layer is formed by the ALD method is above 60°C and below 150°C.

[0015] One embodiment of the present invention is a display device comprising a plurality of pixels on a first insulating layer, wherein each of the plurality of pixels includes a light-emitting device and a light-receiving device. The light-emitting device includes a first conductive layer disposed along an opening of the first insulating layer, a second insulating layer on the first conductive layer, an EL layer on the first conductive layer and the second insulating layer, and a common electrode on the EL layer. The common electrode is shared among the plurality of pixels. The second insulating layer is on the first conductive layer and in contact with the first conductive layer, and is disposed below the EL layer. The first conductive layers of adjacent pixels in the plurality of pixels are separated from each other by a third insulating layer containing an inorganic material and a fourth insulating layer containing an organic material. The side surfaces of the first conductive layer and the side surfaces of the EL layer have areas in contact with the third insulating layer. The fourth insulating layer is on the third insulating layer and in contact with the third insulating layer, and is disposed below the common electrode. The light-receiving device has the function of detecting at least one of visible light and infrared light.

[0016] In the above structure, the light-receiving device is preferably used as an image sensor.

[0017] In the above structure, the light-receiving device is preferably used as a touch sensor or a near-touch sensor.

[0018] One embodiment of the present invention is a display device including a first pixel on a first insulating layer and a second pixel disposed adjacent to the first pixel. The first pixel includes a light-emitting device comprising a first conductive layer disposed along a first opening of the first insulating layer, a second insulating layer on the first conductive layer, and an EL layer on both the first and second insulating layers. The second pixel includes a light-receiving device comprising a second conductive layer disposed along a second opening of the first insulating layer, a third insulating layer on the second conductive layer, and an active layer on both the second and third insulating layers. The side surfaces of the first conductive layer, the EL layer, the second conductive layer, and the active layer have regions that contact a fourth insulating layer. A fifth insulating layer is included, disposed on and in contact with the fourth insulating layer. The second insulating layer is on and in contact with the first conductive layer and disposed below the EL layer. The third insulating layer is on and in contact with the second conductive layer and disposed below the active layer. The fourth insulating layer comprises an inorganic material, and the fifth insulating layer comprises an organic material.

[0019] In the above structure, preferably, a common electrode is included on the EL layer and the active layer, and the third insulating layer and the fifth insulating layer are disposed below the common electrode.

[0020] 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 with low power consumption can be provided. According to one embodiment of the present invention, a display device that easily achieves high definition can be provided. According to one embodiment of the present invention, a display device that combines high display quality and high definition can be provided. According to one embodiment of the present invention, a display device with high contrast can be provided.

[0021] According to one embodiment of the present invention, a display device with 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 aforementioned display device with 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.

[0022] Note that the description of these effects does not preclude the existence of other effects. Also note that one embodiment of the present invention does not necessarily require all of the above-described effects. Furthermore, effects other than those described above can be derived from the description in the specification, drawings, claims, etc. Simple Explanation of the Diagram

[0023] Figures 1A to 1D are diagrams illustrating examples of the structure of a display device. Figures 2A to 2C are illustrations of examples of manufacturing methods for display devices. Figures 3A to 3C are illustrations of examples of manufacturing methods for display devices. Figures 4A to 4C are illustrations of examples of manufacturing methods for display devices. Figures 5A to 5C are illustrations showing examples of manufacturing methods for display devices. Figures 6A to 6E are diagrams showing examples of the structure of a display device. Figures 7A to 7F are diagrams showing examples of the structure of a display device. [Figure 8] is a perspective view showing an example of a display device. [Figure 9A], [Figure 9B] and [Figure 9C] are cross-sectional views showing an example of a display device. [Fig. 10A] is a diagram showing an example of the structure of a display device. [Fig. 10B] to [Fig. 10D] are diagrams showing examples of the structure of a pixel circuit. [Figure 11A] and [Figure 11B] are diagrams showing examples of the structure of a display device. [Figure 12A] and [Figure 12B] are diagrams showing examples of the structure of a display device. [Figure 13] is a diagram showing an example of the structure of a display device. [Figure 14A] and [Figure 14B] are perspective views showing an example of a display module. Figures 15A to 15E are diagrams illustrating an example of pixels in a display device. Figures 16A through 16G are diagrams illustrating an example of pixels in a display device. Figures 17A to 17C are schematic diagrams illustrating an example of an electronic device. Figures 18A through 18D are diagrams illustrating an example of pixels in a display device. [Figure 19A] is a cross-sectional view showing an example of a display device. [Figure 19B] and [Figure 19C] are diagrams showing an example of a circuit diagram of the pixels of a display device. Figures 20A to 20F are diagrams showing examples of the structure of a light-emitting device. [Figure 21A] and [Figure 21B] are cross-sectional views showing an example of a display device. [Figure 22A] and [Figure 22B] are cross-sectional views showing an example of a display device. [Figure 23A] and [Figure 23B] are figures illustrating an example of an electronic device. Figures 24A through 24D are illustrations of an example of an electronic device. Figures 25A through 25F are illustrations of an example of an electronic device. Figures 26A through 26G are illustrations of an example of an electronic device. Implementation

[0024] The embodiments will now be described with reference to the drawings. Note that the embodiments can be implemented in many different ways, and those skilled in the art will readily understand that the methods and details can be varied in many ways without departing from the spirit and scope of the invention. Therefore, the invention should not be construed as being limited to the contents described in the following embodiments.

[0025] Note that in the inventive structures described below, the same element symbols are used in different figures to represent the same parts or parts with the same function, and repeated descriptions are omitted. Furthermore, when representing parts with the same function, the same shading lines are sometimes used without additional element symbols.

[0026] Note that in the various figures described in this specification, the size of components, the thickness of layers, and areas are sometimes exaggerated for clarity. Therefore, the invention is not limited to the dimensions shown in the figures.

[0027] The ordinal numbers such as "first" and "second" used in this specification are appended to avoid confusion of components, and are not intended to limit the number of components.

[0028] In this specification and other materials, the terms "film" and "layer" may be interchanged. For example, sometimes "conductive layer" or "insulating layer" may be replaced with "conductive film" or "insulating film," respectively.

[0029] Note that in this specification, the EL layer refers to a layer disposed between a pair of electrodes of a light-emitting element and including at least a light-emitting material (also called a light-emitting layer) or a stack including a light-emitting layer.

[0030] In this specification and the like, the display panel of one embodiment of the display device refers to a panel capable of displaying (outputting) images, etc., on a display surface. Therefore, the display panel is one embodiment of the output device.

[0031] In this specification, etc., a structure in which connectors such as FPC (Flexible Printed Circuit) or TCP (Tape Carrier Package) are mounted on the substrate of a display panel, or a structure in which ICs are directly mounted on the substrate in the form of COG (Chip On Glass) is referred to as a display panel module or display module, or simply as a display panel, etc.

[0032] The light-emitting element of one embodiment of the present invention may also include a layer comprising a material with high hole injection capacity, a material with high hole transport capacity, a material with high electron transport capacity, a material with high electron injection capacity, a bipolar material, etc.

[0033] Furthermore, the aforementioned light-emitting layer and the layer containing substances with high hole injection capacity, high hole transport capacity, high electron transport capacity, high electron injection capacity, bipolar substances, etc., may respectively contain inorganic compounds or polymeric compounds (oligomers, dendritic polymers, or polymers, etc.) such as quantum dots. For example, by using quantum dots in the light-emitting layer, they can also be used as light-emitting materials.

[0034] As quantum dot materials, colloidal quantum dot materials, alloy-type quantum dot materials, core-shell quantum dot materials, and nucleated quantum dot materials can be used. Alternatively, materials containing elements from Groups 12 and 16, 13 and 15, and 14 and 16 can also be used. Or, quantum dot materials containing elements such as cadmium, selenium, zinc, sulfur, phosphorus, indium, tellurium, lead, gallium, arsenic, and aluminum can be used.

[0035] In this specification, etc., devices manufactured using a metal mask or FMM (Fine Metal Mask) are sometimes referred to as devices having an MM (Metal Mask) structure. Furthermore, in this specification, etc., devices manufactured without a metal mask or FMM are sometimes referred to as devices having an MML (Metal Mask Less) structure.

[0036] Furthermore, in this specification, the structure in which light-emitting devices of each color (here, blue (B), green (G), and red (R)) are separately formed or coated with light-emitting layers is sometimes referred to as an SBS (Side By Side) structure. Additionally, in this specification, a light-emitting device capable of emitting white light is sometimes referred to as a white light-emitting device. A white light-emitting device, combined with a color layer (e.g., a color filter), can realize a display device that displays in full color.

[0037] Furthermore, light-emitting devices can be broadly categorized into single-structure and series-structure devices. A preferred single-structure device has the following structure: a light-emitting unit is included between a pair of electrodes, and this light-emitting unit includes one or more light-emitting layers. To obtain white light emission, the light-emitting layers are selected such that their light emission colors are complementary. For example, by making the light emission colors of the first and second light-emitting layers complementary, a structure in which the entire light-emitting device emits white light can be obtained. The same applies to light-emitting devices comprising three or more light-emitting layers.

[0038] By using light-emitting layers that emit the same color of light in each light-emitting unit, a light-emitting device with increased brightness per specified current and higher reliability than a single-structure device can be achieved. To obtain white light emission in a series structure, a structure is used that combines the light emitted from the light-emitting layers of multiple light-emitting units to achieve white light emission. Note that the combination of light emission colors to obtain white light emission is the same as in the single-structure device. Furthermore, in a series-structure device, it is preferable to provide an intermediate layer such as a charge-generating layer between multiple light-emitting units.

[0039] The series-connected device preferably has the following structure: two or more light-emitting units are included between a pair of electrodes, and each light-emitting unit includes more than one light-emitting layer. To obtain white light emission, a structure is used to combine the light emitted from the light-emitting layers of the multiple light-emitting units to obtain white light emission. Note that the structure for obtaining white light emission is the same as that in the single-structure device. Furthermore, in the series-connected device, it is preferable to provide an intermediate layer such as a charge-generating layer between the multiple light-emitting units.

[0040] Furthermore, when comparing the aforementioned white light-emitting devices (single-structure or series-structure) and SBS structure light-emitting devices, the SBS structure light-emitting device exhibits lower power consumption than the white light-emitting device. Therefore, the SBS structure light-emitting device is preferable for reducing power consumption. On the other hand, the manufacturing process for white light-emitting devices is simpler than that for SBS structure light-emitting devices, thereby reducing manufacturing costs or increasing manufacturing yield, making it a better choice.

[0041] Implementation Method 1 In this embodiment, an example of the structure of a display device according to one embodiment of the present invention and an example of a method for manufacturing the display device are described.

[0042] One embodiment of the present invention is a display device including light-emitting elements (also called light-emitting devices). The display device includes at least two light-emitting elements that emit light of different colors. Each light-emitting element includes a pair of electrodes and an EL layer between the pair of electrodes. As light-emitting elements, electroluminescent elements such as organic EL elements and inorganic EL elements can be used. In addition, light-emitting diodes (LEDs) can also be used. In one embodiment of the present invention, the light-emitting element is preferably an organic EL element (organic electroluminescent element). Two or more light-emitting elements emitting different colors each include an EL layer containing different materials. For example, by including three light-emitting elements that respectively emit red (R), green (G), or blue (B) light, a full-color display device can be realized.

[0043] Here, it is known that when fabricating EL layers between light-emitting elements of different colors, a vapor deposition method using a shadow mask such as a metal mask is employed. However, this method is not easy to achieve high resolution and high aperture ratio because the shape and position of the island-like organic film differ from the design due to various influences such as the precision of the metal mask, misalignment between the metal mask and the substrate, metal mask deflection, and vapor scattering leading to an enlarged outline of the deposited film. In addition, during vapor deposition, debris caused by material adhering to the metal mask is sometimes generated. This debris may cause poor patterning of the light-emitting elements. Furthermore, short circuits caused by debris may occur. Additionally, a cleaning process for the material adhering to the metal mask is required. Therefore, resolution (also known as pixel density) is improved by analogy by employing special pixel arrangement methods such as Pentile arrangement.

[0044] In one embodiment of the present invention, the EL layer is processed into a fine pattern without using a shadow mask such as a metal mask. Therefore, a display device with high resolution and high aperture ratio, which was previously difficult to achieve, can be realized. Furthermore, since the EL layers can be manufactured separately, a display device with very vivid and high-contrast display quality can be realized.

[0045] For simplicity, the process of fabricating the EL layers of two different colored light-emitting elements will be described here. First, a first EL film and a first sacrificial film are formed by stacking conductive films that serve as pixel electrodes. Next, a photoresist mask is formed on the first sacrificial film. Then, a portion of the first sacrificial film and a portion of the first EL film are etched using the photoresist mask to form the first EL layer and the first sacrificial layer on the first EL layer.

[0046] Next, a second EL film and a second sacrificial film are stacked to form a second EL layer and a second sacrificial layer on the second EL layer. Then, using the first and second sacrificial layers as masks, a conductive film that becomes a pixel electrode is processed to form a first pixel electrode overlapping the first EL layer and a second pixel electrode overlapping the second EL layer. Through the above steps, the first EL layer and the second EL layer can be formed separately. Finally, the first and second sacrificial layers are removed to form a common electrode, thereby forming light-emitting elements of two colors.

[0047] Furthermore, by repeatedly performing the above process, EL layers with three or more light-emitting elements can be formed, thereby enabling display devices that include light-emitting elements with three or four or more colors.

[0048] In one embodiment of the present invention, a sacrificial layer can be formed using a photoresist mask, and the EL layer and pixel electrode can be processed using the formed sacrificial layer. Therefore, a light-emitting element can be formed without using different photoresist masks when processing the pixel electrode and EL layer. Thus, a light-emitting element can be formed without providing leeway at the ends of the pixel electrode and EL layer. By reducing the leeway, the light-emitting area can be made larger, thereby increasing the aperture ratio of the light-emitting element. Furthermore, by reducing the leeway, the pixel size can be reduced, thereby achieving higher resolution in the display device. Additionally, the number of times photoresist masks are used can be reduced, thus simplifying the manufacturing process, reducing costs, and improving yield.

[0049] When EL layers of different colors are adjacent to each other, it is difficult to set the spacing between adjacent EL layers to less than 10 μm, for example, in the formation method using a metal mask. However, in the method described above, it can be reduced to less than 3 μm, less than 2 μm, or less than 1 μm. For example, by using an LSI exposure apparatus, the spacing can also 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 ​​non-light-emitting regions that may exist between two light-emitting elements can be significantly reduced, and the aperture ratio can be close to 100%. For example, aperture ratios of 50% or more, 60% or more, 70% or more, 80% or more, or even 90% or more but less than 100% can be achieved.

[0050] Furthermore, the pattern of the EL layer itself can be significantly reduced compared to the case where a metal mask is used. Additionally, when forming the EL layer separately using a metal mask, the thickness differs between the center and ends of the pattern, thus reducing the effective area usable as a light-emitting region relative to the overall pattern area. On the other hand, in the above manufacturing method, the pattern is formed by depositing a film of uniform thickness, resulting in a uniform pattern thickness. Even with fine patterns, almost the entire area can be used as a light-emitting region. Therefore, the above manufacturing method achieves both high resolution and high aperture ratio.

[0051] Thus, by means of the above manufacturing method, a display device with micro-light-emitting elements integrated can be realized, and the clarity can be improved by analogy without special pixel arrangement methods such as Pentile. Therefore, a display device with a clarity of 500ppi or more, 1000ppi or more, or 2000ppi or more, or even 3000ppi or more, or even 5000ppi or more can be realized by using a so-called stripe arrangement in which R, G, and B are all arranged in one direction.

[0052] Furthermore, according to one embodiment of the present invention, miniature light-emitting elements can be manufactured with high precision, thus enabling complex pixel arrangement methods. For example, in addition to stripe arrangements, various arrangement methods such as S-stripes, Bayer arrangements, and Delta arrangements can also be used.

[0053] In this specification, the aperture ratio (effective light-emitting area ratio) refers to the ratio of the area of ​​a region that can be considered as the light-emitting area within a pixel to the area of ​​a pixel calculated from the pixel pitch of the display device.

[0054] Hereinafter, more specific structural examples and manufacturing method examples of a display device according to one embodiment of the present invention will be described with reference to the drawings.

[0055] [Example 1 of a display device structure] Figure 1A shows a top view of a display device 100 according to an embodiment of the present invention. The display device 100 includes a plurality of red-emitting light-emitting elements 110R, a plurality of green-emitting light-emitting elements 110G, and a plurality of blue-emitting light-emitting elements 110B. In Figure 1A, the symbols R, G, and B are attached to the light-emitting areas of each light-emitting element for easy distinction.

[0056] Light-emitting elements 110R, 110G, and 110B are all arranged in a matrix. Figure 1A shows a so-called striped arrangement of light-emitting elements of the same color arranged in one direction. Note that the arrangement of light-emitting elements is not limited to this; triangular, zigzag, or pentile arrangements can also be used.

[0057] As light-emitting elements 110R, 110G, and 110B, it is preferable to use EL devices such as OLED (Organic Light Emitting Diode) or QLED (Quantum-dot Light Emitting Diode). Examples of light-emitting materials included in the EL device include fluorescent materials, phosphorescent materials, inorganic compounds (quantum dot materials, etc.), and materials exhibiting thermally activated delayed fluorescence (TADF) materials.

[0058] Figure 1B is a cross-sectional view corresponding to the dashed lines A1-A2 and C1-C2 in Figure 1A, and Figure 1C is a cross-sectional view corresponding to the dashed lines B1-B2.

[0059] In the cross-sectional view shown in Figure 1B, light-emitting elements 110R, 110G, and 110B (hereinafter collectively referred to as light-emitting elements 110) are disposed on layer 401. Light-emitting element 110R includes a pixel electrode 111R, an EL layer 112R, and a common electrode 113. Light-emitting element 110G includes a pixel electrode 111G, an EL layer 112G, and a common electrode 113. Light-emitting element 110B includes a pixel electrode 111B, an EL layer 112B, and a common electrode 113. Note that pixel electrodes 111R, 111G, and 111B are collectively referred to as pixel electrodes 111.

[0060] Although Figure 1B shows a simplified example of layer 401 with conductive layers 241R, 241G, and 241B (hereinafter collectively referred to as conductive layers 241) disposed on substrate 301, it is preferable that a semiconductor element is disposed in layer 401. Examples of semiconductor elements include transistors, diodes, and capacitors.

[0061] Specifically, for example, a transistor is disposed in layer 401, and conductive layer 241 is used as the source electrode, drain electrode or gate electrode included in the transistor.

[0062] Alternatively, conductive layer 241 may be electrically connected to a semiconductor element disposed in layer 401. Conductive layer 241 may be used, for example, as wiring, electrodes, etc.

[0063] The conductive layers 241R, 241G, and 241B are electrically connected to the light-emitting elements 110R, 110G, and 110B, respectively.

[0064] An insulating layer 255 is provided on layer 401, including conductive layer 241, and the insulating layer 255 on conductive layer 241 has a plurality of openings. Figure 1B shows openings 129R, 129G, and 129B (hereinafter collectively referred to as openings 129) as openings. In the example shown here, opening 129R is provided on conductive layer 241R, opening 129G is provided on conductive layer 241G, and opening 129B is provided on conductive layer 241B. Conductive layers 117R, 117G, and 117B (hereinafter collectively referred to as conductive layers 117) are respectively provided in openings 129R, 129G, and 129B. Conductive layer 117 is provided in the openings 129 and on insulating layer 255. In addition, conductive layer 117 is preferably provided along the bottom and side surfaces of openings 129. Conductive layer 117 is electrically connected to conductive layer 241. The conductive layer 117 is preferably in contact with the top surface of the conductive layer 241 inside the opening 129.

[0065] The conductive layer 117 shown in Figure 1C is provided with a recess along the opening of the insulating layer 255. Preferably, the insulating layer 132 is provided in a manner that is embedded in the recess.

[0066] The insulating layer 132 has the function of planarizing the recesses of the conductive layer 117. In other words, by including the insulating layer 132, the planarity of the formed surfaces of each layer of the light-emitting element 110 is improved. In the light-emitting element, for example, when the coverage of the EL layer decreases, it is possible to create a thin area of ​​the EL layer, resulting in a short circuit between the lower electrode and the common electrode. In addition, when the coverage of the common electrode decreases, it is possible for the common electrode to be cut off or thinned, resulting in an increase in resistance, etc. By providing the insulating layer 132, each layer of the light-emitting element can be uniformly disposed, thereby realizing a display device with high reliability and high display quality.

[0067] As the insulating layer 132, an insulating layer containing organic materials can be appropriately used. For example, as the insulating layer 132, acrylic resin, polyimide resin, epoxy resin, polyimide resin, polyimide-polyamide resin, silicone resin, benzocyclobutene resin, phenolic resin, and precursors of the above resins can be used. Alternatively, a photosensitive resin can be used as the insulating layer 132. The photosensitive resin can be a positive or negative material.

[0068] By using a photosensitive resin to form the insulating layer 132, the insulating layer 132 can be formed through only exposure and development processes, which can reduce the impact of dry etching or wet etching on the surface of the conductive layer 117. In addition, by using a negative photosensitive resin to form the insulating layer 132, sometimes the same photomask (exposure mask) used for forming the opening 129 can be used to form the insulating layer 132.

[0069] Pixel electrode 111R is disposed on conductive layer 117R and insulating layer 132. Preferably, pixel electrode 111R has a first region contacting the top surface of conductive layer 117R and a second region contacting the top surface of insulating layer 132. Preferably, the height of the top surface of conductive layer 117R in contact with the first region and the height of the top surface of insulating layer 132 in contact with the second region are approximately equal.

[0070] Pixel electrode 111G is disposed on conductive layer 117G and insulating layer 132. Preferably, pixel electrode 111G has a first region contacting the top surface of conductive layer 117G and a second region contacting the top surface of insulating layer 132. Preferably, the height of the top surface of conductive layer 117G in contact with the first region and the height of the top surface of insulating layer 132 in contact with the second region are approximately equal.

[0071] Pixel electrode 111B is disposed on conductive layer 117B and insulating layer 132. Preferably, pixel electrode 111B has a first region contacting the top surface of conductive layer 117B and a second region contacting the top surface of insulating layer 132. Preferably, the height of the top surface of conductive layer 117B in contact with the first region is approximately equal to the height of the top surface of insulating layer 132 in contact with the second region.

[0072] EL layers 112R, 112G, and 112B are respectively disposed on pixel electrode 111R, pixel electrode 111G, and pixel electrode 111B. A common electrode 113 is disposed on EL layer 112R, EL layer 112G, and EL layer 112B (hereinafter collectively referred to as EL layer 112).

[0073] EL layer 112R contains a luminescent organic compound that emits at least red light. EL layer 112G contains a luminescent organic compound that emits at least green light. EL layer 112B contains a luminescent organic compound that emits at least blue light.

[0074] EL layers 112R, EL layers 112G, and EL layers 112B all include layers of luminescent organic compounds (luminescent layers). In addition to the luminescent material (guest material), the luminescent layers may also contain one or more compounds (host material, auxiliary material). As host and auxiliary materials, one or more substances with a band gap larger than the luminescent material (guest material) are used. Preferably, compounds that form excited-state complexes are used in combination as host and auxiliary materials. For efficient formation of excited-state complexes, it is particularly preferred to combine compounds that readily accept holes (hole transport materials) and compounds that readily accept electrons (electron transport materials).

[0075] Low-molecular-weight compounds or high-molecular-weight compounds can be used as light-emitting elements, and inorganic compounds (such as quantum dot materials) can also be included.

[0076] In addition to the light-emitting layer, EL layers 112R, 112G, and 112B may also include one or more of the following: an electron injection layer, an electron transport layer, a hole injection layer, and a hole transport layer.

[0077] Alternatively, a common layer 114 can be disposed between the EL layer 112 and the common electrode 113. Similar to the common electrode 113, the common layer 114 is disposed across multiple light-emitting elements. The common layer 114 covers the EL layers 112R, EL layers 112G, and EL layers 112B. Including the common layer 114 simplifies the manufacturing process, thus reducing manufacturing costs. The common layer 114 and the common electrode 113 can be formed continuously without etching or other processes during their fabrication. Therefore, the interface between the common layer 114 and the common electrode can be clean, resulting in good characteristics within the light-emitting element.

[0078] The common layer 114 is preferably in contact with one or more of the top surfaces of EL layers 112R, EL layers 112G and EL layers 112B.

[0079] EL layers 112R, EL layers 112G, and EL layers 112B are preferably light-emitting layers, for example, comprising at least one light-emitting material emitting one color. Additionally, the common layer 114 is preferably a layer comprising one or more of an electron injection layer, an electron transport layer, a hole injection layer, and a hole transport layer. In a light-emitting element where a pixel electrode is used as the anode and a common electrode is used as the cathode, the common layer 114 may, for example, employ a structure including an electron injection layer or a structure comprising both an electron injection layer and an electron transport layer.

[0080] Pixel electrodes 111R, 111G, and 111B are all disposed in each light-emitting element. Additionally, a common electrode 113 is disposed as a continuous layer shared by all light-emitting elements. One of the pixel electrodes and the common electrode 113 uses a conductive film that is transparent to visible light, while the other uses a reflective conductive film. By making each pixel electrode transparent and the common electrode 113 reflective, a bottom-emitting type (bottom-emitting type) display device can be realized; conversely, by making each pixel electrode reflective and the common electrode 113 transparent, a top-emitting type (top-emitting structure) display device can be realized. Furthermore, by making both each pixel electrode and the common electrode 113 transparent, a double-sided emitting type (double-sided emitting structure) display device can also be realized.

[0081] A protective layer 121 is provided on the common electrode 113 to cover the light-emitting elements 110R, 110G, and 110B. The protective layer 121 prevents impurities such as water from diffusing from above to each light-emitting element. In addition, by making both the pixel electrode and the common electrode translucent, external light can pass through the light-emitting elements, thereby enabling a display through which the background can be seen, i.e., a transparent display.

[0082] The protective layer 121 may, for example, have a single-layer structure or a multilayer structure comprising at least an inorganic insulating film. As the inorganic insulating film, for example, oxide films or nitride films such as silicon oxide films, silicon oxynitride films, silicon oxynitride films, silicon nitride films, aluminum oxide films, aluminum oxynitride films, hafnium oxide films, etc., may be used. Alternatively, semiconductor materials such as indium gallium oxide and indium gallium zinc oxide may also be used as the protective layer 121.

[0083] Alternatively, a laminated film of inorganic and organic insulating films can be used as the protective layer 121. For example, it is preferable to sandwich an organic insulating film between a pair of inorganic insulating films. Furthermore, the organic insulating film is preferably used as a planarization film. This allows the top surface of the organic insulating film to be flattened, thereby improving the coverage of the inorganic insulating film on the organic insulating film and thus enhancing the barrier properties. In addition, since the top surface of the protective layer 121 is flattened, the influence of the uneven shape of the underlying structure can be reduced when structures (e.g., color filters, electrodes of touch sensors, or lens arrays, etc.) are placed above the protective layer 121, which is preferable.

[0084] Alternatively, the structure may have a resin layer bonded to the substrate on the top surface of the protective layer 121.

[0085] In the cross-section shown in FIG. 1C, two light-emitting elements 110G are disposed adjacent to each other. In the cross-section shown in FIG. 1C, the conductive layer 241 is not provided in the layer 401, and the opening overlapping with the conductive layer 241 is not provided in the insulating layer 255 either. Therefore, the pixel electrode 111G included in the light-emitting element 110G is disposed in the flat area of the insulating layer 255.

[0086] In addition, FIG. 1A shows a connection electrode 111C electrically connected to the common electrode 113. The connection electrode 111C is supplied with the potential (for example, anode potential or cathode potential) to be supplied to the common electrode 113. The connection electrode 111C is disposed outside the display area where the light-emitting elements 110R and the like are arranged. In addition, in FIG. 1A, the common electrode 113 is indicated by a dashed line.

[0087] The connection electrode 111C may be disposed along the outer periphery of the display area. For example, it may be disposed along one side of the outer periphery of the display area, or may be disposed along two or more sides of the outer periphery of the display area. That is, when the top surface shape of the display area is square, the top surface shape of the connection electrode 111C may be strip-shaped, L-shaped, "冂" -shaped (square bracket-shaped), or quadrilateral.

[0088] In addition, FIG. 1B shows a cross-section corresponding to the dotted line C1 - C2 in FIG. 1A. In the cross-section shown by C1 - C2, an area 130 where the connection electrode 111C on the conductive layer 117C is electrically connected to the common electrode 113 is provided. In the area 130, the common electrode 113 is disposed on the connection electrode 111C, and the protective layer 121 is disposed to cover the common electrode 113. The connection electrode 111C and the common electrode 113 are preferably in contact. In addition, in the connection portion between the connection electrode 111C and the common electrode 113, the insulating layer 131 is disposed in contact with the end portions of the connection electrode 111C and the conductive layer 117C.

[0089] In addition, as shown in FIG. 1D, a structure in which the insulating layer 131 is not provided near the connection portion between the connection electrode 111C and the common electrode 113 may also be provided.

[0090] The insulating layer 131 is provided between the adjacent light-emitting elements 110. In FIG. 1B, the insulating layer 131 is located between the respective pixel electrodes 111 included in the light-emitting element 110 and between the respective EL layers 112. In addition, the common electrode 113 is disposed on the insulating layer 131.

[0091] The insulating layer 131 includes an insulating layer 131a and an insulating layer 131b. The insulating layer 131b is disposed in such a way that it contacts the side surfaces of each pixel electrode 111 included in the light-emitting element 110 and the side surfaces of the EL layer 112. In addition, in cross-section, the insulating layer 131a is disposed on the insulating layer 131b in contact with the insulating layer 131b in such a way that it fills the recess of the insulating layer 131b.

[0092] In Figure 1, the insulating layer 131 is disposed between the EL layers 112 of adjacent pixels so as to have a mesh (or grid or matrix) shape when viewed from above.

[0093] The insulating layer 131 may be disposed, for example, between two EL layers 112 that emit different colors. Alternatively, the insulating layer 131 may be disposed, for example, between two EL layers 112 that emit the same color. Alternatively, the insulating layer 131 may be disposed between two EL layers 112 that emit different colors instead of between two EL layers 112 that emit the same color.

[0094] When viewed from above, the insulating layer 131 is disposed, for example, between two EL layers 112.

[0095] The end of the EL layer 112 preferably has a region that contacts the insulating layer 131b.

[0096] By providing an insulating layer 131 between light-emitting elements that emit different colors, contact between EL layers 112R, EL layer 112G, and EL layer 112G can be prevented. This effectively prevents unintended light emission caused by current flowing through adjacent EL layers. Consequently, contrast can be improved, enabling a display device with high display quality.

[0097] Alternatively, the insulating layer 131 can be formed only between pixels emitting different colors, without separating adjacent pixels emitting the same color. In this case, the insulating layer 131 can be configured in a striped shape when viewed from above. By configuring the insulating layer 131 in a striped shape, compared to configuring it in a grid pattern, no space is needed to form the insulating layer 131, thus increasing the aperture ratio. When the insulating layer 131 is configured in a striped shape, adjacent EL layers of the same color can also be processed into strips to ensure continuity in the column direction.

[0098] The common electrode 113 is disposed in contact with the top surface of the EL layer 112, the top surface of the insulating layer 131a, and the top surface of the insulating layer 131b. Between adjacent light-emitting elements, the ends of the pixel electrode 111 and the EL layer 112 form a step between the regions where the pixel electrode 111 and the EL layer 112 are disposed and the regions where the pixel electrode 111 and the EL layer 112 are not disposed. In one embodiment of the display device of the present invention, this step is flattened by including the insulating layers 131a and 131b. Compared to the case where the common electrode 113 is in contact with the insulating layer 255 between adjacent light-emitting elements, the coverage of the common electrode can be improved, thus suppressing poor connection due to disconnection. Alternatively, it can suppress the increase in resistance caused by the common electrode 113 being locally thinned due to the step.

[0099] Furthermore, when the end of the pixel electrode 111 is approximately aligned with the end of the EL layer 112, a short circuit may occur between the common electrode 113 and the pixel electrode 111 when the common electrode 113 is formed on the EL layer 112. In one embodiment of the present invention, by providing insulating layers 131a and 131b between adjacent EL layers 112, the unevenness of the formation surface of the common electrode 113 can be reduced, thereby improving the coverage of the common electrode 113 at the end of the EL layer 112, thereby achieving good conductivity of the common electrode 113. In addition, short circuits between the common electrode 113 and the pixel electrode 111 can be suppressed.

[0100] To improve the flatness of the formation surface of the common electrode 113, the top surfaces of the insulating layer 131a and the insulating layer 131b are preferably substantially aligned with the top surface of the EL layer 112. Furthermore, the top surface of the insulating layer 131 is preferably flat. Note that the top surfaces of the insulating layer 131a, the insulating layer 131b, and the EL layer 112 do not need to be aligned.

[0101] The insulating layer 131b has an area that contacts the side of the EL layer 112 and serves as a protective insulating layer for the EL layer 112. By providing the insulating layer 131b, oxygen, moisture, or their constituent elements can be prevented from entering the interior from the side of the EL layer 112, thereby enabling a display device with high reliability.

[0102] In cross-section, when the width of the insulating layer 131b in the region contacting the side of the EL layer 112 is large, the spacing of the EL layers 112 sometimes increases, resulting in a decrease in the aperture ratio. Conversely, when the width of the insulating layer 131b is small, the effect of suppressing oxygen, moisture, or their constituent elements from entering the interior from the side of the EL layer 112 sometimes decreases. Preferably, the width of the insulating layer 131b in the region contacting the side of the EL layer 112 is 3 nm or more and 200 nm or less, more preferably 3 nm or more and 150 nm or less, further preferably 5 nm or more and 150 nm or less, even more preferably 5 nm or more and 100 nm or less, still more preferably 10 nm or more and 100 nm or less, and most preferably 10 nm or more and 50 nm or less. By setting the width of the insulating layer 131b within the above range, a display device with high aperture ratio and high reliability can be achieved.

[0103] The insulating layer 131b can be an insulating layer containing inorganic materials. The insulating layer 131b can be a single layer or a stack of materials such as aluminum oxide, magnesium oxide, hafnium oxide, gallium oxide, indium gallium zinc oxide, silicon oxide, silicon oxynitride, silicon nitride, or silicon oxynitride. In particular, a high selectivity ratio of aluminum oxide to the EL layer 112 during etching is preferred, as the aluminum oxide has the function of protecting the EL layer 112 during the formation of the insulating layer 131b (described later). Especially, by using inorganic insulating materials such as aluminum oxide, hafnium oxide, and silicon oxide formed using the ALD method as the insulating layer 131b, a film with fewer pinholes can be formed, resulting in an insulating layer 131b with excellent protective function against the EL layer 112.

[0104] Note that in this specification, "oxynitride" refers to a material in which the oxygen content is greater than the nitrogen content, while "nitrogen oxide" refers to a material in which the nitrogen content is greater than the oxygen content. For example, when described as "silicon oxynitride," it refers to a material in which the oxygen content is greater than the nitrogen content, while when described as "silicon oxynitride," it refers to a material in which the nitrogen content is greater than the oxygen content.

[0105] The insulating layer 131b can be formed by sputtering, chemical vapor deposition (CVD), molecular beam epitaxy (MBE), pulsed laser deposition (PLD), atomic layer deposition (ALD), etc. Furthermore, the insulating layer 131b is well-suited for formation using the ALD method, which offers good coverage.

[0106] The insulating layer 131a disposed on the insulating layer 131b has the function of planarizing the recesses of the insulating layer 131b formed between adjacent light-emitting elements. In other words, by including the insulating layer 131a, the flatness of the formation surface of the common electrode 113 is improved. As the insulating layer 131a, an insulating layer containing organic materials can be used. For example, acrylic resin, polyimide resin, epoxy resin, polyimide resin, polyimide-polyimide resin, silicone resin, benzocyclobutene resin, phenolic resin, and precursors of the above resins can be used as the insulating layer 131a. In addition, a photosensitive resin can be used as the insulating layer 131a. The photosensitive resin can be a positive material or a negative material.

[0107] By using photosensitive resin to form the insulating layer 131a, the insulating layer 131a can be formed through only exposure and development processes, which can reduce the impact of dry etching or wet etching on the surface of the conductive layer 117.

[0108] The height difference between the top surface of the insulating layer 131a and the top surface of the EL layer 112 is preferably less than 0.5 times the thickness of the insulating layer 131a, and more preferably less than 0.3 times the thickness of the insulating layer 131a. Alternatively, the insulating layer 131a can be provided such that the top surface of the EL layer 112 is higher than the top surface of the insulating layer 131a. Alternatively, the insulating layer 131a can be provided such that the top surface of the insulating layer 131a is higher than the top surface of the light-emitting layer included in the EL layer 112. Furthermore, the thickness of the insulating layer 131a is preferably more than 0.3 times, more than 0.5 times, or more than 0.7 times the thickness from the bottom surface of the conductive layer 117 on the insulating layer 255 to the top surface of the EL layer 112.

[0109] When a conductive film that reflects visible light is used as the pixel electrode 111, materials such as silver, aluminum, titanium, tantalum, molybdenum, platinum, gold, titanium nitride, and tantalum nitride can be used. Alternatively, an alloy can be used as the pixel electrode 111. For example, an alloy containing silver can be used. As an alloy containing silver, an alloy containing silver, palladium, and copper can be used, for example. Furthermore, an alloy containing aluminum can be used, for example. Additionally, two or more layers can be formed using these materials.

[0110] Furthermore, as the pixel electrode 111, a conductive film that is transparent to visible light can be used on a conductive film that is reflective to visible light. As a conductive material that is transparent to visible light, conductive oxides such as indium oxide, indium tin oxide, indium zinc oxide, zinc oxide, zinc oxide containing gallium, indium tin oxide containing silicon, and indium zinc oxide containing silicon can be used. Alternatively, an oxide of a conductive material that is reflective to visible light can also be used, and this oxide can be formed by oxidizing the surface of the conductive material that is reflective to visible light. Specifically, titanium oxide can also be used, for example. Titanium oxide can also be formed, for example, by oxidizing the surface of titanium.

[0111] By setting an oxide on the surface of the pixel electrode 111, oxidation reactions with the pixel electrode 111 can be suppressed during the formation of the EL layer 112.

[0112] Furthermore, by stacking a conductive film that is transparent to visible light on a conductive film that is reflective to visible light as a pixel electrode 111, the conductive film that is transparent to visible light can be used as an optical adjustment layer.

[0113] The optical path length can be adjusted by including an optical adjustment layer in the pixel electrode 111. The optical path length of each light-emitting element corresponds, for example, to the sum of the thickness of the optical adjustment layer and the thickness of the layer disposed in the EL layer 112 as the lower layer containing the film containing the luminescent compound.

[0114] In light-emitting elements, by using microcavity structures (micro-resonator structures) to vary the optical path length, light of a specific wavelength can be amplified. This allows for the creation of display devices with improved color purity.

[0115] For example, a microcavity structure can be achieved by varying the thickness of the EL layer 112 in each light-emitting element. For instance, a structure could be adopted where the EL layer 112R of the light-emitting element 110R, which emits light with the longest wavelength, is the thickest, and the EL layer 112B of the light-emitting element 110B, which emits light with the shortest wavelength, is the thinnest. Furthermore, not limited to this, the thickness of each EL layer can be adjusted considering factors such as the wavelength of light emitted by each light-emitting element, the optical properties of the layers constituting the light-emitting element, and the electrical properties of the light-emitting element.

[0116] In Figure 1B, for simplicity, the EL layer 112 in each light-emitting element is not shown in a way that clearly distinguishes their thicknesses. However, as mentioned above, in order to better adjust the optical path length, the thickness of each light-emitting element is appropriately adjusted to enhance the light corresponding to the wavelength of each light-emitting element.

[0117] [Example 1 of manufacturing method] Hereinafter, an example of a method for manufacturing a display device according to an embodiment of the present invention will be described with reference to the drawings. The display device 100 shown in FIG. 1A will be used as an example for description. FIGS. 2A to 5B are cross-sectional schematic diagrams of each process in the manufacturing method of the display device shown below.

[0118] Thin films (insulating films, semiconductor films, conductive films, etc.) constituting display devices can be formed using methods such as sputtering, chemical vapor deposition (CVD), vacuum evaporation, pulsed laser deposition (PLD), and atomic layer deposition (ALD). CVD methods include plasma-enhanced chemical vapor deposition (PECVD) and thermal CVD. Furthermore, metal-organic chemical vapor deposition (MOCVD) is one type of thermal CVD method.

[0119] In addition, the thin films (insulating films, semiconductor films, conductive films, etc.) constituting the display device can be formed using methods such as spin coating, dip coating, spray coating, inkjet coating, distributor coating, screen printing, flatbed printing, doctor knife coating, slot coating, roller coating, curtain coating, and doctor knife coating.

[0120] Furthermore, when processing the thin film constituting the display device, photolithography and other methods can be used. Besides the methods mentioned above, nanoimprinting, sandblasting, and peeling methods can also be used to process the thin film. Additionally, island-shaped thin films can be directly formed using shadow mask deposition methods such as metal masks.

[0121] Photolithography typically involves two methods. One method involves forming a photoresist mask on the film to be processed, then processing the film using etching or similar techniques, and finally removing the photoresist mask. The other method involves depositing a photosensitive film, followed by exposure and development to shape the film into the desired form.

[0122] In photolithography, the light used for exposure can be, for example, i-line (wavelength 365nm), g-line (wavelength 436nm), h-line (wavelength 405nm), or a mixture of these. Additionally, ultraviolet light, KrF lasers, or ArF lasers can also be used. Furthermore, immersion exposure techniques can be employed. Extreme ultraviolet (EUV) light or X-rays can also be used as the light for exposure. Electron beams can also be used instead of the light used for exposure. When using EUV light, X-rays, or electron beams, extremely fine processing can be achieved, making them preferable. Furthermore, when exposure is performed using scanning with an electron beam, a photomask is not required.

[0123] As a method for etching thin films, dry etching, wet etching, and sandblasting can be used.

[0124] [Preparation of substrate 301] As substrate 301, a substrate with heat resistance sufficient to withstand subsequent heat treatment can be used. When using an insulating substrate as substrate 301, glass substrates, quartz substrates, sapphire substrates, ceramic substrates, organic resin substrates, etc., can be used. In addition, single-crystal semiconductor substrates or polycrystalline semiconductor substrates made of materials such as silicon or silicon carbide, compound semiconductor substrates made of materials such as silicon and germanium, SOI substrates, and other semiconductor substrates can also be used.

[0125] Next, semiconductor elements are formed on substrate 301, and layer 401 is provided. Layer 401 is a layer on which a semiconductor circuit is formed on the aforementioned semiconductor substrate or insulating substrate. Layer 401 includes substrate 301 and semiconductor circuit formed on substrate 301. The semiconductor circuit includes a semiconductor element having conductive layers 241 (conductive layers 241R, 241G, and 241B in FIG. 2A). Alternatively, the semiconductor circuit may include conductive layers 241 as wiring or plugs electrically connected to the semiconductor element. Examples of semiconductor elements include transistors, diodes, and capacitors. The semiconductor circuit is preferably configured as, for example, a pixel circuit, a gate line drive circuit (gate driver), or a source line drive circuit (gate driver). In addition, it may be configured as an arithmetic circuit, a memory circuit, etc.

[0126] Next, an insulating layer 255 is deposited on layer 401, which includes conductive layer 241R, conductive layer 241G and conductive layer 241B.

[0127] As the insulating layer 255, for example, an inorganic insulating layer, an organic insulating layer, or a laminate structure of an inorganic insulating layer and an organic insulating layer can be used. Organic insulating layers are sometimes used as planarization films, so they are preferred.

[0128] As an insulating film that serves as an insulating layer such as insulating layer 255, silicon oxide, silicon oxynitride, silicon oxynitride, silicon nitride, aluminum oxide, aluminum oxynitride, aluminum oxynitride, aluminum nitride, etc. can be used.

[0129] Note that in this specification, "silicon oxynitride" refers to a material in which the oxygen content is greater than the nitrogen content, while "silicon oxynitride" refers to a material in which the nitrogen content is greater than the oxygen content. Additionally, in this specification, "aluminum oxynitride" refers to a material in which the oxygen content is greater than the nitrogen content, and "aluminum oxynitride" refers to a material in which the nitrogen content is greater than the oxygen content.

[0130] Furthermore, as the insulating film that serves as the insulating layer 255, an organic insulating film can be used, for example. Materials suitable for use in organic insulating films include, for example, acrylic resin, polyimide resin, epoxy resin, polyimide resin, polyimide-polyamine resin, silicone resin, benzocyclobutene resin, phenolic resin, and precursors of the aforementioned resins.

[0131] After the insulating film, which forms the insulating layer 255, is deposited, planarization treatment can be performed using methods such as chemical mechanical polishing (CMP).

[0132] By planarizing the surface of the insulating layer 255, the thickness uniformity of the layers constituting the light-emitting element formed on the insulating layer 255 can sometimes be improved. By improving the thickness uniformity of the layers, short circuits in the light-emitting element can sometimes be suppressed. In addition, by improving the thickness uniformity of the layers, the reliability of the light-emitting element can sometimes be improved.

[0133] Next, an opening 129 is provided in the insulating layer 255 in such a way that the top surface of the conductive layer 241 is exposed.

[0134] Next, a conductive film 117f, which serves as a conductive layer 117, is provided on the insulating layer 255 and the exposed conductive layer 241. Preferably, the conductive film 117f is provided along the bottom and side of the opening 129.

[0135] [Formation of insulating layer 132] Next, an insulating layer 132 is formed by embedding the recess of the conductive film 117f (Fig. 2A).

[0136] The insulating layer 132 can be formed, for example, by etching the top surface of the insulating film, which will become the insulating layer 132, substantially uniformly without using a photoresist mask after the insulating film is deposited on the entire surface of the substrate 301. Such a uniform etching and planarization process is also known as etch-back.

[0137] Alternatively, the insulating layer 132 can be formed, for example, by removing a portion of the film that will become the insulating layer 132 after it has been deposited over the entire surface. Here, by using a photosensitive resin as the film that becomes the insulating layer 132, the insulating layer 132 can be formed without etching using photoresist masks, hard masks, or other etching masks. Furthermore, since the photosensitive resin can be processed only through exposure and development processes, the insulating layer 132 can be formed without using dry etching methods. Therefore, the process can be simplified. Also, a portion of the top of the insulating layer 132 can be etched to adjust the surface height.

[0138] Examples of materials that can be used as the insulating film for insulating layer 132 include acrylic resin, polyimide resin, epoxy resin, polyimide resin, polyimide-polyamide resin, silicone resin, benzocyclobutene resin, phenolic resin, and precursors of the above resins. Additionally, a photosensitive resin can be used as the insulating film for insulating layer 132. The photosensitive resin can be a positive or negative material.

[0139] The etching of the insulating layer 132 can be performed using dry etching or wet etching. Alternatively, it can be etched using oxygen plasma ashing. Oxygen plasma ashing offers advantages such as high controllability and good in-plane uniformity, making it suitable for processing large substrates; therefore, it is suitable for removing only a portion of the insulating layer 132. Furthermore, chemical mechanical polishing (CMP) can also be used for etching the insulating layer 132.

[0140] Next, a conductive film 111f, which serves as a pixel electrode 111, is disposed on the conductive film 117f.

[0141] When using a conductive film that is reflective to visible light as the pixel electrode 111, it is preferable to use a material with high reflectivity (e.g., silver or aluminum) throughout the visible light wavelength region. This not only improves the light extraction efficiency of the light-emitting element but also enhances color reproduction.

[0142] [Formation of EL film 112Rf] Next, an EL film 112Rf, which will later become the EL layer 112R, is deposited on the conductive film 111f.

[0143] The EL film 112Rf includes at least a film containing a luminescent compound. In addition, it may also contain one or more films used as an electron injection layer, electron transport layer, charge generation layer, hole transport layer, or hole injection layer. The EL film 112Rf can be formed, for example, by vapor deposition, sputtering, or inkjet printing. Furthermore, it is not limited to these methods; the above-described deposition methods can be used appropriately.

[0144] [Formation of sacrificial membranes 144a and 146a] Next, a sacrificial film 144a is formed by covering the EL film 112Rf. In addition, the sacrificial film 144a is provided in contact with the top surface of the connecting electrode 111C.

[0145] Next, a sacrificial membrane 146a is formed on the sacrificial membrane 144a.

[0146] When forming the sacrificial films 144a and 146a, methods such as sputtering, ALD (thermal ALD, PEALD), or vacuum evaporation can be used. Preferably, a formation method that causes less damage to the EL layer is used. As the sacrificial film 144a is formed directly on the EL film 112Rf, it is preferable to use ALD or vacuum evaporation to form the sacrificial film 144a compared to sputtering.

[0147] As the sacrificial membrane 144a, inorganic membranes such as metal membranes, alloy membranes, metal oxide membranes, semiconductor membranes, and inorganic insulating membranes can be appropriately used.

[0148] Alternatively, oxide films can be used as the sacrificial film 144a. Typically, oxide films or oxynitride films such as silicon oxide, silicon oxynitride, aluminum oxide, aluminum oxynitride, hafnium oxide, and hafnium oxynitride can be used. Nitride films can also be used as the sacrificial film 144a, for example. Specifically, nitrides such as silicon nitride, aluminum nitride, hafnium nitride, titanium nitride, tantalum nitride, tungsten nitride, gallium nitride, and germanium nitride can be used. This inorganic insulating material can be formed by deposition methods such as sputtering, CVD, or ALD. ALD is particularly preferred as the sacrificial film 144a formed directly on the EL film 112Rf.

[0149] Furthermore, the sacrificial film 144a can be made of metallic materials such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, titanium, aluminum, yttrium, zirconium, and tantalum, or alloys containing such metallic materials. In particular, low-melting-point materials such as aluminum or silver are preferred.

[0150] Alternatively, metal oxides such as indium gallium zinc oxide (In-Ga-Zn oxide, also denoted as IGZO) can be used as the sacrificial film 144a. Other suitable oxides include indium oxide, indium zinc oxide (In-Zn oxide), indium tin oxide (In-Sn oxide), indium titanium oxide (In-Ti oxide), indium tin zinc oxide (In-Sn-Zn oxide), indium titanium zinc oxide (In-Ti-Zn oxide), and indium gallium tin zinc oxide (In-Ga-Sn-Zn oxide). Alternatively, silicon-containing indium tin oxide can also be used.

[0151] Alternatively, the aforementioned materials can be used when element M (selected from 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) is used in place of gallium. In particular, M is preferably selected from one or more of gallium, aluminum, and yttrium.

[0152] As the sacrificial membrane 146a, the materials described above that can be used for the sacrificial membrane 144a can be used. Alternatively, as the sacrificial membrane 144a, one of the materials described above can be selected, and as the sacrificial membrane 146a, another material can be selected. Furthermore, as the sacrificial membrane 144a, one or more of the materials described above can be selected, and as the sacrificial membrane 146a, a material other than the material selected by the sacrificial membrane 144a can be selected.

[0153] The sacrificial film 144a can be a film that has high resistance to etching of various EL films such as EL film 112Rf, that is, a film with a large etching selectivity. In addition, the sacrificial film 144a is particularly preferably a film that can be removed by wet etching with minimal damage to the various EL films.

[0154] Alternatively, the sacrificial membrane 144a can be made of a material that is at least soluble in a chemically stable solvent that is readily soluble in the uppermost layer of the EL membrane 112Rf. In particular, a material soluble in water or alcohol can be appropriately used for the sacrificial membrane 144a. When depositing the sacrificial membrane 144a, it is preferable to coat the sacrificial membrane 144a using a wet deposition method while it is dissolved in a solvent such as water or alcohol, followed by a heat treatment to evaporate the solvent. In this case, by performing the heat treatment under reduced pressure, the solvent can be removed at a low temperature and for a short time, thus reducing thermal damage to the EL membrane 112Rf, which is preferable.

[0155] Wet deposition methods used to form the sacrificial film 144a include spin coating, dip coating, spray coating, inkjet coating, dispenser coating, screen printing, flatbed printing, doctor knife coating, slot coating, roller coating, curtain coating, and doctor blade coating.

[0156] As the sacrificial membrane 144a, organic materials such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinylpyrrolidone, polyethylene glycol, polyglycerol, pullulan, water-soluble cellulose, or alcohol-soluble polyamide resin can be used.

[0157] As the sacrificial membrane 146a, a membrane with a wider range of choices than the sacrificial membrane 144a can be used.

[0158] Especially preferred is that the sacrificial film 144a uses an inorganic insulating material such as aluminum oxide, hafnium oxide, or silicon oxide formed by the ALD method, and the sacrificial film 146a uses an indium-containing metal oxide such as indium gallium zinc oxide (also referred to as In-Ga-Zn oxide or IGZO) formed by sputtering.

[0159] Alternatively, an organic film suitable for EL films such as EL film 112Rf can be used as the sacrificial film 146a. For example, the same organic film used for EL film 112Rf, EL film 112Gf, or EL film 112Bf can be used as the sacrificial film 146a. By using such an organic film, the deposition apparatus can be shared with EL film 112Rf, which is preferable. Furthermore, the sacrificial layer 147a can be removed while etching EL film 112Rf, thereby simplifying the process.

[0160] For example, when dry etching with a fluorine-containing gas (also known as a fluorine-based gas) is used in the etching of the sacrificial film 144a, silicon, silicon nitride, silicon oxide, tungsten, titanium, molybdenum, tantalum, tantalum nitride, alloys containing molybdenum and niobium, or alloys containing molybdenum and tungsten can be used for the sacrificial film 146a. Here, as a film with a wider etching selectivity (i.e., a slower etching rate) compared to the aforementioned dry etching using fluorine-based gases, metal oxide films such as IGZO and ITO can be used for the sacrificial film 144a.

[0161] [Formation of photoresist mask 143a] Next, a photoresist mask 143a is formed on the sacrificial film 146a (Fig. 2B). Note that Fig. 2B shows an example where the EL film 112Rf is not deposited in region 130. In the deposition of the EL film 112Rf, a metal mask can be used when masking region 130. Since the metal mask used at this time can also avoid masking the pixel area of ​​the display, a high-resolution mask is not required.

[0162] The photoresist mask 143a can use photoresist materials containing photosensitive resin, such as positive photoresist materials or negative photoresist materials.

[0163] Here, when a photoresist mask 143a is formed on the sacrificial film 146a, if defects such as pinholes exist in the sacrificial film 146a, the EL film 112Rf may be dissolved by the solvent of the photoresist material. By using inorganic insulating materials such as alumina, hafnium oxide, and silicon oxide formed by the ALD method as the sacrificial film 144a, a film with fewer pinholes can be formed, and the above-mentioned defects can be prevented.

[0164] [Etching of sacrificial films 144a and 146a] Next, by etching away portions of sacrificial films 146a and 144a that are not covered by photoresist mask 143a, island-shaped or strip-shaped sacrificial layers 145a and 147a are formed. Here, in FIG2C, sacrificial layers 145a and 147a are formed on the region in conductive film 111f that becomes pixel electrode 111R and on the region in conductive film 111f that becomes connection electrode 111C.

[0165] Preferably, a portion of the sacrificial film 146a is removed by etching using a photoresist mask 143a to form a sacrificial layer 147a. Then, the photoresist mask 143a is removed, and the sacrificial film 144a is etched using the sacrificial layer 147a as a hard mask. When etching the sacrificial film 146a, it is preferable to use etching conditions with a high selectivity to the sacrificial film 144a. The etching forming the hard mask can be done using wet etching or dry etching, and pattern shrinkage can be suppressed by using dry etching. For example, when an inorganic insulating material such as alumina, hafnium oxide, or silicon oxide formed by the ALD method is used as the sacrificial film 144a, and an indium-containing metal oxide such as indium gallium zinc oxide (also referred to as In-Ga-Zn oxide or IGZO) formed by sputtering is used as the sacrificial film 146a, the sacrificial film 146a formed by sputtering is etched to form a hard mask.

[0166] The photoresist mask 143a can be removed by wet etching or dry etching. In particular, it is preferred to remove the photoresist mask 143a by dry etching (also known as plasma ashing) using oxygen gas as the etching gas.

[0167] By etching the sacrificial film 144a using the sacrificial layer 147a as a hard mask, the photoresist mask 143a can be removed while the EL film 112Rf is covered by the sacrificial film 144a. In particular, the electrical properties of the EL film 112Rf are sometimes negatively affected when exposed to oxygen, so this is preferable when performing etching using oxygen gases such as plasma ashing.

[0168] Next, the sacrificial layer 147a is used as a mask and the sacrificial film 144a is removed by etching to form an island-shaped or strip-shaped sacrificial layer 145a (FIG. 2C). Note that in the manufacturing method of the display device according to one embodiment of the present invention, either the sacrificial layer 145a or the sacrificial layer 147a may not be used.

[0169] [Etching of EL film 112Rf] Next, an island-shaped or strip-shaped EL layer 112R is formed by etching away a portion of the EL film 112Rf that is not covered by the sacrificial layer 145a.

[0170] When etching the EL film 112Rf, it is preferable to use dry etching with an etching gas that does not contain oxygen as the main component. This suppresses the deterioration of the EL film 112Rf, resulting in a highly reliable display device. Examples of etching gases that do not contain oxygen as the main component include rare gases such as CF₄, C₄F₈, SF₆, CHF₃, Cl₂, H₂O, BCl₃, or He. Alternatively, a mixture of the above gases and an oxygen-free diluent gas can be used as the etching gas. Here, a portion of the sacrificial layer 145a can also be removed during the etching of the EL film 112Rf. For example, in a sacrificial film 144a with a two-layer structure, when an inorganic insulating material such as alumina, hafnium oxide, or silicon oxide formed by the ALD method is used as the lower layer, and an indium-containing metal oxide such as indium gallium zinc oxide (also referred to as In-Ga-Zn oxide or IGZO) formed by sputtering is used as the upper layer, the upper layer can also be etched during the etching of the EL film 112Rf.

[0171] Note that the etching of the EL film 112Rf is not limited to the above methods. It can be carried out by dry etching using other gases or by wet etching.

[0172] Furthermore, when etching the EL film 112Rf using an etching gas containing oxygen or dry etching with oxygen, the etching rate can be increased. This allows etching to be performed at low power while maintaining a sufficient etching rate, thus reducing etching-related damage. Additionally, defects such as the adhesion of reaction products during etching can be suppressed. For example, an etching gas in which oxygen is added to an etching gas whose main components do not contain oxygen can be used.

[0173] [Formation of EL layer 112G and EL layer 112B] Next, an EL film 112Gf, which forms the EL layer 112G, is deposited on the sacrificial layer 145a. For details on the EL film 112Gf, please refer to the description of the EL film 112Rf.

[0174] Next, a sacrificial film 144b is deposited on the EL film 112Gf. For details on sacrificial film 144b, please refer to the description of sacrificial film 144a.

[0175] Next, sacrificial film 146b is deposited on sacrificial film 144b. For details on sacrificial film 146b, please refer to the description of sacrificial film 146a.

[0176] Next, a photoresist mask 143b is formed on the sacrificial film 146b (Figure 3A).

[0177] Next, sacrificial layer 145b, sacrificial layer 147b, and EL layer 112G are formed (Figure 3B). The formation of sacrificial layer 145b, sacrificial layer 147b, and EL layer 112G can be referred to the formation of sacrificial layer 145a, sacrificial layer 147a, and EL layer 112R.

[0178] Next, an EL film 112Bf, which forms the EL layer 112B, is deposited on the sacrificial layers 147a and 147b. For details on the EL film 112Bf, please refer to the description of the EL film 112Rf.

[0179] Next, a sacrificial film 144c is deposited on the EL film 112Bf. For details on sacrificial film 144c, please refer to the description of sacrificial film 144a.

[0180] Next, sacrificial film 146c is deposited on sacrificial film 144c. For details on sacrificial film 146c, please refer to the description of sacrificial film 146a.

[0181] Next, a photoresist mask 143c is formed on the sacrificial film 146c (Fig. 3C).

[0182] Next, sacrificial layer 145c, sacrificial layer 147c, and EL layer 112B are formed (Figure 4A). The formation of sacrificial layer 145c, sacrificial layer 147c, and EL layer 112B can be referred to the formation of sacrificial layer 145a, sacrificial layer 147a, and EL layer 112R.

[0183] [Formation of insulating layer 131] Next, an insulating film 131bf (Fig. 4B) is formed to become the insulating layer 131b. Preferably, the insulating film 131bf is a film containing inorganic materials. Furthermore, the insulating film 131bf is disposed to cover the sacrificial layers 145a, 145b, 145c, EL layer 112, and pixel electrode 111. For example, the insulating film 131bf can be a single layer or a stack of materials such as aluminum oxide, magnesium oxide, hafnium oxide, gallium oxide, indium gallium zinc oxide, silicon oxide, silicon oxynitride, silicon nitride, or silicon oxynitride.

[0184] The insulating film 131bf can be formed by sputtering, chemical vapor deposition (CVD), molecular beam epitaxy (MBE), pulsed laser deposition (PLD), atomic layer deposition (ALD), etc. The insulating film 131bf is suitable for formation using the ALD method, which has good coverage.

[0185] The insulating film 131bf can be a single layer or a stack of materials such as aluminum oxide, magnesium oxide, hafnium oxide, gallium oxide, indium gallium zinc oxide, silicon oxide, silicon oxynitride, silicon nitride, or silicon oxynitride. In particular, a high selectivity ratio of aluminum oxide to EL layer 112 during etching is preferred because the aluminum oxide has the function of protecting EL layer 112 during the formation of the insulating layer 131b, which will be described later.

[0186] By forming an insulating film 131bf using the ALD method, a film with fewer pinholes can be formed, thus forming an insulating layer 131b with excellent protective function for the EL layer 112.

[0187] The deposition temperature of the insulating film 131bf is preferably lower than the heat resistance temperature of the EL layer 112.

[0188] Here, aluminum oxide is formed as the insulating film 131bf using the ALD method. The temperature for forming the insulating film 131bf by the ALD method is preferably 60°C or higher and 150°C or lower, more preferably 70°C or higher and 115°C or lower, and even more preferably 80°C or higher and 100°C or lower. By forming the insulating film 131bf at this temperature, a dense insulating film can be obtained, and damage to the EL layer 112 can be reduced.

[0189] Next, an insulating film 131af (Fig. 4C) is formed to form the insulating layer 131a. The insulating film 131af is disposed in such a way that it is embedded in the recess of the insulating film 131bf. The insulating film 131af is preferably a planarization film.

[0190] As the insulating film 131af, it is preferable to use an insulating film containing organic materials, and resin is preferably used as the organic material.

[0191] Examples of materials that can be used for the insulating film 131af include acrylic resin, polyimide resin, epoxy resin, polyimide resin, polyimide-polyamide resin, silicone resin, benzocyclobutene resin, phenolic resin, and precursors of the above resins. Additionally, a photosensitive resin can be used as the insulating film 131af. The photosensitive resin can be a positive or negative material.

[0192] By using photosensitive resin to form the insulating film 131af, the insulating film 131af can be formed through only exposure and development processes, which can reduce damage to the layers constituting the light-emitting element 110, especially the EL layer. In addition, by using negative photosensitive resin to form the insulating layer 132, sometimes the same photomask (exposure mask) used for forming the opening 129 can be used to form the insulating layer 132.

[0193] Next, an insulating layer 131a is formed (Fig. 5A). The insulating layer 131a can be formed, for example, by etching the top surface of the insulating film 131af in a substantially uniform manner. Such a uniform etching and planarization process is also called etch-back.

[0194] Alternatively, the insulating layer 131a can be formed, for example, by removing a portion of the insulating film 131af using a photomask. Here, by using a photosensitive resin as the insulating film 131af, the insulating layer 131a can be formed without etching using photoresist masks, hard masks, or other etching masks. Furthermore, since the photosensitive resin can be processed only through exposure and development processes, the insulating layer 131a can be formed without using dry etching methods. Therefore, the process can be simplified. In addition, damage to the EL layer caused by etching the insulating film 131af can be reduced. Furthermore, the surface height can be adjusted by etching a portion of the top of the insulating layer 131a.

[0195] Next, the insulating film 131bf is etched to expose the top surfaces of the sacrificial layers 145a, 145b, and 145c. Thus, an insulating layer 131b is formed covering the sides of the EL layers 112R, 112G, and 112B.

[0196] The etching of the insulating film 131bf can be performed using dry etching or wet etching. Alternatively, etching can be performed using oxygen plasma ashing. Furthermore, chemical mechanical polishing (CMP) can also be used for etching the insulating film 131bf.

[0197] Note that during the etching of the insulating film 131bf, it is preferable to suppress damage to the EL layer 112 caused by etching. Therefore, for example, it is preferable to use a material with a high etch selectivity ratio to the EL layer 112 as the insulating film 131bf.

[0198] By using inorganic materials as the insulating film 131bf, the selectivity to the EL layer 112 can sometimes be improved. Furthermore, the insulating layer 131b can be a single layer or a stack of materials such as aluminum oxide, magnesium oxide, hafnium oxide, gallium oxide, indium gallium zinc oxide, silicon oxide, silicon oxynitride, silicon nitride, or silicon oxynitride. In particular, aluminum oxide has a high selectivity to the EL layer 112 during etching, and it functions to protect the EL layer 112 during the formation of the insulating layer 131b (described later), making it preferable. Especially, by using inorganic insulating materials such as aluminum oxide, hafnium oxide, and silicon oxide formed using the ALD method as the insulating layer 131b, a film with fewer pinholes can be formed, resulting in an insulating layer 131b with excellent protective function against the EL layer 112.

[0199] When forming insulating films 131af and 131bf, the height of their top surfaces can be adjusted according to the etching amount. Here, it is preferable to adjust the etching amount so that the insulating layer 131b covers the side surface of the EL layer 112. In particular, it is preferable to adjust the etching amount so that the insulating layer 131b covers the side surface of the light-emitting layer included in the EL layer 112.

[0200] Furthermore, the flatness of the surface of the insulating film 131bf containing organic material can vary depending on the unevenness of the surface being formed and the density of the pattern formed on the surface. Additionally, the flatness of the insulating film 131bf can vary depending on factors such as the viscosity of the material used as the insulating film 131bf. For example, sometimes the thickness of the insulating film 131bf in the region not overlapping the EL layer 112 is smaller than the thickness of the region of the insulating film 131bf on and over the EL layer 112. In this case, for example, during the etching back of the insulating film 131bf, the height of the top surface of the insulating layer 131 may be lower than the height of the top surfaces of the sacrificial layers 147a, 147b, and 147c, or the height of the top surfaces of the sacrificial layers 145a, 145b, and 145c.

[0201] In addition, the insulating film 131bf sometimes has a concave curved surface shape (depression shape) or a convex curved surface shape (expansion shape) in the region between multiple EL layers 112.

[0202] [Removal of the sacrificial layer] Next, sacrificial layers 145a, 147a, 145b, 147b, 145c, and 147c are removed, exposing the top surfaces of EL layers 112R, 112G, and 112B (Fig. 5B).

[0203] Sacrificial layers 145a, 147a, 145b, 147b, 145c, and 147c can be removed by wet etching or dry etching. In this case, it is preferable to use a method that minimizes damage to EL layers 112R, EL layers 112G, and EL layers 112B.

[0204] Through the above steps, EL layer 112R, EL layer 112G and EL layer 112B can be formed respectively.

[0205] As shown in Figure 5B, etching is performed with the top surfaces of insulating layer 131a and insulating layer 131b approximately aligned with the top surface of EL layer 112. By aligning the top surfaces of insulating layer 131a and insulating layer 131b approximately with the top surface of EL layer, the unevenness of the surface on which the common electrode 113 is disposed can be reduced during the formation of the common electrode 113 shown in Figure 5C (described later), thereby improving coverage.

[0206] [The formation of public layer 114] Next, a common layer 114 is formed. Note that in the case of a structure that does not include a common layer 114, a common electrode 113 can be formed by covering EL layers 112R, EL layers 112G and EL layers 112B.

[0207] [Formation of common electrode 113] Next, a common electrode 113 is formed on the common layer 114 (FIG. 5C). The common electrode 113 can be formed, for example, by sputtering or vapor deposition. Note that FIG. 5C shows an example in which the common layer 114 is not deposited in region 130. In the deposition of the common layer 114, a metal mask can be used when masking region 130. Since the metal mask used at this time can also not mask the pixel area of ​​the display, a high-resolution mask is not required. Note that in region 130, the common layer 114 can also be provided on the connecting electrode 111C, and then the common electrode 113 can be provided. That is, in region 130, the common layer 114 can also be included between the connecting electrode 111C and the common electrode 113.

[0208] The above process can be used to manufacture light-emitting elements 110R, 110G, and 110B.

[0209] [Formation of protective layer 121] Next, a protective layer 121 is formed on the common electrode 113. When depositing the inorganic insulating film for the protective layer 121, sputtering, PECVD, or ALD methods are preferred. In particular, ALD is preferred because it provides good step coverage and is less prone to defects such as pinholes. Furthermore, inkjet printing is preferred when depositing the organic insulating film because it allows for uniform film formation in the desired area.

[0210] The display device 100 shown in FIG1A can be manufactured by the above process.

[0211] [Example of variation 1] A modified example of the display device 100 is described with reference to Figures 6 and 7.

[0212] Figure 6A is a partial cross-sectional view of the display device 100 shown in Figure 1B.

[0213] Figure 6B is an enlarged view of the region 138 surrounded by the dotted line in Figure 6A. Additionally, Figures 6C to 6E show variant examples of Figure 6B.

[0214] Pixel electrode 111R is disposed on conductive layer 117R and insulating layer 132. Pixel electrode 111R preferably has a first region that contacts the top surface of conductive layer 117R and a second region that contacts the top surface of insulating layer 132.

[0215] In Figure 6C, the top surface height of the conductive layer 117R in contact with the first region is higher than the top surface height of the insulating layer 132 in contact with the second region. Furthermore, the top surface of the insulating layer 132 has a shape that gently dips towards the center.

[0216] Furthermore, in Figure 6D, the top surface height of the conductive layer 117R in contact with the first region is lower than the top surface height of the insulating layer 132 in contact with the second region. Additionally, the top surface of the insulating layer 132 has a shape that gently expands towards the center in a convex manner.

[0217] Furthermore, as shown in FIG6E, the insulating layer 132 has a region that is higher than the top surface of the conductive layer 117R. Alternatively, the insulating layer 132 may be formed in a way that is wider than the width of the recess in the conductive layer 117R. In this case, the insulating layer 132 may also have a structure that contacts not only the inner wall of the recess in the conductive layer 117R but also the top surface of the conductive layer 117R.

[0218] Figure 7A is an enlarged view of region 139 surrounded by the double-dotted line in Figure 6A. Additionally, Figures 7B to 7F show variations of Figure 7A.

[0219] In Figure 7A, the top surface of insulating layer 131a is approximately aligned with the top surface of EL layer 112R. Additionally, the top surface of insulating layer 131a is approximately aligned with the top surface of EL layer 112G. Furthermore, the top surface of insulating layer 131b is approximately aligned with the top surface of EL layer 112R. Additionally, the top surface of insulating layer 131b is approximately aligned with the top surface of EL layer 112G.

[0220] In Figure 7B, the top surface of insulating layer 131a has a region that is higher than the top surface of EL layer 112R. Additionally, the top surface of insulating layer 131a has a region that is higher than the top surface of EL layer 112G. Furthermore, the top surface of insulating layer 131a has a shape that gently expands towards the center in a convex shape.

[0221] In Figure 7C, insulating layer 131a has a region that is higher than the top surfaces of EL layer 112R and EL layer 112G. Additionally, in region 139, display device 100 includes at least one of sacrificial layer 145a and sacrificial layer 147a. Insulating layer 131a has a first region that is higher than the top surfaces of EL layer 112R and EL layer 112G and located outside insulating layer 131b. This first region is located on at least one of sacrificial layer 145a and sacrificial layer 147a. Furthermore, in region 139, display device 100 includes at least one of sacrificial layer 145b and sacrificial layer 147b. Insulating layer 131a has a second region that is higher than the top surfaces of EL layer 112R and EL layer 112G and located outside insulating layer 131b. This second region is located on at least one of sacrificial layer 145b and sacrificial layer 147b.

[0222] In Figure 7D, the top surface of insulating layer 131a is lower than the top surface of EL layer 112R. Furthermore, the top surface of insulating layer 131a has a region that is lower than the top surface of EL layer 112G. Additionally, the top surface of insulating layer 131a has a shape that gently dips towards the center.

[0223] In Figure 7E, the top surface of insulating layer 131b has a region that is higher than the top surface of EL layer 112R. Additionally, the top surface of insulating layer 131b has a region that is higher than the top surface of EL layer 112G. That is, on the surface where the common layer 114 is formed, insulating layer 131b protrudes to form a convex portion.

[0224] In the formation of insulating layer 131b, for example, when insulating layer 131b is formed in such a way that its height is approximately equal to that of sacrificial layer 145a, sacrificial layer 145b and sacrificial layer 145c, as shown in FIG7E, sometimes insulating layer 131b is formed in a protruding shape.

[0225] In Figure 7F, the top surface of insulating layer 131b is lower than the top surface of EL layer 112R. Furthermore, the top surface of insulating layer 131b is lower than the top surface of EL layer 112G. That is, a recess is formed in insulating layer 131b on the surface where the common layer 114 is formed.

[0226] At least a portion of the structural examples shown in this embodiment and the corresponding diagrams can be appropriately combined with other structural examples or diagrams.

[0227] Implementation Method 2 In this embodiment, an example of the structure of a display device according to one embodiment of the present invention is described.

[0228] The display device in this embodiment can be a high-resolution display device or a large-screen display device. Therefore, the display device in this embodiment can be used, for example, as a display unit for devices such as: electronic devices with large screens, such as televisions, desktop or laptop computers, monitors for computers, digital signage, large game consoles such as pinball machines, etc.; digital cameras; digital video cameras; digital photo frames; mobile phones; portable game consoles; smartphones; watch-type terminals; tablet terminals; portable information terminals; and audio playback devices.

[0229] [Example 2 of a display device structure] Figure 8 shows a perspective view of the display device 400A, and Figure 9A shows a cross-sectional view of the display device 400A.

[0230] The display device 400A has a structure that attaches substrate 452 and substrate 451. In Figure 8, substrate 452 is indicated by dashed lines.

[0231] Display device 400A includes a display unit 462, circuitry 464, and wiring 465, etc. Figure 8 shows an example in which display device 400A is equipped with IC 473 and FPC 472. Therefore, the structure shown in Figure 8 can also be referred to as a display module including display device 400A, IC (integrated circuit), and FPC.

[0232] For example, a scan line drive circuit can be used as circuit 464.

[0233] Wiring 465 has the function of supplying signals and power to display unit 462 and circuit 464. The signals and power are input to wiring 465 from the outside via FPC 472 or IC 473.

[0234] Figure 8 shows an example of IC 473 being mounted on substrate 451 using COG (Chip On Glass) or COF (Chip On Film) methods. IC 473 can be, for example, an IC including scan line drive circuitry or signal line drive circuitry. Note that the display device 400A and the display module do not necessarily need to have an IC mounted on them. Alternatively, the IC can be mounted on an FPC using COF or similar methods.

[0235] Figure 9A shows an example of a cross-section of a portion of the display device 400A, including a portion of the area of ​​FPC 472, a portion of the circuit 464, a portion of the display section 462, and a portion of the area including the end.

[0236] The display device 400A shown in Figure 9A includes transistors 201 and 205, a light-emitting element 430a emitting red light, a light-emitting element 430b emitting green light, and a light-emitting element 430c emitting blue light between substrates 451 and 452.

[0237] The light-emitting elements 430a, 430b and 430c can be the light-emitting elements illustrated in Embodiment 1.

[0238] Here, when a pixel of a display device includes three sub-pixels having light-emitting elements that emit different colors from each other, examples of these three sub-pixels include sub-pixels of colors R, G, and B, and sub-pixels of colors yellow (Y), cyan (C), and magenta (M). When four of the above-mentioned sub-pixels are included, examples of these four sub-pixels include sub-pixels of colors R, G, B, and white (W), and sub-pixels of colors R, G, B, and Y.

[0239] The protective layer 410 and the substrate 452 are bonded together by the adhesive layer 442. As a seal for the light-emitting element, a solid sealing structure or a hollow sealing structure can be used. In Figure 9A, the space 443 surrounded by the substrate 452, the adhesive layer 442, and the substrate 451 is filled with an inert gas (nitrogen or argon, etc.), employing a hollow sealing structure. The adhesive layer 442 may also overlap with the light-emitting element. Furthermore, the space 443 surrounded by the substrate 452, the adhesive layer 442, and the substrate 451 may also be filled with a resin different from the adhesive layer 442.

[0240] A portion of conductive layers 418a, 418b, and 418c are formed in an opening in the insulating layer 214 such that the top surface of the conductive layer 222b included in the transistor 205 is exposed. Each of the conductive layers 418a, 418b, and 418c is connected to the conductive layer 222b included in the transistor 205 through an opening in the insulating layer 214. The pixel electrode contains a material that reflects visible light, and the counter electrode contains a material that transmits visible light. Other portions of the conductive layers 418a, 418b, and 418c are disposed on the insulating layer 214.

[0241] The conductive layer 117 shown in the above embodiment can be used as conductive layer 418a, conductive layer 418b and conductive layer 418c.

[0242] As the insulating layer 214, the insulating layer 255 shown in the above embodiment can be referred to.

[0243] Conductive layers 411a, 411b, and 411c are disposed on conductive layers 418a, 418b, and 418c. EL layers 416a, 416b, and 416c, which are included in the light-emitting element 430a, 430b, and 430c, are disposed on conductive layers 411a, 411b, and 411c. An insulating layer 414 is disposed in each of the recesses of conductive layers 418a, 418b, and 418c. The insulating layer 414 can be the insulating layer 132 shown in the above embodiment.

[0244] The pixel electrode 111 shown in the above embodiment can be used as conductive layers 411a, 411b, and 411c.

[0245] An insulating layer 421 is provided in the area between light-emitting elements 430a and 430b and on the insulating layer 214, and in the area between light-emitting elements 430b and 430c and on the insulating layer 214. The insulating layer 421 can refer to the insulating layer 131 shown in the above embodiment.

[0246] The light-emitting element emits light onto one side of the substrate 452. The substrate 452 is preferably made of a material with high transmittance to visible light.

[0247] Transistors 201 and 205 are both disposed on substrate 451. These transistors can be formed using the same material and the same process.

[0248] Insulating layers 211, 213, 215, and 214 are sequentially disposed on substrate 451. A portion of insulating layer 211 serves as the gate insulating layer for each transistor. A portion of insulating layer 213 serves as the gate insulating layer for each transistor. Insulating layer 215 is disposed to cover the transistor. Insulating layer 214 is disposed to cover the transistor and serves as a planarization layer. Furthermore, there is no particular limitation on the number of gate insulating layers and the number of insulating layers covering the transistor; there can be one or more.

[0249] Preferably, at least one of the insulating layers covering the transistor is made of a material that does not readily diffuse impurities such as water and hydrogen. This allows the insulating layer to function as a barrier layer. By employing this structure, the diffusion of impurities from the outside into the transistor can be effectively suppressed, thereby improving the reliability of the display device.

[0250] Inorganic insulating films are preferably used as insulating layers 211, 213, and 215. Examples of inorganic insulating films include silicon nitride films, silicon oxynitride films, silicon oxide films, silicon oxynitride films, aluminum oxide films, and aluminum nitride films. Additionally, hafnium oxide films, yttrium oxide films, zirconium oxide films, gallium oxide films, tantalum oxide films, magnesium oxide films, lanthanum oxide films, cerium oxide films, and neodymium oxide films can also be used. Furthermore, two or more of the above-mentioned insulating films can be laminated.

[0251] Here, the barrier properties of organic insulating films are often lower than those of inorganic insulating films. Therefore, it is preferable that the organic insulating film includes an opening near the end of the display device 400A. This can prevent impurities from entering through the organic insulating film from the end of the display device 400A. Alternatively, the organic insulating film can be formed with its end located inside the end of the display device 400A, so that the organic insulating film is not exposed at the end of the display device 400A.

[0252] The insulating layer 214 used as the planarization layer is preferably an organic insulating film. Materials suitable for use as organic insulating films include, for example, acrylic resins, polyimide resins, epoxy resins, polyimide resins, polyimide-polyimide resins, silicone resins, benzocyclobutene resins, phenolic resins, and precursors of the above resins.

[0253] In region 228 shown in FIG9A, an opening is formed in the two-layer structure of the stacked insulating layer 214 and the insulating layer 421b on the insulating layer 214. The insulating layer 421b can be formed using the same material as the insulating layer 421. In addition, the insulating layer 421b is formed, for example, by the same process as the insulating layer 421. A protective layer 410 is formed to cover the opening. By using an inorganic layer as the protective layer 410, even when using an organic insulating film as the insulating layer 214, impurities can be prevented from entering the display section 462 from the outside through the insulating layer 214. As a result, the reliability of the display device 400A can be improved.

[0254] Transistors 201 and 205 include: a conductive layer 221 serving as a gate; an insulating layer 211 serving as a gate insulating layer; a conductive layer 222a serving as one of the source and drain; a conductive layer 222b serving as the other of the source and drain; a semiconductor layer 231; an insulating layer 213 serving as a gate insulating layer; and a conductive layer 223 serving as a gate. Here, multiple layers obtained by processing the same conductive film are represented by the same shaded line. 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.

[0255] There are no particular limitations on the transistor structure included in the display device of this embodiment. For example, planar transistors, interleaved transistors, or anti-interleaved transistors can be used. Furthermore, the transistors can have a top-gate structure or a bottom-gate structure. Alternatively, gates can be provided above and below the semiconductor layer forming the channel.

[0256] Transistors 201 and 205 employ a structure in which a semiconductor layer forming a channel is sandwiched between two gates. Alternatively, the two gates can be connected, and the transistor can be driven by supplying the same signal to both gates. Or, the threshold voltage of the transistor can be controlled by applying a potential to one of the two gates to control the threshold voltage and applying a potential to the other to drive it.

[0257] There are no particular restrictions on the crystallinity of the semiconductor material used for transistors; amorphous semiconductors, crystalline semiconductors (microcrystalline semiconductors, polycrystalline semiconductors, single-crystal semiconductors, or semiconductors with crystalline regions in some of them) can be used. Using crystalline semiconductors can suppress the degradation of transistor characteristics, making them preferable.

[0258] The semiconductor layer of the transistor is preferably made of metal oxide (oxide semiconductor). That is, the display device of this embodiment preferably uses a transistor (hereinafter, OS transistor) that contains metal oxide in the channel forming region. In addition, the semiconductor layer of the transistor may also contain silicon. Examples of silicon include amorphous silicon, crystalline silicon (low-temperature polycrystalline silicon, monocrystalline silicon, etc.).

[0259] For example, the semiconductor layer preferably comprises indium, M (M being selected from one or more of gallium, aluminum, silicon, boron, yttrium, tin, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, or magnesium), and zinc. In particular, M is preferably selected from one or more of aluminum, gallium, yttrium, or tin.

[0260] In particular, as the semiconductor layer, it is preferable to use an oxide (IGZO) containing indium (In), gallium (Ga) and zinc (Zn).

[0261] When using In-M-Zn oxide in a semiconductor layer, the number of In atoms in the In-M-Zn oxide is preferably greater than or equal to the number of M atoms. Examples of atomic ratios of the metal elements in this In-M-Zn oxide include In:M:Zn = 1:1:1 or similar, In:M:Zn = 1:1:1.2 or similar, In:M:Zn = 2:1:3 or similar, In:M:Zn = 3:1:2 or similar, In:M:Zn = 4:2:3 or similar, In:M:Zn = 4:2:4.1 or similar, In:M:Zn = 5:1:3 or similar, In:M:Zn = 5:1:6 or similar, In:M:Zn = 5:1:7 or similar, In:M:Zn = 5:1:8 or similar, In:M:Zn = 6:1:6 or similar, In:M:Zn = 5:2:5 or similar, etc. Furthermore, "similar" composition includes a range of ±30% of the desired atomic ratio.

[0262] When the atomic number ratio of In:Ga:Zn is recorded as In:Ga:Zn = 4:2:3 or similar, the following cases are included: when the atomic number ratio of In is 4, the atomic number ratio of Ga is 1 or more and 3 or less, and the atomic number ratio of Zn is 2 or more and 4 or less. Furthermore, when the atomic number ratio of In:Ga:Zn is recorded as In:Ga:Zn = 5:1:6 or similar, the following cases are included: when the atomic number ratio of In is 5, the atomic number ratio of Ga is greater than 0.1 and less than 2, and the atomic number ratio of Zn is 5 or more and less than 7. Furthermore, when the atomic number ratio of In:Ga:Zn is recorded as In:Ga:Zn = 1:1:1 or similar, the following cases are included: when the atomic number ratio of In is 1, the atomic number ratio of Ga is greater than 0.1 and less than 2, and the atomic number ratio of Zn is greater than 0.1 and less than 2.

[0263] The transistors included in circuit 464 and the transistors included in display unit 462 can have the same structure or different structures. The multiple transistors included in circuit 464 can have the same structure or two or more different structures. Similarly, the multiple transistors included in display unit 462 can have the same structure or two or more different structures.

[0264] A connection portion 204 is provided in a region of substrate 451 that does not overlap with substrate 452. In the connection portion 204, wiring 465 is electrically connected to FPC 472 via a conductive layer 466 and a connection layer 242. The conductive layer 466 can be a conductive film processed with the same conductive film as the pixel electrode, or a conductive film obtained by processing a laminated film of the same conductive film as the pixel electrode and a conductive film of the same conductive film as the optical adjustment layer. The conductive layer 466 is exposed on the top surface of the connection portion 204. Therefore, the connection portion 204 can be electrically connected to FPC 472 via the connection layer 242.

[0265] Preferably, a light-shielding layer 417 is provided on the surface of the substrate 452 on the substrate 451 side. Furthermore, various optical components can be disposed on the outer side of the substrate 452. As optical components, polarizing plates, retardation plates, light diffusion layers (diffusion films, etc.), anti-reflection layers, and condensing films can be used. In addition, an antistatic film that inhibits dust adhesion, a water-repellent film that is not easily soiled, a hard coating film that inhibits damage during use, and an impact-absorbing layer can also be disposed on the outer side of the substrate 452.

[0266] By forming a protective layer 410 covering the light-emitting element, impurities such as water can be prevented from entering the light-emitting element, thereby improving the reliability of the light-emitting element.

[0267] In the region 228 near the end of the display device 400A, it is preferable that the insulating layer 215 and the protective layer 410 are in contact with each other through an opening in the insulating layer 214. In particular, it is especially preferable that the inorganic insulating film contained in the insulating layer 215 and the inorganic insulating film contained in the protective layer 410 are in contact with each other. This can prevent impurities from entering the display section 462 from the outside through the organic insulating film. Therefore, the reliability of the display device 400A can be improved.

[0268] Substrates 451 and 452 can be made of glass, quartz, ceramic, sapphire, resin, metal, alloy, or semiconductor. The substrate on the side from which light is extracted from the light-emitting element uses a material that allows the light to pass through. By using a flexible material for substrates 451 and 452, the flexibility of the display device can be improved. A polarizing plate can be used as substrate 451 or substrate 452.

[0269] The following materials can be used as substrates 451 and 452: polyester resins such as polyethylene terephthalate (PET) or polyethylene naphthalate (PEN), polyacrylonitrile resins, acrylic resins, polyimide resins, polymethyl methacrylate resins, polycarbonate (PC) resins, polyether ether (PES) resins, polyamide resins (nylon, aromatic polyamides, etc.), 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, etc. Alternatively, glass with a flexible thickness can be used as one or both of substrates 451 and 452.

[0270] When a circular polarizer is superimposed on a display device, it is preferable to use a substrate with high optical isotropy as the substrate included in the display device. The substrate with high optical isotropy has lower birefringence (or, in other words, less birefringence).

[0271] The absolute value of the retardation value of a substrate with high optical isotropy is preferably below 30 nm, more preferably below 20 nm, and even more preferably below 10 nm.

[0272] Examples of films with high optical isotropy include cellulose triacetate (also known as TAC), cyclic olefin polymer (COP) films, cyclic olefin copolymer (COC) films, and acrylic films.

[0273] When a thin film is used as a substrate, the display panel may experience shape changes such as wrinkles due to water absorption by the film. Therefore, it is preferable to use a thin film with a low water absorption rate as the substrate. For example, it is preferable to use a thin film with a water absorption rate of 1% or less, more preferably a thin film with a water absorption rate of 0.1% or less, and even more preferably a thin film with a water absorption rate of 0.01% or less.

[0274] As the adhesive layer, various curing adhesives can be used, including UV-curing adhesives, reaction-curing adhesives, thermosetting adhesives, and anaerobic adhesives. Examples of these adhesives include epoxy resins, acrylic resins, silicone resins, phenolic resins, polyimide resins, 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 preferred. Two-component mixed resins can also be used. Furthermore, adhesive sheets can also be used.

[0275] As the connecting layer 242, anisotropic conductive film (ACF) or anisotropic conductive paste (ACP) can be used.

[0276] Materials that can be used as gates, sources, and drains of transistors, as well as conductive layers such as wiring and electrodes in display devices, include metals such as aluminum, titanium, chromium, nickel, copper, yttrium, zirconium, molybdenum, silver, tantalum, or tungsten, or alloys with the above metals as the main component. Single layers or stacks of films containing these materials can be used.

[0277] Furthermore, as a transparent conductive material, conductive oxides such as indium oxide, indium tin oxide, indium zinc oxide, zinc oxide, and gallium-containing zinc oxide, or graphene, can be used. Alternatively, metallic materials such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, or titanium, or alloys containing such metallic materials, can be used. Alternatively, nitrides of the metallic materials (e.g., titanium nitride) can also be used. Furthermore, when using metallic or alloy materials (or their nitrides), it is preferable to form them thin enough to be transparent. Furthermore, a multilayer film of the above materials can be used as a conductive layer. For example, using a multilayer film of an alloy of silver and magnesium with indium tin oxide is preferred as it improves conductivity. The above materials can also be used as conductive layers constituting various wirings and electrodes in a display device, and as conductive layers included in light-emitting elements (conductive layers used as pixel electrodes or common electrodes).

[0278] Examples of insulating materials that can be used in various insulating layers include resins such as acrylic resin or epoxy resin, and inorganic insulating materials such as silicon oxide, silicon oxynitride, silicon oxynitride, silicon nitride, or aluminum oxide.

[0279] Transistors 205 and 201 include: a conductive layer 221 serving as a gate; an insulating layer 211 serving as a gate insulating layer; a semiconductor layer comprising a channel forming region 231i and a pair of low-resistance regions 231n; a conductive layer 222a connected to one of the pair of low-resistance regions 231n; a conductive layer 222b connected to the other of the pair of low-resistance regions 231n; an insulating layer 225 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 forming region 231i. The insulating layer 225 is located between the conductive layer 223 and the channel forming region 231i.

[0280] Conductive layers 222a and 222b are connected to the low-resistance region 231n through openings provided in insulating layers 215 and 225. One of conductive layers 222a and 222b is used as a source, and the other is used as a drain.

[0281] Figure 9B shows an example of insulating layer 225 covering the top and side surfaces of semiconductor layer. Conductive layers 222a and 222b are connected to low-resistance region 231n through openings provided in insulating layers 225 and 215.

[0282] On the other hand, in the transistor 209 shown in FIG9C, the insulating layer 225 overlaps with the channel forming region 231i of the semiconductor layer 231 but does not overlap with the low-resistance region 231n. For example, the structure shown in FIG9C can be formed by processing the insulating layer 225 with the conductive layer 223 as a mask. In FIG9C, the insulating layer 215 covers the insulating layer 225 and the conductive layer 223, and the conductive layers 222a and 222b are respectively connected to the low-resistance region 231n through the openings of the insulating layer 215. Furthermore, an insulating layer 218 covering the transistor can also be provided. The structure of the transistor 209 shown in FIG9C can be used as the transistor 205 and the transistor 201.

[0283] Furthermore, all transistors included in the pixel circuit that drives the light-emitting element can be silicon-containing transistors in the semiconductor layer where the channel is formed. Examples of silicon include monocrystalline silicon, polycrystalline silicon, and amorphous silicon. In particular, transistors containing low-temperature polycrystalline silicon (LTPS) in the semiconductor layer (hereinafter also referred to as LTPS transistors) can be used. LTPS transistors have high field-effect mobility and good frequency characteristics.

[0284] By using silicon-based transistors such as LTPS transistors, circuits requiring high-frequency driving (e.g., source driver circuits) and display units can be formed on the same substrate. Therefore, the external circuitry mounted to the display device can be simplified, reducing component and installation costs.

[0285] Furthermore, it is preferable to use a transistor containing metal oxide (hereinafter also referred to as oxide semiconductor) in the semiconductor forming the channel (hereinafter also referred to as OS transistor) in at least one of the transistors included in the pixel circuit. OS transistors have a much higher field-effect mobility than amorphous silicon. In addition, the leakage current between the source and drain of an OS transistor in the off-state (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 maintained for a long period. Furthermore, by using OS transistors, the power consumption of the display device can be reduced.

[0286] By using LTPS transistors as part of the transistors included in the pixel circuit and OS transistors as other transistors, a display device with low power consumption and high driving capability can be realized. Furthermore, the structure combining LTPS transistors and OS transistors is sometimes called LTPO. As a more preferred example, it is preferable to use OS transistors as transistors used as switches to control the conduction / non-conduction between wirings and LTPS transistors as transistors to control current.

[0287] For example, one of the transistors disposed in the pixel circuit is used as a transistor to control the current flowing through the light-emitting element, and can also be called a driving transistor. One of the source and drain electrodes of the driving transistor is electrically connected to the pixel electrode of the light-emitting element. Preferably, an LTPS transistor is used as the driving transistor. Therefore, the current flowing through the light-emitting element in the pixel circuit can be increased.

[0288] On the other hand, another transistor in the pixel circuit, used as a switch to control pixel selection / deselection, can also be called a selection transistor. The gate of the selection transistor is electrically connected to the gate line, and one of its source and drain is electrically connected to the source line (signal line). Preferably, an OS transistor is used for selection. Therefore, even with a significantly low frame rate (e.g., below 1 fps), pixel grayscale can be maintained, thereby reducing power consumption by stopping the driver when displaying static images.

[0289] Thus, one embodiment of the present invention can realize a display device that combines high aperture ratio, high definition, high display quality and low power consumption.

[0290] Below, we will illustrate more specific structural examples with reference to the diagrams.

[0291] [Example 3 of a display device structure] Figure 10A is a block diagram of the display device 10. The display device 10 includes a display unit 11, a driving circuit unit 12, a driving circuit unit 13, etc.

[0292] The display unit 11 includes a plurality of pixels 30 arranged in a matrix. Each pixel 30 includes sub-pixels 21R, 21G, and 21B. Each of the sub-pixels 21R, 21G, and 21B includes a light-emitting element that serves as a display element.

[0293] Pixel 30 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 drive circuit section 12. Wiring GL is electrically connected to drive circuit section 13. Drive circuit section 12 is used as a source line drive circuit (also called a source driver), and drive circuit section 13 is used as a gate line drive circuit (also called a gate driver). Wiring GL is used as a gate line, and wiring SLR, wiring SLG, and wiring SLB are each used as a source line.

[0294] Subpixel 21R includes a light-emitting element that emits red light. Subpixel 21G includes a light-emitting element that emits green light. Subpixel 21B includes a light-emitting element that emits blue light. Therefore, the display device 10 can perform full-color display. Furthermore, pixel 30 may also include subpixels with light-emitting elements that emit other colors of light. For example, pixel 30 may also include, in addition to the three subpixels mentioned above, subpixels with light-emitting elements that emit white light or subpixels with light-emitting elements that emit yellow light.

[0295] The wiring GL is electrically connected to sub-pixels 21R, 21G, and 21B arranged in the row direction (the extension direction of wiring GL). The wiring SLR, wiring SLG, and wiring SLB are electrically connected to sub-pixels 21R, 21G, or 21B arranged in the column direction (the extension direction of wiring SLR, etc.).

[0296] [Example of pixel circuit structure] Figure 10B shows an example of a circuit diagram for pixel 21, which can be used for sub-pixels 21R, 21G, and 21B. Pixel 21 includes transistors M1, M2, and M3, capacitor C1, and light-emitting element EL. Additionally, wiring GL and wiring SL are electrically connected to pixel 21. Wiring SL corresponds to any one of wiring SLR, wiring SLG, and wiring SLB shown in Figure 10A.

[0297] The gate of transistor M1 is electrically connected to wiring GL, one of its source and drain is electrically connected to wiring SL, and the other of its source and drain is electrically connected to one electrode of capacitor C1 and the gate of transistor M2. One of the source and drain of transistor M2 is electrically connected to wiring AL, and the other of its source and drain is electrically connected to one electrode of light-emitting element EL, the other electrode of capacitor C1, and one of the source and drain of transistor M3. The gate of transistor M3 is electrically connected to wiring GL, and the other of its source and drain is electrically connected to wiring RL. The other electrode of light-emitting element EL is electrically connected to wiring CL.

[0298] Transistor M1 and transistor M3 are used as switches. Transistor M2 is used as a transistor to control the current flowing through the light-emitting element EL. For example, it can also be said that transistor M1 is used as a selection transistor and transistor M2 is used as a driving transistor.

[0299] Here, it is preferable to use LTPS transistors for all transistors M1 to M3. Alternatively, it is preferable to use OS transistors for transistors M1 and M3, and LTPS transistors for transistor M2.

[0300] Alternatively, transistors M1 to M3 can all be OS transistors. In this case, one or more of the plurality of transistors included in the drive circuit section 12 and the plurality of transistors included in the drive circuit section 13 can be LTPS transistors, while the other transistors can be OS transistors. For example, the transistors provided in the display section 11 can be OS transistors, while the transistors in the drive circuit section 12 and the drive circuit section 13 can be LTPS transistors.

[0301] As an OS transistor, a transistor in which an oxide semiconductor is used as the semiconductor layer in which the channel is formed can be used. For example, the semiconductor layer preferably comprises indium, M (M is selected from gallium, aluminum, silicon, boron, yttrium, tin, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, or 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 (also described as IGZO) comprising indium (In), gallium (Ga), and zinc (Zn) is preferably used. Alternatively, an oxide comprising indium (In), tin (Sn), and zinc (Zn) is preferably used. Alternatively, an oxide comprising indium (In), gallium (Ga), tin (Sn), and zinc (Zn) is preferably used.

[0302] Using an oxide semiconductor transistor with a wider band gap and lower carrier density than silicon allows for 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 extended periods. Therefore, it is particularly preferable to use oxide semiconductor transistors for transistors M1 and M3 connected in series with capacitor C1. By using oxide semiconductor transistors for transistors M1 and M3, leakage of the charge stored in capacitor C1 through transistors M1 or M3 can be prevented. Furthermore, the charge stored in capacitor C1 can be maintained for extended periods, allowing for the display of still images without rewriting the data of pixel 21.

[0303] Wiring SL is supplied with a data potential D. Wiring GL is supplied with a selection signal. This selection signal includes a potential that turns the transistor on and a potential that turns the transistor off.

[0304] Wiring RL is supplied with a reset potential. Wiring AL is supplied with an anode potential. Wiring CL is supplied with a cathode potential. The anode potential in pixel 21 is higher than the cathode potential. Additionally, the reset potential supplied to wiring RL can be a potential such that the potential difference between the reset potential and the cathode potential is less than the critical voltage of the light-emitting element EL. The reset potential can be a potential higher than the cathode potential, the same as the cathode potential, or lower than the cathode potential.

[0305] Note that in Figure 10B, the transistor is an n-channel transistor, but a p-channel transistor can also be used.

[0306] In addition, the transistors included in pixel 21 are preferably arranged and formed on the same substrate.

[0307] The transistor included in pixel 21 may be a transistor comprising a pair of gates overlapping a semiconductor layer.

[0308] When a transistor comprising a pair of gates has a structure in which the two gates are electrically connected to each other and supplied with the same potential, it offers advantages such as increased on-state current and improved saturation characteristics. Furthermore, a potential controlling the threshold voltage of the transistor can be supplied to one of the gates. Additionally, by supplying a constant potential to one of the gates, the stability of the transistor's electrical characteristics can be improved. For example, one gate of the transistor can be electrically connected to a wiring supplied with a constant potential, or the other gate can be electrically connected to the source or drain of the transistor itself.

[0309] The pixel 21 shown in Figure 10C is an example of using a transistor including a pair of gates for transistors M1 and M3. In each of transistors M1 and M3, the pair of gates are electrically connected to each other. By adopting such a structure, the data writing period for pixel 21 can be shortened.

[0310] Pixel 21 shown in Figure 10D is an example of using a transistor including a pair of gates not only for transistors M1 and M3, but also for transistor M2. The pair of gates of transistor M2 are electrically connected to each other. By using such a transistor for transistor M2, the saturation characteristics are improved, thus making it easier to control the luminous brightness of the light-emitting element EL, and improving display quality.

[0311] [Example of a cross-sectional structure of a display device] The following describes structural examples of transistors and light-emitting elements that can be used in the above-mentioned display devices.

[0312] [Structure Example 1] Figure 11A is a cross-sectional view including light-emitting element 330R, light-emitting element 330G (hereinafter collectively referred to as light-emitting element 330) and transistor 310.

[0313] Transistor 310 is a transistor in which polysilicon is used as the semiconductor layer. In the structure shown in FIG11A, for example, transistor 310 corresponds to transistor M2 of pixel 21, and light-emitting elements 330R and 330G correspond to light-emitting elements EL. That is, FIG11A is an example of one of the source and drain electrodes of transistor 310 being electrically connected to the pixel electrode of light-emitting element 330.

[0314] In Figure 11A, a light-emitting element 330R, a light-emitting element 330G, and a transistor 310 are disposed between substrate 301 and substrate 302.

[0315] Transistor 310 includes a semiconductor layer 311, an insulating layer 312, and a conductive layer 313. Semiconductor layer 311 includes a channel forming region 311i and a low-resistance region 311n. Semiconductor layer 311 comprises silicon. Semiconductor layer 311 preferably comprises polycrystalline silicon. A portion of insulating layer 312 is used as a gate insulating layer. A portion of conductive layer 313 is used as a gate electrode.

[0316] Note that the semiconductor layer 311 may also contain a metal oxide (also known as an oxide semiconductor) exhibiting semiconductor properties. In this case, the transistor 310 may be referred to as an OS transistor.

[0317] The low-resistance region 311n is a region containing impurity elements. For example, if the transistor 310 is an n-channel transistor, phosphorus or arsenic can be added to the low-resistance region 311n. On the other hand, if the transistor 310 is a p-channel transistor, boron or aluminum can be added to the low-resistance region 311n. In addition, in order to control the critical voltage of the transistor 310, the aforementioned impurities can also be added to the channel forming region 311i.

[0318] An insulating layer 321 is disposed on a substrate 301. A semiconductor layer 311 is disposed on the insulating layer 321. An insulating layer 312 is disposed such that it covers both the semiconductor layer 311 and the insulating layer 321. A conductive layer 313 is disposed on the insulating layer 312 at a position overlapping with the semiconductor layer 311.

[0319] Additionally, an insulating layer 322 is provided to cover the conductive layer 313 and the insulating layer 312. Conductive layers 314a and 314b are provided on the insulating layer 322. Conductive layers 314a and 314b are electrically connected to the low-resistance region 311n through openings formed in the insulating layers 322 and 312. A portion of the conductive layer 314a is used as one of the source electrode and the drain electrode, and a portion of the conductive layer 314b is used as the other of the source electrode and the drain electrode. Furthermore, an insulating layer 323 is provided to cover the conductive layers 314a, 314b, and the insulating layer 322.

[0320] The light-emitting element 330R includes, from the substrate 301 side, a conductive layer 331a, a conductive layer 331b, an EL layer 332R, a common layer 334, and a conductive layer 333. Conductive layers 331a and 331b serve as pixel electrodes. Conductive layer 331a serves as a connection electrode electrically connecting conductive layer 314b and conductive layer 331b. Conductive layer 333 serves as a common electrode. The light-emitting element 330G is identical to the light-emitting element 330R except that it includes an EL layer 332G instead of the EL layer 332R.

[0321] A conductive layer 331a is disposed on an insulating layer 323, and is electrically connected to a conductive layer 314b through an opening in the insulating layer 323. An insulating layer 361 is disposed in a recess (pit) in the conductive layer 331a located at the connection point with the conductive layer 314b. The insulating layer 361 is preferably made of an organic resin material. A conductive layer 331b is disposed covering both the conductive layer 331a and the insulating layer 361. The conductive layer 331b is disposed in contact with the top surface of the conductive layer 331a, and they are electrically connected. Because the conductive layer 331b is used as a reflective electrode, its top surface preferably has a high visible light reflectivity.

[0322] An EL layer 332R or an EL layer 332G is disposed on the conductive layer 331b.

[0323] Here, an insulating layer 362 and an insulating layer 363 are provided between the EL layer 332R and the EL layer 332G.

[0324] The insulating layer 362 is disposed in such a manner that it contacts each side surface of the EL layer 332R, conductive layer 331b and conductive layer 331a included in the light-emitting element 330R, each side surface of the EL layer 332G, conductive layer 331b and conductive layer 331a included in the light-emitting element 330G, and the top surface of the insulating layer 323.

[0325] The insulating layer 362 has a U-shaped cross-section. An insulating layer 363 is provided in a recess (pit) embedded in the insulating layer 362. The insulating layer 363, like the insulating layer 361, is preferably made of an organic resin material.

[0326] Both non-photosensitive organic resins and photosensitive organic resins can be used as insulating layers 361 and 363. Examples of materials that can be used for insulating layers 361 and 363 include acrylic resins, polyimide resins, epoxy resins, polyimide resins, polyimide-polyimide resins, silicone resins, benzocyclobutene resins, phenolic resins, and precursors of these resins.

[0327] In addition, a common layer 334 is provided to cover EL layer 332R, EL layer 332G, insulating layer 362, and insulating layer 363, and a conductive layer 333 is provided to cover the common layer 334. In addition, an insulating layer 335 is provided to cover the conductive layer 333.

[0328] The insulating layer 335 serves as a barrier film to suppress the diffusion of impurities such as water into the light-emitting elements 330R and 330G. Preferably, the insulating layer 335 comprises at least an inorganic insulating film.

[0329] In addition, an adhesive layer 325 is provided on the insulating layer 335, and the substrate 301 and the substrate 302 are bonded together by the adhesive layer 325.

[0330] Here, EL layers 332R and EL layers 332G are formed without using a metal mask. Therefore, the thickness of EL layers 332R and EL layers 332G is approximately uniform from the center to the ends. Furthermore, EL layers 332R and EL layers 332G are processed such that their sides face each other on the insulating layer 323. On the other hand, for example, when a metal mask is used, EL layers 332R and EL layers 332G tend to be thinner closer to their ends and have less defined outlines, so in many cases, well-defined sides are not formed.

[0331] The distance between the side surface of EL layer 332R and the side surface of EL layer 332G can be as close as less than 10 μm, less than 8 μm, less than 5 μm, less than 3 μm, less than 2 μm or less than 1 μm.

[0332] The EL layer 332R may include an emissive layer that emits at least a first color. Additionally, the EL layer 332G may include an emissive layer that emits at least a second color that is different from the first color.

[0333] Furthermore, EL layer 332R and EL layer 332G can each be stacked with at least two or more light-emitting layers. In this case, a charge-generating layer can also be disposed between the stacked light-emitting layers. Preferably, the charge-generating layer included in EL layer 332R and the charge-generating layer included in EL layer 332G contain the same compound.

[0334] Furthermore, at this time, the two light-emitting layers included in EL layer 332R or EL layer 332G can contain light-emitting materials that emit different colors. Preferably, EL layer 332R and EL layer 332G are light-emitting layers containing the same light-emitting material. For example, by making the light emitted by the multiple light-emitting layers complementary colors, a white-emitting light-emitting element can be obtained. For example, by stacking a light-emitting layer that emits red light, a light-emitting layer that emits blue light, and a light-emitting layer that emits green light, white light can be obtained.

[0335] Alternatively, the two light-emitting layers comprising EL layer 332R or EL layer 332G may contain light-emitting materials that exhibit the same color. In particular, the two light-emitting layers preferably contain the same light-emitting material. For example, EL layer 332R may be stacked with a light-emitting layer that exhibits red light, and EL layer 332G may be stacked with a light-emitting layer that exhibits green light.

[0336] [Structure Example 2] Figure 11B shows a transistor 310a including a pair of gate electrodes. The main difference between the transistor 310a shown in Figure 11B and the transistor 310 shown in Figure 11A is that it includes a conductive layer 315 and an insulating layer 316.

[0337] A conductive layer 315 is disposed on an insulating layer 321. An insulating layer 316 is disposed to cover both the conductive layer 315 and the insulating layer 321. A semiconductor layer 311 is disposed such that at least a channel forming region 311i overlaps with the conductive layer 315 across the insulating layer 316.

[0338] In the transistor 310a shown in FIG11B, a portion of the conductive layer 313 is used as the first gate electrode, and a portion of the conductive layer 315 is used as the second gate electrode. At this time, a portion of the insulating layer 312 is used as the first gate insulating layer, and a portion of the insulating layer 316 is used as the second gate insulating layer.

[0339] Here, when the first gate electrode and the second gate electrode are electrically connected, in the region not shown, the conductive layer 313 and the conductive layer 315 are electrically connected by openings formed in the insulating layer 312 and the insulating layer 316. Alternatively, when the second gate electrode is electrically connected to the source or drain electrode, in the region not shown, the conductive layer 314a or conductive layer 314b and the conductive layer 315 are electrically connected by openings formed in the insulating layer 322, the insulating layer 312, and the insulating layer 316.

[0340] When using LTPS transistors for all transistors constituting pixel 21, transistor 310 illustrated in FIG11A or transistor 310a illustrated in FIG11B can be used. In this case, transistor 310a can be used for all transistors constituting pixel 21, transistor 310 can be used for all transistors, or transistor 310a and transistor 310 can be used in combination.

[0341] [Structure Example 3] The following describes examples of transistors with silicon as the semiconductor layer and transistors with metal oxide as the semiconductor layer.

[0342] Figure 12A shows a cross-sectional schematic diagram including transistor 310a, transistor 350, light-emitting element 330R and light-emitting element 330G.

[0343] Transistor 310a, light-emitting element 330R and light-emitting element 330G can refer to the above-described structural examples 1 and 2.

[0344] Transistor 350 is a transistor in which metal oxide is used as the semiconductor layer. In the structure shown in FIG12A, for example, transistor 350 corresponds to transistor M1 of pixel 21. That is, FIG12A is an example of one of the source and drain of transistor 310a being electrically connected to the conductive layer 331a of light-emitting element 330R or light-emitting element 330G.

[0345] Additionally, Figure 12A shows an example of transistor 350 including a pair of gates.

[0346] Transistor 350 includes a conductive layer 355, an insulating layer 322, a semiconductor layer 351, an insulating layer 352, and a conductive layer 353. A portion of the conductive layer 353 is used as the first gate of the transistor 350, and a portion of the conductive layer 355 is used as the second gate of the transistor 350. At this time, a portion of the insulating layer 352 is used as the first gate insulating layer of the transistor 350, and a portion of the insulating layer 322 is used as the second gate insulating layer of the transistor 350.

[0347] A conductive layer 355 is disposed on an insulating layer 312. An insulating layer 322 is disposed to cover the conductive layer 355. A semiconductor layer 351 is disposed on the insulating layer 322. An insulating layer 352 is disposed to cover both the semiconductor layer 351 and the insulating layer 322. A conductive layer 353 is disposed on the insulating layer 352 and has a region overlapping the semiconductor layer 351 and the conductive layer 355.

[0348] Additionally, an insulating layer 326 is provided to cover the insulating layer 352 and the conductive layer 353. Conductive layers 354a and 354b are provided on the insulating layer 326. Conductive layers 354a and 354b are electrically connected to the semiconductor layer 351 through openings formed in the insulating layers 326 and 352. A portion of the conductive layer 354a is used as one of the source electrode and the drain electrode, and a portion of the conductive layer 354b is used as the other of the source electrode and the drain electrode. Furthermore, an insulating layer 323 is provided to cover the conductive layers 354a, 354b, and the insulating layer 326.

[0349] Here, conductive layers 314a and 314b, which are electrically connected to transistor 310a, are preferably formed from the same conductive film as conductive layers 354a and 354b. Figure 12A shows a structure in which conductive layers 314a, 314b, 354a, and 354b are formed on the same surface (i.e., in contact with the top surface of insulating layer 326) and contain the same metallic element. In this case, conductive layers 314a and 314b are electrically connected to the low-resistance region 311n through openings formed in insulating layers 326, 352, 322, and 312. This simplifies the manufacturing process and is therefore preferable.

[0350] Furthermore, the conductive layer 313, used as the first gate electrode of transistor 310a, and the conductive layer 355, used as the second gate electrode of transistor 350, are preferably formed by processing the same conductive film. Figure 12A shows a structure in which the conductive layer 313 and the conductive layer 355 are formed on the same surface (i.e., in contact with the top surface of the insulating layer 312) and contain the same metallic element. This simplifies the manufacturing process and is therefore preferable.

[0351] In Figure 12A, the insulating layer 352, which is used as the first gate insulating layer of the transistor 350, covers the end of the semiconductor layer 351. However, as shown in Figure 12B for transistor 350a, the insulating layer 352 can also be processed in a manner in which the shape of its top surface is approximately the same as the shape of the top surface of the conductive layer 353.

[0352] In this specification, "generally consistent top surface shape" means that at least a portion of the edges of each layer in a stack overlaps. For example, it means that the upper and lower layers are processed using the same masking pattern or a portion thereof. However, in reality, there are cases where the edges do not overlap, and sometimes the upper layer is located inside or outside the lower layer; these cases can also be described as having "generally consistent top surface shape".

[0353] [Structure Example 4] Figure 13 illustrates an example of a structure different from the one described above. The main difference between the display device shown in Figure 13 and the structure described above is the interchangeability of transistors 310a and 350, etc.

[0354] In Figure 13, transistor 350 is electrically connected to the pixel electrode. That is, an example is shown where transistor 350 corresponds to transistor M2 in pixel 21. In this case, transistor 310a corresponds to transistor M1, transistor M3, or other transistors.

[0355] This structure enables the creation of display devices that combine high aperture ratio, high definition, high display quality, and low power consumption.

[0356] At least a portion of the structural examples shown in this embodiment and the corresponding diagrams can be appropriately combined with other structural examples or diagrams.

[0357] At least a portion of this embodiment can be implemented in combination with other embodiments described in this specification.

[0358] Implementation Method 3 In this embodiment, an example of a display device structure different from that described above will be explained.

[0359] The display device in this embodiment can be a high-definition display device. Therefore, for example, the display device in this embodiment can be used as the display part of wearable devices that can be worn on the head, such as watch-type or bracelet-type information terminal devices (wearable devices), VR devices such as head-mounted displays, and AR devices such as glasses-type displays.

[0360] [Display Module] Figure 14A is a perspective view of display module 280. Display module 280 includes display device 400C and FPC 290.

[0361] The display module 280 includes a substrate 291 and a substrate 292. The display module 280 includes a display section 281. The display section 281 is the image display area in the display module 280, and can display light from each pixel disposed in the pixel section 284.

[0362] Figure 14B is a perspective view of one side of the structure of the substrate 291. A circuit section 282, a pixel circuit section 283 on the circuit section 282, and a pixel section 284 on the pixel circuit section 283 are stacked on the substrate 291. Furthermore, a terminal section 285 for connecting to the FPC 290 is provided on a portion of the substrate 291 that does not overlap with the pixel section 284. The terminal section 285 is electrically connected to the circuit section 282 via a wiring section 286 composed of multiple wirings.

[0363] The pixel unit 284 includes a plurality of pixels 284a arranged periodically. An enlarged view of a pixel 284a is shown on the right side of FIG14B. Pixel 284a includes light-emitting elements 430a, 430b, and 430c that emit different colors from each other. The plurality of light-emitting elements can also be arranged in a stripe arrangement as shown in FIG14B. By employing a stripe arrangement, the light-emitting elements of one embodiment of the present invention can be arranged in a high density in the pixel circuit, thus providing a high-definition display device. Alternatively, various arrangement methods such as triangular arrangement and Pentile arrangement can also be used.

[0364] The pixel circuit section 283 includes a plurality of pixel circuits 283a arranged periodically.

[0365] A pixel circuit 283a controls the light emission of the three light-emitting elements included in a pixel 284a. A pixel circuit 283a can be composed of three circuits controlling the light emission of a single light-emitting element. For example, the pixel circuit 283a can have a structure that includes at least one selection transistor, one current control transistor (driving transistor), and a capacitor for each light-emitting element. In this case, the gate of the selection transistor is input with a gate signal, and either the source or drain is input with a source signal. This realizes an active matrix display device.

[0366] The circuit section 282 includes circuitry for driving each pixel circuit 283a of the pixel circuit section 283. For example, it preferably includes one or both of a gate line driving circuit and a source line driving circuit. Furthermore, it may also include at least one of an arithmetic circuit, a memory circuit, and a power supply circuit.

[0367] The FPC290 is used for wiring to supply video signals or power potentials to the circuit section 282 from the outside. Additionally, ICs can be mounted on the FPC290.

[0368] The display module 280 can adopt a structure in which one or both of the pixel circuit section 283 and the circuit section 282 are stacked on the lower side of the pixel section 284, so that the display section 281 can have an extremely high aperture ratio (effective display area ratio). For example, the aperture ratio of the display section 281 can be 40% or more and less than 100%, preferably 50% or more and less than 95%, more preferably 60% or more and less than 95%. In addition, the pixels 284a can be arranged in an extremely high density, thereby enabling the display section 281 to have extremely high resolution. For example, the display section 281 preferably has pixels 284a arranged with a resolution of 20,000 ppi or less, or 30,000 ppi or less and more than 2,000 ppi, more preferably more than 3,000 ppi, further preferably more than 5,000 ppi, and even more preferably more than 6,000 ppi.

[0369] This high-definition display module 280 is suitable for use in VR devices such as head-mounted displays or AR devices such as glasses. For example, because the display module 280 has an extremely high-definition display section 281, even when the display section of the display module 280 is magnified through a lens, the user cannot see any pixels, thereby achieving a highly immersive display. Furthermore, the display module 280 can also be applied to electronic devices with relatively small display sections. For example, it is suitable for use in the display section of wearable electronic devices such as watch-type devices.

[0370] The pixel 103 shown in Figure 1A is arranged in a stripe pattern. The pixel 103 shown in Figure 1A consists of three sub-pixels: R, G, and B. Sub-pixels R, G, and B each include a light-emitting device with a different emitted color. For example, sub-pixels R, G, and B can be red, green, and blue sub-pixels, respectively.

[0371] Pixel 103 shown in Figure 15A uses an S-shaped stripe arrangement. Pixel 103 shown in Figure 15A is composed of three sub-pixels: R, G, and B.

[0372] The pixel 103 shown in Figure 15B includes a sub-pixel G with a top surface shape that is approximately trapezoidal and rounded at the corners, a sub-pixel R with a top surface shape that is approximately triangular and rounded at the corners, and a sub-pixel B with a top surface shape that is approximately quadrilateral or hexagonal and rounded at the corners. Furthermore, the light-emitting area of ​​sub-pixel G is larger than that of sub-pixel R. Thus, the shape and size of each sub-pixel can be determined independently. For example, the higher the reliability of the light-emitting device included in a sub-pixel, the smaller the size of that sub-pixel can be. For example, sub-pixels R, G, and B can be red, green, and blue sub-pixels, respectively.

[0373] Pixels 125a and 125b shown in Figure 15C are arranged in a Pentile pattern. Figure 15C shows an example of pixel 125a, which includes sub-pixels R and G, and pixel 125b, which includes sub-pixels G and B, arranged alternately. For example, sub-pixels R, G, and B can be red, green, and blue sub-pixels, respectively.

[0374] Pixels 125a and 125b shown in Figures 15D and 15E are arranged in a Delta pattern. Pixel 125a includes two sub-pixels (sub-pixels R and G) in the upper row (first row) and one sub-pixel (sub-pixel B) in the lower row (second row). Pixel 125b includes one sub-pixel (sub-pixel B) in the upper row (first row) and two sub-pixels (sub-pixels R and G) in the lower row (second row).

[0375] Figure 15D is an example of an approximately quadrilateral top surface shape with rounded corners for each sub-pixel, and Figure 15E is an example of a circular top surface shape for each sub-pixel.

[0376] In photolithography, the finer the pattern being processed, the more significant the effect of light diffraction becomes. Therefore, when transferring the pattern from the photomask through exposure, its fidelity deteriorates, making it difficult to process the photomask into the desired shape. Consequently, even if the photomask pattern is rectangular, it is easy to form a pattern with rounded corners. Thus, the top surface shape of a subpixel sometimes takes the form of a polygon with rounded corners, an ellipse, or a circle.

[0377] Furthermore, in a method for manufacturing a display device according to one embodiment of the present invention, the EL layer is processed into an island shape using a photoresist mask. The photoresist film formed on the EL layer needs to be cured at a temperature lower than the heat resistance temperature of the EL layer. Therefore, depending on the heat resistance temperature of the EL layer material and the curing temperature of the photoresist material, the photoresist film is sometimes not fully cured. The insufficiently cured photoresist film sometimes takes on a shape far from the desired shape during processing. As a result, the top surface shape of the EL layer is sometimes a polygonal shape with rounded corners, an ellipse, or a circle, etc. For example, when a photoresist mask with a square top surface shape is to be formed, sometimes a photoresist mask with a circular top surface shape is formed and the top surface shape of the EL layer is circular.

[0378] To ensure the top surface of the EL layer has the desired shape, a technique called OPC (Optical Proximity Correction) can be used to pre-correct the mask pattern in a way that aligns with the design pattern and the transfer pattern. Specifically, in OPC, correction patterns are added to the corners and other parts of the pattern on the mask pattern.

[0379] The pixels 103 shown in Figures 16A to 16C are arranged in a stripe pattern. Pixel 103 in Figures 16A to 16C consists of four sub-pixels: R, G, B, and W. Sub-pixels R, G, B, and W each include a light-emitting device with a different emitted color. For example, sub-pixels R, G, B, and W can be red, green, blue, and white sub-pixels, respectively.

[0380] Figure 16A shows an example where each sub-pixel has a rectangular top surface shape; Figure 16B shows an example where each sub-pixel has a top surface shape connecting two semicircles and a rectangle; and Figure 16C shows an example where each sub-pixel has an elliptical top surface shape.

[0381] The pixels 103 shown in Figures 16D to 16F are arranged in a matrix. The pixels 103 shown in Figures 16D to 16F are composed of four sub-pixels: R, G, B, and W.

[0382] Figure 16D shows an example where each subpixel has a square top surface shape, Figure 16E shows an example where each subpixel has an approximately square top surface shape with rounded corners, and Figure 16F shows an example where each subpixel has a circular top surface shape. In Figure 16G, the upper row (first row) includes subpixels R, G, and B, and the lower row (second row) includes three subpixels W. In other words, in Figure 16G, the left column (first column) includes subpixels R and W, the middle column (second column) includes subpixels G and W, and the right column (third column) includes subpixels B and W.

[0383] An electronic device including a display device according to one embodiment of the present invention may have one or both of a flash function using sub-pixels (W) and an illumination function using sub-pixels (W).

[0384] Here, the white light emitted by the sub-pixel (W) can be either a brief, high-brightness light like a flash or strobe light, or a light with high color rendering index like a reading lamp. Note that when using white light for reading lamps, etc., the color temperature of the white light emission can be lowered. For example, by using bulb light (e.g., 2500K or higher but lower than 3250K) or warm white (e.g., 3250K or higher but lower than 3800K) as white light, a light source that is less irritating to the eyes can be achieved.

[0385] The strobe function can be implemented, for example, with a structure that emits light repeatedly in short cycles or without emitting light. Furthermore, the flash function can be implemented, for example, with a structure that generates a flash by instantaneous discharge using principles such as double-layer electrical discharge.

[0386] For example, when the electronic device 50 has a camera function, images can be captured at night by using the strobe function or flash function, as shown in FIG17A. Here, the display device of the electronic device 50 is used as a surface light source, and the subject is less likely to cast shadows, thereby capturing clear images. Note that the strobe function or flash function is not limited to nighttime use. When the electronic device 50 has a strobe function or flash function, the color temperature of white light emission can be increased. For example, the color temperature of the light emitted from the electronic device 50 can be set to white (e.g., above 3800K and below 4500K), daylight white (e.g., above 4500K and below 5500K), or daylight color (e.g., above 5500K and below 7100K).

[0387] Furthermore, when the flash intensity is too high, areas with varying brightness may appear entirely white in the image (overexposure). Conversely, when the flash intensity is insufficient, darker areas may appear entirely black in the image (underexposure). To address this, by detecting the brightness around the subject using the light-receiving device included in the display device, the light emitted by the light-emitting devices included in the sub-pixels can be adjusted to the optimal amount of light. In other words, the electronic device 50 also functions as an exposure meter.

[0388] Furthermore, the strobe and flash functions can be used for crime prevention or self-defense. For example, as shown in Figure 17B, by emitting light from the electronic device 50 at an assailant, the assailant may be momentarily frightened. Additionally, in emergency situations such as being attacked by an assailant, it can be difficult to calmly fire a self-defense light with a narrow beam towards the assailant's face. To address this, because the display device of the electronic device 50 is a surface light source, even if the orientation of the display device is slightly off, the light from the display device can still be emitted into the assailant's field of vision.

[0389] Note that, as shown in Figure 17B, when the display device of electronic device 50 is used as a crime prevention flash or a self-defense flash, it is preferable to increase the brightness compared to the nighttime shooting shown in Figure 17A. Furthermore, by making the display device emit light intermittently multiple times, it is easier to frighten the perpetrator temporarily. Additionally, electronic device 50 can also emit a loud beeping sound to seek help from the surroundings. By emitting a sound near the perpetrator's face, it is preferable to frighten the perpetrator temporarily not only through light but also through sound.

[0390] Furthermore, in order to improve the color rendering index (CRI) of the light-emitting device included in the sub-pixel W, it is preferable to increase the number of light-emitting layers included in the light-emitting device or the types of light-emitting materials contained in the light-emitting layers. Therefore, a broad emission spectrum with intensity over a wider wavelength range can be obtained, and light emission with higher CRI, close to that of sunlight, can be achieved.

[0391] For example, as shown in Figure 17C, the electronic device 50, which can achieve high color rendering index, can also be used as a reading lamp. In Figure 17C, the electronic device 50 is fixed to the table 54 using a support 52. By using this support 52, the electronic device 50 can be used as a reading lamp. Because the display device of the electronic device 50 is used as a surface light source, objects (books in Figure 17C) are less likely to cast shadows, and the distribution of light reflected from the objects is slow. Therefore, the visibility of the objects is improved, making it easier to see them. In addition, because white light-emitting devices have a broad emission spectrum, blue light is also relatively reduced. As a result, eye fatigue and other eye strain can be reduced for users of the electronic device 50.

[0392] Note that the structure of the support 52 is not limited to the structure shown in FIG17C. An arm or movable part may be appropriately provided to maximize the range of motion. Furthermore, in FIG17C, the support 52 clamps the electronic device 50, but the present invention is not limited thereto. For example, a structure that appropriately uses magnets or suction cups may also be used.

[0393] The preferred luminous color for lighting is white. Note that there are no particular restrictions on the luminous color used for lighting; implementers may also appropriately choose one or more of the most suitable luminous colors, such as white, blue, purple, blue-violet, green, yellow-green, yellow, orange, and red.

[0394] This implementation method can be appropriately combined with other implementation methods.

[0395] Implementation Method 4 In this embodiment, an example of a display device according to one embodiment of the present invention, including a light-receiving device, is described.

[0396] In the display device of this embodiment, a pixel may include multiple sub-pixels having light-emitting devices that emit light of different colors. For example, a pixel may include three types of sub-pixels. Examples of these three types of sub-pixels include sub-pixels of red (R), green (G), and blue (B), and sub-pixels of yellow (Y), cyan (C), and magenta (M). Alternatively, a pixel may include four types of sub-pixels. Examples of these four types of sub-pixels include sub-pixels of R, G, B, and white (W), and sub-pixels of R, G, B, and Y.

[0397] There are no particular restrictions on the arrangement of subpixels; various arrangement methods can be used. Examples of subpixel arrangements include stripe arrangement, S-stripe arrangement, matrix arrangement, Delta arrangement, Bayer arrangement, Pentile arrangement, etc.

[0398] Furthermore, examples of the top surface shape of a sub-pixel include triangles, quadrilaterals (including rectangles and squares), pentagons, polygons with rounded corners, ellipses, and circles. Here, the top surface shape of the sub-pixel corresponds to the top surface shape of the light-emitting area of ​​the light-emitting device.

[0399] In a display device according to one embodiment of the present invention, a pixel may also include a light-receiving device (also called a light-receiving element).

[0400] In a display device where pixels include both light-emitting and light-receiving devices, the pixels have a light-receiving function, so the display device can detect the contact or proximity of an object while displaying an image. For example, not only can all sub-pixels included in the display device display images, but some sub-pixels can emit light as a light source and cause other sub-pixels to display images.

[0401] In one embodiment of the present invention, the display unit of the display device has light-emitting devices arranged in a matrix, thereby enabling the display of images. Additionally, the display unit also has light-receiving devices arranged in a matrix, and in addition to image display, it possesses one or both of imaging and sensing functions. The display unit can be used as an image sensor or a touch sensor. That is, by detecting light from the display unit, images can be captured or the proximity or contact of an object (fingers, hands, or pens, etc.) can be detected. Furthermore, the display device of one embodiment of the present invention can use the light-emitting devices as the light source for the sensor. Therefore, it is not necessary to separately provide a light-receiving unit and a light source with the display device, thus reducing the number of components in the electronic device.

[0402] In a display device according to one embodiment of the present invention, when light emitted by a light-emitting device included in the display section is reflected (or scattered) by an object, a light-receiving device can detect the reflected light (or scattered light), thereby enabling the capture of images or the detection of touch even in the dark.

[0403] When a light-receiving device is used as an image sensor, the display device can capture images using the light-receiving device. For example, the display device of this embodiment can be used as a scanner.

[0404] For example, image sensors can be used to acquire data based on fingerprints, palm prints, etc. In other words, biometric sensors can be integrated into the display device. By integrating biometric sensors into the display device, compared to having separate display devices and biometric sensors, the number of parts in the electronic device can be reduced, thereby enabling miniaturization and weight reduction of the electronic device.

[0405] Furthermore, when a light-receiving device is used in a touch sensor, the display device can use the light-receiving device to detect the approach or contact of an object.

[0406] As a light-receiving device, for example, a pn-type or pin-type photodiode can be used. The light-receiving device is used as a photoelectric conversion device (also called a photoelectric conversion element) to generate charge by detecting light incident on it. The amount of charge generated by the light-receiving device depends on the amount of light incident on it.

[0407] In particular, organic photodiodes with a layer containing organic compounds are preferred as light-receiving devices. Organic photodiodes are easy to make thin, lightweight and large-area, and have high flexibility in shape and design, thus they can be applied to a wide variety of display devices.

[0408] In one embodiment of the present invention, an organic EL device is used as a light-emitting device, and an organic photodiode is used as a light-receiving device. The organic EL device and the organic photodiode can be formed on the same substrate. Therefore, the organic photodiode can be installed in a display device using an organic EL device.

[0409] The pixels shown in Figures 18A and 18B include sub-pixels G, B, R, and PS.

[0410] The pixels shown in Figure 18A are arranged in a stripe pattern. The pixels shown in Figure 18B are arranged in a matrix pattern.

[0411] The pixels shown in Figures 18C and 18D include sub-pixels G, B, R, PS, and IRS.

[0412] Figures 18C and 18D show examples of a pixel arranged in two rows and three columns. The upper row (first row) has three subpixels (subpixel G, subpixel B, and subpixel R). In Figure 18C, the lower row (second row) has three subpixels (one subpixel PS and two subpixels IRS). On the other hand, in Figure 18D, the lower row (second row) has two subpixels (one subpixel PS and one subpixel IRS). Note that the layout of the subpixels is not limited to the structures in Figures 18A to 18D.

[0413] Sub-pixel R includes a light-emitting device that emits red light. Sub-pixel G includes a light-emitting device that emits green light. Sub-pixel B includes a light-emitting device that emits blue light.

[0414] Both the sub-pixel PS and the sub-pixel IRS include light-receiving devices. There are no particular limitations on the wavelength of light detected by the sub-pixel PS and the sub-pixel IRS.

[0415] The light-receiving area of ​​a subpixel (PS) is smaller than that of a subpixel (IRS). A smaller light-receiving area results in a narrower imaging range, which helps suppress blurring and improve resolution. Therefore, by using a subpixel (PS), imaging can be performed with higher clarity or resolution compared to using a subpixel (IRS). For example, a subpixel (PS) can be used for personal identification using fingerprints, palm prints, irises, vein shapes (including vein and artery shapes), or faces.

[0416] The light-receiving device included in the sub-pixel PS preferably detects visible light, and more preferably detects one or more of the following colors: blue, purple, blue-violet, green, yellow-green, yellow, orange, and red. Additionally, the light-receiving device included in the sub-pixel PS can also detect infrared light.

[0417] Additionally, subpixel IRS can be used in touch sensors (also known as direct touch sensors) or air touch sensors (also known as hover sensors, levitating touch sensors, contactless sensors, or non-contact sensors). The wavelength of light detected by the subpixel IRS can be appropriately determined depending on the application. For example, a subpixel IRS is preferably designed to detect infrared light. This allows for touch detection even in darkness.

[0418] Here, a touch sensor or air touch sensor can detect the approach or contact of an object (finger, hand, or pen, etc.). A touch sensor can detect an object when the display device is in direct contact with it. Alternatively, an air touch sensor can detect an object even if it is not in contact with the display device. For example, preferably, the display device can detect the object within a distance of 0.1 mm to 300 mm, more preferably 3 mm to 50 mm, between the display device and the object. By employing this structure, operation can be performed without direct contact between the object and the display device; in other words, the display device can be operated in a non-contact (contactless) manner. By adopting the above structure, the risk of the display device becoming dirty or damaged can be reduced, or the object can operate the display device without directly contacting stains (e.g., garbage or viruses) adhering to it.

[0419] By setting two light-receiving devices in a single pixel, two additional functions can be added in addition to the display function, thus realizing the multi-functionality of the display device.

[0420] Because high-definition imaging is required, it is preferable to place subpixels (PS) among all the pixels included in the display device. On the other hand, compared to detection using subpixels (PS), subpixel sensors (IRS) used for touch sensors or air touch sensors do not require high precision; therefore, subpixel IRS can be placed among only a portion of the pixels included in the display device. By making the number of subpixel IRS included in the display device less than the number of subpixels (PS), the detection speed can be improved.

[0421] Here, the structure of the light-receiving device that can be used for sub-pixel PS and sub-pixel IRS is explained.

[0422] The light-receiving device includes at least an active layer between a pair of electrodes, which serves as a photoelectric conversion layer. In this specification, one of the electrodes is sometimes referred to as the pixel electrode and the other as the common electrode.

[0423] One electrode of the pair of electrodes included in the light-receiving device is used as the anode, and the other electrode is used as the cathode. The following explanation uses the case where the pixel electrode is used as the anode and the common electrode is used as the cathode as an example. That is, by applying a reverse bias voltage between the pixel electrode and the common electrode to drive the light-receiving device, the light incident on the light-receiving device can be detected, a charge can be generated, and the charge can be extracted in the form of a current.

[0424] The light-receiving device can also be manufactured using the same methods as the light-emitting device. The island-shaped active layer (also known as the photoelectric conversion layer) included in the light-receiving device is not formed by patterning a metal mask, but by depositing a film that will become the active layer on the entire surface and then processing it. Therefore, the island-shaped active layer can be formed with a uniform thickness. In addition, by setting a sacrificial layer on the active layer, damage to the active layer during the manufacturing process of the display device can be reduced, thereby improving the reliability of the light-receiving device.

[0425] Note that layers shared by the light-receiving and light-emitting devices sometimes have different functions in the light-emitting and light-receiving devices. In this specification, components are sometimes referred to according to their function in the light-emitting device. For example, a 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, an electron injection layer functions as both an electron injection layer and an electron transport layer in both the light-emitting and light-receiving devices. Furthermore, layers shared by the light-receiving and light-emitting devices sometimes have the same function in both the light-emitting and light-receiving devices. For example, a hole transport layer is used as a hole transport layer in both the light-emitting and light-receiving devices, and an electron transport layer is used as an electron transport layer in both the light-emitting and light-receiving devices.

[0426] The active layer of the light-receiving device comprises a semiconductor. Examples of such semiconductors include inorganic semiconductors such as silicon and organic semiconductors containing organic compounds. In this embodiment, an example of using an organic semiconductor as the semiconductor contained in the active layer is shown. Because of the use of an organic semiconductor, the light-emitting layer and the active layer can be formed using the same method (e.g., vacuum evaporation), and the manufacturing equipment can be shared, which is preferable.

[0427] Examples of electron-accepting organic semiconductor materials that can be used as n-type semiconductors in the active layer include fullerenes (e.g., C60, C70, etc.) and fullerene derivatives. Fullerenes have a soccer ball shape, which is energy stable. Fullerenes have deep (low) HOMO and LUMO energy levels. Because of their deep LUMO energy level, fullerenes exhibit extremely high electron acceptor activity. Generally, when π-electron conjugation (resonance), as in benzene, expands in a plane, electron donor activity increases. On the other hand, fullerenes, with their spherical shape, exhibit high electron acceptor activity despite the extensive expansion of π-electrons. This high electron acceptor activity allows for rapid and efficient charge separation, which is beneficial for light-receiving devices. Both C60 and C70 have broad absorption bands in the visible light region, especially C70, which has a larger π-electron conjugation class than C60 and also exhibits a broad absorption band in the long-wavelength region, making it a preferred choice. In addition, examples of fullerene derivatives include methyl [6,6]-phenyl-C71-butyrate (abbreviated as PC70BM), methyl [6,6]-phenyl-C61-butyrate (abbreviated as PC60BM), and 1',1”,4',4”-tetrahydro-bis[1,4]methanenaphthaleno[1,2:2',3',56,60:2”,3”][5,6]fullerene-C60 (abbreviated as ICBA).

[0428] Materials that can be used as n-type semiconductors include metal complexes with a quinoline skeleton, metal complexes with a benzoquinoline skeleton, metal complexes with a chloroazole skeleton, metal complexes with a thiazole skeleton, chlorodiazole derivatives, triazole derivatives, imidazole derivatives, chloroazole derivatives, thiazole derivatives, phenoline derivatives, quinoline derivatives, benzoquinoline derivatives, quinoline derivatives, dibenzoquinoline derivatives, pyridine derivatives, bipyridine derivatives, pyrimidine derivatives, naphthalene derivatives, anthracene derivatives, coumarin derivatives, rhodamine derivatives, triazine derivatives, quinone derivatives, etc.

[0429] Examples of p-type semiconductor materials containing active layers include copper(II) phthalocyanine (CuPc), tetraphenyldibenzoperiflanthene (DBP), zinc phthalocyanine (ZnPc), tin phthalocyanine (SnPc), and quinacridone, which are organic semiconductor materials with electronic donor properties.

[0430] In addition, examples of materials that can be used as p-type semiconductors include carbazole derivatives, thiophene derivatives, furan derivatives, and compounds with an aromatic amine skeleton. Furthermore, examples of materials that can be used as p-type semiconductors include naphthalene derivatives, anthracene derivatives, pyrene derivatives, triphenylene derivatives, benzo[a]furan derivatives, benzo[a]thiophene derivatives, indole derivatives, dibenzo[a]furan derivatives, dibenzo[a]thiophene derivatives, indole-carbazole derivatives, violet derivatives, phthalocyanine derivatives, naphthylphthalocyanine derivatives, quinacridone derivatives, polyphenylene oxide derivatives, poly[a]benzene oxide derivatives, poly[a]benzene oxide derivatives, poly[a]benzene oxide derivatives, polyvinylcarbazole derivatives, or polythiophene derivatives.

[0431] The HOMO energy level of organic semiconductor materials with electron donor properties is preferably shallower (higher) than that of organic semiconductor materials with electron acceptor properties. Similarly, the LUMO energy level of organic semiconductor materials with electron donor properties is preferably shallower (higher) than that of organic semiconductor materials with electron acceptor properties.

[0432] Preferably, spherical fullerenes are used as organic semiconductor materials with electron-accepting properties, and even more preferably, organic semiconductor materials with shapes similar to planar structures are used as organic semiconductor materials with electron-donating properties. Molecules with similar shapes tend to aggregate easily, and when the same type of molecules aggregate, the carrier transport can be improved because the energy levels of the molecular orbitals are similar.

[0433] For example, it is preferable to co-deposit an n-type semiconductor and a p-type semiconductor to form the active layer. Alternatively, an n-type semiconductor and a p-type semiconductor can be stacked to form the active layer.

[0434] The light-receiving device may also include layers other than the active layer, such as layers containing materials with high hole transport, materials with high electron transport, or bipolar materials (materials with both high electron and hole transport). Furthermore, it is not limited to these; it may also include layers containing materials with high hole injection, hole blocking materials, materials with high electron injection, or electron blocking materials.

[0435] Light-receiving devices can use low-molecular-weight compounds or high-molecular-weight compounds, and may also contain inorganic compounds. The layers constituting the light-receiving device can be formed by methods such as vapor deposition (including vacuum vapor deposition), transfer printing, printing, inkjet printing, and coating.

[0436] For example, polymers such as poly(3,4-ethylenedioxythiophene) / poly(styrene sulfonic acid) (PEDOT / PSS) and inorganic compounds such as molybdenum oxide and copper iodide (CuI) can be used as hole transport materials. Additionally, inorganic compounds such as zinc oxide (ZnO) can be used as electron transport materials.

[0437] Alternatively, the active layer can also use polymers such as poly[[4,8-bis[5-(2-ethylhexyl)-2-thiophene]benzo[1,2-b:4,5-b']dithienyl-2,6-diyl]-2,5-thiophenediyl[5,7-bis(2-ethylhexyl)-4,8-dioxo-4H,8H-benzo[1,2-c:4,5-c']dithienyl-1,3-diyl]] (abbreviated as PBDB-T) or PBDB-T derivatives, which serve as donors. For example, methods such as dispersing acceptor materials into PBDB-T or PBDB-T derivatives can be used.

[0438] Furthermore, three or more materials can be mixed as the active layer. For example, in order to expand the wavelength region, a third material can be mixed in addition to n-type and p-type semiconductor materials. In this case, the third material can be a low-molecular-weight compound or a high-molecular-weight compound.

[0439] The above describes the light-receiving device.

[0440] Figure 19A shows a structural example of the cross-section corresponding to the dashed lines D1-D2 shown in Figure 18A.

[0441] By using an active layer that can be used as a light-receiving element instead of an EL layer in the structure of the light-emitting element 110 shown in the above embodiment, a light-receiving element can be constructed.

[0442] Figures 18A and 19A show examples where a light-emitting element 110R is used as the light-emitting element (light-emitting device) included in sub-pixel R, and a light-receiving element 110PS with visible light detection function is used as the light-receiving element (light-receiving device) included in sub-pixel PS. The light-receiving element 110PS has the following structure: in the structure of the light-emitting element 110 shown in the above embodiment, an active layer 112PS capable of being used for a light-receiving element with visible light detection function is used instead of the EL layer 112. The light-receiving element 110PS includes a conductive layer 117PS, an insulating layer 132 on the conductive layer 117PS, a pixel electrode 111PS on the conductive layer 117PS and the insulating layer 132, and an active layer 112PS on the pixel electrode 111PS. Additionally, a common electrode 113 is provided on the active layer 112PS. A common layer 114 may also be provided between the common electrode 113 and the active layer 112PS. Note that the conductive layer 117PS is provided on the insulating layer 255 and within the opening of the insulating layer 255. The conductive layer 117PS is electrically connected to the conductive layer 241 (here, conductive layer 241PS) disposed in the semiconductor circuit 401.

[0443] Figure 19B shows an example of a subpixel with a light-receiving device, while Figure 19C shows an example of a subpixel with a light-emitting device.

[0444] The pixel circuit PIX1 shown in Figure 19B includes a light-receiving device PD, transistors M11, M12, M13, and M14, and a capacitor C2. Here, an example of using a photodiode as the light-receiving device PD is shown.

[0445] The cathode of the light-receiving device PD is electrically connected to wiring V1, and the anode is electrically connected to one of the source and drain electrodes of transistor M11. The gate of transistor M11 is electrically connected to wiring TX, and the other of its source and drain electrodes is electrically connected to one electrode of capacitor C2, one of the source and drain electrodes of transistor M12, and the gate of transistor M13. The gate of transistor M12 is electrically connected to wiring RES, and the other of its source and drain electrodes is electrically connected to wiring V2. One of the source and drain electrodes of transistor M13 is electrically connected to wiring V3, and the other of its source and drain electrodes is electrically connected to one of the source and drain electrodes of transistor M14. The gate of transistor M14 is electrically connected to wiring SE, and the other of its source and drain electrodes is electrically connected to wiring OUT1.

[0446] Wiring V1, wiring V2, and wiring V3 are each supplied with a constant potential. When the photodetector PD is driven with a reverse bias, a potential lower than that of wiring V1 is supplied to wiring V2. Transistor M12 is controlled by a signal supplied to wiring RES, causing the potential of the node connected to the gate of transistor M13 to be reset to the potential supplied to wiring V2. Transistor M11 is controlled by a signal supplied to wiring TX, controlling the timing of the potential changes of the aforementioned nodes according to the current flowing through the photodetector PD. Transistor M13 is used as an amplifying transistor to output the potential based on the aforementioned nodes. Transistor M14 is controlled by a signal supplied to wiring SE and is used as a selection transistor, which is used to read the output based on the potential of the aforementioned nodes using an external circuit connected to wiring OUT1.

[0447] The pixel circuit PIX2 shown in Figure 19C includes a light-emitting device EL, transistors M15, M16, and M17, and a capacitor C3. Here, an example of using a light-emitting diode as the light-emitting device EL is shown. In particular, an organic EL device is preferred as the light-emitting device EL.

[0448] The gate of transistor M15 is electrically connected to wiring VG, one of its source and drain is electrically connected to wiring VS, and the other of its source and drain is electrically connected to one electrode of capacitor C3 and the gate of transistor M16. One of the source and drain of transistor M16 is electrically connected to wiring V4, and the other of its source and drain is electrically connected to the anode of light-emitting device EL and one of the source and drain of transistor M17. The gate of transistor M17 is electrically connected to wiring MS, and the other of its source and drain is electrically connected to wiring OUT2. The cathode of light-emitting device EL is electrically connected to wiring V5.

[0449] Wiring V4 and wiring V5 are each supplied with a constant potential. The anode side and cathode side of the light-emitting device EL can be set to a high potential and a potential lower than the anode side, respectively. Transistor M15, controlled by a signal supplied to wiring VG, is used as a selection transistor to control the selection state of the pixel circuit PIX2. Furthermore, transistor M16 is used as a drive transistor to control the current flowing through the light-emitting device EL based on the potential supplied to its gate. When transistor M15 is in the on state, the potential supplied to wiring VS is supplied to the gate of transistor M16, and the brightness of the light-emitting device EL can be controlled based on this potential. Transistor M17, controlled by a signal supplied to wiring MS, outputs the potential between transistor M16 and the light-emitting device EL to the outside via wiring OUT2.

[0450] In the display panel of this embodiment, the light-emitting devices can also emit light in a pulsed manner to display images. By shortening the driving time of the light-emitting devices, the power consumption of the display panel can be reduced and heat generation suppressed. In particular, organic EL devices have excellent frequency characteristics, so they are preferred. For example, the frequency can be above 1kHz and below 100MHz.

[0451] Here, the transistors M11, M12, M13 and M14 included in the pixel circuit PIX1, and the transistors M15, M16 and M17 included in the pixel circuit PIX2 are preferably transistors whose semiconductor layer forming their channels comprises metal oxide (oxide semiconductor).

[0452] Using metal oxide transistors with wider band gaps and lower carrier densities than silicon allows for extremely low off-state currents. Consequently, due to their small off-state currents, the charge stored in the capacitor connected in series with the transistor can be maintained for extended periods. Therefore, transistors M11, M12, and M15 connected in series with capacitor C2 or C3 are preferably transistors containing oxide semiconductors. Furthermore, by using transistors that similarly utilize oxide semiconductors in other transistors, manufacturing costs can be reduced.

[0453] Furthermore, transistors M11 to M17 can also be transistors whose semiconductor forming their channels comprises silicon. In particular, it is preferable to use highly crystalline silicon such as monocrystalline or polycrystalline silicon, as this can achieve high field-efficiency mobility and higher operating speed.

[0454] Furthermore, one or more of transistors M11 to M17 may be transistors containing oxide semiconductors, while the other transistors may be transistors containing silicon.

[0455] In Figures 19B and 19C, an n-channel transistor is used as the transistor, but a p-channel transistor can also be used.

[0456] The transistors included in pixel circuit PIX1 and pixel circuit PIX2 are preferably arranged on the same substrate. More preferably, the transistors included in pixel circuit PIX1 and pixel circuit PIX2 are mixed and formed in one region and arranged periodically.

[0457] Furthermore, it is preferable to provide one or more layers, including one or both transistors and capacitors, at a location overlapping with the light-receiving device (PD) or the light-emitting device (EL). This reduces the effective area occupied by each pixel circuit, thereby enabling a high-definition light-receiving or display section.

[0458] As described above, the display device of this embodiment, by incorporating two light-receiving devices within a single pixel, can add two additional functions besides the display function, thereby achieving multi-functionality. For example, it can realize high-definition video recording and sensing functions such as touch sensors or air touch sensors. Furthermore, by combining pixels with two light-receiving devices with pixels having other structures, the functionality of the display device can be further enhanced. For example, pixels including light-emitting devices that emit infrared light or various sensor devices can be used.

[0459] This implementation method can be appropriately combined with other implementation methods.

[0460] Implementation Method 5 In this embodiment, a light-emitting device that can be used in a display device according to one embodiment of the present invention will be described.

[0461] <Examples of light-emitting device structures> As shown in Figure 20A, the light-emitting device includes an EL layer 786 between a pair of electrodes (lower electrode 772 and upper electrode 788). The EL layer 786 may be composed of multiple layers such as layer 4420, light-emitting layer 4411, and layer 4430. Layer 4420 may include, for example, a layer containing a substance with high electron injection capability (electron injection layer) and a layer containing a substance with high electron transport capability (electron transport layer). Light-emitting layer 4411 may, for example, contain a light-emitting compound. Layer 4430 may, for example, include a layer containing a substance with high hole injection capability (hole injection layer) and a layer containing a substance with high hole transport capability (hole transport layer).

[0462] The structure including layer 4420, light-emitting layer 4411 and layer 4430 disposed between a pair of electrodes can be used as a single light-emitting unit. In this specification, the structure of FIG20A is referred to as a single structure.

[0463] Figure 20B shows a modified example of the EL layer 786 included in the light-emitting device shown in Figure 20A. Specifically, the light-emitting device shown in Figure 20B includes layer 4430-1 on the lower electrode 772, layer 4430-2 on layer 4430-1, light-emitting layer 4411 on layer 4430-2, layer 4420-1 on light-emitting layer 4411, layer 4420-2 on layer 4420-1, and upper electrode 788 on layer 4420-2. For example, when the lower electrode 772 is used as the anode and the upper electrode 788 is used as the cathode, layer 4430-1 is used as the hole injection layer, layer 4430-2 is used as the hole transport layer, layer 4420-1 is used as the electron transport layer, and layer 4420-2 is used as the electron injection layer. Alternatively, when the lower electrode 772 is used as the cathode and the upper electrode 788 is used as the anode, layer 4430-1 is used as the electron injection layer, layer 4430-2 is used as the electron transport layer, layer 4420-1 is used as the hole transport layer, and layer 4420-2 is used as the hole injection layer. By employing the above layer structure, carriers can be efficiently injected into the light-emitting layer 4411, thereby improving the recombination efficiency of carriers within the light-emitting layer 4411.

[0464] Furthermore, as shown in Figures 20C and 20D, the structure in which multiple light-emitting layers (light-emitting layers 4411, 4412, and 4413) are disposed between layer 4420 and layer 4430 is also a variation of the single structure.

[0465] As shown in Figures 20E and 20F, the structure in which multiple light-emitting units (EL layers 786a and 786b) are connected in series with an intermediate layer (charge generation layer) 4440 is referred to as a series structure in this specification. While the structure shown in Figures 20E and 20F is referred to as a series structure in this specification, it is not limited to this; for example, a series structure may also be referred to as a stacked structure. By employing a series structure, a light-emitting device capable of emitting light with high brightness can be realized.

[0466] In Figure 20C, light-emitting layers 4411, 4412, and 4413 that emit light of the same color can also be used.

[0467] Alternatively, different luminescent materials can be used for luminescent layers 4411, 4412, and 4413. When the light emitted by each of luminescent layers 4411, 4412, and 4413 is in a complementary color relationship, white light emission can be obtained. Figure 20D shows an example of a color layer 785 used as a color filter. By allowing white light to pass through the color filter, light of the desired color can be obtained.

[0468] Alternatively, in Figure 20E, the same luminescent material can be used for both luminescent layers 4411 and 4412. Or, luminescent materials emitting different colors of light can be used for both luminescent layers 4411 and 4412. When the light emitted by luminescent layer 4411 and the light emitted by luminescent layer 4412 are complementary colors, white light emission can be obtained. Figure 20F shows an example where a color layer 785 is also provided.

[0469] Note that in Figures 20C, 20D, 20E and 20F, as shown in Figure 20B, layers 4420 and 4430 can also have a stacked structure consisting of two or more layers.

[0470] The structure in which light-emitting layers (blue (B), green (G) and red (R)) are formed separately for each light-emitting device is called an SBS (Side By Side) structure.

[0471] The color of light emitted by the light-emitting device can be red, green, blue, cyan, magenta, yellow, or white, depending on the material constituting the EL layer 786. Furthermore, when the light-emitting device has a microcavity structure, the color purity can be further improved.

[0472] White light-emitting devices preferably have a structure in which the light-emitting layer contains two or more light-emitting materials. To obtain white light emission, two or more light-emitting materials whose light emission is in a complementary color relationship can be selected. For example, by making the light emission color of the first light-emitting layer complementary to the light emission color of the second light-emitting layer, a light-emitting device that emits white light throughout the device can be obtained. Furthermore, the same applies to light-emitting devices that include three or more light-emitting layers.

[0473] The luminescent layer preferably comprises two or more luminescent materials, each exhibiting the spectral characteristics of R (red), G (green), B (blue), Y (yellow), and O (orange). Alternatively, it preferably comprises two or more luminescent materials, each exhibiting the spectral characteristics of R, G, and B.

[0474] Here, we illustrate a specific structural example of a light-emitting device.

[0475] A light-emitting device includes at least a light-emitting layer. In addition, as a layer other than the light-emitting layer, the light-emitting device may also include a layer containing a material with high hole injection capacity, a material with high hole transport capacity, a hole blocking material, a material with high electron transport capacity, an electron blocking material, a material with high electron injection capacity, or a bipolar material (a material with both high electron transport capacity and high hole transport capacity).

[0476] Light-emitting devices can use low-molecular-weight compounds or high-molecular-weight compounds, and may also include inorganic compounds. The layers constituting the light-emitting device can be formed by methods such as vapor deposition (including vacuum vapor deposition), transfer printing, printing, inkjet printing, and coating.

[0477] For example, in addition to the light-emitting layer, a light-emitting device may also include one or more of the following: a hole injection layer, a hole transport layer, a hole barrier layer, an electron barrier layer, an electron transport layer, and an electron injection layer.

[0478] The hole injection layer is a layer that injects holes from the anode into the hole transport layer and contains a material with high hole injection properties. Materials with high hole injection properties can include aromatic amine compounds, composite materials containing both hole transport materials and acceptor materials (electron acceptor materials), etc.

[0479] The hole transport layer is a layer that transports holes injected from the anode through the hole injection layer to the light-emitting layer. The hole transport layer contains a hole-transporting material. Preferably, the hole transporting material is a substance with a hole mobility of 1 × 10⁻⁶ cm² / Vs or higher. However, any substance other than those mentioned above can be used, as long as its hole transportability is higher than its electron transportability. Preferably, the hole transporting material is a π-electron-rich heteroaromatic compound (e.g., carbazole derivatives, thiophene derivatives, furan derivatives, etc.) or an aromatic amine (a compound containing an aromatic amine skeleton), which are materials with high hole transportability.

[0480] The electron transport layer is the layer that transports electrons injected from the cathode through the electron injection layer to the light-emitting layer. The electron transport layer contains an electron transport material. Preferably, the electron transport material is a substance with an electron mobility of 1 × 10⁻⁶ cm² / Vs or higher. However, any substance other than those mentioned above can be used, as long as its electron transport capability is higher than its hole transport capability. As electron transport materials, metal complexes with a quinoline skeleton, metal complexes with a benzoquinoline skeleton, metal complexes with an oxazole skeleton, metal complexes with a thiazole skeleton, etc., can be used. Materials with high electron transport capabilities, such as oxadiazole derivatives, triazole derivatives, imidazole derivatives, oxazole derivatives, thiazole derivatives, phenobarbital derivatives, quinoline derivatives with quinoline ligands, benzoquinoline derivatives, quinoline derivatives, dibenzoquinoline derivatives, pyridine derivatives, bipyridine derivatives, pyrimidine derivatives, nitrogen-containing heteroaromatic compounds, and other π-electron-deficient heteroaromatic compounds, can also be used.

[0481] The electron injection layer is a layer containing a material with high electron injection capability, through which electrons are injected from the cathode into the electron transport layer. Alkali metals, alkaline earth metals, or compounds containing these substances can be used as materials with high electron injection capability. Composite materials containing both electron transport materials and donor materials (electron donor materials) can also be used as materials with high electron injection capability.

[0482] As an electron injection layer, alkali metals, alkaline earth metals, or their compounds can be used, such as lithium, cesium, lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF₂), lithium 8-(hydroxyoxoline) (Liq), lithium 2-(2-pyridyl)phenol (LiPP), lithium 2-(2-pyridyl)-3-hydroxypyridine (LiPPy), lithium 4-phenyl-2-(2-pyridyl)phenol (LiPPP), lithium oxide (LiO₂x), cesium carbonate, etc.

[0483] Furthermore, materials with electron transport properties can also be used as the aforementioned electron injection layer. For example, compounds with non-shared electron pairs and electron-deficient heteroaromatic rings can be used in materials with electron transport properties. Specifically, compounds containing at least one of pyridine rings, diazine rings (pyrimidine rings, pyrazine rings, pyrazine rings), and triazine rings can be used.

[0484] For organic compounds with non-shared electron pairs, the lowest unoccupied molecular orbital (LUMO) is preferably above -3.6 eV and below -2.3 eV. Additionally, cyclic voltammetry (CV), photoelectron spectroscopy, optical absorption spectroscopy, and inverse photoelectron spectroscopy are generally used to estimate the highest occupied molecular orbital (HOMO) and LUMO levels of organic compounds.

[0485] For example, 4,7-diphenyl-1,10-phenanthroline (BPhen), 2,9-bis(naphthyl-2-yl)-4,7-diphenyl-1,10-phenanthroline (NBPhen), diquinoline[2,3-a:2',3'-c]phenazine (HATNA), and 2,4,6-tris[3'-(pyridin-3-yl)biphenyl-3-yl]-1,3,5-triazine (TmPPPyTz) can be used in organic compounds with non-shared electron pairs. Furthermore, compared to BPhen, NBPhen exhibits a higher glass transition temperature (Tg) and better heat resistance.

[0486] The luminescent layer is a layer containing a luminescent substance. The luminescent layer may contain one or more luminescent substances. Furthermore, substances exhibiting luminescent colors such as blue, purple, blue-violet, green, yellow-green, yellow, orange, and red are appropriately used as luminescent substances. Additionally, substances emitting near-infrared light may also be used as luminescent substances.

[0487] Examples of luminescent materials include fluorescent materials, phosphorescent materials, TADF materials, and quantum dot materials.

[0488] Examples of fluorescent materials include pyrene derivatives, anthracene derivatives, triphenylene derivatives, fumonisin derivatives, carbazole derivatives, dibenzothiophene derivatives, dibenzofuran derivatives, dibenzoquinoline derivatives, quinoline derivatives, pyridine derivatives, pyrimidine derivatives, phenanthrene derivatives, and naphthalene derivatives.

[0489] Examples of phosphorescent materials include organometallic complexes (especially iridium complexes) with 4H-triazole, 1H-triazole, imidazole, pyrimidine, pyrazine, and pyridine skeletons, organometallic complexes (especially iridium complexes) with phenylpyridine derivatives having electron-withdrawing groups as ligands, platinum complexes, and rare earth metal complexes.

[0490] In addition to the luminescent material (guest material), the luminescent layer may also contain one or more organic compounds (host material, auxiliary material, etc.). One or more organic compounds may be hole transport materials and electron transport materials, or both. Furthermore, bipolar materials or TADF materials may also be used as one or more organic compounds.

[0491] For example, the luminescent layer is preferably a combination of a phosphorescent material, a hole transport material that readily forms excited-state complexes, and an electron transport material. By employing such a structure, ExTET (Exciplex-Triplet Energy Transfer), which utilizes energy transfer from the excited-state complex to the luminescent material (phosphorescent material), can be efficiently obtained. By selecting a mixture of materials that forms excited-state complexes whose wavelengths overlap with the absorption band of the lowest energy side of the luminescent material, energy transfer can be facilitated, resulting in efficient luminescence. This structure enables the simultaneous achievement of high efficiency, low-voltage operation, and long lifetime in the luminescent device.

[0492] [Example 4 of a display device structure] Refer to Figures 21 and 22 to illustrate an example of the structure of a light-emitting device.

[0493] Figure 21A shows a cross-sectional schematic diagram of the display device 500. The display device 500 includes a light-emitting device 550R that emits red light, a light-emitting device 550G that emits green light, and a light-emitting device 550B that emits blue light. Note that in this embodiment, the description of the light-receiving device included in the display device is omitted.

[0494] The light-emitting device 550R has a structure in which two light-emitting units (light-emitting unit 512R_1 and light-emitting unit 512R_2) are stacked with an intermediate layer 531 between a pair of electrodes (electrode 501 and electrode 502). Similarly, the light-emitting device 550G includes light-emitting unit 512G_1 and light-emitting unit 512G_2, and the light-emitting device 550B includes light-emitting unit 512B_1 and light-emitting unit 512B_2.

[0495] Electrode 501 is used as a pixel electrode and is disposed in each light-emitting device. Electrode 502 is used as a common electrode and is disposed together in multiple light-emitting devices.

[0496] The light-emitting unit 512R_1 includes layers 521, 522, 523R, and 524. The light-emitting unit 512R_2 includes layers 522, 523R, and 524. Furthermore, the light-emitting device 550R includes a layer 525 between the light-emitting unit 512R_2 and the electrode 502. Note that layer 525 can also be considered as part of the light-emitting unit 512R_2.

[0497] Layer 521 may include, for example, a layer containing a substance with high hole injection capacity (hole injection layer). Layer 522 may include, for example, a layer containing a substance with high hole transport capacity (hole transport layer). Layer 524 may include, for example, a layer containing a substance with high electron transport capacity (electron transport layer). Layer 525 may include, for example, a layer containing a substance with high electron injection capacity (electron injection layer).

[0498] Alternatively, it may have the following structure: layer 521 includes an electron injection layer, layer 522 includes an electron transport layer, layer 524 includes a hole transport layer, and layer 525 includes a hole injection layer.

[0499] Note that layers 522, 523R, and 524 may have the same or different structures (materials, thicknesses, etc.) in light-emitting units 512R_1 and 512R_2.

[0500] In Figure 21A, layers 521 and 522 are shown respectively, but are not limited to these. For example, when layer 521 has the functions of both a hole injection layer and a hole transport layer, or when layer 521 has the functions of both an electron injection layer and an electron transport layer, layer 522 may be omitted.

[0501] The intermediate layer 531 has the function of injecting electrons into one of the light-emitting units 512R_1 and 512R_2 and injecting holes into the other when a voltage is applied between the electrodes 501 and 502. The intermediate layer 531 can also be called a charge generation layer.

[0502] As the intermediate layer 531, materials suitable for use in electron injection layers, such as lithium, can be appropriately used, for example. Furthermore, materials suitable for use in hole injection layers can be appropriately used, for example, as the intermediate layer. Additionally, the intermediate layer can be a layer comprising a hole transport material and an acceptor material (electron receiver material). Furthermore, the intermediate layer can be a layer comprising an electron transport material and a donor material. By forming an intermediate layer including such a layer, the rise in driving voltage during the stacking of light-emitting units can be suppressed.

[0503] Note that the light-emitting layer 523R of the light-emitting device 550R contains a light-emitting material that emits red light, the light-emitting layer 523G of the light-emitting device 550G contains a light-emitting material that emits green light, and the light-emitting layer 523B of the light-emitting device 550B contains a light-emitting material that emits blue light. Note that the light-emitting devices 550G and 550B respectively have a structure in which the light-emitting layer 523R of the light-emitting device 550R is replaced by light-emitting layers 523G and 523B, respectively; other structures are the same as those of the light-emitting device 550R.

[0504] Note that layers 521, 522, 524, and 525 can have the same or different structures (materials, thicknesses, etc.) in light-emitting devices of different colors.

[0505] As with light-emitting devices 550R, 550G, and 550B, a structure in which multiple light-emitting units are connected in series with an intermediate layer 531 is referred to as a series structure in this specification. On the other hand, a structure with one light-emitting unit between a pair of electrodes is called a single structure. Note that while this specification refers to it as a series structure, it is not limited to this; for example, a series structure may also be called a stacked structure. Note that by employing a series structure, a light-emitting device capable of emitting high brightness can be realized. Furthermore, compared to a single structure, a series structure can reduce the current required to achieve the same brightness, thus improving reliability.

[0506] As with LEDs 550R, 550G, and 550B, a structure in which a light-emitting layer is formed separately for each LED is sometimes called an SBS (Side By Side) structure. Because the SBS structure allows for optimization of materials and structure for each LED, the flexibility in material and structural selection is increased, making it easier to achieve improvements in brightness and reliability.

[0507] Display device 500 can be described as having both a series structure and an SBS structure. Therefore, it possesses the advantages of both. Note that, as shown in FIG21A, display device 500, due to its structure forming two levels of light-emitting units in series, can also be referred to as a two-level series structure. Furthermore, in the two-level series structure shown in FIG21A, a second light-emitting unit including a red light-emitting layer is stacked on top of a first light-emitting unit including a red light-emitting layer. Similarly, in the two-level series structure shown in FIG21A, a second light-emitting unit including a green light-emitting layer is stacked on top of a first light-emitting unit including a green light-emitting layer, and a second light-emitting unit including a blue light-emitting layer is stacked on top of a first light-emitting unit including a blue light-emitting layer.

[0508] In Figure 21A, light-emitting unit 512R_1, intermediate layer 531, light-emitting unit 512R_2, and layer 525 can be formed as an island-shaped layer. Alternatively, light-emitting unit 512G_1, intermediate layer 531, light-emitting unit 512G_2, and layer 525 can be formed as an island-shaped layer. Light-emitting unit 512B_1, intermediate layer 531, light-emitting unit 512B_2, and layer 525 can also be formed as an island-shaped layer.

[0509] Figure 21B is a variation of the display device 500 shown in Figure 21A. The display device 500 shown in Figure 21B is an example in which a common layer 525 is provided between each light-emitting device, similar to the electrode 502. In this case, the layer 525 can be referred to as a common layer. In this way, by providing more than one common layer among multiple light-emitting devices, the manufacturing process can be simplified, thereby reducing manufacturing costs.

[0510] In Figure 21B, light-emitting unit 512R_1, intermediate layer 531, and light-emitting unit 512R_2 can be formed as an island-shaped layer. Furthermore, light-emitting unit 512G_1, intermediate layer 531, and light-emitting unit 512G_2 can be formed as an island-shaped layer. Light-emitting unit 512B_1, intermediate layer 531, and light-emitting unit 512B_2 can also be formed as an island-shaped layer.

[0511] The display device 500 shown in Figure 22A is an example of three stacked light-emitting units. In Figure 22A, in the light-emitting device 550R, a light-emitting unit 512R_3 is stacked on top of the light-emitting unit 512R_2, separated by an intermediate layer 531. The light-emitting unit 512R_3 includes layer 522, light-emitting layer 523R, and layer 524, etc. The light-emitting unit 512R_3 can use the same structure as the light-emitting unit 512R_2. Furthermore, the light-emitting unit 512G_3 included in the light-emitting device 550G and the light-emitting unit 512B_3 included in the light-emitting device 550B are also the same.

[0512] Figure 22B shows an example of stacked n light-emitting units (n is an integer greater than 2).

[0513] Thus, by increasing the number of light-emitting units stacked together, the brightness obtained from the light-emitting device with the same current can be increased accordingly. Furthermore, by increasing the number of light-emitting units stacked together, the current required to obtain the same brightness can be reduced, and the power consumption of the light-emitting device can be reduced accordingly.

[0514] Note that there are no particular restrictions on the light-emitting material of the light-emitting layer in the display device 500. For example, in the display device 500 shown in FIG. 21A, it may have the following structure: the light-emitting layer 523R included in the light-emitting unit 512R_1 has a phosphorescent material, the light-emitting layer 523R included in the light-emitting unit 512R_2 has a phosphorescent material, the light-emitting layer 523G included in the light-emitting unit 512G_1 has a fluorescent material, the light-emitting layer 523G included in the light-emitting unit 512G_2 has a fluorescent material, the light-emitting layer 523B included in the light-emitting unit 512B_1 has a fluorescent material, and the light-emitting layer 523B included in the light-emitting unit 512B_2 has a fluorescent material.

[0515] Alternatively, the display device 500 shown in FIG21A may have the following structure: the light-emitting layer 523R included in the light-emitting unit 512R_1 has a phosphorescent material, the light-emitting layer 523R included in the light-emitting unit 512R_2 has a phosphorescent material, the light-emitting layer 523G included in the light-emitting unit 512G_1 has a phosphorescent material, the light-emitting layer 523G included in the light-emitting unit 512G_2 has a phosphorescent material, the light-emitting layer 523B included in the light-emitting unit 512B_1 has a fluorescent material, and the light-emitting layer 523B included in the light-emitting unit 512B_2 has a fluorescent material.

[0516] Note that the display device of one embodiment of the present invention may also have a structure in which all light-emitting layers contain fluorescent materials or a structure in which all light-emitting layers contain phosphorescent materials.

[0517] Alternatively, in the display device 500 shown in FIG21A, a structure may be adopted in which the light-emitting layer 523R included in the light-emitting unit 512R_1 uses a phosphorescent material and the light-emitting layer 523R included in the light-emitting unit 512R_2 uses a fluorescent material, or a structure in which the light-emitting layer 523R included in the light-emitting unit 512R_1 uses a fluorescent material and the light-emitting layer 523R included in the light-emitting unit 512R_2 uses a phosphorescent material. That is to say, the light-emitting materials of the first-level light-emitting layer and the second-level light-emitting layer may be different. Note that although the content described here concerns the light-emitting units 512R_1 and 512R_2, the light-emitting units 512G_1 and 512G_2, as well as the light-emitting units 512B_1 and 512B_2, may also adopt the same structure.

[0518] This implementation method can be appropriately combined with other implementation methods.

[0519] Implementation Method 6 In this embodiment, a metal oxide (referred to as an oxide semiconductor) that can be used with the OS transistor described in the above embodiments is explained.

[0520] The metal oxide preferably contains at least indium or zinc. It is particularly preferred to contain both indium and zinc. Furthermore, it is also preferred to contain aluminum, gallium, yttrium, or tin. Additionally, it may contain one or more elements selected from boron, silicon, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, magnesium, and cobalt.

[0521] In addition, metal oxides can be formed by sputtering, chemical vapor deposition (CVD) such as metal organic chemical vapor deposition (MOCVD), or atomic layer deposition (ALD).

[0522] <Classification of Crystal Structures> Examples of crystalline structures for oxide semiconductors include amorphous (including completely amorphous), CAAC (c-axis-aligned crystalline), nc (nanocrystalline), CAC (cloud-aligned composite), single crystal, and polycrystalline.

[0523] The crystal structure of a film or substrate can be evaluated using X-ray diffraction (XRD) spectroscopy. For example, the XRD spectrum obtained can be measured using GIXD (Grazing-Incidence XRD). Furthermore, the GIXD method is also known as the thin film method or the Seemann-Bohlin method.

[0524] For example, the peak shapes of the XRD patterns on a quartz glass substrate are generally symmetrical. On the other hand, the peak shapes of the XRD patterns on an IGZO film with a crystalline structure are not symmetrical. Asymmetrical peak shapes in the XRD patterns indicate the presence of crystals in the film or substrate. In other words, unless the XRD peak shapes are symmetrical, it cannot be said that the film or substrate is in an amorphous state.

[0525] Furthermore, the crystal structure of the film or substrate can be evaluated using diffraction patterns observed by nano-beam electron diffraction (NBED). For example, observing a halo pattern in the diffraction pattern of a quartz glass substrate confirms that the quartz glass is in an amorphous state. However, a spot-like pattern without a halo is observed in the diffraction pattern of an IGZO film formed at room temperature. Therefore, it can be inferred that the IGZO film formed at room temperature is in an intermediate state, neither crystalline nor amorphous, and it cannot be concluded that the IGZO film is amorphous.

[0526] <<Structure of Oxide Semiconductors>> Furthermore, when focusing on the structure of oxide semiconductors, the classification of oxide semiconductors sometimes differs from the classifications described above. For example, oxide semiconductors can be classified into single-crystal oxide semiconductors and other non-single-crystal oxide semiconductors. Examples of non-single-crystal oxide semiconductors include, for instance, CAAC-OS and nc-OS, as mentioned above. In addition, non-single-crystal oxide semiconductors include polycrystalline oxide semiconductors, a-like OS (amorphous-like oxide semiconductor), and amorphous oxide semiconductors, etc.

[0527] Here, we will explain the details of CAAC-OS, nc-OS, and a-like OS.

[0528] [CAAC-OS] CAAC-OS is an oxide semiconductor comprising multiple crystalline regions, whose c-axis is aligned in a specific direction. This specific direction refers to the thickness direction of the CAAC-OS film, the normal direction of the formed surface of the CAAC-OS film, or the normal direction of the surface of the CAAC-OS film. Furthermore, a crystalline region is a region exhibiting a periodic atomic arrangement. Note that when atomic arrangement is considered as lattice arrangement, a crystalline region is also a region with a consistent lattice arrangement. Moreover, CAAC-OS has a region where multiple crystalline regions are connected in the ab-plane direction, and sometimes this region exhibits distortion. Distortion refers to the portion of the lattice arrangement direction that changes between lattice-aligned regions and other lattice-aligned regions within the region where multiple crystalline regions are connected. In other words, CAAC-OS refers to an oxide semiconductor with c-axis alignment but no obvious alignment in the ab-plane direction.

[0529] Furthermore, each of the aforementioned crystalline regions is composed of one or more microcrystals (crystals with a maximum diameter of less than 10 nm). When a crystalline region is composed of a single microcrystal, the maximum diameter of that region is less than 10 nm. Conversely, when a crystalline region is composed of multiple microcrystals, the size of that region can sometimes be around tens of nm.

[0530] Furthermore, in In-M-Zn oxides (where element M is selected from one or more of aluminum, gallium, yttrium, tin, and titanium), CAAC-OS tends to have a layered crystal structure (also called a layered structure) consisting of layers containing indium (In) and oxygen (hereinafter, In layer) and layers containing element M, zinc (Zn), and oxygen (hereinafter, (M,Zn) layer). In addition, indium and element M can substitute for each other. Therefore, sometimes the (M,Zn) layer contains indium. Furthermore, sometimes the In layer contains element M. Note that sometimes the In layer contains Zn. This layered structure is observed, for example, as a lattice image in high-resolution TEM (Transmission Electron Microscope) images.

[0531] For example, when performing structural analysis on CAAC-OS films using an XRD apparatus, peaks representing c-axis alignment are detected at or near 2θ = 31˚ in out-of-plane XRD measurements using θ / 2θ scanning. Note that the position (2θ value) of the peaks representing c-axis alignment can vary depending on the type and composition of the metallic elements constituting CAAC-OS.

[0532] Furthermore, for example, multiple bright spots (spots) were observed in the electron diffraction pattern of the CAAC-OS film. Additionally, when the spot (also known as the direct spot) of the incident electron beam passing through the sample is taken as the center of symmetry, one spot and other spots were observed at point-symmetrical positions.

[0533] When observing the crystalline region from the aforementioned specific directions, although the lattice arrangement in this region is primarily hexagonal, the unit lattice is not limited to a regular hexagon; there are also cases of non-regular hexagonal lattice arrangements. Furthermore, pentagonal, heptagonal, and other lattice arrangements are sometimes observed in the aforementioned distortions. Moreover, no clear grain boundary is observed near the distortions in CAAC-OS. In other words, the lattice arrangement distortion inhibits grain boundary formation. This may be because CAAC-OS can accommodate distortions due to the low density of oxygen atoms along the ab-plane direction and the change in interatomic bonding distance caused by the substitution of metal atoms.

[0534] Furthermore, crystalline structures with clearly defined grain boundaries are referred to as polycrystalline. Grain boundaries act as recombination centers, trapping carriers and potentially leading to a decrease in the transistor's on-state current and field-effect mobility. Therefore, CAAC-OS, which lacks clearly defined grain boundaries, is one of the crystalline oxides that provides an excellent crystalline structure for the semiconductor layer of the transistor. Note that a Zn-containing structure is preferred for constructing CAAC-OS. For example, In-Zn oxides and In-Ga-Zn oxides are preferred because they can further suppress grain boundary formation compared to In oxides.

[0535] CAAC-OS is an oxide semiconductor with high crystallinity and no clearly defined grain boundaries. Therefore, it can be said that in CAAC-OS, the reduction in electron mobility due to grain boundaries is less likely to occur. Furthermore, the crystallinity of oxide semiconductors can sometimes decrease due to the incorporation of impurities and the formation of defects; therefore, CAAC-OS can be considered an oxide semiconductor with few impurities and defects (such as oxygen vacancies). Thus, oxide semiconductors containing CAAC-OS exhibit stable physical properties. Consequently, oxide semiconductors containing CAAC-OS possess high heat resistance and high reliability. Moreover, CAAC-OS is also stable against high temperatures (so-called thermal budget) in the manufacturing process. Therefore, by using CAAC-OS in OS transistors, process flexibility can be increased.

[0536] [nc-OS] In nc-OS, the atomic arrangement in tiny regions (e.g., regions larger than 1 nm and smaller than 10 nm, particularly regions larger than 1 nm and smaller than 3 nm) exhibits periodicity. In other words, nc-OS possesses tiny crystallinity. Furthermore, for example, these tiny crystallinity sizes are between 1 nm and 10 nm, particularly between 1 nm and 3 nm; these tiny crystallinity sizes are referred to as nanocrystals. Moreover, no regularity in crystallinity orientation is observed between different nanocrystals in nc-OS. Therefore, no alignment is observed in the overall film. Thus, sometimes nc-OS is indistinguishable from a-like OS or amorphous oxide semiconductors in certain analytical methods. For example, when performing structural analysis on nc-OS films using an XRD apparatus, no peaks indicating crystallinity are detected in out-of-plane XRD measurements using θ / 2θ scanning. Furthermore, when performing electron diffraction (also known as selected area electron diffraction) on nc-OS films using an electron beam with a beam diameter larger than that of nanocrystals (e.g., larger than 50 nm), a diffraction pattern resembling a halo pattern is observed. On the other hand, when electron diffraction (also known as nano-beam electron diffraction) is performed on nc-OS films using an electron beam whose beam diameter is close to or smaller than the size of nanocrystals (e.g., more than 1 nm and less than 30 nm), sometimes an electron diffraction pattern of multiple spots is observed in an annular region centered on a direct spot.

[0537] [a-like OS] a-like OS is an oxide semiconductor with a structure intermediate between nc-OS and amorphous oxide semiconductors. a-like OS contains voids or low-density regions. That is, a-like OS has lower crystallinity than nc-OS and CAAC-OS. Furthermore, the hydrogen concentration in a-like OS films is higher than that in nc-OS and CAAC-OS films.

[0538] <<The Structure of Oxide Semiconductors>> Next, the details of the aforementioned CAC-OS will be explained. Furthermore, CAC-OS is related to material composition.

[0539] [CAC-OS] CAC-OS, for example, refers to a composition in which elements are non-uniformly distributed within a metal oxide, wherein the size of the material containing the non-uniformly distributed elements is 0.5 nm or more and 10 nm or less, preferably 1 nm or more and 3 nm or approximately. Note that, below, the state in which one or more metal elements are non-uniformly distributed within a metal oxide and the regions containing those metal elements are mixed is also referred to as mosaic or patch-like, wherein the size of the region is 0.5 nm or more and 10 nm or less, preferably 1 nm or more and 3 nm or approximately.

[0540] Furthermore, CAC-OS refers to a structure in which the material is divided into a first region and a second region, forming a mosaic-like structure, with the first region distributed throughout the film (hereinafter also referred to as cloud-like). In other words, CAC-OS refers to a composite metal oxide having a structure that combines the first and second regions.

[0541] Here, the atomic ratios of In, Ga, and Zn relative to the metal elements constituting the CAC-OS in In-Ga-Zn oxide are denoted as [In], [Ga], and [Zn]. For example, in the CAC-OS of In-Ga-Zn oxide, a first region is a region where [In] is greater than [In] in the composition of the CAC-OS film. Furthermore, a second region is a region where [Ga] is greater than [Ga] in the composition of the CAC-OS film. Alternatively, for example, a first region is a region where [In] is greater than [In] in the second region and [Ga] is less than [Ga] in the second region. Furthermore, a second region is a region where [Ga] is greater than [Ga] in the first region and [In] is less than [In] in the first region.

[0542] Specifically, the first region mentioned above is a region whose main component is indium oxide or indium zinc oxide. Furthermore, the second region mentioned above is a region whose main component is gallium oxide or gallium zinc oxide. In other words, the first region can be referred to as a region whose main component is In. Furthermore, the second region can be referred to as a region whose main component is Ga.

[0543] Note that sometimes the clear boundaries between the first region and the second region mentioned above are not observable.

[0544] Furthermore, CAC-OS in In-Ga-Zn oxides refers to a structure in which regions dominated by Ga and regions dominated by In are irregularly arranged in a mosaic pattern within a material containing In, Ga, Zn, and O. Therefore, it can be inferred that CAC-OS has a structure with uneven distribution of metallic elements.

[0545] CAC-OS can be formed, for example, by sputtering without heating the substrate. When forming CAC-OS by sputtering, the deposition gas can be any one or more selected from inert gases (typically argon), oxygen gases, and nitrogen gases. Furthermore, the lower the oxygen flow rate in the total flow rate of the deposition gas during deposition, the better; for example, it is preferable that the oxygen flow rate in the total flow rate of the deposition gas during deposition is 0% or more and less than 30%, more preferably 0% or more and less than 10%.

[0546] For example, in CAC-OS of In-Ga-Zn oxide, based on the EDX surface analysis (mapping) image obtained by Energy Dispersive X-ray spectroscopy (EDX), a structure with an unevenly distributed and mixed structure of regions with In as the main component (first region) and regions with Ga as the main component (second region) can be identified.

[0547] Here, the first region has higher conductivity than the second region. That is, when carriers flow through the first region, it exhibits the conductivity of a metal oxide. Therefore, when the first region is distributed in a cloud-like manner within the metal oxide, a high field mobility (μ) can be achieved.

[0548] On the other hand, the second region is a region with higher insulation than the first region. That is, when the second region is distributed in a metal oxide, leakage current can be suppressed.

[0549] When CAC-OS is used in transistors, the complementary effect of conductivity arising from the first region and insulation arising from the second region enables CAC-OS to possess switching functionality (the function of controlling on / off). In other words, a portion of the CAC-OS material exhibits conductivity while another portion exhibits insulation, resulting in a semiconductor function within the overall material. By separating the conductivity and insulation functions, each function can be maximized. Therefore, by using CAC-OS in transistors, large on-state current (Ion), high field-efficiency mobility (μ), and excellent switching performance can be achieved.

[0550] Furthermore, transistors using CAC-OS exhibit high reliability. Therefore, CAC-OS is best suited for various semiconductor devices, such as display devices.

[0551] Oxide semiconductors possess various structures and properties. In one embodiment of the present invention, the oxide semiconductor may also include two or more of the following: amorphous oxide semiconductor, polycrystalline oxide semiconductor, a-like OS, CAC-OS, nc-OS, and CAAC-OS.

[0552] <Transistors with oxide semiconductor properties> Next, the use of the aforementioned oxide semiconductor in transistors will be explained.

[0553] By using the aforementioned oxide semiconductors in transistors, transistors with high field-effect mobility can be realized. Furthermore, transistors with high reliability can be achieved.

[0554] It is preferable to use oxide semiconductors with low carrier concentrations in transistors. For example, the carrier concentration in the oxide semiconductor is 1×10¹⁷ cm⁻³ or less, preferably 1×10¹⁵ cm⁻³ or less, more preferably 1×10¹³ cm⁻³ or less, further preferably 1×10¹¹ cm⁻³ or less, and even more preferably less than 1×10¹⁰ cm⁻³ and greater than 1×10⁻⁹ cm⁻³. When the purpose is to reduce the carrier concentration of the oxide semiconductor film, the impurity concentration in the oxide semiconductor film can be reduced to reduce the defect state density. In this specification, the state of low impurity concentration and low defect state density is referred to as high purity nature or substantially high purity nature. Furthermore, oxide semiconductors with low carrier concentrations are sometimes referred to as high purity nature or substantially high purity nature oxide semiconductors.

[0555] Because high-purity or essentially high-purity oxide semiconductor films have a low defect state density, they may also have a low trap state density.

[0556] Furthermore, the charge trapped in the trap state of an oxide semiconductor takes a relatively long time to dissipate, sometimes acting like a fixed charge. Therefore, the electrical properties of transistors forming channel formation regions in oxide semiconductors with high trap state density are sometimes unstable.

[0557] Therefore, reducing the impurity concentration in the oxide semiconductor is effective in stabilizing the electrical properties of the transistor. To further reduce the impurity concentration in the oxide semiconductor, it is preferable to also reduce the impurity concentration in the adjacent film. Examples of impurities include hydrogen, nitrogen, alkali metals, alkaline earth metals, iron, nickel, and silicon.

[0558] <Impurities> Here, we will explain the effects of various impurities in oxide semiconductors.

[0559] When an oxide semiconductor contains silicon or carbon, one of the elements in Group 14, defect states are formed in the oxide semiconductor. Therefore, the concentration of silicon or carbon in the oxide semiconductor and near the interface with the oxide semiconductor (the concentration measured by secondary ion mass spectrometry) is set to 2 × 10¹⁸ atoms / cm³ or less, preferably 2 × 10¹⁷ atoms / cm³ or less.

[0560] Furthermore, when oxide semiconductors contain alkali metals or alkaline earth metals, defect states can sometimes be formed, thus creating carriers. Therefore, transistors using oxide semiconductors containing alkali metals or alkaline earth metals tend to have always-on characteristics. Therefore, the concentration of alkali metals or alkaline earth metals in the oxide semiconductor, as measured by SIMS, should be 1 × 10¹⁸ atoms / cm³ or less, preferably 2 × 10¹⁶ atoms / cm³ or less.

[0561] When oxide semiconductors contain nitrogen, electrons are readily generated as carriers, increasing the carrier concentration and resulting in n-type polarization. Consequently, transistors using nitrogen-containing oxide semiconductors tend to exhibit always-on characteristics. Alternatively, when nitrogen is included in the oxide semiconductor, trapped states can sometimes form. As a result, the electrical properties of the transistor can sometimes be unstable. Therefore, the nitrogen concentration in the oxide semiconductor, measured using SIMS, is set to be below 5 × 10¹⁹ atoms / cm³, preferably below 5 × 10¹⁸ atoms / cm³, more preferably below 1 × 10¹⁸ atoms / cm³, and even more preferably below 5 × 10¹⁷ atoms / cm³.

[0562] Hydrogen contained in oxide semiconductors reacts with oxygen bonded to metal atoms to form water, thus sometimes creating oxygen vacancies. When hydrogen enters these oxygen vacancies, electrons are sometimes generated as carriers. Furthermore, sometimes a portion of the hydrogen bonds with oxygen bonded to metal atoms, generating electrons as carriers. Therefore, transistors using oxide semiconductors containing hydrogen tend to have always-on characteristics. Thus, it is preferable to minimize the amount of hydrogen in the oxide semiconductor. Specifically, in the oxide semiconductor, the hydrogen concentration measured using SIMS is set to be less than 1 × 10²⁰ atoms / cm³, preferably less than 1 × 10¹⁹ atoms / cm³, more preferably less than 5 × 10¹⁸ atoms / cm³, and even more preferably less than 1 × 10¹⁸ atoms / cm³.

[0563] By using oxide semiconductors with sufficiently reduced impurities in the channel formation region of a transistor, the transistor can be made to have stable electrical characteristics.

[0564] At least a portion of this embodiment can be implemented in combination with other embodiments described in this specification.

[0565] Implementation Method 7 In this embodiment, Figures 23 to 26 are used to illustrate an electronic device according to one embodiment of the present invention.

[0566] The electronic device of this embodiment includes a display device according to one embodiment of the present invention. The display device according to one embodiment of the present invention is easily made high-definition, high-resolution, and large-scale. Therefore, the display device according to one embodiment of the present invention can be used in the display section of various electronic devices.

[0567] Furthermore, the display device according to one embodiment of the present invention can be manufactured at low cost, thereby reducing the manufacturing cost of electronic devices.

[0568] As electronic devices, in addition to electronic devices with large screens such as televisions, desktop or laptop personal computers, monitors for computers, digital signage, and large game consoles such as pinball machines, other examples include digital cameras, digital camcorders, digital photo frames, mobile phones, portable game consoles, portable information terminals, and audio playback devices.

[0569] In particular, because the display device of one embodiment of the present invention can improve clarity, it can be appropriately used in electronic devices that include a small display section. Examples of such electronic devices include, for example, information terminal devices (wearable devices) such as watch-type and bracelet-type devices, VR devices such as head-mounted displays, and AR devices such as glasses-type displays. Furthermore, SR devices and MR devices can also be cited as wearable devices.

[0570] A display device according to one embodiment of the present invention preferably has extremely high resolution, such as HD (1280×720 pixels), FHD (1920×1080 pixels), WQHD (2560×1440 pixels), WQXGA (2560×1600 pixels), 4K2K (3840×2160 pixels), 8K4K (7680×4320 pixels), etc. Particularly preferred is 4K2K, 8K4K, or higher resolution. Furthermore, the pixel density (clarity) in the display device according to one embodiment of the present invention is preferably 300 ppi or higher, more preferably 500 ppi or higher, further preferably 1000 ppi or higher, even more preferably 2000 ppi or higher, still more preferably 3000 ppi or higher, still more preferably 5000 ppi or higher, and still more preferably 7000 ppi or higher. By using the aforementioned high-resolution or high-definition display devices, the sense of realism and depth can be further enhanced in personal electronic devices such as portable or home-use devices.

[0571] The electronic device of this embodiment can be assembled along the curved surfaces of the inner or outer walls of a house or high-rise building, or the interior or exterior decoration of a car.

[0572] The electronic device in this embodiment may also include an antenna. By receiving signals through the antenna, images and information can be displayed on the display unit. Furthermore, when the electronic device includes both an antenna and a secondary battery, contactless power transmission can be achieved using the antenna.

[0573] The electronic device in this embodiment may also include a sensor (which has the function of measuring factors such as force, displacement, position, velocity, acceleration, angular velocity, rotational speed, distance, light, liquid, magnetism, temperature, chemical substance, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, tilt, vibration, odor, or infrared radiation).

[0574] The electronic device of this embodiment can have various functions. For example, it can have the following functions: displaying various information (still images, moving images, text images, etc.) on the display unit; touch panel function; displaying calendar, date or time, etc.; executing various software (programs); performing wireless communication function; reading programs or data stored in the storage medium; etc.

[0575] The electronic device 6500 shown in Figure 23A is a portable information terminal device that can be used as a smartphone.

[0576] The electronic device 6500 includes a housing 6501, a display unit 6502, a power button 6503, a button 6504, a speaker 6505, a microphone 6506, a camera 6507, and a light source 6508. The display unit 6502 has a touch panel function.

[0577] The display unit 6502 may use a display device according to one embodiment of the present invention.

[0578] Figure 23B is a cross-sectional view of one end of the microphone 6506, including the housing 6501.

[0579] A light-transmitting protective member 6510 is provided on one side of the display surface of the housing 6501. The space surrounded by the housing 6501 and the protective member 6510 contains a display panel 6511, an optical member 6512, a touch sensor panel 6513, a printed circuit board 6517, a battery 6518, etc.

[0580] The display panel 6511, optical component 6512 and touch sensor panel 6513 are fixed to the protective component 6510 using an adhesive layer (not shown).

[0581] In the area outside the display unit 6502, a portion of the display panel 6511 is folded back, and this folded portion is connected to an FPC 6515. An IC 6516 is mounted on the FPC 6515. The FPC 6515 is connected to terminals disposed on a printed circuit board 6517.

[0582] The display panel 6511 can use a flexible display (a flexible display device) according to one embodiment of the present invention. This allows for the realization of an extremely lightweight electronic device. Furthermore, since the display panel 6511 is extremely thin, a large-capacity battery 6518 can be installed while minimizing the thickness of the electronic device. Additionally, by folding a portion of the display panel 6511 to provide a connection portion with the FPC 6515 on the back of the pixel portion, a narrow-bezel electronic device can be realized.

[0583] Figure 24A shows an example of a television set. In the television set 7100, a display unit 7000 is assembled in a housing 7101. The structure in which the housing 7101 is supported by a bracket 7103 is shown here.

[0584] A display device according to an embodiment of the present invention can be applied to the display unit 7000.

[0585] The television 7100 shown in FIG. 24A can be operated using the operation switch provided in the housing 7101 and the separately provided remote control 7111. Alternatively, a touch sensor can be provided in the display unit 7000, allowing operation of the television 7100 by touching the display unit 7000 with a finger or similar object. Furthermore, the remote control 7111 can also have a display unit that displays information output from the remote control 7111. Using the operation keys or touch panel provided in the remote control 7111, channel and volume can be adjusted, and the images displayed on the display unit 7000 can be manipulated.

[0586] In addition, the 7100 television set includes a receiver and a modem. The receiver can be used to receive general television broadcasts. Furthermore, the modem connects to a wired or wireless communication network, enabling one-way (from sender to receiver) or two-way (between sender and receiver, or between receivers, etc.) information communication.

[0587] Figure 24B shows an example of a laptop computer. The laptop computer 7200 includes a casing 7211, a keyboard 7212, a pointing device 7213, an external connection port 7214, etc. A display unit 7000 is assembled in the casing 7211.

[0588] A display device according to an embodiment of the present invention can be applied to the display unit 7000.

[0589] Figures 24C and 24D show an example of a digital signage.

[0590] The digital signage 7300 shown in Figure 24C includes a housing 7301, a display unit 7000, and a speaker 7303. It may also include LEDs, operation keys (including a power switch or operation switch), connection terminals, various sensors, a microphone, etc.

[0591] Figure 24D shows a digital signage 7400 mounted on a cylindrical column 7401. The digital signage 7400 includes a display section 7000 disposed along the curved surface of the column 7401.

[0592] In Figures 24C and 24D, a display device including a transistor according to an embodiment of the present invention can be applied to the display unit 7000.

[0593] The larger the display unit (7000), the more information it can provide at once. A larger display unit (7000) is also more likely to attract attention, which can improve the effectiveness of advertising.

[0594] By using a touch panel for the display unit 7000, not only can static or dynamic images be displayed on the display unit 7000, but users can also operate it intuitively, which is superior. In addition, when used to provide information such as route information or traffic information, the intuitive operation can improve ease of use.

[0595] As shown in Figures 24C and 24D, the digital signage 7300 or 7400 is preferably able to wirelessly communicate with a user's smartphone or other information terminal device 7311 or 7411. For example, advertising information displayed on the display unit 7000 can be displayed on the screen of the information terminal device 7311 or 7411. Furthermore, the display on the display unit 7000 can be switched by operating the information terminal device 7311 or 7411.

[0596] Furthermore, the game can be executed on the digital signage 7300 or 7400 using the screen of information terminal device 7311 or 7411 as the operating unit (controller). Thus, multiple users can participate in the game simultaneously and enjoy the experience.

[0597] Figure 25A is an external view of the camera 8000 with the viewfinder 8100 installed.

[0598] The camera 8000 includes a housing 8001, a display unit 8002, operation buttons 8003, a shutter button 8004, etc. Furthermore, the camera 8000 is equipped with a detachable lens 8006. In the camera 8000, the lens 8006 and the housing can also be formed as a single unit.

[0599] The camera 8000 can take pictures by pressing the shutter button 8004 or touching the display 8002, which is used as a touch panel.

[0600] The housing 8001 includes an insert with electrodes, which can be connected to the viewfinder 8100 and to a flash unit, etc.

[0601] The viewfinder 8100 includes a housing 8101, a display unit 8102, and buttons 8103, etc.

[0602] The housing 8101 is mounted to the camera 8000 via an inserter that fits into the camera 8000. The viewfinder 8100 can display images received from the camera 8000 on the display unit 8102.

[0603] Button 8103 is used as a power button, etc.

[0604] The display device according to one embodiment of the present invention can be used in the display unit 8002 of a camera 8000 and the display unit 8102 of a viewfinder 8100. Alternatively, a viewfinder may be built into the camera 8000.

[0605] Figure 25B is an external view of the 8200 head-mounted display.

[0606] The head-mounted display 8200 includes a mounting section 8201, a lens 8202, a main body 8203, a display section 8204, and a cable 8205. Furthermore, a battery 8206 is built into the mounting section 8201.

[0607] Power is supplied from battery 8206 to main body 8203 via cable 8205. Main body 8203 is equipped with a wireless receiver and can display received image information on display unit 8204. In addition, main body 8203 has a camera, which can be used as an input method to utilize information from the user's eye movements or eyelid movements.

[0608] Furthermore, multiple electrodes can be provided at the user-contacted location of the mounting unit 8201 to detect the current flowing through the electrodes in response to the user's eye movements, thereby enabling the recognition of the user's gaze. Additionally, it can also monitor the user's pulse based on the current flowing through the electrodes. The mounting unit 8201 can incorporate various sensors such as temperature sensors, pressure sensors, and acceleration sensors, and may also have functions such as displaying the user's biometric information on the display unit 8204 or changing the image displayed on the display unit 8204 in sync with the user's head movements.

[0609] The display device according to one embodiment of the present invention can be used in the display unit 8204.

[0610] Figures 25C to 25E are external views of the head-mounted display 8300. The head-mounted display 8300 includes a housing 8301, a display unit 8302, a strap-shaped fixing tool 8304, and a pair of lenses 8305.

[0611] The user can see the display on the display unit 8302 through the lens 8305. Preferably, the display unit 8302 is curved, as this allows the user to experience a high degree of realism. Furthermore, by viewing the image displayed on different areas of the display unit 8302 through the lens 8305, it is possible to perform 3D displays utilizing parallax. Moreover, one embodiment of the present invention is not limited to a structure with one display unit 8302; two display units 8302 may also be provided, with one display unit positioned for each of the user's eyes.

[0612] The display device according to one embodiment of the present invention can be used in the display unit 8302. The display device according to one embodiment of the present invention can also achieve extremely high resolution. For example, as shown in FIG25E, even when the display is magnified using the lens 8305, the pixels are not easily visible to the user. That is to say, the display unit 8302 can be used to allow the user to see images with a higher degree of realism.

[0613] Figure 25F is an external view of the goggle-type head-mounted display 8400. The head-mounted display 8400 includes a pair of housings 8401, a mounting part 8402, and a buffer member 8403. Each of the pair of housings 8401 is provided with a display part 8404 and a lens 8405. By displaying different images on the pair of display parts 8404, three-dimensional display utilizing parallax can be performed.

[0614] The user can see the display on the display unit 8404 through the lens 8405. The lens 8405 has a focus adjustment mechanism that can adjust the position of the lens 8405 according to the user's vision. The display unit 8404 is preferably square or a horizontally elongated rectangle. This improves the realism.

[0615] The mounting part 8402 is preferably plastic and elastic so that it can be adjusted to fit the user's face size without falling off. Additionally, a portion of the mounting part 8402 preferably has a vibration mechanism for use as a bone conduction headphone. Thus, simply installing the headphone allows users to enjoy video and sound without the need for headphones, speakers, or other audio equipment. Furthermore, it can also have the function of wirelessly outputting audio data to the housing 8401.

[0616] The mounting part 8402 and the cushioning member 8403 are the parts that come into contact with the user's face (forehead, cheeks, etc.). By ensuring a close contact between the cushioning member 8403 and the user's face, light leakage can be prevented, thereby further enhancing the immersive experience. The cushioning member 8403 is preferably made of a soft material to ensure a close contact with the user's face when the user wears the head-mounted display 8400. For example, materials such as rubber, silicone rubber, polyurethane, and sponge can be used. Furthermore, when the cushioning member 8403 is made of a material that covers the surface of the sponge or similar material, such as cloth or leather (natural or synthetic leather), gaps are less likely to form between the user's face and the cushioning member 8403, thus appropriately preventing light leakage. Additionally, using such materials not only provides a skin-friendly feel but also prevents the user from feeling cold when wearing the device, especially in colder seasons. It is also preferable that components in contact with the user's skin, such as the cushioning member 8403 and the mounting part 8402, have a detachable structure, making cleaning and replacement easier.

[0617] The electronic devices shown in Figures 26A to 26G include a housing 9000, a display unit 9001, a speaker 9003, operation keys 9005 (including a power switch or operation switch), a connection terminal 9006, a sensor 9007 (which has the function of measuring the following factors: force, displacement, position, velocity, acceleration, angular velocity, rotational speed, distance, light, liquid, magnetism, temperature, chemical substance, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, tilt, vibration, odor, or infrared radiation), a microphone 9008, etc.

[0618] The electronic devices shown in Figures 26A to 26G have various functions. For example, they may have the following functions: displaying various information (still images, moving images, and text images, etc.) on a display unit; a touch panel function; displaying a calendar, date, or time; controlling processing using various software (programs); performing wireless communication; reading and processing programs or data stored in a storage medium; etc. Note that the functions of an electronic device are not limited to the above-mentioned functions, but can have various functions. An electronic device may include multiple display units. Furthermore, a camera or similar device may be installed in the electronic device to enable it to have the following functions: capturing still or moving images and storing the captured images in a storage medium (external storage medium or storage medium built into the camera); displaying the captured images on a display unit; etc.

[0619] The display device according to one embodiment of the present invention can be used in the display unit 9001.

[0620] The electronic devices shown in Figures 26A to 26G will now be described in detail.

[0621] Figure 26A is a perspective view showing a portable information terminal 9101. The portable information terminal 9101 can be used, for example, as a smartphone. Note that a speaker 9003, a connection terminal 9006, a sensor 9007, etc., can also be provided in the portable information terminal 9101. Furthermore, as a portable information terminal 9101, text and image information can be displayed on multiple surfaces. Examples of three illustrations 9050 are shown in Figure 26A. Additionally, information 9051, shown as a dashed rectangle, can be displayed on other surfaces of the display unit 9001. Examples of information 9051 include notifications of received emails, SNS messages, or phone calls; the subject of emails or SNS messages; the sender's name; the date; the time; remaining battery level; and the antenna signal strength. Alternatively, illustrations 9050 can be displayed in the same locations where information 9051 is displayed.

[0622] Figure 26B is a perspective view showing a portable information terminal 9102. The portable information terminal 9102 has the function of displaying information on three or more surfaces of the display unit 9001. Here, examples are shown where information 9052, information 9053, and information 9054 are displayed on different surfaces. For example, when the portable information terminal 9102 is placed in a jacket pocket, the user can check information 9053 displayed in a position visible from above the portable information terminal 9102. The user can check this display without taking the portable information terminal 9102 out of the pocket, thereby determining whether to answer a call.

[0623] Figure 26C is a perspective view of the tablet terminal 9103. The tablet terminal 9103 can, for example, perform various applications such as mobile phone calls, email, article reading and editing, music playback, internet communication, and computer games. The tablet terminal 9103 includes a display unit 9001, a camera 9002, a microphone 9008, and a speaker 9003 on the front of its casing 9000; operation keys 9005 as buttons on the left side of the casing 9000; and a connection terminal 9006 on its bottom surface.

[0624] Figure 26D is a perspective view showing a watch-type portable information terminal 9200. The portable information terminal 9200 can be used, for example, as a smartwatch (registered trademark). Furthermore, the display surface of the display unit 9001 is curved, allowing display along its curved surface. Additionally, the portable information terminal 9200 can perform hands-free calls, for example, by communicating with a headset capable of wireless communication. Furthermore, by utilizing the connection terminal 9006, the portable information terminal 9200 can transmit data and charge with other information terminals. Charging can also be performed wirelessly.

[0625] Figures 26E to 26G are perspective views showing the foldable portable information terminal 9201. Furthermore, Figure 26E is a perspective view of the portable information terminal 9201 in its unfolded state, Figure 26G is a perspective view of its folded state, and Figure 26F is a perspective view of the intermediate state during the transition from one of the states in Figures 26E and 26G to the other. The portable information terminal 9201 offers good portability in its folded state, and in its unfolded state, it provides a large, seamless display area, resulting in excellent browsing capabilities. The display unit 9001 included in the portable information terminal 9201 is supported by three housings 9000 connected by hinges 9055. The display unit 9001 can be bent, for example, within a radius of curvature of 0.1 mm or more and 150 mm or less.

[0626] At least a portion of the structural examples shown in this embodiment and the corresponding diagrams can be appropriately combined with other structural examples or diagrams.

[0627] C1: Capacitor C2: Capacitor C3: Capacitor M1: Transistor M2: Transistor M3: Transistor M11: Transistor M12: Transistor M13: Transistor M14: Transistor M15: Transistor M16: Transistor M17: Transistor OUT1: Wiring OUT2: Wiring PIX1: Pixel Circuit PIX2: Pixel Circuit V1: Wiring V2: Wiring V3: Wiring V4: Wiring V5: Wiring 10: Display device 11: Display Section 12: Drive Circuit Section 13: Drive Circuit Section 21: pixels 21B: Subpixel 21G: Subpixel 21R: Subpixel 30 pixels 50: Electronic devices 52: Support 54: Table 100: Display device 103: pixels 110: Light-emitting element 110B: Light-emitting element 110G: Light-emitting element 110PS: Light receiving element 110R: Light-emitting element 111: Pixel Electrode 111B: Pixel Electrode 111C: Connecting electrode 111f: Conductive film 111G: Pixel Electrode 111PS: Pixel Electrode 111R: Pixel Electrode 112: EL layer 112B: EL layer 112Bf:EL membrane 112G:EL layer 112Gf:EL membrane 112PS: Active layer 112R:EL layer 112Rf:EL membrane 113: Common electrode 114: Public Layer 117: Conductive layer 117B: Conductive layer 117C: Conductive layer 117f: Conductive film 117G: Conductive layer 117PS: Conductive layer 117R: Conductive layer 121: Protective layer 125a: pixels 125b: pixels 129: Opening 129B: Opening 129G: Opening 129R: Opening 130: Area 131: Insulation layer 131a: Insulation layer 131af: Insulating film 131b: Insulation layer 131bf: Insulating film 132: Insulation layer 138: Area 139: Area 143a: Light-blocking mask 143b: Light-blocking mask 143c: Light-blocking mask 144a: Sacrificial membrane 144b: Sacrificial membrane 144c: Sacrificial membrane 145a: Sacrificial Layer 145b: Sacrificial Layer 145c: Sacrifice Layer 146a: Sacrificial membrane 146b: Sacrificial membrane 146c: Sacrificial membrane 147a: Sacrificial Layer 147b: Sacrificial Layer 147c: Sacrifice Layer 201: Transistor 204: Connecting part 205: Transistor 209: Transistor 211: Insulation layer 213: Insulation layer 214: Insulation layer 215: Insulation layer 218: Insulation layer 221: Conductive layer 222a: Conductive layer 222b: Conductive layer 223: Conductive layer 225: Insulation layer 228: Area 231: Semiconductor layer 231i: Channel Formation Area 231n: Low resistance region 241: Conductive layer 241B: Conductive layer 241G: Conductive layer 241PS: Conductive layer 241R: Conductive layer 242: Connection Layer 255: Insulation layer 280: Display Module 281: Display Section 282: Circuit Section 283: Pixel Circuit Section 283a: Pixel Circuit 284: Pixels 284a: pixels 285: Terminal section 286: Wiring Department 290:FPC 291:Substrate 292:Substrate 301:Substrate 302:Substrate 310: Transistor 310a: Transistor 311: Semiconductor layer 311i: Channel Formation Area 311n: Low resistance region 312: Insulation layer 313: Conductive layer 314a: Conductive layer 314b: Conductive layer 315: Conductive layer 316: Insulation layer 321: Insulation layer 322: Insulation layer 323: Insulation layer 325: Adhesive layer 326: Insulation layer 330: Light-emitting element 330G: Light-emitting element 330R: Light-emitting element 331a: Conductive layer 331b: Conductive layer 332G:EL layer 332R:EL layer 333: Conductive layer 334: Public Layer 335: Insulation layer 350: Transistor 350a: Transistor 351: Semiconductor layer 352: Insulation layer 353: Conductive layer 354a: Conductive layer 354b: Conductive layer 355: Conductive layer 361: Insulation layer 362: Insulation layer 363: Insulation layer 400A: Display device 400C: Display device 401: Floor 410: Protective layer 411a: Conductive layer 411b: Conductive layer 411c: Conductive layer 414: Insulation layer 416a: EL layer 416b: EL layer 416c: EL layer 417: Light-shielding layer 418a: Conductive layer 418b: Conductive layer 418c: Conductive layer 421: Insulation layer 421b: Insulation layer 430a: Light-emitting element 430b: Light-emitting element 430c: Light-emitting element 442: Adhesive layer 443: Space 451:Substrate 452:Substrate 462: Display Unit 464: Circuit 465: Wiring 466: Conductive layer 472:FPC 473:IC 500: Display device 501: Electrode 502: Electrode 512B_1: Light-emitting unit 512B_2: Light-emitting unit 512B_3: Light-emitting unit 512G_1: Light-emitting unit 512G_2: Light-emitting unit 512G_3: Light-emitting unit 512R_1: Light-emitting unit 512R_2: Light-emitting unit 512R_3: Light-emitting unit 521: Floor 522: Floor 523B: Emissive layer 523G: Emissive Layer 523R: Emissive Layer 524: Floor 525: Floor 531: Intermediate Layer 550B: Light-emitting device 550G: Light-emitting device 550R: Light-emitting device 772: Lower electrode 785: Color Layer 786: EL layer 786a: EL layer 786b: EL layer 788: Upper electrode 4411: Emissive Layer 4412: Emissive layer 4413: Emissive layer 4420: Layer 4420-1: Layer 4420-2: Floor 4430: Layer 4430-1: Layer 4430-2: Floor 6500: Electronic Devices 6501: Casing 6502: Display Unit 6503: Power button 6504: Button 6505: Speaker 6506: Microphone 6507: Camera 6508: Light Source 6510: Protective components 6511: Display panel 6512: Optical components 6513: Touch sensor panel 6515:FPC 6516:IC 6517: Printed Circuit Board 6518: Battery 7000: Display Section 7100: Television 7101: Outer casing 7103: Bracket 7111: Remote Control 7200: Laptop 7211: Outer casing 7212: Keyboard 7213: Pointing device 7214: External connection port 7300: Digital Kanban 7301: Outer casing 7303: Speaker 7311: Information Terminal Equipment 7400: Digital Kanban 7401: Pillar 7411: Information Terminal Equipment 8000: Camera 8001: Casing 8002: Display Unit 8003: Operation button 8004: Shutter button 8006: Lens 8100: Viewfinder 8101: Outer casing 8102: Display Unit 8103: Button 8200: Head-mounted display 8201: Installation Department 8202: Lens 8203: Main Body 8204: Display Unit 8205: Cable 8206: Battery 8300: Head-mounted display 8301: Outer casing 8302: Display Unit 8304: Fixing tools 8305: Lens 8400: Head-mounted display 8401: Outer casing 8402: Installation Department 8403: Buffer component 8404: Display Unit 8405: Lens 9000: Casing 9001: Display Unit 9002: Camera 9003: Speaker 9005: Operation Key 9006: Connection terminal 9007: Sensor 9008: Microphone 9050: Illustration 9051: News 9052: News 9053: News 9054: News 9055: Hinges 9101: Portable Information Terminal 9102: Portable Information Terminal 9103: Tablet Terminal 9200: Portable Information Terminal 9201: Portable Information Terminal

Claims

1. A display device comprising a plurality of pixels on a first insulating layer, wherein, Each of the plurality of pixels includes a first conductive layer disposed along an opening of the first insulating layer, a second insulating layer on the first conductive layer, an EL layer on the first conductive layer and the second insulating layer, and a common electrode on the EL layer. The common electrode of the plurality of pixels is shared. The second insulating layer is on the first conductive layer and contacts the first conductive layer, and is disposed below the EL layer. The first conductive layers of adjacent pixels of the plurality of pixels are separated by a third insulating layer containing inorganic material and a fourth insulating layer containing organic material. The side surfaces of the first conductive layer and the side surfaces of the EL layer have areas that contact the third insulating layer. The fourth insulating layer is on the third insulating layer and contacts the third insulating layer, and is disposed below the common electrode.

2. The display device of claim 1, wherein the third insulating layer comprises aluminum and oxygen.

3. A display device, comprising: The first pixel on the first insulating layer; The first pixel includes a first light-emitting element comprising a first conductive layer disposed along a first opening of the first insulating layer, a second insulating layer on the first conductive layer, a first EL layer on the first conductive layer and the second insulating layer, and a common electrode on the first EL layer. The second pixel includes a second light-emitting element comprising a second conductive layer disposed along a second opening of the first insulating layer, a third insulating layer on the second conductive layer, a second EL layer on the second conductive layer and the third insulating layer, and the common electrode on the second EL layer. It also includes a fourth insulating layer, the sides of the first conductive layer, the first EL layer, the second conductive layer, and the second EL layer having regions contacting the fourth insulating layer. Finally, it includes a fifth insulating layer disposed on and in contact with the fourth insulating layer, and disposed below the common electrode. The second insulating layer is disposed on and in contact with the first conductive layer, and disposed below the first EL layer. The third insulating layer is on and in contact with the second conductive layer and is disposed below the second EL layer. The fourth insulating layer contains an inorganic material, and the fifth insulating layer contains an organic material.

4. The display device as claimed in claim 3, wherein the fourth insulating layer comprises aluminum and oxygen.

5. A display device comprising a plurality of pixels on a first insulating layer, wherein, Each of the plurality of pixels includes a light-emitting device and a light-receiving device. The light-emitting device includes a first conductive layer disposed along an opening of the first insulating layer, a second insulating layer on the first conductive layer, an EL layer on the first conductive layer and the second insulating layer, and a common electrode on the EL layer. The common electrode is shared among the plurality of pixels. The second insulating layer is on the first conductive layer and in contact with the first conductive layer, and is disposed below the EL layer. The first conductive layers of adjacent pixels in the plurality of pixels are separated from each other by a third insulating layer containing inorganic material and a fourth insulating layer containing organic material. The side surfaces of the first conductive layer and the side surfaces of the EL layer have areas in contact with the third insulating layer. The fourth insulating layer is on the third insulating layer and in contact with the third insulating layer, and is disposed below the common electrode. The light-receiving device has the function of detecting at least one of visible light and infrared light.

6. The display device of claim 5, wherein the light-receiving device is used as an image sensor.

7. The display device of claim 5, wherein the light-receiving device is used as a touch sensor or an air touch sensor.

8. A display device, comprising: The first pixel on the first insulating layer; The first pixel includes a light-emitting device comprising a first conductive layer disposed along a first opening of the first insulating layer, a second insulating layer on the first conductive layer, and an EL layer on the first conductive layer and the second insulating layer. The second pixel includes a light-receiving device comprising a second conductive layer disposed along a second opening of the first insulating layer, a third insulating layer on the second conductive layer, and an active layer on the second conductive layer and the third insulating layer. The side surfaces of the first conductive layer, the EL layer, the second conductive layer, and the active layer have regions that contact a fourth insulating layer. The second insulating layer is disposed on and in contact with the fourth insulating layer. The third insulating layer is disposed on and in contact with the second conductive layer and is disposed below the EL layer. The fourth insulating layer comprises an inorganic material, and the fifth insulating layer comprises an organic material.

9. The display device of claim 8, including a common electrode on the EL layer and the active layer, wherein the third insulating layer and the fifth insulating layer are disposed below the common electrode.

Images