Method for manufacturing a display device

Abstract

The present invention provides a high-definition display device. Provided is a display device comprising: a light emitting element that has a first electrode, an organic compound layer, and a second electrode; a first transistor that is electrically connected to the first electrode; a second transistor that is electrically connected to a gate of the first transistor; and an insulating body that is provided in a manner covering the ends of the first electrode, wherein the first transistor has silicon in a channel-forming region, the second transistor has an oxide semiconductor in a channel forming region, and the ends of the organic compound layer are positioned at the opening portion of the insulating body.

Description

[Technical Field]

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

[0002] In addition to the above, examples of technical fields of one aspect of the present invention include semiconductor devices, light-emitting devices, electronic devices, and input devices (for example, touch sensors, etc.), methods for driving them, and methods for manufacturing them. [Background technology]

[0003] One method for manufacturing a display device equipped with an organic EL is to form the EL layer using an inkjet method (see Patent Document 1). [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2001-185354 [Overview of the project] [Problems that the invention aims to solve]

[0005] In the above-mentioned Patent Document 1, it was necessary to match the nozzle diameter of the inkjet device with the size of the opening, and therefore, miniaturization of the nozzle diameter was essential to obtain a high-definition display device. However, there are limits to how much the nozzle diameter can be miniaturized.

[0006] In view of the above, one aspect of the present invention aims to improve the resolution of a display device having at least one organic compound layer fabricated by a wet process. Another aspect of the present invention aims to provide the above-mentioned display device and a method for fabricating the same.

[0007] Furthermore, the description of these problems does not preclude the existence of other problems. Moreover, one aspect of the present invention does not need to solve all of these problems. Other problems will naturally become apparent from the description in the specification, drawings, claims, etc., and it is possible to extract other problems from the description in the specification, drawings, claims, etc. [Means for solving the problem]

[0008] In view of the above problems, one aspect of the present invention is a display device comprising: a light-emitting element having a first electrode, an organic compound layer, and a second electrode; a first transistor electrically connected to the first electrode; a second transistor electrically connected to the gate of the first transistor; and an insulator provided to cover the end of the first electrode, wherein the first transistor has silicon in its channel-forming region, the second transistor has an oxide semiconductor in its channel-forming region, and the end of the organic compound layer is located at an opening in the insulator.

[0009] Another aspect of the present invention is a display device comprising a light-emitting element having a first electrode, an organic compound layer, and a second electrode; a first transistor electrically connected to the first electrode; a second transistor electrically connected to the gate of the first transistor; and an insulator provided to cover the end of the first electrode, wherein the first transistor has silicon in its channel-forming region, the second transistor has an oxide semiconductor in its channel-forming region, and the end of the organic compound layer does not overlap with the upper surface of the insulator.

[0010] Another aspect of the present invention is a display device comprising: a light-emitting element having a first electrode, an organic compound layer, and a second electrode; a first transistor electrically connected to the first electrode; a second transistor electrically connected to the gate of the first transistor; and an insulator provided to cover the end of the first electrode, wherein the first transistor has silicon in its channel-forming region, the second transistor has an oxide semiconductor in its channel-forming region, the end of the organic compound layer is located at an opening in the insulator, and the thickness of the organic compound layer is greater in the region near the insulator than in the central region of the opening in the insulator.

[0011] Another aspect of the present invention is a display device comprising: a light-emitting element having a first electrode, an organic compound layer, and a second electrode; a first transistor electrically connected to the first electrode; a second transistor electrically connected to the gate of the first transistor; and an insulator provided to cover the end of the first electrode, wherein the first transistor has silicon in its channel-forming region, the second transistor has an oxide semiconductor in its channel-forming region, the end of the organic compound layer does not overlap with the upper surface of the insulator, and the thickness of the organic compound layer is greater in the region near the insulator than in the central region of the opening of the insulator.

[0012] In any one of another aspects of the present invention, the organic compound layer is preferably one or more selected from a hole injection layer, a hole transport layer, and a light-emitting layer. Or, in any one of an aspect of the present invention, the organic compound layer is preferably one or both selected from a hole injection layer and a hole transport layer.

[0013] In any one of another aspects of the present invention, the oxide semiconductor preferably comprises indium, gallium, and zinc.

[0014] In any one of another aspects of the present invention, the channel formation region of the first transistor preferably has polycrystalline silicon.

[0015] Another aspect of the present invention is a method for manufacturing a display device, comprising: forming a first transistor having silicon in a channel formation region and a second transistor having an oxide semiconductor in a channel formation region on a substrate; forming a first electrode of a first light-emitting element electrically connected to the first transistor; forming an insulator having a first opening and a second opening that overlap at least with the first electrode on the first transistor and the second transistor; forming a first material layer containing an organic compound of the first light-emitting element in the first opening and a second material layer containing an organic compound of the second light-emitting element in the second opening, respectively, by a wet process; selectively forming a first resist mask and a second resist mask on the first material layer and the second material layer, respectively; processing the first material layer using the first resist mask to form a third material layer that does not overlap with the upper surface of the insulator; and processing the second material layer using the second resist mask to form a fourth material layer that does not overlap with the upper surface of the insulator.

[0016] Another aspect of the present invention is a method for manufacturing a display device, comprising: forming a first transistor having silicon in a channel formation region and a second transistor having an oxide semiconductor in a channel formation region on a substrate; forming a first electrode of a first light-emitting element electrically connected to the first transistor; forming an insulator having a first opening and a second opening that overlap at least with the first electrode on the first transistor and the second transistor; forming a first material layer containing the light-emitting material of the first light-emitting element in the first opening and a second material layer containing the light-emitting material of the second light-emitting element in the second opening, respectively, by a wet process; selectively forming a first resist mask and a second resist mask on the first material layer and the second material layer, respectively; processing the first material layer using the first resist mask to form a third material layer that does not overlap with the upper surface of the insulator; and processing the second material layer using the second resist mask to form a fourth material layer that does not overlap with the upper surface of the insulator.

[0017] In any one of another aspect of the present invention, it is preferable to use an inkjet method or a spin coating method in the wet method.

[0018] In any one of another aspect of the present invention, it is preferable to form a sacrificial layer under the first resist mask and the second resist mask.

Advantages of the Invention

[0019] According to one aspect of the present invention, it is possible to provide a high-definition display device and a method for manufacturing the same. According to one aspect of the present invention, since the display device can be manufactured by a wet method, cost reduction can be achieved.

[0020] Note that the description of these effects does not prevent the existence of other effects. Note that one aspect of the present invention does not necessarily have to have all of these effects. Note that other effects will be apparent from the description in the specification, drawings, claims, etc., and it is possible to extract these other effects from the description in the specification, drawings, claims, etc.

Brief Description of the Drawings

[0021] FIGS. 1A to 1E are diagrams for explaining a method for manufacturing a display device according to an embodiment. FIGS. 2A to 2E are diagrams for explaining a method for manufacturing a display device according to an embodiment. FIGS. 3A to 3F are diagrams for explaining a light-emitting element according to an embodiment. FIGS. 4A to 4E are diagrams for explaining a method for manufacturing a display device according to an embodiment. FIG. 5 is a flowchart for explaining a method for manufacturing a display device according to an embodiment. FIG. 6A is a diagram showing a configuration example of a display device. FIGS. 6B to 6D are diagrams showing configuration examples of pixel circuits. FIGS. 7A to 7D are diagrams showing cross-sections of transistors. FIGS. 8A to 8E are diagrams for explaining the configuration of an information processing device according to an embodiment. Figures 9A to 9E illustrate the configuration of an information processing device according to an embodiment. Figures 10A and 10B illustrate the configuration of an information processing device according to an embodiment. [Modes for carrying out the invention]

[0022] The embodiments will be described below with reference to the drawings. However, it will be readily apparent to those skilled in the art that the embodiments can be implemented in many different ways, and their form and details can be modified in various ways without departing from the spirit and scope. Accordingly, the present invention is not to be construed as being limited to the following descriptions of embodiments, etc.

[0023] In the configuration of the invention described below, the same reference numerals are used in common across different drawings for parts that are identical or have similar functions, and repeated explanations are omitted. Furthermore, when referring to similar functions, the hatch patterns are the same, and reference numerals may not be assigned.

[0024] In this specification, ordinal numbers such as "the first," "the second," etc., are used to avoid confusion of constituent elements and do not imply any numerical limitation.

[0025] In this specification, for example, when we refer to "B on A" or "B below A," it is not necessarily required that A and B have areas in contact.

[0026] In this specification, the terms "film" and "layer" are interchangeable. For example, the terms "conductive layer" and "insulating layer" may be interchangeable with "conductive film" and "insulating film," respectively.

[0027] In this specification, a display panel, which is one form of a display device, has the function of displaying (outputting) images or the like on its display surface. Therefore, a display panel is one form of an output device.

[0028] In this specification, a display panel module or display module may refer to a display panel substrate on which connectors such as FPC (Flexible Printed Circuit) or TCP (Tape Carrier Package) are attached, or on which ICs are mounted using a COG (Chip On Glass) method or the like. A display panel module or display module is one form of a display device.

[0029] In this specification, the terms "source" and "drain" of a transistor are interchangeable depending on the transistor's polarity and the potential applied to each terminal. Generally, in an n-channel transistor, the terminal to which a low potential is applied is called the source, and the terminal to which a high potential is applied is called the drain. In a p-channel transistor, the terminal to which a low potential is applied is called the drain, and the terminal to which a high potential is applied is called the source. In practice, the terms "source" and "drain" may be interchangeable according to the above potential relationship, but in this specification, when explaining the connection relationship of a transistor, the terms "source" and "drain" are fixed for convenience.

[0030] In this specification and other documents, the source and drain of a transistor may be described using the terms first electrode and second electrode.

[0031] In this specification, the source of a transistor refers to the source region, which is part of the semiconductor layer that functions as the active layer, or the source electrode connected to the semiconductor layer. Similarly, the drain of a transistor refers to the drain region, which is part of the semiconductor layer, or the drain electrode connected to the semiconductor layer. The gate of a transistor refers to the gate electrode.

[0032] In this specification, the state in which transistors are connected in series means, for example, a state in which only one of the sources or drains of the first transistor is connected to only one of the sources or drains of the second transistor. The state in which transistors are connected in parallel means a state in which one of the sources or drains of the first transistor is connected to one of the sources or drains of the second transistor, and the other of the sources or drains of the first transistor is connected to the other of the sources or drains of the second transistor.

[0033] In this specification, "connection" may refer to an electrical connection, and includes a state in which current, voltage, or potential can be supplied or transmitted. Therefore, it also includes states in which devices are connected to each other via elements such as wiring, resistors, diodes, and transistors. Furthermore, electrical connection also includes states in which devices are directly connected to each other without the use of elements such as wiring, resistors, diodes, and transistors.

[0034] In this specification, a conductive layer may have multiple functions, such as wiring or electrodes. When a wiring is described as being connected to an electrode in this specification, this includes the case where there is a single conductive layer that has both of the above functions.

[0035] In this specification, a device in which a light-emitting layer is formed using a metal mask (MM) may be referred to as a light-emitting device having a metal mask (MM) structure. Depending on the miniaturization of the aperture, the metal mask may be referred to as a fine metal mask (FMM, high-resolution metal mask). Furthermore, in this specification, a device in which a light-emitting layer is fabricated without using a metal mask or fine metal mask may be referred to as a light-emitting device having a metal maskless (MML) structure.

[0036] In this specification, a light-emitting element is a laminate having a pair of electrodes with an organic compound layer sandwiched between them, and may be referred to as a light-emitting device. The organic compound layer is a laminate that includes at least a light-emitting layer, and the light-emitting layer, etc., may be referred to as a functional layer. In addition to the light-emitting layer, the functional layer may be a hole injection layer, a hole transport layer, an electron transport layer, or an electron injection layer. The pair of electrodes function as an anode and a cathode.

[0037] In this specification, a structure in which the light-emitting layers are painted separately for each color of light-emitting element (for example, red (R), green (G), and blue (B)) may be referred to as an SBS (Side By Side) structure. Also, in this specification, a light-emitting element capable of emitting white light may be referred to as a white light-emitting element. A white light-emitting element can be combined with a colored layer to create a full-color display device. An example of a colored layer is a color filter.

[0038] Furthermore, light-emitting devices can be broadly classified into single structures and tandem structures. A single structure has one light-emitting unit between a pair of electrodes. A light-emitting unit is a laminate that does not include electrodes but includes one or more light-emitting layers. In a single structure, to obtain white light emission, one light-emitting unit should have two or more light-emitting layers, and the light emitted from each light-emitting layer should be complementary in color. For example, by making the light-emitting color of the first light-emitting layer and the light-emitting color of the second light-emitting layer complementary in color, a configuration that emits white light as a whole can be obtained. Similarly, in the case of a light-emitting device having three or more light-emitting layers, a configuration that emits white light can be obtained by satisfying the complementary color relationship.

[0039] A tandem structure preferably has two or more light-emitting units between a pair of electrodes, and each light-emitting unit preferably includes one or more light-emitting layers. In a tandem structure, it is preferable to provide intermediate layers, such as charge-generating layers, between multiple light-emitting units. In a tandem structure, to obtain white light emission, the structure should be such that the light from the light-emitting layers of two or more light-emitting units is combined to produce white light emission. In addition, the structure that produces white light emission should satisfy the complementary color relationship, similar to the single structure.

[0040] Furthermore, when comparing the aforementioned white light-emitting elements (single or tandem structure) with SBS structure light-emitting elements, SBS structure light-emitting elements can consume less power than white light-emitting elements. If you want to keep power consumption low, it is preferable to use SBS structure light-emitting elements. On the other hand, white light-emitting elements are preferable because their manufacturing process is simpler than that of SBS structure light-emitting elements, which can lead to lower manufacturing costs or higher manufacturing yields.

[0041] (Embodiment 1) In this embodiment, a display device according to one aspect of the present invention and a method for manufacturing the same (referred to as manufacturing method 1) will be described.

[0042] A method for manufacturing a display device according to one aspect of the present invention includes a step of forming an organic compound layer on a light-emitting element by a wet process. The organic compound layer on the light-emitting element includes layers having hole-injecting material, hole-transporting material, light-emitting material, electron-transporting material, or electron-injecting material. Each of the above layers will be referred to as a hole-injecting layer, hole-transporting layer, light-emitting layer, electron-transporting layer, or electron-injecting layer. The hole-injecting layer may be abbreviated as HIL, which stands for Hole Injection Layer. The hole-transporting layer may be abbreviated as HTL, which stands for Hole Transport Layer. The electron-injecting layer may be abbreviated as EIL, which stands for Electron Injection Layer. The electron-transporting layer may be abbreviated as ETL, which stands for Electron Transport Layer. Details of each layer will be described later.

[0043] The wet method is a method of obtaining a liquid composition by liquefying a material having a predetermined function by dissolving or dispersing it in a solvent, and then applying the liquid composition. Examples of materials having a predetermined function include hole-injecting materials, hole-transporting materials, luminescent materials, electron-transporting materials, or electron-injecting materials. The liquid composition may be referred to as a droplet or ink material. After application, the liquid composition can be solidified or thinned through a drying or curing process to obtain an organic compound layer having each of the above layers.

[0044] Wet processes include inkjet printing, spin coating, coating, nozzle printing, and gravure printing, but details will be described later. Wet processes can reduce costs because they produce less waste material compared to vapor deposition.

[0045] <Method for manufacturing a display device 1> In the method 1 for manufacturing the display device described in this embodiment, one or more of a hole injection layer, a hole transport layer, and a light-emitting layer are applied as the organic compound layer formed by a wet process, and an inkjet method is used as the wet process. To manufacture one or more of the hole injection layer, hole transport layer, and light-emitting layer by the inkjet method, each droplet may contain a solvent and a hole injection material, a solvent and a hole transport material, or a solvent and a light-emitting material. Note that the solvent may not be necessary depending on the material. The inkjet device for achieving the inkjet method will be described later.

[0046] Figure 1A shows a first substrate 100 of the display device, a first electrode 102 provided on the first substrate 100, and an insulator 105 that covers at least the ends of the first electrode 102 and has an area that overlaps with the first electrode 102 in a top view, that is, an opening 104 in which the first electrode 102 is exposed. Semiconductor elements and the like are provided on the first substrate 100. The materials used for the first substrate 100 will be described later.

[0047] Semiconductor elements often use transistors, and the first substrate 100 is sometimes referred to as a transistor substrate. Transistors function as switching elements, and these switching elements can control the light-emitting or non-light-emitting state of the light-emitting element. A transistor that controls the light-emitting or non-light-emitting state is sometimes referred to as a driving transistor. In a pixel circuit, a selection transistor may be provided in addition to the driving transistor, and the selection transistor is controlled by a gate signal or the like. When a pixel circuit has multiple transistors, ordinal numbers such as the first transistor and the second transistor may be added to distinguish them from each other.

[0048] A display device in which each light-emitting element is provided with a semiconductor element is sometimes called an active-matrix display device. A display device in which multiple light-emitting elements are provided with a semiconductor element in common is sometimes called a passive-matrix display device. The method for manufacturing a display device according to one aspect of the present invention can be applied to both active-matrix display devices and passive-matrix display devices.

[0049] The first electrode 102 shown in Figure 1A corresponds to one of the pair of electrodes of the light-emitting element and functions as either a cathode or anode depending on the light-emitting element. Therefore, the conductive material used for the first electrode 102 should be selected considering the work function corresponding to the cathode or anode. Conductive materials that can be used for the first electrode 102 will be described later.

[0050] Furthermore, if the first electrode 102 is made of a light-transmitting conductive material, a display device with a so-called bottom-emission structure can be provided, in which the light from the light-emitting element is emitted downward from the first electrode 102, that is, towards the first substrate 100. Light-transmitting refers to the ability to transmit visible light. Also, if the first electrode 102 is made of a reflective conductive material, a display device with a so-called top-emission structure can be provided, in which the light from the light-emitting element is emitted upward from the first electrode 102. Reflective refers to the ability to reflect visible light. The method for manufacturing a display device according to one aspect of the present invention can be applied to either a display device with a bottom-emission structure or a display device with a top-emission structure.

[0051] As shown in Figure 1A, the end of the first electrode 102 may be inclined with respect to the surface to be formed, but since it is covered with an insulator 105, the end of the first electrode 102 may be perpendicular or approximately perpendicular to the surface to be formed. The inclined end is sometimes described as a taper. When the first electrode 102 is a laminated structure of conductive material, the end of the lower layer may be inclined and the end of the upper layer may be perpendicular or approximately perpendicular. Alternatively, when the first electrode 102 is a laminated structure of conductive material, the end of the lower layer may be perpendicular or approximately perpendicular and the end of the upper layer may be inclined.

[0052] The insulator 105 is located at the boundary, or between, adjacent light-emitting elements, and may be referred to as a partition, bank, or dam. Adjacent light-emitting elements refer to adjacent light-emitting elements, and they do not need to be in direct contact with each other. As shown in Figure 1A, adjacent light-emitting elements are arranged with at least the lower electrodes separated by a gap, and are partitioned as a single light-emitting element by the insulator 105, thus defining an independent light-emitting element. In Figure 1A, which is a cross-sectional view, the insulator 105 appears to be separate, but when viewed from above, the insulator 105 has a continuous structure and is provided with a selective opening. That is, the insulator 105 has an opening 104 through which the first electrode 102 is exposed. The opening 104 can be formed using a photolithography method or the like. Photolithography methods include a method in which a resist mask is formed on the thin film to be processed, the thin film is processed by etching or the like, and the resist mask is removed, and a method in which a photosensitive thin film is formed, and then exposed and developed to process the thin film into the desired shape. The materials used for the insulator 105 will be described later.

[0053] Figure 1B shows the process of dropping droplets containing hole injection material onto a first electrode 102 using an inkjet method, dropping droplets containing hole transport material using an inkjet method, or sequentially dropping droplets containing hole injection material and droplets containing hole transport material using an inkjet method. A droplet 109 is dropped from a nozzle 110 towards an opening 104 provided in the first substrate 100, and the droplet 109 contains either hole transport material or hole injection material. When dropping the droplet 109, the nozzle 110 of the inkjet device is moved relative to the first substrate 100 to produce a linear hole injection layer, a linear hole transport layer, or a linear hole transport layer stacked on top of a linear hole injection layer. Depending on the amount of droplets, they may not form linearly but may be separated by an insulator 105, thus producing island-shaped hole injection layers, island-shaped hole transport layers, or island-shaped hole transport layers stacked on top of an island-shaped hole injection layer. As shown in Figure 1B, island-shaped hole injection layers and island-shaped hole transport layers can be described as having their ends located at the openings of the insulator. Having the ends of the hole injection layer or hole transport layer located at the openings of the insulator means that, as shown in Figure 1B, these ends do not overlap with the upper surface of the insulator. When these are laminated, it is also possible to form island-shaped hole transport layers on linear hole injection layers, or linear hole transport layers on island-shaped hole injection layers.

[0054] To reiterate, a hole injection layer can be formed using droplets containing a hole injection material. Alternatively, a hole injection layer can be formed using droplets containing a hole transport material. This allows the hole injection layer to be fabricated using a wet process and the hole transport layer using a method other than a wet process. Furthermore, the hole injection layer may be fabricated using a method other than a wet process and the hole transport layer using a wet process. Additionally, both the hole injection layer and the hole transport layer can be fabricated using a wet process. Of course, both the hole injection layer and the hole transport layer may also be fabricated using a method other than a wet process.

[0055] The droplet 109 that was previously dropped into the opening 104 becomes the material layer 113. Figure 1B shows the state where the edge of the material layer 113 is located at the opening of the insulator 105. The material layer 113 has a hole injection layer from which the solvent, etc., has been removed from the droplet 109. The material layer 113 also has a hole transport layer from which the solvent, etc., has been removed from the droplet 109. Furthermore, the material layer 113 has the hole injection layer and the hole transport layer located above it.

[0056] To remove the solvent from the droplet 109, a drying process may be performed. Heat may be applied during the drying process. Furthermore, a curing process may be performed to harden the material layer 113. The curing process may include one or both of the following: a light irradiation process and a heating process. Ultraviolet or infrared light may be used as the light source for the light irradiation.

[0057] When both the hole injection layer and the hole transport layer are fabricated using a wet process, it is preferable to begin dropping the hole transport layer after one or both of the drying and curing processes selected for the hole injection layer have been completed. After such a process, the edges of the hole injection layer may not coincide with the edges of the hole transport layer.

[0058] One or both of the hole transport layer and the hole injection layer can be common to each light-emitting element. "Common" means that each light-emitting element can share one or both of the selected hole transport layer and hole injection layer. Each light-emitting element may include elements that exhibit different emission colors, or elements that exhibit the same emission color.

[0059] Since the material layer 113 is often layered, the common material layer is sometimes referred to as the common layer. When one or both of the hole transport layer and the hole injection layer are selected as the common layer, these are sometimes called the lower common layer of the light-emitting element.

[0060] The common layer may be independent for each light-emitting element, or it may be continuous for each light-emitting element across the insulator 105. Considering this, the droplet 109 for the common layer does not need to be selectively dropped into the opening 104, but can be continuously dropped into multiple openings 104. In an inkjet device used for continuous dropping into multiple openings 104, having multiple nozzles 110 is preferable for higher productivity. Furthermore, productivity can be increased by making the diameter of the nozzle 110 larger than the width of the opening 104. Also, the droplet 109 may be dropped in a continuous line without interruption.

[0061] Methods other than inkjet printing can be used to fabricate the common layer; for example, spin coating may be used. Using spin coating, droplets 109 can be coated over the entire surface to be formed, including the openings 104.

[0062] Vacuum deposition may be used to fabricate the common layer. Vacuum deposition is preferred. Using vapor deposition, the deposition material can be deposited over the entire surface to be formed, including the opening 104.

[0063] Furthermore, the hole injection layer and the hole transport layer can be a common layer, but they only need to be selectively formed at the opening 104 and do not need to be formed on the upper surface of the insulator 105. Therefore, the volume of the droplets 109 required to form them can be small compared to the volume of the opening 104. Under these conditions, the droplets 109 will be dropped at the opening 104 and not on the upper surface of the insulator 105. However, by further surface treatment of the insulator 105, the droplets 109 can be selectively dropped at the opening 104. This surface treatment includes a treatment that gives the surface of the insulator 105 hydrophilicity or hydrophobicity to the solvent of the droplets 109.

[0064] In some cases, the side surface of the insulator 105 is inclined at the opening 104. This inclination of the side surface is sometimes referred to as a taper. Surface treatment may be applied to the insulator 105 with an inclined side surface. However, even without surface treatment, the droplet 109 can be dropped into the opening 104 by utilizing the inclination.

[0065] Figure 1C explains the film thickness of the material layer 113 formed by the wet method, using a magnified view of the area circled in Figure 1B, i.e., the end of the insulator 105. First, the lower end of the insulator 105 is taken as the center (C). The distance L1 is defined as the distance from this center (C) to the end of the material layer 113 (the end that overlaps with the slope of the insulator 105). The same distance L1 is marked on the side opposite the end of the material layer 113 from the center (C), indicating the range of distance L1 from the center (C). The range of distance L1 that includes the end of the insulator 105 is called the vicinity region of the insulator 105. In the vicinity region of the insulator 105, the film thickness of the material layer 113 is thicker. The film thickness of the material layer 113 is often thickest in the region that overlaps with the center (C). Thus, the film thickness of the material layer 113 is greater in the vicinity region of the insulator 105 than in the region that includes the center of the opening 104 (the central region of the opening). The material layer 113, which is thickened in the vicinity of the insulator 105, can be said to have been fabricated by a wet process.

[0066] Figure 1D shows how an organic compound material containing the light-emitting material of a light-emitting element is dropped using a wet method, typically an inkjet method. When the light-emitting material corresponds to red, green, and blue, nozzles 120, 130, and 140 are prepared. When dropping droplets containing each light-emitting material, a material layer 113 is formed on the underside of each droplet, and the nozzles 120, 130, and 140 move relative to the first substrate 100. The droplets dropped from each nozzle are droplets 121, 131, and 141. Each droplet contains either a red light-emitting material, a green light-emitting material, or a blue light-emitting material.

[0067] Furthermore, the light-emitting layer containing the light-emitting material is often thicker than one or both of the hole transport layer and the hole injection layer. Therefore, the amount of droplets 121, 131, and 141 dropped is greater than that of droplet 109. Droplets 121, 131, and 141 may be dropped on the opening 104 and outside the opening 104, respectively. That is, droplets 121, 131, and 141 may also be dropped on the upper surface of the insulator 105. Note that droplets 121, 131, and 141 may be dropped on the opening 104 but not on the upper surface of the insulator 105.

[0068] Therefore, material layers 122, 132, and 142 corresponding to droplets 121, 131, and 141 are also formed on the upper surface of the insulator 105, as shown in Figure 1E. To distinguish between material layers 122, 132, and 142, they are sometimes referred to as the first material layer, the second material layer, and the third material layer. Alternatively, material layers 122, 132, and 142 may be collectively referred to as each material layer. One of the material layers is the light-emitting layer, which has a layer containing a light-emitting material from which the solvent, etc., has been removed from the droplet. The light-emitting layer includes a layer containing a red light-emitting material (sometimes referred to as the red light-emitting layer), a layer containing a green light-emitting material (sometimes referred to as the green light-emitting layer), and a layer containing a blue light-emitting material (sometimes referred to as the blue light-emitting layer).

[0069] Furthermore, a drying process may be used to remove solvents and other substances from the droplets. Heat may be applied during the drying process. A curing process may also be used to harden the material layer 113. The curing process may include one or both of the following: a light irradiation process and a heating process. Ultraviolet or infrared light may be used as the light source for the light irradiation.

[0070] In the light-emitting layer, the film thickness in the region overlapping with the upper surface of the insulator 105 is often thinner than the film thickness in the region overlapping with the opening 104.

[0071] Furthermore, the light-emitting layer, like the material layer 113, is thickened in the region near the insulator 105. That is, the thickness of each material layer is greater in the region near the insulator 105 than in the central region of the insulator opening. The light-emitting layer, which is thickened in the region near the insulator, can be said to have been fabricated by a wet process.

[0072] As shown in Figure 2A, a sacrificial layer 150 is formed on material layers 122, 132, and 142. The sacrificial layer is provided to protect the material layer (which is the target of processing and is sometimes referred to as the workpiece layer) from process damage when it is processed by etching or other methods. For this reason, the sacrificial layer 150 may be formed to be thicker than the light-emitting layer. The materials used for the sacrificial layer 150 will be described later.

[0073] As shown in Figure 2B, a first resist mask RES1, a second resist mask RES2, and a third resist mask RES3 are formed so as to overlap with the light-emitting layer. The first resist mask RES1, the second resist mask RES2, and the third resist mask RES3 are each preferably formed in a position that overlaps with the first electrode 102. According to the cross-sectional view in Figure 2B, the width of the first resist mask RES1 is the same as or smaller than the width of the opening 104. The widths of the second resist mask RES2 and the third resist mask RES3 are also preferably the same as the width of the first resist mask RES1. Negative resists or positive resists can each be used for the first resist mask RES1, the second resist mask RES2, and the third resist mask RES3.

[0074] As shown in Figure 2C, the material layer 122 is processed using the first resist mask RES1, specifically by removing a portion of it to form the processed material layer 123. The material layer 132 is processed using the second resist mask RES2, specifically by removing a portion of it to form the processed material layer 133. The material layer 142 is processed using the third resist mask RES3, specifically by removing a portion of it to form the processed material layer 143. Photolithography can be used for the processing steps. One photolithography method involves forming a resist mask on the thin film to be processed, processing the thin film by etching or the like, and then removing the resist mask.

[0075] As shown in Figure 2C, the sacrificial layer 150 is removed simultaneously with the first resist mask RES1, the second resist mask RES2, and the third resist mask RES3, thereby obtaining the processed material layers 123, 133, and 143. The edges of the processed material layers 123, 133, and 143 do not overlap with the upper surface of the insulator 105, and the edges of each processed material layer are located in the opening 104. However, to suppress the occurrence of crosstalk, it is sufficient that the processed material layers 123, 133, and 143 are separated from each other, and the edges of each processed material layer may be located in a region that overlaps with the upper surface of the insulator 105.

[0076] Furthermore, to suppress the occurrence of crosstalk, a portion of the material layer may be insulated and electrically separated. By irradiating the material layer in the region overlapping with the upper surface of the insulator 105 with a laser or the like, a portion of the material layer can be insulated.

[0077] Since the processing is carried out with a sacrificial layer 150 in place, it is preferable that each material layer does not suffer damage during the process.

[0078] The processing steps can include etching or laser ablation. For etching, dry etching or wet etching can be used. In the laser ablation method, a light-absorbing layer or a light-reflecting layer may be placed before irradiating with a laser.

[0079] Through the processing steps, fine light-emitting elements can be provided regardless of the nozzle diameter. In this way, high-definition display devices can be provided. Furthermore, through the processing steps, the material layers, typically the light-emitting layers, are separated in adjacent light-emitting elements, thus providing a display device with reduced crosstalk.

[0080] Adjacent light-emitting elements are preferably of different colors, but they may also be of the same color. For example, material layer 123 can be a red light-emitting element, material layer 133 a green light-emitting element, and material layer 143 a blue light-emitting element. Such a structure in which light-emitting layers are colored differently is sometimes referred to as an SBS structure. Furthermore, although an example has been given of a configuration with three colors, it is not limited to this. For example, a configuration with four or more colors may also be used.

[0081] In one embodiment of the present invention, a method for manufacturing a display device includes a step of forming an organic compound layer, i.e., a functional layer of a light-emitting element, using a method including a wet process, rather than using a metal mask, and a step of processing the organic compound layer thereafter. By going through such a process, it is possible to realize a high-definition display device or a display device with a high aperture ratio, which has been difficult to achieve until now. Furthermore, since the organic compound layer can be made independent after the processing step, the occurrence of crosstalk can be suppressed.

[0082] Furthermore, since the organic compound layer includes a light-emitting layer, the light-emitting layer can be painted differently for each light-emitting element. A display device having painted light-emitting layers can provide a vivid and high-contrast display.

[0083] Furthermore, a sacrificial layer can be created on the workpiece during the processing step, reducing the process damage suffered by the workpiece and improving the reliability of the display device.

[0084] As shown in Figure 2D, one or more layers 160 are formed, selected from a layer having an electron-transporting material and a layer having an electron-injecting material. The layer having an electron-transporting material is sometimes referred to as the electron-transport layer. The layer having an electron-injecting material is sometimes referred to as the electron-injection layer. One or both of the layers selected from the electron-transporting layer and the electron-injection layer may be a common layer, and when one or both of the layers selected from the electron-transporting layer and the electron-injection layer are used as a common layer, these are sometimes referred to as the upper common layer of the light-emitting element.

[0085] Methods other than inkjet printing can be used to fabricate the common layer; for example, spin coating may be used.

[0086] The common layer may be formed using a vapor deposition method. Vacuum deposition is preferred as the vapor deposition method.

[0087] As shown in Figure 2E, the second electrode 161 is formed by vapor deposition, sputtering, or CVD. Vacuum vapor deposition is preferred for vapor deposition. The second electrode 161 is a common layer and functions as an electrode, and is therefore sometimes referred to as a common electrode.

[0088] A protective film may be provided on the second electrode 161.

[0089] In one embodiment of the present invention, a pattern is formed by photolithography during the separation process of a material layer having a light-emitting material. As described above, it is preferable to perform the photolithography pattern formation once rather than multiple times corresponding to each light-emitting element. Material layers formed by the wet method may be difficult to coat with high precision due to limitations such as nozzle diameter, but high-precision processing is possible by pattern formation using photolithography. Therefore, a high-precision light-emitting device (display device) can be manufactured.

[0090] In a material layer containing a light-emitting material, depending on its conductivity, crosstalk may occur. Therefore, as shown in the manufacturing method of one embodiment of the present invention, high-precision processing by pattern formation using photolithography makes it possible to suppress the occurrence of crosstalk between adjacent light-emitting devices. A charge generation layer may also be processed by photolithography as the material layer. The edges (sides) of a material layer containing a light-emitting material processed by pattern formation using photolithography have a sharp shape relative to the surface to which it is formed, which is suitable for suppressing the occurrence of crosstalk.

[0091] The materials and other components that can be used in each component will be explained.

[0092] <Regarding the material of the first substrate> The first substrate 100 can be made of materials such as glass, quartz, ceramics, sapphire, or organic resin. Because these materials are translucent, light from the light-emitting element can be extracted from the first substrate 100. Although referred to as a "substrate," using, for example, an organic resin among the above materials allows for flexibility. Furthermore, it becomes possible to create a thinner film than the typical image of a "substrate," allowing it to be formed into a film. In other words, the first substrate 100 can take on both a flexible form and a film form, depending on the material used. In addition to the above materials, metal substrates made of metal or alloy materials can also be used. Since these materials are not translucent, they should be used when it is not necessary to extract light from the light-emitting element from the first substrate 100.

[0093] <Regarding the material of the first electrode> When the first electrode 102 is used as the cathode, metals, alloys, electrically conductive compounds, or mixtures thereof with a small work function (specifically, 3.8 eV or less) can be used. Specific examples of such cathode materials include elements belonging to Group 1 or Group 2 of the periodic table, namely alkali metals such as lithium (Li) or cesium (Cs), and alkaline earth metals such as magnesium (Mg), calcium (Ca), and strontium (Sr), or alloys containing these (MgAg, AlLi, etc.), or rare earth metals such as europium (Eu) and ytterbium (Yb), or alloys containing these. However, by providing an electron injection layer between the cathode and the electron transport layer, various conductive materials such as Al, Ag, ITO, silicon, or indium oxide-tin oxide containing silicon oxide can be used as the cathode, regardless of the magnitude of the work function. Films of these conductive materials can be formed using sputtering, inkjet, or spin coating methods.

[0094] When the first electrode 102 is used as the anode, it is preferable to use a metal, alloy, conductive compound, or mixture thereof with a large work function (specifically, 4.0 eV or more). Specifically, examples include indium tin oxide (ITO), indium tin oxide containing silicon or silicon oxide, indium zinc oxide (IZO), and indium oxide (IWZO) containing tungsten oxide and zinc oxide. These conductive metal oxide films are usually deposited by sputtering, but they may also be fabricated using methods such as the sol-gel method. For example, indium zinc oxide can be formed by sputtering using a target to which 1 wt% to 20 wt% of zinc oxide is added relative to indium oxide. Furthermore, indium oxide containing tungsten oxide and zinc oxide (IWZO) can be formed by a sputtering method using a target containing 0.5 wt% to 5 wt% tungsten oxide and 0.1 wt% to 1 wt% zinc oxide relative to indium oxide. Other examples include gold (Au), platinum (Pt), nickel (Ni), tungsten (W), chromium (Cr), molybdenum (Mo), iron (Fe), cobalt (Co), copper (Cu), palladium (Pd), or metallic nitrides (e.g., titanium nitride). In addition, by placing the above-mentioned composite material in contact with the anode, the anode material can be selected regardless of the work function.

[0095] <Regarding insulating materials> The insulator can be an organic or inorganic material. For example, the insulator may contain an organic resin such as polyimide resin, polyamide resin, acrylic resin, siloxane resin, silicone resin, epoxy resin, or phenolic resin. Another example is that the insulator may contain one or more of the following: aluminum oxide, magnesium oxide, silicon oxide, silicon oxide nitride, silicon oxide nitride, silicon nitride, gallium oxide, germanium oxide, yttrium oxide, zirconium oxide, lanthanum oxide, neodymium oxide, hafnium oxide, and tantalum oxide. It may also have a laminated structure of the above materials. Furthermore, materials to which impurity elements such as lanthanum (La), nitrogen, and zirconium (Zr) have been added may also be used.

[0096] It is preferable to give the upper and lower ends of the insulator 105 curvature. Using a positive-type photosensitive acrylic resin as the insulator 105 allows for the creation of the aforementioned curved surfaces. Alternatively, the insulator 105 can be made of either a negative-type or positive-type photosensitive resin.

[0097] <Regarding the victim group> The sacrificial layer 150 can be a film with high resistance to etching of material layers 122, 132, and 142, i.e., a film with a high etching selectivity ratio. Furthermore, it is preferable that the sacrificial layer 150 has a laminated structure of a first sacrificial layer and a second sacrificial layer having different etching selectivity ratios. Additionally, the sacrificial layer 150 can be a film that can be removed by a wet etching method that causes minimal damage to each material layer.

[0098] As the sacrificial layer 150, for example, an inorganic film such as a metal film, alloy film, metal oxide film, semiconductor film, or inorganic insulating film can be used. Furthermore, the sacrificial layer 150 can be formed by various film deposition methods such as sputtering, vapor deposition, CVD, and ALD.

[0099] As the sacrificial layer 150, for example, metallic materials such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, titanium, aluminum, yttrium, zirconium, and tantalum, or alloy materials containing such metallic materials, can be used. In particular, it is preferable to use low-melting-point materials such as aluminum or silver.

[0100] Furthermore, metal oxides such as indium gallium zinc oxide (In-Ga-Zn oxide, also written as IGZO) can be used as the sacrificial layer 150. In addition, indium oxide, indium zinc oxide (In-Zn oxide), indium tin oxide (In-Sn oxide), indium titanium oxide (In-Ti oxide), indium tin zinc oxide (In-Sn-Zn oxide), indium titanium zinc oxide (In-Ti-Zn oxide), indium gallium tin zinc oxide (In-Ga-Sn-Zn oxide), etc. can be used. Alternatively, indium tin oxide containing silicon can also be used.

[0101] Furthermore, the above-mentioned method can also be applied when element M (where M is one or more selected from aluminum, silicon, boron, yttrium, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, or magnesium) is used instead of gallium. In particular, it is preferable that M be one or more selected from gallium, aluminum, or yttrium.

[0102] Furthermore, inorganic insulating materials such as aluminum oxide, hafnium oxide, and silicon oxide can be used as the sacrificial layer 150.

[0103] Furthermore, it is preferable to use a material that is soluble in a chemically stable solvent for the sacrificial layer 150, at least for the film located at the top of each material layer, that is, the film located on the surface to which the sacrificial layer 150 is formed. Materials soluble in water or alcohol can be suitably used for the sacrificial layer 150. When forming the sacrificial layer 150, it is preferable to apply it using a wet film formation method while dissolved in a solvent such as water or alcohol, and then perform a heat treatment to evaporate the solvent. At this time, performing the heat treatment under a reduced pressure atmosphere is preferable because it allows the solvent to be removed at a low temperature and in a short time, thereby reducing thermal damage to each material layer.

[0104] Furthermore, when the sacrificial layer 150 is made into a laminated structure, the layer formed from the aforementioned material can be designated as the first sacrificial layer, and a second sacrificial layer can be formed on top of it.

[0105] In this case, the second sacrificial layer is a film used as a hard mask when etching the first sacrificial layer. Furthermore, the first sacrificial layer is exposed during processing of the second sacrificial layer. Therefore, the first and second sacrificial layers are selected based on their high etching selectivity ratios. Thus, the film that can be used for the second sacrificial layer can be selected according to the etching conditions of the first and second sacrificial layers.

[0106] For example, when dry etching using a fluorine-containing gas (also called a fluorine-based gas) is used for etching the second sacrificial layer, 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 second sacrificial layer. Here, metal oxide films such as IGZO and ITO can be used for the first sacrificial layer as films that allow for a higher selectivity ratio for etching (i.e., a slower etching rate) compared to dry etching using the above-mentioned fluorine-based gas.

[0107] However, the second sacrificial layer can be selected from a variety of materials, depending on the etching conditions of the first sacrificial layer and the etching conditions of the second sacrificial layer. For example, it can be selected from among the films that can be used for the first sacrificial layer.

[0108] Furthermore, a nitride film can be used as the second sacrificial layer. Specifically, nitrides such as silicon nitride, aluminum nitride, hafnium nitride, titanium nitride, tantalum nitride, tungsten nitride, gallium nitride, and germanium nitride can be used.

[0109] Alternatively, an oxide film can be used as the second sacrificial layer. Typically, oxide films or oxynitride films such as silicon oxide, silicon oxynitride, aluminum oxide, aluminum oxynitride, hafnium oxide, and hafnium oxynitride can be used.

[0110] <About the wet method> Wet methods include inkjet printing and spin coating, but also encompass other coating methods, nozzle printing, and gravure printing. In inkjet printing and spin coating, the liquid composition is often referred to as droplets, but it may also be referred to as ink material. Similarly, while it may be described as dropping droplets, it may also be described as coating the ink material.

[0111] Examples of solvents that can be used when forming these compounds using wet methods include chlorine-based solvents such as dichloroethane, trichloroethane, chlorobenzene, and dichlorobenzene; ether-based solvents such as tetrahydrofuran, dioxane, anisole, and methylanisole; aromatic hydrocarbon solvents such as toluene, xylene, mesitylene, ethylbenzene, hexylbenzene, and cyclohexylbenzene; aliphatic hydrocarbon solvents such as cyclohexane, methylcyclohexane, pentane, hexane, heptane, octane, nonane, decane, dodecane, and bicyclohexyl; ketone-based solvents such as acetone, methyl ethyl ketone, benzophenone, and acetophenone; ester-based solvents such as ethyl acetate, butyl acetate, ethyl cellosolve acetate, methyl benzoate, and phenyl acetate; polyhydric alcohol-based solvents such as ethylene glycol, glycerin, and hexanediol; alcohol-based solvents such as isopropyl alcohol and cyclohexanol; sulfoxide-based solvents such as dimethyl sulfoxide; and amide-based solvents such as methylpyrrolidone and dimethylformamide. Furthermore, one or more solvents can be used.

[0112] <About inkjet printers> An inkjet printer has a nozzle. The diameter of the opening (also called the nozzle diameter) from which liquid droplets are ejected is between a few micrometers and several tens of micrometers. The part containing the nozzle is sometimes called the head. The head is equipped with a droplet ejection control unit to dispense liquid droplets, which may include a piezoelectric element (piezo element), for example. This pressure element can change the volume of the ink material tank connected to the nozzle, thereby dispensing liquid droplets. The volume of one droplet is often between a few parts per liter (pl) and several tens of pl, depending on the nozzle diameter. Depending on the material, 1 pl of liquid droplet can be considered to be the amount that forms a cube of about 10 μm.

[0113] As display devices become higher resolution, the apertures 104 become smaller. On the other hand, there are limits to how much the nozzle diameter of an inkjet device can be reduced due to mechanical processing. In other words, the apertures 104 become smaller than the nozzle diameter. In such cases, droplets may be dropped across multiple apertures. In such cases, processing using a resist mask is suitable for obtaining high-resolution display devices.

[0114] <About the Resist Mask (RES)> Negative or positive type materials can be used for resist masks. A resist mask is formed by creating a resist material and exposing it with a specific light. With negative type materials, the exposed areas have reduced solubility in the developer, so after development, the exposed areas remain. In other words, the exposed areas are used as the resist mask. With positive type materials, the exposed areas have increased solubility in the developer, so after development, the unexposed areas remain. In other words, the unexposed areas are used as the resist mask. Excimer lasers, electron beams, or ultraviolet light can be used as the light source for exposure. Using a resist mask makes it possible to perform fine processing with dimensions of several tens of nanometers to 10 μm, preferably 100 nm to 5 μm.

[0115] <About light-emitting elements> Figure 3A shows a schematic diagram of a single-structure light-emitting element. The light-emitting element has a light-emitting unit 103 between a pair of electrodes, a first electrode 102 and a second electrode 161. The first electrode 102 corresponds to the anode, and the second electrode 161 corresponds to the cathode. The light-emitting unit 103 has a hole transport region 17, a light-emitting layer 13, and an electron transport region 18. The light-emitting layer 13 is sometimes referred to as the light-emitting region.

[0116] The hole transport region 17 may have a hole injection layer 11 and a hole transport layer 12, but hole transport is possible even if only one of the hole injection layer 11 and the hole transport layer 12 is present. One or both of the hole injection layer 11 and the hole transport layer 12 can be fabricated by a wet process. Subsequently, one or both of the hole injection layer 11 and the hole transport layer 12 can be processed by photolithography or the like, and the occurrence of crosstalk can be suppressed when one or both of the hole injection layer 11 and the hole transport layer 12 are separated.

[0117] Figure 3A shows a configuration in which the hole transport region 17 has a hole injection layer 11 and a hole transport layer 12, specifically in which the hole injection layer 11 and the hole transport layer 12 are provided sequentially starting from the first electrode 102. One or both of the hole injection layer 11 and the hole transport layer 12 can be fabricated by a wet process.

[0118] The electron transport region 18 may have an electron transport layer 14 and an electron injection layer 15, but electron transport is possible even if only one of the electron transport layer 14 or the electron injection layer 15 is present. Figure 3A shows a configuration in which the electron transport layer 14 and the electron injection layer 15 are provided in order from the light-emitting layer 13.

[0119] By a wet process, one or both of the electron transport layer 14 and the electron injection layer 15 can be fabricated. Subsequently, by processing one or both of the electron transport layer 14 and the electron injection layer 15, the occurrence of crosstalk can be suppressed.

[0120] Furthermore, the light-emitting unit 103 may have other functional layers. Examples of other functional layers include one or more layers selected from a carrier block layer, an exciton block layer, and a charge generation layer. One or more layers selected from the carrier block layer, exciton block layer, and charge generation layer can be fabricated by a wet process. Subsequently, the occurrence of crosstalk can be suppressed by processing one or more layers selected from the carrier block layer, exciton block layer, and charge generation layer using a photolithography method or the like.

[0121] The light-emitting layer 13 contains at least a light-emitting material, that is, a light-emitting organic compound. The light-emitting layer 13 can be fabricated by a wet process using droplets containing the light-emitting material and a solvent. Subsequently, the occurrence of crosstalk can be suppressed by processing the light-emitting layer 13 using a method such as photolithography.

[0122] Furthermore, the hole transport region 17 contains at least one organic compound that possesses hole-transporting properties. The organic compound possessing hole-transporting properties is sometimes referred to as the hole-transporting material. The hole transport region 17 can be prepared by a wet process using droplets containing the hole-transporting material and a solvent.

[0123] In the case of a light-emitting element having a hole injection layer 11 and a hole transport layer 12, both the hole injection layer 11 and the hole transport layer 12 must contain at least a hole-transporting material to exhibit the function of each layer.

[0124] The electron transport region 18 contains at least an organic compound having electron transport properties. An organic compound having electron transport properties is sometimes referred to as an electron transport material. The electron transport region 18 can be fabricated by a wet process using droplets containing the electron transport material and a solvent. In the case of a light-emitting element having an electron transport layer 14 and an electron injection layer 15, both the electron transport layer 14 and the electron injection layer 15 must contain at least an electron transport material to exhibit the functions of each layer.

[0125] The hole transport region 17 has a hole-transporting material and therefore has the function of transporting holes between the first electrode 102 and the light-emitting layer 13. For this reason, it is preferable that the organic compound used in the hole transport region 17 contains a material with a skeleton that has relatively high hole-transporting properties. Examples of skeletons with high hole-transporting properties include π-electron-rich heteroaromatic ring skeletons selected from arylamine skeletons, pyrrole skeletons, carbazole skeletons, and thiophene skeletons.

[0126] Since the electron transport region 18 has an electron-transporting material, it has the function of transporting electrons between the second electrode 161 and the light-emitting layer 13. For this reason, it is preferable that the organic compound used in the electron transport region 18 contains a material with relatively high electron-transporting properties.

[0127] In one embodiment of the present invention, at least one of the above-mentioned organic compounds can be formed by a wet process, thereby reducing the manufacturing cost of the display device.

[0128] Furthermore, as shown in Figure 3B, a charge generation layer 16 may be provided corresponding to the electron injection layer 15 in Figure 3A. The charge generation layer 16 is a layer that can inject holes into the layer in contact with the cathode side and electrons into the layer in contact with the anode side by applying a potential. The charge generation layer 16 includes at least a P-type layer 23. The P-type layer 23 is preferably formed using an organic compound listed as a material that can constitute the hole injection layer 11. The P-type layer 23 may also be a film containing an acceptor material in addition to the organic compound. Furthermore, it may be constructed by laminating a film containing an acceptor material and a film containing a hole transport material. By applying a potential to the P-type layer 23, electrons are injected into the electron transport layer 14 and holes are injected into the second electrode 161, thereby operating the light-emitting element. The charge generation layer 16 can be fabricated by a wet process. Furthermore, the P-type layer 23 of the charge generation layer 16 can be fabricated by a wet process.

[0129] Furthermore, it is preferable for the charge generation layer 16 to have one or both of the following in addition to the P-type layer 23: an electron relay layer 22 and an electron injection buffer layer 24, as this improves the electron injection efficiency into the electron transport layer 14. Figure 3B shows a configuration in which both the electron relay layer 22 and the electron injection buffer layer 24 are provided in addition to the P-type layer 23, with the electron relay layer 22 and the electron injection buffer layer 24 located between the second electrode 161 and the electron transport layer 14. One or both of the electron relay layer 22 and the electron injection buffer layer 24 of the charge generation layer 16 can be fabricated by a wet process.

[0130] Furthermore, the light-emitting element may have a configuration in which multiple light-emitting layers are stacked, as shown in Figure 3C. In Figure 3C, light-emitting layers 13a, 13b, and 13c are stacked in order from the first electrode 102 side. This stacked configuration, in which no charge generation layer is located between the layers, can be considered as a single light-emitting unit, and the light-emitting element shown in Figure 3C is a variation of the single structure. One or more selected from light-emitting layers 13a, 13b, and 13c can be fabricated by a wet process.

[0131] In Figures 3A to 3C, the hole transport region 17 is configured to include two layers: a hole injection layer 11 and a hole transport layer 12. When forming a layer that can come into contact with the first electrode 102, such as the hole injection layer 11 or the hole transport layer 12, by a wet process, it is preferable that a material exhibiting acceptor properties is simultaneously included in the highly hole-transporting framework. Examples of such acceptor properties include sulfonic acid compounds, fluorine compounds, trifluoroacetic acid compounds, propionic acid compounds, or metal oxides.

[0132] As the material for the droplets applied by the wet method (referred to as the ink material), polymer materials, low molecular weight materials, or dendrimers can be used as is. Alternatively, polymer materials, low molecular weight materials, or dendrimers dispersed in a solvent, or polymer materials, low molecular weight materials, or dendrimers dissolved in a solvent, may be used as the ink material. Furthermore, polymer materials may be obtained by mixing one or more monomers. When mixing one or more monomers, the mixed ink material may be applied, and after application, crosslinking, condensation, polymerization, coordination, or the formation of salt bonds may be induced by heating or energy light irradiation.

[0133] Furthermore, the above ink material may include other functional materials such as surfactants or viscosity modifiers.

[0134] The amine compound used in the ink material can be a primary amine, a secondary amine, or a tertiary amine, with secondary amines being particularly preferred. When applying an ink material made by mixing multiple monomers and polymerizing it after application, it is preferable to use a secondary amine and an aryl sulfonic acid as the monomers.

[0135] The secondary amine preferably has a substituted or unsubstituted aryl group having 6 to 14 carbon atoms, or a substituted or unsubstituted π-electron-rich heteroaryl group having 6 to 12 carbon atoms. Examples of the aryl group include a phenyl group, biphenyl group, naphthyl group, fluorenyl group, phenantrenyl group, or anthryl group. The phenyl group is preferred because it has good solubility and lower raw material costs. Examples of the heteroaryl group include a carbazole skeleton, pyrrole skeleton, thiophene skeleton, furan skeleton, or imidazole skeleton.

[0136] Furthermore, it is preferable for secondary amines to have multiple bonds formed via arylamines or heteroarylamines, as this improves the film quality after coating, heating, or curing. When there are many of the above bonds, it is preferable that oligomers or polymers are formed.

[0137] The secondary amine may have a plurality of amine skeletons. In this case, a part of the amine skeleton may be a primary amine or a tertiary amine. However, it is preferable that the proportion of the secondary amine is larger than the proportion of the primary amine or the tertiary amine. The number of the plurality of amine skeletons is preferably 1000 or less, more preferably 10 or less, and the molecular weight of the secondary amine is preferably 100,000 or less. Further, when an amine skeleton substituted with fluorine is used, the compatibility with a compound substituted with fluorine is improved, which is preferable.

[0138] As the secondary amine, for example, an organic compound represented by the following general formula (G1) etc. is preferable and suitable for the wet method.

[0139]

Chemical formula

[0140] However, in the above general formula (G1), Ar 11 to Ar 13 one or more of which represent hydrogen, and Ar 14 to Ar 17 represent a substituted or unsubstituted aromatic ring having 6 to 14 carbon atoms. As the aromatic ring having 6 to 14 carbon atoms, a benzene ring, a bisbenzene ring, a naphthalene ring, a fluorene ring, a phenanthrene ring, or an anthracene ring can be used. Note that Ar 12 and Ar 16 , Ar 14 and Ar 16 , Ar 11 and Ar 14 , Ar 14 and Ar 15 , Ar 15 and Ar 17 , Ar 13 and Ar 17 may be bonded to each other to form a ring. Further, p represents an integer of 0 or more and 1000 or less, preferably 0 or more and 3 or less. Note that the molecular weight of the organic compound represented by the above general formula (G1) is preferably 100,000 or less.

[0141] As the tertiary amine, for example, an organic compound represented by the following general formula (G2) is preferred and is suitable for the wet process.

[0142] [ka]

[0143] However, in the above general formula (G2), Ar 21 ~Ar 23 represents a substituted or unsubstituted aryl group having 6 to 14 carbon atoms, which may be bonded to each other and form a ring. Also, Ar 21 ~Ar 23 If the substituent has substituents, the substituent may be a group consisting of multiple diarylamino groups or carbazolyl groups linked together. Furthermore, the organic compound represented by the above general formula (G2) may have ether bonds, sulfide bonds, or amine-mediated bonds, and when it has multiple aryl groups, the presence of these bonds improves solubility in the solvent, which is preferable. Furthermore, the organic compound represented by the above general formula (G2) may have alkyl groups as substituents, and in this case as well, they may have ether bonds, sulfide bonds, or amine-mediated bonds.

[0144] As specific examples of secondary amines, it is preferable to use organic compounds represented by the following structural formulas (Am2-1) to (Am2-32). The organic compounds represented by the following structural formulas (Am2-1) to (Am2-32) have an NH group.

[0145] [ka]

[0146] [ka]

[0147] [ka]

[0148] [ka]

[0149] [ka]

[0150] Amine compounds can be mixed with sulfonic acid compounds and used in ink materials. When mixed with sulfonic acid compounds, carriers are easily generated, improving conductivity. Mixing with sulfonic acid compounds is sometimes referred to as p-doping. Using a secondary amine as the amine compound is preferable because it can form bonds through dehydration reactions with the mixed sulfonic acid compound. When the compound to be mixed with the amine compound is a fluoride, using a fluoride as the amine compound, such as those with the above structural formulas (Am2-2), (Am2-22) to (Am2-28), or (Am2-31), is preferable because it improves compatibility.

[0151] Furthermore, thiophene derivatives may be used instead of secondary amines. Specific examples of thiophene derivatives include organic compounds represented by structural formulas (T-1) to (T-4) below, polythiophene, or poly(3,4-ethylenedioxythiophene) (PEDOT). Mixing thiophene derivatives with sulfonic acid compounds facilitates carrier generation and improves conductivity. This mixing with sulfonic acid compounds is sometimes referred to as p-doping.

[0152] [ka]

[0153] Sulfonic acid compounds are materials that exhibit acceptability. Examples of sulfonic acid compounds include aryl sulfonic acids. Aryl sulfonic acids only need to have a sulfo group, and can be sulfonic acids, sulfonates, alkoxysulfonic acids, halogenated sulfonic acids, or sulfonic acid anions. These sulfo groups may be multiple. The aryl group of the aryl sulfonic acid can be a substituted or unsubstituted aryl group having 6 to 16 carbon atoms. Examples of aryl groups include phenyl, biphenyl, naphthyl, fluorenyl, phenantrenyl, anthryl, or pyrenyl groups, with naphthyl groups being particularly preferred due to their good solubility and transportability in solvents. Aryl sulfonic acids may also have multiple aryl groups. Furthermore, aryl sulfonic acids with fluorine-substituted aryl groups are preferred because they can adjust the LUMO (Lowest Unoccupied Molecular Orbital) level to be deeper (larger negative). Furthermore, arylsulfonic acid may have ether bonds, sulfide bonds, or amine-mediated bonds. When it has multiple aryl groups, these bonds improve solubility in the solvent and are therefore preferable. Also, arylsulfonic acid may have alkyl groups as substituents, or the substituents may be ether bonds, sulfide bonds, or amine-mediated bonds. Furthermore, arylsulfonic acid may be substituted for part of the polymer. Polyethylene, nylon, polystyrene, or polyfluorenylene can be used as the polymer, but polystyrene or polyfluorenylene are preferred due to their good conductivity.

[0154] Specific examples of compounds containing arylsulfonic acid (arylsulfonic acid compounds) include, for example, organic compounds represented by structural formulas (S-1) to (S-15) below. Polymers having sulfo groups, such as poly(4-styrenesulfonic acid) (PSS), can also be used. By using arylsulfonic acid compounds, electrons can be accepted from shallow electron donors (amine compounds, carbazole compounds, or thiophene compounds, etc.) in the HOMO (highest occupied molecular orbital), and by mixing with the electron donor, hole injection or hole transport properties from the electrode can be achieved. By using a fluorine compound instead of the arylsulfonic acid compound, the LUMO level can be adjusted to be deeper (having a more negative energy level).

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[0159] The ink material obtained by mixing the above-mentioned secondary amine and sulfonic acid compound may further contain a tertiary amine. Tertiary amines are more electrochemically and photochemically stable than secondary amines, and when mixed, they exhibit good hole transport properties. As the tertiary amine, for example, organic compounds represented by the following structural formulas (Am3-1) to (Am3-7) are preferred. In addition to the tertiary amine, other materials with hole transport properties may be appropriately mixed into the ink material.

[0160] [ka]

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[0162] In addition to aryl sulfonic acid compounds, cyano compounds such as tetracyanoquinodimethane compounds can also be used as electron acceptors. Specifically, examples include 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ) or dipyradino[2,3-f:2′,3′-h]quinoxaline-2,3,6,7,10,11-hexacarbonnitrile (HAT-CN6).

[0163] Furthermore, it is preferable that the ink material obtained by mixing the above monomers contains either or both of a 3,3,3-trifluoropropyltrimethoxysilane compound or a phenyltrimethoxysilane compound, as this improves wettability when a film is formed by a wet process.

[0164] When a layer deposited by a wet process using an ink material containing at least two monomers, such as a secondary amine or thiophene and an aryl sulfonic acid, is measured by ToF-SIMS, a signal is observed around m / z=80 in the negative mode. The signal at m / z=80 originates from the SO3 anion in the aryl sulfonic acid. On the other hand, signals originating from the amine monomer are not easily observed in the above layer. If a light-emitting device having this layer exhibits sufficient luminescence, it is evidence that the layer possesses sufficient hole transport capability. When the above signal and other analytical results are obtained in a light-emitting device that can emit light, it is found that the layer has sufficient hole transport capability, and the absence of observation of the amine or other backbone responsible for hole transport capability suggests that the monomers are bonded together to form a polymer compound film. The above analytical results indicate that the layer was formed by a wet process.

[0165] Furthermore, the sulfonic acid compounds represented by the above structural formulas (S-1) or (S-2) are preferred because they have many sulfo groups, can form three-dimensional bonds with amine compounds, and tend to stabilize the film. In addition to the signal at m / z=80, a signal at m / z=901 is observed in the negative mode in the layer prepared using the aryl sulfonic acid compound. A signal at m / z=328 is also observed as a product ion.

[0166] In one embodiment of the present invention, it is preferable to use an iridium complex represented by the following structural formula as the light-emitting material. The iridium complex shown below is preferable because it has an alkyl group, making it readily soluble in solvents and easy to prepare as an ink material.

[0167] [ka]

[0168] Furthermore, when the luminescent layer containing the iridium complex represented by the above structural formula is measured by ToF-SIMS, it has been found that in the positive mode, signals appear at m / z=1676 or at the product ions m / z=1181 and m / z=685.

[0169] <About the tandem structure> Figure 3D shows a tandem-structured light-emitting element (also called a stacked light-emitting element or a stacked light-emitting element) in which multiple light-emitting units are stacked. This light-emitting element has at least a first light-emitting unit 103a and a second light-emitting unit 103b between the anode and the cathode. One of the light-emitting units has a configuration that is substantially the same as the light-emitting unit 103 shown in Figure 3A, etc.

[0170] In a tandem-structured light-emitting element, a first light-emitting unit 103a and a second light-emitting unit 103b are stacked between a first electrode 102 and a second electrode 161, and a charge generation layer 16 is provided between the first light-emitting unit 103a and the second light-emitting unit 103b. The charge generation layer 16 can be fabricated by a wet process. Subsequently, the occurrence of crosstalk can be suppressed by processing the charge generation layer 16.

[0171] The first light-emitting unit 103a and the second light-emitting unit 103b may have the same configuration or different configurations. In the case of different configurations, it is preferable that the first light-emitting unit 103a and the second light-emitting unit 103b emit complementary colors that produce white light when illuminated. Furthermore, by using a color filter with the white-emitting light-emitting element, full-color display becomes possible.

[0172] The charge generation layer 16 has the function of injecting electrons into one light-emitting unit and holes into the other light-emitting unit when a voltage is applied to the first electrode 102 and the second electrode 161. That is, when a voltage is applied such that the potential of the first electrode 102 is higher than the potential of the second electrode 161, the charge generation layer 16 only needs to inject electrons into the first light-emitting unit 103a and holes into the second light-emitting unit 103b.

[0173] The charge generation layer 16 is preferably formed with the same configuration as the charge generation layer 16 described in Figure 3B. A composite material of an organic compound and a metal oxide is a suitable material for the charge generation layer 16. This composite material is preferable because it exhibits excellent carrier implantation and carrier transport properties, enabling low-voltage and low-current operation.

[0174] Alternatively, the light-emitting unit may have a charge generation layer on the anode side. In this configuration, the charge generation layer can also serve as the hole injection layer of the light-emitting unit, so it is not necessary to provide a hole injection layer on the anode side of the light-emitting unit.

[0175] Furthermore, the charge generation layer 16 may have an electron injection buffer layer 24 as described in Figure 3B.

[0176] Since the electron injection buffer layer 24 plays the role of an electron injection layer in the anode-side light-emitting unit, an electron injection layer does not need to be provided in the anode-side light-emitting unit.

[0177] The above describes a tandem structure element having two light-emitting units, but the same principles can be applied to tandem structure elements with three or more light-emitting units stacked on top of each other.

[0178] By arranging multiple light-emitting units between a pair of electrodes and placing a charge generation layer between them, it is possible to achieve high-brightness light emission while maintaining a low current density, and to realize a light-emitting element with a long lifespan. Furthermore, it is possible to realize a light-emitting device that can be driven at a low voltage and consumes low power.

[0179] Furthermore, by making the emitted colors of each light-emitting unit different, it is possible to obtain the emission of a desired color from the light-emitting element as a whole. For example, in a light-emitting element having two light-emitting units, it is possible to obtain a light-emitting element that emits white light as a whole by obtaining red and green emitted colors from the first light-emitting unit and blue emitted color from the second light-emitting unit.

[0180] Furthermore, the light-emitting material in the light-emitting unit described with reference to Figure 3 may be a phosphorescent material or a fluorescent material. The light-emitting layer of the light-emitting unit can be fabricated by a wet process using a phosphorescent material or a fluorescent material and a solvent. Subsequently, the light-emitting layer can be processed by photolithography or the like to suppress the occurrence of crosstalk.

[0181] <About top-emission type> Figure 3E shows the direction of light extraction from the light-emitting element with an upward arrow, illustrating a top-emission type where light is extracted from the second electrode 161 side. The first electrode 102 corresponds to the first electrode 102 shown in Figure 1, etc., but since the light is not blocked by the semiconductor element positioned below the first electrode 102, the aperture ratio is expected to be higher. In this way, it is possible to increase the aperture ratio by changing the direction of light extraction from the light-emitting element.

[0182] <About bottom emission type> Figure 3F shows a bottom emission type where the direction of light extraction is indicated by a downward arrow, and light is extracted from the side of the first electrode 102. The first electrode 102 corresponds to the first electrode 102 shown in Figure 1, etc., but the light may be blocked by a semiconductor element placed below the first electrode 102. However, by using a semiconductor element with high light transmittance, a high aperture ratio can be maintained.

[0183] The details described in this embodiment can be used in combination with other embodiments.

[0184] (Embodiment 2) This embodiment describes a method 2 for manufacturing a display device according to one aspect of the present invention. Method 2 differs from method 1 in the order of steps for manufacturing the sacrificial layer 150.

[0185] <Method for manufacturing a display device 2> Similar to Embodiment 1 described above, the light-emitting layer is formed by a wet process, such as an inkjet method. Then, as shown in Figure 4A, an electron transport layer 160a, which is the upper common layer of the light-emitting element, is formed. The method or materials for manufacturing the electron transport layer 160a can be found in Embodiment 1, etc.

[0186] As shown in Figure 4B, a sacrificial layer 150 is formed. The method or materials for producing the sacrificial layer 150 can be found in Embodiment 1, etc.

[0187] As shown in Figure 4C, resist masks RES1, RES2, and RES3 are formed. Methods and materials for manufacturing resist masks RES1, RES2, and RES3 can be found in Embodiment 1, etc.

[0188] As shown in Figure 4D, the material layer 122 and electron transport layer 160a are processed using a first resist mask RES1 by photolithography or the like, specifically by removing a portion of them to form a processed material layer 123 and a processed first electron transport layer 126a. The material layer 132 and electron transport layer 160a are processed using a second resist mask RES2, specifically by removing a portion of them to form a processed material layer 133 and a processed second electron transport layer 136a. The material layer 142 and electron transport layer 160a are processed using a third resist mask RES3, specifically by removing a portion of them to form a processed material layer 143 and a processed third electron transport layer 146a.

[0189] Since the processing is carried out with a sacrificial layer 150 in place, it is preferable that the individual material layers do not disappear. Furthermore, the sacrificial layer 150 can be removed simultaneously with the first resist mask RES1 to the third resist mask RES3.

[0190] After removal, material layers 123, 133, and 143 corresponding to the light-emitting layer can be obtained. A first electron transport layer 126a, a second electron transport layer 136a, and a third electron transport layer 146a can be obtained on the light-emitting layer. The electron transport layer is an upper common layer of the light-emitting element, but it may also be processed using a resist mask. Crosstalk can be suppressed.

[0191] As shown in Figure 4E, the electron injection layer 160b and the second electrode 161 are formed. The method or materials for fabricating the electron injection layer 160b and the second electrode 161 can be found in Embodiment 1.

[0192] The above manufacturing method 2 will be explained using a flowchart.

[0193] As shown in step S11 of Figure 5, a semiconductor element, an insulator 105 having a first electrode 102 and an opening 104 of the light-emitting element is formed on the first substrate 100. Such step S11 includes the semiconductor element fabrication process, also known as the backplane process.

[0194] As shown in step S12 of Figure 5, the lower common layer of the light-emitting element is fabricated. The lower common layer can be one or more selected from the hole injection layer and the hole transport layer.

[0195] The common layer can be formed using a wet process. Examples of wet processes include inkjet printing or spin coating.

[0196] The common layer may be formed using a vapor deposition method. Vacuum deposition is preferred as the vapor deposition method.

[0197] As shown in step S13 of Figure 5, each light-emitting layer is fabricated using a wet process.

[0198] The light-emitting layer can be formed using a wet process. Examples of wet processes include inkjet printing or spin coating.

[0199] As shown in step S14 of Figure 5, the upper common layer of the light-emitting element is fabricated. The upper common layer can be one or more selected from the electron injection layer and the electron transport layer, but for example, an electron transport layer is formed.

[0200] The common layer can be formed using a wet process. Examples of wet processes include inkjet printing or spin coating.

[0201] The common layer may be formed using a vapor deposition method. Vacuum deposition is preferred as the vapor deposition method.

[0202] As shown in step S15 of Figure 5, a sacrificial layer is formed.

[0203] As shown in step S16 of Figure 5, the material layer is processed using photolithography or the like. This process is preferable because it is performed with a sacrificial layer in place, preventing the individual material layers from being lost. Note that a resist mask is required for processing using photolithography or the like.

[0204] As shown in step S17 of Figure 5, the sacrificial layer is removed. At the same time, the resist mask is removed.

[0205] As shown in step S18 of Figure 5, the upper common layer of the light-emitting element is fabricated. The upper common layer can be one or more selected from the electron injection layer and the electron transport layer, but for example, an electron injection layer is formed.

[0206] As shown in step S19 of Figure 5, the second electrode of the light-emitting element is fabricated. This completes the process described above using Figure 4, etc.

[0207] Next, preferably as shown in step S20 of Figure 5, a protective film is formed on the second electrode. The protective film can be fabricated by sputtering or plasma CVD. The protective film may have an inorganic material, and silicon oxide, silicon nitride, silicon oxynitride, or aluminum oxide can be used. The protective film may also use a laminated structure in which these materials are stacked.

[0208] Next, as shown in step S21 of Figure 5, the product is sealed with a second substrate. For sealing, a solid sealing structure or a hollow sealing structure can be applied. A solid sealing structure is a structure that seals with an adhesive such as an organic resin. In a solid sealing structure, the second substrate can be omitted. A hollow sealing structure is a structure that seals by filling the enclosed space with an inert gas (such as nitrogen or argon).

[0209] The details described in this embodiment can be used in combination with other embodiments.

[0210] (Embodiment 3) This embodiment describes an example of a transistor configuration that can be applied to a display device according to one aspect of the present invention. In particular, it describes a case in which a transistor containing silicon is used as the semiconductor in which the channel is formed. The semiconductor containing silicon is sometimes referred to as a silicon layer.

[0211] One aspect of the present invention is a display device having a light-emitting element and a pixel circuit in its display section. The display device can be a full-color display device by having, for example, three types of light-emitting elements that emit red (R), green (G), or blue (B) light, respectively. To distinguish between the three types of light-emitting elements that emit red (R), green (G), and blue (B) light, they may be referred to as the first light-emitting element, the second light-emitting element, and the third light-emitting element.

[0212] Furthermore, it is preferable that all transistors included in the pixel circuit that drives the light-emitting element have silicon in the semiconductor layer where the channel is formed. Examples of silicon include single-crystal silicon, polycrystalline silicon, and amorphous silicon. In particular, it is preferable to use transistors having low-temperature polysilicon (LTPS (Low Temperature Poly Silicon)) in the semiconductor layer (hereinafter also referred to as LTPS transistors). LTPS transistors have silicon crystallized within a temperature range that can be formed on a glass substrate, and have high field-effect mobility and good frequency characteristics.

[0213] By using silicon-based transistors such as LTPS transistors, circuits that need to be driven at high frequencies (for example, source driver circuits) can be fabricated on the same board as the display unit. This simplifies the external circuits implemented in the display device, reducing component and mounting costs.

[0214] Furthermore, it is preferable that at least one of the transistors included in the pixel circuit is a transistor having a metal oxide (hereinafter also referred to as an oxide semiconductor) as its semiconductor (hereinafter also referred to as an OS transistor).

[0215] The oxide semiconductor is not particularly limited in terms of crystallinity, and any amorphous semiconductor, single-crystal semiconductor, or semiconductor having crystalline properties other than single crystal (microcrystalline semiconductor, polycrystalline semiconductor, or semiconductor having a crystalline region in part) may be used. Using a single-crystal semiconductor or a crystalline oxide semiconductor is preferable because it can suppress the degradation of transistor characteristics.

[0216] The band gap of the oxide semiconductor is preferably 2 eV or more, and more preferably 2.5 eV or more. By using a metal oxide with a large band gap as the oxide semiconductor, the off-current of the OS transistor can be reduced.

[0217] The metal oxide preferably contains at least indium or zinc, and more preferably indium and zinc. For example, the metal oxide preferably contains indium, M (where M is one or more selected from gallium, aluminum, yttrium, tin, silicon, boron, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, magnesium, and cobalt), and zinc. In particular, M is preferably one or more selected from gallium, aluminum, yttrium, and tin, and gallium is more preferred. A metal oxide containing indium, M, and zinc is sometimes called an In-M-Zn oxide.

[0218] When the metal oxide is an In-M-Zn oxide, it is preferable that the atomic ratio of In in the In-M-Zn oxide is equal to or greater than the atomic ratio of M. Examples of such In-M-Zn oxide atomic ratios of metal elements include compositions where In:M:Zn=1:1:1 or close to it, In:M:Zn=1:1:1.2 or close to it, In:M:Zn=2:1:3 or close to it, In:M:Zn=3:1:2 or close to it, In:M:Zn=4:2:3 or close to it, In:M:Zn=4:2:4.1 or close to it, In:M:Zn=5:1:3 or close to it, In:M:Zn=5:1:6 or close to it, In:M:Zn=5:1:7 or close to it, In:M:Zn=5:1:8 or close to it, In:M:Zn=6:1:6 or close to it, In:M:Zn=5:2:5 or close to it, and so on. Note that "close to it" compositions include a range of ±30% of the desired atomic ratio. Increasing the atomic ratio of indium in a metal oxide can increase the on-current or field-effect mobility of an OS transistor.

[0219] The following explains the case where Ga is applied to M. When the atomic ratio is described as In:Ga:Zn=4:2:3 or a composition close to it, it includes the case where, when the atomic ratio of In is 4, the atomic ratio of Ga is 1 or more and 3 or less, and the atomic ratio of Zn is 2 or more and 4 or less. Also, when the atomic ratio is described as In:Ga:Zn=5:1:6 or a composition close to it, it includes the case where, when the atomic ratio of In is 5, the atomic ratio of Ga is greater than 0.1 and 2 or less, and the atomic ratio of Zn is 5 or more and 7 or less. Also, when the atomic ratio is described as In:Ga:Zn=1:1:1 or a composition close to it, it includes the case where, when the atomic ratio of In is 1, the atomic ratio of Ga is greater than 0.1 and 2 or less, and the atomic ratio of Zn is greater than 0.1 and 2 or less.

[0220] Furthermore, the atomic ratio of In in an In-M-Zn oxide may be less than the atomic ratio of M. Examples of such atomic ratios of metal elements in an In-M-Zn oxide include compositions where In:M:Zn = 1:3:2 or close to it, compositions where In:M:Zn = 1:3:3 or close to it, and compositions where In:M:Zn = 1:3:4 or close to it. By increasing the atomic ratio of M in the metal oxide, it is possible to increase the band gap of the In-M-Zn oxide and improve its resistance to photo-negative bias stress testing. Specifically, it is possible to reduce the change in threshold voltage or the change in shift voltage (Vsh) measured in the NBTIS (Negative Bias Temperature Illumination Stress) test of an OS transistor. Note that the shift voltage (Vsh) is defined as the Vg at which the tangent line at the point where the slope of the drain current (Id)-gate voltage (Vg) curve is maximum intersects the straight line where Id = 1 pA.

[0221] OS transistors have extremely high field-effect mobility compared to transistors using amorphous silicon. Furthermore, OS transistors exhibit remarkably low source-drain leakage current (hereinafter also referred to as off-current) in the off state, allowing them to retain charge stored in a capacitor connected in series with the OS transistor for extended periods. By applying such OS transistors, the power consumption of display devices can be reduced.

[0222] By using LTPS transistors for some of the multiple transistors included in the pixel circuit and OS transistors for others, a display device with low power consumption and high driving capability can be realized. A more preferable example is to apply OS transistors to transistors that function as switches to control conduction and non-conductivity between wiring, and to apply LTPS transistors to transistors that control current.

[0223] Among the multiple transistors provided in the pixel circuit, there is a transistor called a drive transistor that functions to control the current flowing through the light-emitting element. One of the source and drain of the drive transistor is electrically connected to the pixel electrode of the light-emitting element. It is preferable to use an LTPS transistor for this drive transistor. This allows the current flowing through the light-emitting element in the pixel circuit to be increased.

[0224] On the other hand, among the multiple transistors provided in the pixel circuit, there is a transistor called a selection transistor that functions as a switch to control the selection and deselection of pixels. The gate of the selection transistor is electrically connected to the gate line, and one of the source and drain is electrically connected to the source line (signal line). It is preferable to use an OS transistor for this selection transistor. This makes it possible to maintain the gradation of pixels even when the frame frequency is significantly reduced (for example, 1 fps or less), so that the clock signal from the gate driver etc. can be stopped when displaying a still image, and power consumption can be reduced.

[0225] Below, we will explain more specific configuration examples with reference to the drawings.

[0226] [Example of a display device configuration] Figure 6A shows a block diagram of the display device 410. The display device 410 includes a display unit 411, a drive circuit unit 412, a drive circuit unit 413, etc. The drive circuit unit 412 has a source driver, and the drive circuit unit 413 has a gate driver.

[0227] The display unit 411 has a plurality of pixels 430 arranged in a matrix. The pixels 430 include sub-pixels 421R, 421G, and 421B. Each of the sub-pixels 421R, 421G, and 421B has a light-emitting element, which functions as a display element.

[0228] Pixel 430 is electrically connected to wiring GL, wiring SLR, wiring SLG, and wiring SLB. Wiring SLR, wiring SLG, and wiring SLB are each electrically connected to drive circuit unit 412. Wiring GL is electrically connected to drive circuit unit 413. Drive circuit unit 412 functions as a source driver (also called a source line drive circuit), and drive circuit unit 413 functions as a gate driver (also called a gate line drive circuit). Wiring GL functions as a gate line, and wiring SLR, wiring SLG, and wiring SLB each function as source lines.

[0229] Sub-pixel 421R has a light-emitting element that emits red light. Sub-pixel 421G has a light-emitting element that emits green light. Sub-pixel 421B has a light-emitting element that emits blue light. This allows the display device 410 to display in full color. Pixel 430 may also have sub-pixels that emit other light-emitting elements. For example, in addition to the three sub-pixels described above, pixel 430 may have a sub-pixel that emits white light, or a sub-pixel that emits yellow light, etc.

[0230] Wiring GL is electrically connected to sub-pixels 421R, 421G, and 421B, which are arranged in the row direction (the direction in which wiring GL extends). Wiring SLR, SLG, and SLB are electrically connected to sub-pixels 421R, 421G, or 421B, respectively, which are arranged in the column direction (the direction in which wiring SLR, etc. extends) (sub-pixels arranged in the column direction are not shown).

[0231] [Example of pixel circuit configuration] Figure 6B shows an example of a pixel circuit 422 that can be applied to the sub-pixels 421R, 421G, and 421B. The pixel circuit 422 has transistors M1, M2, M3, capacitor C1, and light-emitting element EL. The pixel circuit 422 also has wiring GL and wiring SL. Wiring SL corresponds to one of the wirings SLR, SLG, and SLB shown in Figure 6A.

[0232] Transistor M1 has its gate electrically connected to wiring GL, one of its source and drain electrically connected to wiring SL, and the other of its source and drain electrically connected to one electrode of capacitor C1 and the gate of transistor M2. Transistor M2 has one of its source and drain electrically connected to wiring AL, and the other of its source and drain electrically connected to one electrode of light-emitting element EL, the other electrode of capacitor C1, and one of its source and drain electrical connections of transistor M3. One electrode of light-emitting element EL corresponds to, for example, the first electrode. Transistor M3 has its gate electrically connected to wiring GL, and the other of its source and drain electrically connected to wiring RL. The other electrode of light-emitting element EL is electrically connected to wiring CL. One electrode of light-emitting element EL corresponds to, for example, the second electrode.

[0233] A data potential D is applied to wiring SL. A selection signal is applied to wiring GL. This selection signal includes a potential that makes a transistor, whose gate is electrically connected to wiring GL, conduct, and a potential that makes it non-conductive.

[0234] A reset potential is applied to wiring RL. An anode potential is applied to wiring AL. A cathode potential is applied to wiring CL. In the pixel circuit 422, the anode potential is set to a potential higher than the cathode potential. The reset potential applied to wiring RL can be set to a potential such that the potential difference between the reset potential and the cathode potential is smaller than the threshold voltage of the light-emitting element EL. The reset potential can be set to a potential higher than the cathode potential, the same as the cathode potential, or lower than the cathode potential.

[0235] Transistors M1 and M3 function as switches. Transistors that function as switches are sometimes referred to as selection transistors. Transistor M2 functions as a transistor for controlling the current flowing through the light-emitting element EL. Transistors that function for controlling the current flowing through the light-emitting element EL are sometimes referred to as driving transistors. For example, it can be said that transistor M1 functions as a selection transistor, and transistor M2 functions as a driving transistor.

[0236] Here, it is preferable to apply LTPS transistors to all of transistors M1 through M3. Alternatively, it is preferable to apply OS transistors to transistors M1 and M3 and an LTPS transistor to transistor M2.

[0237] Alternatively, OS transistors may be applied to all of transistors M1 through M3. In this case, one or more of the multiple transistors in the drive circuit unit 412 and the multiple transistors in the drive circuit unit 413 may be LTPS transistors, and the other transistors may be OS transistors. For example, OS transistors may be applied to the transistors provided in the display unit 411, and LTPS transistors may be applied to the transistors provided in the drive circuit unit 412 and the drive circuit unit 413.

[0238] To reiterate, an OS transistor is a transistor that uses an oxide semiconductor in the semiconductor layer where the channel is formed. The oxide semiconductor preferably contains, for example, indium, M (where M is one or more selected from gallium, aluminum, silicon, boron, yttrium, tin, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, and magnesium), and zinc. In particular, it is preferable that M is one or more selected from aluminum, gallium, yttrium, and tin. In particular, it is preferable to use an oxide containing indium, gallium, and zinc (also written as IGZO) as the semiconductor of the OS transistor. Alternatively, it is preferable to use an oxide containing indium, tin, and zinc as the semiconductor of the OS transistor. Alternatively, it is preferable to use an oxide containing indium, gallium, tin, and zinc as the semiconductor of the OS transistor.

[0239] OS transistors using oxide semiconductors, which have a wider bandgap and lower carrier density than silicon, can achieve extremely low off-currents. Therefore, this low off-current allows the charge stored in the capacitor connected in series with the OS transistor to be retained for extended periods. For this reason, it is preferable to use OS transistors made of oxide semiconductors for transistors M1 and M3, which are connected in series with capacitor C1. By using OS transistors as transistors M1 and M3, it is possible to prevent the charge held in capacitor C1 from leaking through either transistor M1 or M3. Furthermore, because the charge held in capacitor C1 can be retained for extended periods, it becomes possible to display still images for extended periods without rewriting the data in pixel 421.

[0240] Note that in Figure 6B, the transistor is shown as an n-channel transistor, but a p-channel transistor can also be used.

[0241] Furthermore, it is preferable that each transistor in the pixel circuit 422 be formed in a row on the same substrate.

[0242] The transistors in the pixel circuit 422 can be transistors having a pair of gates that overlap across a semiconductor layer. The transistors in the pixel circuit 422 are LTPS transistors or OS transistors.

[0243] In a transistor having a pair of gates, configuring the pair of gates to be electrically connected to each other and given the same potential offers advantages such as increased on-current and improved saturation characteristics. Alternatively, one of the pair of gates may be given a potential that controls the transistor's threshold voltage. Furthermore, providing a constant potential to one of the pair of gates can improve the stability of the transistor's electrical characteristics. For example, one of the transistor's gates may be electrically connected to a wiring to which a constant potential is provided, or it may be electrically connected to its own source or drain.

[0244] The pixel circuit 422 shown in Figure 6C is an example in which transistors M1 and M3 are transistors having a pair of gates. The pair of gates of transistors M1 and M3 are electrically connected. This configuration makes it possible to shorten the data writing period to the pixel circuit 422.

[0245] The pixel circuit 422 shown in Figure 6D is an example in which a transistor with a pair of gates is applied to transistor M2, in addition to transistors M1 and M3. The pair of gates of transistor M2 are electrically connected. By applying such a transistor to transistor M2, the saturation characteristics are improved, making it easier to control the luminescence brightness of the light-emitting element EL and improving the display quality.

[0246] [Example of cross-sectional configuration of a display device] The following describes examples of transistor cross-sectional configurations that can be applied to the above-mentioned display device.

[0247] [Configuration Example 1] Figure 7A is a cross-sectional view including transistor 310.

[0248] Transistor 310 is an LTPS transistor provided on substrate 301, with polycrystalline silicon applied to its semiconductor layer. For example, transistor 310 corresponds to transistor M2 in the pixel circuit 422 shown in Figures 6B to 6D. That is, Figure 7A shows an example where one of the source and drain of transistor 310 is electrically connected to the conductive layer 331 of the light-emitting element. The conductive layer 331 may be referred to as the pixel electrode or first electrode of the light-emitting element.

[0249] The transistor 310 has a semiconductor layer 311, an insulating layer 312, a conductive layer 313, etc. The semiconductor layer 311 has a channel formation region 311i and a low-resistance region 311n. At least the channel formation region 311i has silicon, preferably polycrystalline silicon. A part of the insulating layer 312 functions as a gate insulating layer. A part of the conductive layer 313 functions as a gate electrode. The semiconductor layer 311 overlapping with the conductive layer 313 becomes the channel formation region 311i. The conductive layer 313 overlapping with the semiconductor layer 311 also functions as a gate electrode.

[0250] Furthermore, the semiconductor layer 311 may also be configured to include a metal oxide (also called an oxide semiconductor) exhibiting semiconductor properties in at least the channel formation region. In other words, an OS transistor may be used for the transistor 310.

[0251] The low-resistance region 311n is a region containing impurity elements. For example, if transistor 310 is an n-channel type transistor, phosphorus, arsenic, etc., can be added to the low-resistance region 311n. On the other hand, if it is a p-channel type transistor, boron, aluminum, etc., can be added to the low-resistance region 311n. Furthermore, in order to control the threshold voltage of transistor 310, the aforementioned impurities may also be added to the channel formation region 311i.

[0252] An insulating layer 321 is provided on the substrate 301. The semiconductor layer 311 is provided on the insulating layer 321. The insulating layer 312 is provided covering the semiconductor layer 311 and the insulating layer 321. The conductive layer 313 is provided on the insulating layer 312 in a position overlapping with the semiconductor layer 311.

[0253] Furthermore, an insulating layer 322 is provided covering 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 at openings provided in the insulating layers 322 and 312. A portion of the conductive layer 314a functions as one of the source electrode and drain electrode, and a portion of the conductive layer 314b functions as the other of the source electrode and drain electrode. In addition, an insulating layer 323 is provided covering the conductive layer 314a, conductive layer 314b, and insulating layer 322.

[0254] A conductive layer 331, which functions as a pixel electrode, is provided on the insulating layer 323. The conductive layer 331 is provided on the insulating layer 323 and is electrically connected to the conductive layer 354b at an opening provided in the insulating layer 323. Since the conductive layer 331 functions as a reflective electrode, it is preferable that its upper surface has a high reflectivity to visible light. Although omitted here, a functional layer and a common electrode can be laminated on the conductive layer 331, and the light-emitting layer and the like of the functional layer may be formed using a wet process.

[0255] [Configuration Example 2] FIG. 7B shows a transistor 310a having a pair of gate electrodes. The transistor 310a shown in FIG. 7B is mainly different from FIG. 7A in that it has a conductive layer 315 and an insulating layer 316. Note that since the semiconductor layer 311 can also be configured to include a metal oxide (also referred to as an oxide semiconductor) that exhibits semiconductor characteristics at least in the channel formation region, an OS transistor may be applied to the transistor 310a.

[0256] The conductive layer 315 is provided on the insulating layer 321. Further, an insulating layer 316 is provided to cover the conductive layer 315 and the insulating layer 321. The semiconductor layer 311 is provided such that at least the channel formation region 311i overlaps with the conductive layer 315 via the insulating layer 316.

[0257] In the transistor 310a shown in FIG. 7B, a part of the conductive layer 313 functions as the first gate electrode, and a part of the conductive layer 315 functions as the second gate electrode. At this time, a part of the insulating layer 312 functions as the first gate insulating layer, and a part of the insulating layer 316 functions as the second gate insulating layer.

[0258] Here, as shown in FIG. 6C or FIG. 6D, when the first gate electrode and the second gate electrode are electrically connected, in a region not shown, the conductive layer 313 and the conductive layer 315 may be electrically connected through openings provided in the insulating layer 312 and the insulating layer 316. Further, when the second gate electrode and the source or drain are electrically connected, in a region not shown, the conductive layer 314a or the conductive layer 314b and the conductive layer 315 may be electrically connected through openings provided in the insulating layer 322, the insulating layer 312, and the insulating layer 316.

[0259] When LTPS transistors are applied to all the transistors constituting the pixel circuit 422 in Figures 6B to 6D, the transistor 310 exemplified in Figure 7A or the transistor 310a exemplified in Figure 7B can be applied. In this case, transistor 310a may be used for all transistors constituting the pixel circuit, or transistor 310 may be applied to all transistors, or a combination of transistor 310a and transistor 310 may be used.

[0260] [Configuration Example 3] The following describes an example of a configuration that includes both a transistor with a silicon semiconductor layer and an OS transistor with a metal oxide semiconductor layer. The semiconductor layer with a metal oxide is sometimes referred to as an oxide semiconductor layer.

[0261] Figure 7C shows a schematic cross-sectional view including transistors 310a and 350. Although Figure 7C shows an example using transistor 310a, transistor 310 may be used instead of transistor 310a, and a modified version of Figure 7C may include a configuration with transistors 310 and 350. Alternatively, transistor 310 may be used instead of transistor 350, and a modified version of Figure 7C may include a configuration with transistors 310 and 310a.

[0262] For transistor 310, the above configuration example 1 can be used, and for transistor 310a, the above configuration example 2 can be used. Transistor 310a can be an LTPS transistor, and can be applied to one or both selected from transistors M2 and M3 of the pixel circuit 422 in Figures 6B to 6D.

[0263] Transistor 350 can be an OS transistor with a metal oxide applied to the semiconductor layer, and can be applied to transistor M1 of the pixel circuit 422 in Figures 6B to 6D. That is, Figure 7C is an example in which one of the source and drain of transistor 310a is electrically connected to the conductive layer 331.

[0264] Figure 7C also shows an example where transistor 350 has a pair of gates.

[0265] The transistor 350 has a conductive layer 355, an insulating layer 322, a semiconductor layer 351, an insulating layer 352, a conductive layer 353, etc. A portion of the conductive layer 353 functions as the first gate of the transistor 350, and a portion of the conductive layer 355 functions as the second gate of the transistor 350. At this time, a portion of the insulating layer 352 functions as the first gate insulating layer of the transistor 350, and a portion of the insulating layer 322 functions as the second gate insulating layer of the transistor 350.

[0266] The conductive layer 355 is provided on the insulating layer 312. The insulating layer 322 is provided covering the conductive layer 355. The semiconductor layer 351 is provided on the insulating layer 322. The insulating layer 352 is provided covering the semiconductor layer 351 and the insulating layer 322. The conductive layer 353 is provided on the insulating layer 352 and has a region that overlaps with the semiconductor layer 351 and the conductive layer 355.

[0267] Furthermore, an insulating layer 326 is provided covering 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 at openings provided in the insulating layer 326 and insulating layer 352. A portion of the conductive layer 354a functions as one of the source electrode and drain electrode, and a portion of the conductive layer 354b functions as the other of the source electrode and drain electrode. It is preferable that conductive layers 354a and 354b are manufactured using the same process as conductive layers 314a and 314b. In addition, an insulating layer 323 is provided covering the conductive layer 354a, conductive layer 354b, and insulating layer 326.

[0268] Here, it is preferable that the conductive layers 314a and 314b, which are electrically connected to the transistor 310a, are formed by processing the same conductive film as conductive layers 354a and 354b. Figure 7C shows a configuration in which conductive layers 314a, 314b, 354a, and 354b are formed on the same plane (i.e., in contact with the upper surface of the insulating layer 326) and contain the same metal element. In this case, conductive layers 314a and 314b are electrically connected to the low-resistance region 311n through openings provided in the insulating layer 326, insulating layer 352, insulating layer 322, and insulating layer 312. This is preferable because it simplifies the manufacturing process.

[0269] Furthermore, it is preferable that the conductive layer 313, which functions as the first gate electrode of transistor 310a, and the conductive layer 355, which functions as the second gate electrode of transistor 350, are formed by processing the same conductive film. Figure 7C shows a configuration in which the conductive layer 313 and the conductive layer 355 are formed on the same plane (i.e., in contact with the upper surface of the insulating layer 312) and contain the same metal element. This is preferable because it simplifies the manufacturing process.

[0270] In Figure 7C, the insulating layer 352, which functions as the first gate insulating layer of the transistor 350, is configured to cover the edge of the semiconductor layer 351. However, as shown in Figure 7D, the insulating layer 352 may be processed so that its upper surface shape roughly matches that of the conductive layer 353.

[0271] In this specification, "approximately matching top surface shapes" means that at least a portion of the contours overlap between stacked layers. For example, this includes cases where the upper and lower layers are processed with the same mask pattern, or partially with the same mask pattern. However, strictly speaking, the contours may not overlap, and the upper layer may be located inside the lower layer, or the upper layer may be located outside the lower layer; in this case, too, it is said that the "top surface shapes are approximately matching."

[0272] Here, an example where the transistor 310a corresponds to the transistor M2 and is electrically connected to the pixel electrode has been shown, but it is not limited to this. For example, the transistor 350 or the transistor 350a may be configured to correspond to the transistor M2. At this time, the transistor 310a corresponds to one or both selected from the transistors M1 and M3, or other transistors.

[0273] The configuration examples illustrated in this embodiment, and the corresponding drawings and the like, can be appropriately combined with at least a part of other configuration examples, or drawings and the like.

[0274] This embodiment can be implemented by appropriately combining at least a part of it with other embodiments described in this specification.

[0275] (Embodiment 4) In this embodiment, the configuration of the information processing apparatus according to an aspect of the present invention will be described with reference to the drawings.

[0276] FIGS. 8 to 10 are diagrams for explaining the configuration of the information processing apparatus according to an aspect of the present invention. FIG. 8A is a block diagram of the information processing apparatus, and FIGS. 8B to 8E are perspective views for explaining the configuration of the information processing apparatus. Further, FIGS. 9A to 9E are perspective views for explaining the configuration of the information processing apparatus. Further, FIGS. 10A and 10B are perspective views for explaining the configuration of the information processing apparatus.

[0277] <Information Processing Apparatus> The information processing apparatus 5200B described in this embodiment includes an arithmetic unit 5210 and an input / output unit 5220 (see FIG. 8A).

[0278] The arithmetic unit 5210 has a function of supplying operation information and a function of supplying image information based on the operation information.

[0279] The input / output device 5220 includes a display unit 5230, an input unit 5240, a detection unit 5250, a communication unit 5290, a function for supplying operation information, and a function for supplying image information. Furthermore, the input / output device 5220 includes a function for supplying detection information, a function for supplying communication information, and a function for receiving communication information.

[0280] The input unit 5240 has a function to supply operation information. For example, the input unit 5240 supplies operation information based on the user's operation of the information processing device 5200B.

[0281] Specifically, the input unit 5240 can use a keyboard, hardware buttons, pointing device, touch sensor, illuminance sensor, imaging device, voice input device, eye-tracking device, posture detection device, etc.

[0282] The display unit 5230 is equipped with a display device and a function for displaying image information. For example, the display device described in Embodiment 1 can be used in the display unit 5230.

[0283] The detection unit 5250 has a function to supply detection information. For example, it has a function to detect the surrounding environment in which the information processing device is being used and supply it as detection information.

[0284] Specifically, illuminance sensors, imaging devices, posture detection devices, pressure sensors, human presence sensors, etc., can be used in the detection unit 5250.

[0285] The communication unit 5290 has functions for receiving and supplying communication information. For example, it has functions for connecting with other electronic devices or communication networks via wireless or wired communication. Specifically, it has functions such as wireless local area communication, telephone communication, and short-range wireless communication.

[0286] 《Example of Information Processing Device Configuration 1》 For example, the outer shape of the display unit 5230 can be adapted to follow the shape of a cylindrical column or the like (see Figure 8B). It also has a function to change the display method according to the illumination of the usage environment. Furthermore, it has a function to detect the presence of a person and change the displayed content. This allows it to be installed, for example, on a building column. Alternatively, it can display advertisements or information. Or, it can be used for digital signage, etc.

[0287] 《Example of Information Processing Device Configuration 2》 For example, it has a function to generate image information based on the trajectory of the pointer used by the user (see Figure 8C). Specifically, a display device with a diagonal length of 20 inches or more, preferably 40 inches or more, and more preferably 55 inches or more can be used. Alternatively, multiple display devices can be arranged side by side to form a single display area. Alternatively, multiple display devices can be arranged side by side to form a multi-screen. This allows it to be used, for example, in electronic whiteboards, electronic bulletin boards, electronic signboards, etc.

[0288] 《Example of Information Processing Device Configuration 3》 Information can be received from other devices and displayed on the display unit 5230 (see Figure 8D). Alternatively, several options can be displayed. Alternatively, the user can select several options and reply to the source of the information. Alternatively, for example, the display method can be changed according to the illumination of the usage environment. This can reduce the power consumption of the smartwatch (registered trademark). Alternatively, for example, images can be displayed on the smartwatch so that it can be used suitably even in environments with strong ambient light, such as outdoors on a sunny day.

[0289] 《Example of Information Processing Device Configuration 4》 The display unit 5230 has, for example, a curved surface that gently curves along the side of the housing (see Figure 8E). Alternatively, the display unit 5230 includes a display device, which has the function of displaying on, for example, the front, side, top, and back. This allows information to be displayed not only on the front of the mobile phone, but also on the sides, top, and back.

[0290] 《Example of Information Processing Device Configuration 5》 For example, information can be received from the internet and displayed on the display unit 5230 (see Figure 9A). Alternatively, a created message can be viewed on the display unit 5230. Alternatively, a created message can be sent to another device. Alternatively, for example, the display method can be changed according to the illumination of the usage environment. This can reduce the power consumption of the smartphone. Alternatively, for example, images can be displayed on the smartphone so that it can be used suitably even in environments with strong ambient light, such as outdoors on a sunny day.

[0291] 《Example of Information Processing Device Configuration 6》 A remote controller can be used with the input unit 5240 (see Figure 9B). Alternatively, information can be received from a broadcasting station or the internet and displayed on the display unit 5230. Alternatively, the user can be photographed using the detection unit 5250. Alternatively, the user's video can be transmitted. Alternatively, the user's viewing history can be acquired and provided to a cloud service. Alternatively, recommendation information can be acquired from a cloud service and displayed on the display unit 5230. Alternatively, a program or video can be displayed based on the recommendation information. Alternatively, for example, a function can be provided to change the display method according to the illumination of the usage environment. This allows the video to be displayed on the television system in a way that is suitable for use even when strong sunlight shines into the room on a sunny day.

[0292] 《Example of Information Processing Device Configuration 7》 For example, educational materials can be received from the internet and displayed on the display unit 5230 (see Figure 9C). Alternatively, reports can be entered using the input unit 5240 and sent to the internet. Alternatively, correction results or evaluations of reports can be obtained from a cloud service and displayed on the display unit 5230. Alternatively, appropriate educational materials can be selected and displayed based on the evaluation.

[0293] For example, the display unit 5230 can receive image signals from other information processing devices and display them. Alternatively, it can be propped up on a stand or the like and used as a sub-display. This allows images to be displayed on the tablet computer in a way that is suitable for use even in environments with strong ambient light, such as outdoors on a sunny day.

[0294] 《Example of Information Processing Device Configuration 8》 The information processing device includes, for example, multiple display units 5230 (see Figure 9D). For example, it can display images on the display units 5230 while capturing them with the detection unit 5250. Alternatively, it can display captured images on the detection unit. Alternatively, it can use the input unit 5240 to add embellishments to captured images. Alternatively, it can attach messages to captured images. Alternatively, it can transmit images to the internet. Alternatively, it has a function to change the shooting conditions according to the illumination of the usage environment. This allows the subject to be displayed on the digital camera in a way that allows for suitable viewing even in environments with strong ambient light, such as outdoors on a sunny day.

[0295] 《Example of Information Processing Device Configuration 9》 For example, another information processing device can be used as a slave, and the information processing device of this embodiment can be used as a master to control the other information processing device (see Figure 9E). Alternatively, for example, a portion of the image information can be displayed on the display unit 5230, and another portion of the image information can be displayed on the display unit of the other information processing device. An image signal can be supplied. Alternatively, information to be written can be obtained from the input unit of the other information processing device using the communication unit 5290. This allows for the use of a wide display area, for example, by using a portable personal computer.

[0296] 《Example of Information Processing Device Configuration 10》 The information processing device includes, for example, a detection unit 5250 that detects acceleration or orientation (see Figure 10A). Alternatively, the detection unit 5250 can supply information relating to the user's position or the direction the user is facing. Alternatively, the information processing device can generate image information for the right eye and image information for the left eye based on the user's position or the direction the user is facing. Alternatively, the display unit 5230 includes a display area for the right eye and a display area for the left eye. This allows, for example, the display of an immersive virtual reality space on a goggle-type information processing device.

[0297] 《Example of Information Processing Device Configuration 11》 The information processing device includes, for example, an imaging device and a detection unit 5250 that detects acceleration or orientation (see Figure 10B). Alternatively, the detection unit 5250 can supply information relating to the user's position or the direction the user is facing. Alternatively, the information processing device can generate image information based on the user's position or the direction the user is facing. This allows, for example, information to be attached to and displayed on a real-world landscape. Alternatively, images of an augmented reality space can be displayed on a glasses-type information processing device.

[0298] This embodiment can be appropriately combined with other embodiments shown in this specification. [Explanation of symbols]

[0299] AL: wiring, CL: wiring, GL: wiring, RL: wiring, SL: wiring, SLB: wiring, SLG: wiring, SLR: wiring, 11: hole injection layer, 12: hole transport layer, 13a: light-emitting layer, 13b: light-emitting layer, 13c: light-emitting layer, 13: light-emitting layer, 14: electron transport layer, 15: electron injection layer, 16: charge generation layer, 17: hole transport region, 18: electron transport region, 22: electron relay layer, 23: P-type layer, 24: electron injection buffer layer, 100: first substrate, 102: first electrode, 103a: first light-emitting unit T, 103b: Second light-emitting unit, 103: Light-emitting unit, 104: Aperture, 105: Insulator, 109: Droplet, 110: Nozzle, 113: Material layer, 120: Nozzle, 121: Droplet, 122: Material layer, 123: Material layer, 126a: First electron transport layer, 130: Nozzle, 131: Droplet, 132: Material layer, 133: Material layer, 136a: Second electron transport layer, 140: Nozzle, 141: Droplet, 142: Material layer, 143: Material layer, 146a: Third electron transport layer, 150: Sacrificial layer, 1 60a: electron transport layer, 160b: electron injection layer, 160: layer, 161: second electrode, 301: substrate, 310a: transistor, 310: transistor, 311i: channel formation region, 311n: low resistance region, 311: semiconductor layer, 312: insulating layer, 313: conductive layer, 314a: conductive layer, 314b: conductive layer, 315: conductive layer, 316: insulating layer, 321: insulating layer, 322: insulating layer, 323: insulating layer, 326: insulating layer, 331: conductive layer, 350a: transistor, 350: transistor ZISTA, 351: Semiconductor layer, 352: Insulating layer, 353: Conductive layer, 354a: Conductive layer, 354b: Conductive layer, 355: Conductive layer, 410: Display device, 411: Display unit, 412: Drive circuit unit, 413: Drive circuit unit, 421B: Sub-pixel, 421G: Sub-pixel, 421R: Sub-pixel, 421: Pixel, 422: Pixel circuit, 430: Pixel, 5200B: Information processing device, 5210: Arithmetic unit, 5220: Input / output device, 5230: Display unit, 5240: Input unit, 5250: Detection unit, 5290: Communication unit

Claims

1. A first transistor having silicon in the channel formation region and a second transistor having oxide semiconductor in the channel formation region are formed on a substrate. A first electrode of the first light-emitting element is formed, which is electrically connected to the first transistor. An insulator having a first opening and a second opening that overlap at least with the first electrode is formed on the first transistor and the second transistor. A first material layer containing the organic compound of the first light-emitting element is formed in the first opening, and a second material layer containing the organic compound of the second light-emitting element is formed in the second opening, respectively, by a wet process. A first resist mask and a second resist mask are selectively formed on the first material layer and the second material layer, respectively. A method for manufacturing a display device, comprising: processing the first material layer using the first resist mask to form a third material layer so as not to overlap with the upper surface of the insulator; and processing the second material layer using the second resist mask to form a fourth material layer so as not to overlap with the upper surface of the insulator.

2. A first transistor having silicon in the channel formation region and a second transistor having oxide semiconductor in the channel formation region are formed on a substrate. A first electrode of the first light-emitting element is formed, which is electrically connected to the first transistor. An insulator having a first opening and a second opening that overlap at least with the first electrode is formed on the first transistor and the second transistor. A first material layer containing the light-emitting material of the first light-emitting element is formed in the first opening, and a second material layer containing the light-emitting material of the second light-emitting element is formed in the second opening, respectively, by a wet process. A first resist mask and a second resist mask are selectively formed on the first material layer and the second material layer, respectively. A method for manufacturing a display device, comprising: processing the first material layer using the first resist mask to form a third material layer so as not to overlap with the upper surface of the insulator; and processing the second material layer using the second resist mask to form a fourth material layer so as not to overlap with the upper surface of the insulator.

3. In claim 1 or 2, The aforementioned wet method uses either an inkjet method or a spin coating method. Method for manufacturing a display device.

4. In claim 1 or 2, A method for manufacturing a display device, comprising forming a sacrificial layer beneath the first resist mask and the second resist mask.

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