Display device and method for manufacturing display device

Abstract

Provided is a high-definition display device. This display device has a first light-emitting device, a second light-emitting device, and an insulating layer. The first light-emitting device has a first pixel electrode, a first conductive layer on the first pixel electrode, a first EL layer on the first conductive layer, and a common electrode on the first EL layer. The second light-emitting device has a second pixel electrode, a second conductive layer on the second pixel electrode, a second EL layer on the second conductive layer, and a common electrode on the second EL layer. The insulating layer is located between the first pixel electrode and the second pixel electrode. An end of the first conductive layer overlaps the insulating layer. An end of the second conductive layer overlaps the insulating layer. An end of the first EL layer overlaps the first conductive layer. An end of the second EL layer overlaps the second conductive layer.

Description

Display device and method for manufacturing a display device

[0001] One aspect of the present invention relates to a display device, a display module, and electronic equipment. Another aspect of the present invention relates to a method for manufacturing a display device.

[0002] It should be noted that one aspect of the present invention is not limited to the above-mentioned technical field. Examples of technical fields of one aspect of the present invention include semiconductor devices, display devices, light-emitting devices, energy storage devices, memory devices, electronic devices, lighting devices, input devices (e.g., touch sensors), input / output devices (e.g., touch panels), methods for driving them, or methods for manufacturing them.

[0003] In recent years, display devices have been expected to have applications in a variety of uses. For example, large-scale display devices are used in home television systems (also called televisions or television receivers), digital signage (electronic billboards), and PID (Public Information Display). Furthermore, development is progressing on mobile information terminals such as smartphones and tablet devices equipped with touch panels.

[0004] Furthermore, there is a demand for higher resolution display devices. Devices requiring high-resolution display devices include, for example, devices for virtual reality (VR), augmented reality (AR), substitute reality (SR), and mixed reality (MR), which are being actively developed.

[0005] As a display device, for example, a light-emitting device (also called a light-emitting element) has been developed. Light-emitting devices that utilize the electroluminescence (EL) phenomenon (also called EL devices or EL elements) have features such as being easy to make thin and light, being able to respond quickly to input signals, and being able to be driven using a DC constant voltage power supply, and are being applied to display devices.

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

[0007] International Publication No. 2018 / 087625

[0008] Takashi Koida, "High-Mobility Transparent Conductive Film," National Institute of Advanced Industrial Science and Technology (AIST), AIST Photovoltaic Power Generation Research Results Presentation 2019, Internet <URL: https: / / unit.aist.go.jp / rpd-envene / PV / ja / results / 2019 / oral / T13.pdf>

[0009] One aspect of the present invention aims to provide a display device with high detail. One aspect of the present invention aims to provide a display device with high resolution. One aspect of the present invention aims to provide a display device with a high aperture ratio. One aspect of the present invention aims to provide a highly reliable display device. One aspect of the present invention aims to provide a display device with high display quality. One aspect of the present invention aims to provide a display device with high contrast. One aspect of the present invention aims to provide a display device with high visibility. One aspect of the present invention aims to provide a display device with high brightness. One aspect of the present invention aims to provide a novel display device.

[0010] One aspect of the present invention aims to provide a method for manufacturing a display device with high resolution. One aspect of the present invention aims to provide a method for manufacturing a display device with high resolution. One aspect of the present invention aims to provide a method for manufacturing a display device with a high aperture ratio. One aspect of the present invention aims to provide a method for manufacturing a highly reliable display device. One aspect of the present invention aims to provide a method for manufacturing a display device with high display quality. One aspect of the present invention aims to provide a method for manufacturing a display device with high contrast. One aspect of the present invention aims to provide a method for manufacturing a display device with high visibility. One aspect of the present invention aims to provide a method for manufacturing a display device with high brightness. One aspect of the present invention aims to provide a method for manufacturing a novel display device.

[0011] Furthermore, the description of these problems does not preclude the existence of other problems. One aspect of the present invention does not necessarily have to solve all of these problems. It is possible to extract other problems from the description in the specification, drawings, and claims.

[0012] One aspect of the present invention is a display device having a first light-emitting device, a second light-emitting device, and an insulating layer. The first light-emitting device has a first pixel electrode, a first conductive layer on the first pixel electrode, a first EL layer on the first conductive layer, and a common electrode on the first EL layer. The second light-emitting device has a second pixel electrode, a second conductive layer on the second pixel electrode, a second EL layer on the second conductive layer, and a common electrode on the second EL layer. The insulating layer is located between the first pixel electrode and the second pixel electrode. The edges of the first conductive layer overlap with the insulating layer. The edges of the second conductive layer overlap with the insulating layer. The edges of the first EL layer overlap with the first conductive layer. The edges of the second EL layer overlap with the second conductive layer.

[0013] In the aforementioned display device, it is preferable that the first conductive layer and the second conductive layer are separated on an insulating layer.

[0014] In the aforementioned display device, it is preferable that the first conductive layer and the second conductive layer each have a metal oxide.

[0015] In the aforementioned display device, it is preferable that the height of the upper surface of the first pixel electrode is higher than the height of the upper surface of the insulating layer. It is also preferable that the height of the upper surface of the second pixel electrode is higher than the height of the upper surface of the insulating layer.

[0016] In the aforementioned display device, the insulating layer preferably has a resin.

[0017] In the aforementioned display device, it is preferable to have a third conductive layer, a fourth conductive layer, a first layer, and a second layer. The first layer is preferably located on the third conductive layer. The first pixel electrode is preferably in contact with the upper and side surfaces of the first layer and the upper surface of the third conductive layer. The second layer is preferably located on the second conductive layer. The second pixel electrode is preferably in contact with the upper and side surfaces of the second layer and the upper surface of the fourth conductive layer.

[0018] In the aforementioned display device, it is preferable that the insulating layer has a region facing the side surface of the first layer via the first pixel electrode. It is also preferable that the insulating layer has a region facing the side surface of the second layer via the second pixel electrode.

[0019] In the aforementioned display device, it is preferable that the first layer and the second layer each contain a resin.

[0020] One aspect of the present invention is a method for manufacturing a display device, comprising: forming a first pixel electrode and a second pixel electrode; forming an insulating layer between the first pixel electrode and the second pixel electrode; depositing a conductive film on the first pixel electrode, the second pixel electrode and the insulating layer; processing the conductive film to form a first conductive layer in contact with the upper surface of the first pixel electrode and a second conductive layer in contact with the upper surface of the second pixel electrode; depositing a first film on the first conductive layer, the second conductive layer and the insulating layer; processing the first film to form a first EL layer in contact with the upper surface of the first conductive layer; depositing a second film on the first EL layer, the second conductive layer and the insulating layer; processing the second film to form a second EL layer in contact with the upper surface of the second conductive layer.

[0021] In the method for manufacturing the display device described above, it is preferable that the first conductive layer and the second conductive layer each have a metal oxide.

[0022] In the method for manufacturing the display device described above, the insulating layer preferably contains a resin.

[0023] According to one aspect of the present invention, a display device with high resolution can be provided. a high aperture ratio can be provided. According to one aspect of the present invention, a highly reliable display device can be provided. According to one aspect of the present invention, a display device with high display quality can be provided. According to one aspect of the present invention, a display device with high contrast can be provided. According to one aspect of the present invention, a display device with high visibility can be provided. According to one aspect of the present invention, a display device with high brightness can be provided. According to one aspect of the present invention, a novel display device can be provided.

[0024] According to one aspect of the present invention, a method for manufacturing a display device with high resolution can be provided. According to one aspect of the present invention, a method for manufacturing a display device with high resolution can be provided. According to one aspect of the present invention, a method for manufacturing a display device with a high aperture ratio can be provided. According to one aspect of the present invention, a method for manufacturing a display device with high display quality can be provided. According to one aspect of the present invention, a method for manufacturing a display device with high contrast can be provided. According to one aspect of the present invention, a method for manufacturing a display device with high visibility can be provided. According to one aspect of the present invention, a method for manufacturing a display device with high brightness can be provided. According to one aspect of the present invention, a method for manufacturing a novel display device can be provided.

[0025] Furthermore, the description of these effects does not preclude the existence of other effects. One aspect of the present invention does not necessarily have to possess all of these effects. Other effects can be extracted from the description, drawings, and claims.

[0026] Figure 1A is a top view showing an example of a display device. Figure 1B is a cross-sectional view showing an example of a display device. Figures 2A and 2B are cross-sectional views showing an example of a display device. Figure 3 is a cross-sectional view showing an example of a display device. Figures 4A and 4B are cross-sectional views showing an example of a display device. Figures 5A and 5B are cross-sectional views showing an example of a display device. Figures 6A, 6B, 6C, and 6D are top views showing an example of a display device. Figures 7A, 7B, and 7C are cross-sectional views showing an example of a display device. Figures 8A and 8B are cross-sectional views showing an example of a display device. Figures 9A and 9B are cross-sectional views showing an example of a display device. Figures 10A and 10B are cross-sectional views showing an example of a display device. Figures 11A, 11B, and 11C are cross-sectional views showing an example of a display device. Figures 12A and 12B are cross-sectional views showing an example of a display device. Figures 13A and 13B are cross-sectional views showing an example of a display device. Figures 14A and 14B are cross-sectional views showing an example of a display device. Figures 15A and 15B are cross-sectional views showing an example of a display device. Figure 16A is a top view showing an example of a display device. Figure 16B is a cross-sectional view showing an example of a display device. Figures 17A, 17B, and 17C are cross-sectional views showing an example of a method for manufacturing a display device. Figures 18A, 18B, and 18C are cross-sectional views showing an example of a method for manufacturing a display device. Figures 19A, 19B, and 19C are cross-sectional views showing an example of a method for manufacturing a display device. Figures 20A, 20B, and 20C are cross-sectional views showing an example of a method for manufacturing a display device. Figures 21A and 21B are cross-sectional views showing an example of a method for manufacturing a display device. Figures 22A and 22B are cross-sectional views showing an example of a method for manufacturing a display device. Figures 23A and 23B are cross-sectional views showing an example of a method for manufacturing a display device. Figures 24A and 24B are cross-sectional views showing an example of a method for manufacturing a display device. Figures 25A and 25B are cross-sectional views showing an example of a method for manufacturing a display device. Figures 26A and 26B are cross-sectional views showing an example of a method for manufacturing a display device. Figures 27A and 27B are cross-sectional views showing an example of a method for manufacturing a display device. Figures 28A and 28B are cross-sectional views showing an example of a method for manufacturing a display device. Figures 29A and 29B are cross-sectional views showing an example of a method for manufacturing a display device.Figures 30A and 30B are cross-sectional views showing an example of a method for manufacturing a display device. Figures 31A and 31B are cross-sectional views showing an example of a method for manufacturing a display device. Figures 32A and 32B are cross-sectional views showing an example of a method for manufacturing a display device. Figures 33A and 33B are cross-sectional views showing an example of a method for manufacturing a display device. Figures 34A, 34B, 34C, 34D, 34E, 34F, and 34G are diagrams showing an example of a pixel. Figures 35A, 35B, 35C, 35D, 35E, 35F, 35G, 35H, 35I, 35J, and 35K are diagrams showing an example of a pixel. Figures 36A and 36B are top views showing an example of a display device. Figure 37A is a cross-sectional view showing an example of a display device. Figures 37B, 37C, and 37D are cross-sectional views showing an example of a transistor. Figure 38A is a cross-sectional view showing an example of a display device. Figures 38B and 38C are cross-sectional views showing an example of a transistor. Figure 39 is a cross-sectional view showing an example of a display device. Figure 40 is a cross-sectional view showing an example of a display device. Figures 41A and 41B are cross-sectional views showing an example of a display device. Figures 42A and 42B illustrate the carrier concentration dependence of Hall mobility. Figure 42C is a cross-sectional view illustrating an indium oxide film. Figures 43A, 43B, 43C, 43D, 43E, and 43F are diagrams showing examples of the configuration of a light-emitting device. Figures 44A and 44B are diagrams showing examples of the configuration of a light-receiving device. Figures 44C, 44D, and 44E are diagrams showing examples of the configuration of a display device. Figures 45A, 45B, 45C, 45D, and 45E are diagrams showing examples of electronic equipment. Figures 46A, 46B, 46C, and 46D are diagrams showing examples of electronic equipment. Figures 47A, 47B, 47C, 47D, 47E, and 47F show examples of electronic equipment. Figures 48A, 48B, 48C, 48D, 48E, 48F, and 48G show examples of electronic equipment. Figure 49 is a cross-sectional TEM image of a sample according to the embodiment. Figures 50A and 50B are photographs of the display state of the OLED panel according to the embodiment.

[0027] Embodiments will be described in detail with reference to the drawings. However, it will be readily apparent to those skilled in the art that the present invention is not limited to the following description, and that its form and details can be modified in various ways without departing from the spirit and scope of the present invention. Accordingly, the present invention shall not be construed as being limited to the descriptions of the embodiments shown below.

[0028] 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. In addition, when referring to similar functions, the hatching patterns are the same, and reference numerals may not be assigned.

[0029] The position, size, and scope of each component shown in the drawings may not represent the actual position, size, and scope for the sake of ease of understanding. Therefore, the disclosed invention is not necessarily limited to the position, size, and scope disclosed in the drawings.

[0030] In this specification, ordinal numbers such as "first," "second," etc., are used to avoid confusion of components and do not limit the number of components or the order of components (e.g., process order or stacking order). Furthermore, even if a term does not have an ordinal number in this specification, an ordinal number may be added in the claims to avoid confusion of components. Even if a term has an ordinal number in this specification, a different ordinal number may be added in the claims. Even if a term has an ordinal number in this specification, an ordinal number may be omitted in the claims.

[0031] In this specification and drawings, when the same reference numeral is used for multiple elements, and especially when it is necessary to distinguish them, the reference numeral may be accompanied by an identifying numeral such as "_1", "[n]", or "[m,n]". Furthermore, when describing a common matter for multiple elements with identifying numerals, or when it is not necessary to distinguish them, the identifying numeral may be omitted.

[0032] The words "film" and "layer" can be interchanged depending on the context or situation. For example, the term "conductive layer" can be changed to "conductive film." Or, for example, the term "insulating film" can be changed to "insulating layer."

[0033] A transistor is a type of semiconductor device that can perform functions such as amplifying current or voltage, and switching operations that control conduction or non-conductivity. Transistors as used herein include IGFETs (Insulated Gate Field Effect Transistors) and thin-film transistors (TFTs).

[0034] The functions of "source" and "drain" may be reversed when transistors with different polarities are used, or when the direction of current changes during circuit operation. For this reason, in this specification, the terms "source" and "drain" may be used interchangeably. Furthermore, the names of the source and drain of a transistor can be appropriately rephrased as source terminal and drain terminal, or source electrode and drain electrode, depending on the situation.

[0035] The terms "gate" and "back gate" are interchangeable. Therefore, in this specification, the terms "gate" and "back gate" may be used interchangeably. Furthermore, the names of the gate and back gate of a transistor can be appropriately rephrased as gate electrode and back gate electrode, etc., depending on the context.

[0036] In this specification, "connection" includes, for example, "electrical connection." The term "electrical connection" is sometimes used to define the connection relationship of circuit elements as a physical object. Furthermore, "electrical connection" includes both "direct connection" and "indirect connection." "A and B are directly connected" means that A and B are connected without the use of circuit elements (e.g., transistors, switches, etc.; wiring is not considered a circuit element). On the other hand, "A and B are indirectly connected" means that A and B are connected through one or more circuit elements. A and B refer to objects such as elements, circuits, wiring, electrodes, terminals, semiconductor layers, and conductive layers.

[0037] For example, assuming a circuit including A and B is in operation, if there is a timing during the circuit's operation when electrical signals are exchanged or potential interactions occur between A and B, then it can be defined that "A and B are indirectly connected" as physical objects. Furthermore, even if there is a timing during the circuit's operation when no electrical signals are exchanged or potential interactions occur between A and B, if there is a timing during the circuit's operation when electrical signals are exchanged or potential interactions occur between A and B, then it can be defined that "A and B are indirectly connected."

[0038] An example of a case where "A and B are indirectly connected" is when A and B are connected via the source and drain of one or more transistors. On the other hand, an example of a case where "A and B are not indirectly connected" is when an insulator is interposed in the path from A to B. Specifically, this includes cases where a capacitive element is connected between A and B, or where a transistor gate insulating film is interposed between A and B. Therefore, it cannot be said that "the gate (A) of a transistor and the source or drain (B) of a transistor are indirectly connected."

[0039] Another example of a situation where it cannot be said that "A and B are indirectly connected" is when multiple transistors are connected via source and drain in the path from A to B, and a constant potential V is supplied to the nodes between the transistors from a power supply, GND, etc.

[0040] In this specification, unless otherwise specified, on-current refers to the drain current (also called the conduction state) when the transistor is in the on state. Unless otherwise specified, the on state refers to the state in an n-channel transistor where the voltage between the gate and source (gate voltage, also called Vg or Vgs) is equal to or greater than the threshold voltage (also called Vth), and in a p-channel transistor where it is less than or equal to the threshold voltage.

[0041] In this specification, unless otherwise specified, off-current refers to the source-drain leakage current when the transistor is in the off state (also called the non-conductive state or cutoff state). Unless otherwise specified, the off state refers to the state in an n-channel transistor where the voltage between the gate and source is lower than the threshold voltage, and in a p-channel transistor where it is higher than the threshold voltage.

[0042] In this specification, "parallel" means a state in which two lines are positioned at an angle of -10 degrees or more and 10 degrees or less. Therefore, the case of -5 degrees or more and 5 degrees or less is also included. Furthermore, "approximately parallel" means a state in which two lines are positioned at an angle of -30 degrees or more and 30 degrees or less. Furthermore, "perpendicular" means a state in which two lines are positioned at an angle of 80 degrees or more and 100 degrees or less. Therefore, the case of 85 degrees or more and 95 degrees or less is also included. Furthermore, "approximately perpendicular" means a state in which two lines are positioned at an angle of 60 degrees or more and 120 degrees or less.

[0043] In this specification, the top surface shape of a component refers to the contour shape of the component when viewed from above (also called a plan view). Furthermore, a top view refers to viewing from the direction normal to the surface on which the component is formed, or to the surface of the support (e.g., substrate) on which the component is formed.

[0044] In this specification, "matching or roughly matching top 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, it may also be said that the "matching or roughly matching top shapes" apply. Furthermore, when the top shapes match or roughly match, it can also be said that the "edges match or roughly match," or "the edges are aligned or roughly aligned."

[0045] In this specification, a tapered shape refers to a shape in which at least a portion of the side surface of a structure is inclined with respect to the substrate surface or the surface to be formed. The angle formed between the inclined side surface and the substrate surface or the surface to be formed is sometimes referred to as the taper angle.

[0046] In this specification, "step breakage" refers to the phenomenon in which a layer, film, or electrode is divided due to the shape of the surface on which it is formed (e.g., a step).

[0047] In this specification, devices fabricated using a metal mask or FMM (Fine Metal Mask, a high-resolution metal mask) may be referred to as MM (Metal Mask) structured devices. Furthermore, in this specification, devices fabricated without using a metal mask or FMM may be referred to as MML (Metal Maskless) structured devices.

[0048] In this specification, a structure in which different light-emitting layers are created using light-emitting elements (also called light-emitting devices) with different emission wavelengths is sometimes referred to as an SBS (Side By Side) structure.

[0049] In this specification, holes or electrons may be referred to as "carriers." For example, in a light-emitting element, a hole injection layer or electron injection layer may be called a "carrier injection layer," a hole transport layer or electron transport layer may be called a "carrier transport layer," and a hole blocking layer or electron blocking layer may be called a "carrier blocking layer." Note that the above-mentioned carrier injection layer, carrier transport layer, and carrier blocking layer may not always be clearly distinguishable. Furthermore, a single layer may combine the functions of two or three of the carrier injection layer, carrier transport layer, and carrier blocking layer.

[0050] In this specification, a light-emitting element has an EL layer between a pair of electrodes. The EL layer has at least a light-emitting layer. Examples of layers in the EL layer (also called functional layers) include a light-emitting layer, a carrier injection layer (hole injection layer and electron injection layer), a carrier transport layer (hole transport layer and electron transport layer), and a carrier blocking layer (hole blocking layer and electron blocking layer). In this specification, a photodetector (also called a photodetector device) has at least an active layer that functions as a photoelectric conversion layer between a pair of electrodes. In this specification, one of the pair of electrodes may be referred to as a pixel electrode and the other as a common electrode.

[0051] In this specification, "island-like" refers to a state in which two or more layers made of the same material and formed in the same process are physically separated. For example, an island-like light-emitting layer refers to a state in which the light-emitting layer and an adjacent light-emitting layer are physically separated.

[0052] In this specification, the mask layer is located at least above the light-emitting layer (more specifically, the layer that is processed into an island shape among the layers constituting the EL layer) and has the function of protecting the light-emitting layer during the manufacturing process.

[0053] 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.

[0054] In this specification, a display panel on which a connector such as an FPC (Flexible Printed Circuit) or TCP (Tape Carrier Package) is attached, or on which an IC (Integrated Circuit) is mounted using the COG (Chip On Glass) method or COF (Chip On Film) method, may be referred to as a display panel module, display module, or simply a display panel.

[0055] In this specification, flexibility refers to the property of an object being flexible and able to bend. It is the property of an object being able to deform in response to an external force applied to it, regardless of whether it is elastic or able to return to its original shape.

[0056] For example, flexible electronic devices, flexible display devices (also called flexible displays, etc.), flexible batteries (also called flexible batteries, etc.), and flexible substrates (also called flexible substrates, etc.) can each be deformed in response to external forces. Flexible electronic devices, flexible display devices, flexible batteries, and flexible substrates can each be used fixed in a deformed state, used after repeated deformation, or used in an undeformed state. The phrase "deforms in response to external forces" above means that it can be deformed by the average adult's hand without requiring excessive force. Flexibleness can be evaluated using testing machines capable of stress-strain measurement (tensile testing machines, compression testing machines, etc.). In stress-strain measurement, the flexibility of an object can be quantified by applying an external force to the object and measuring the strain of the object caused by the resulting stress.

[0057] In this specification, when an object is described as having flexibility, it means that at least a part of the object is flexible. In other words, a flexible object may have parts that are not flexible.

[0058] In this specification, when two objects are deformed by the same external force, the object that deforms more is said to be the object with higher flexibility. Also, when a first part and a second part of an object are deformed by the same external force, the part that deforms more is said to be the part with higher flexibility.

[0059] (Embodiment 1) In this embodiment, a display device according to one aspect of the present invention will be described with reference to Figures 1A to 16B.

[0060] One aspect of the present invention is a display device having a first light-emitting device, a second light-emitting device, and an insulating layer.

[0061] The first light-emitting device includes a first pixel electrode, a first conductive layer on the first pixel electrode, a first EL layer on the first conductive layer, and a common electrode on the first EL layer. The second light-emitting device includes a second pixel electrode, a second conductive layer on the second pixel electrode, a second EL layer on the second conductive layer, and a common electrode on the second EL layer.

[0062] The first and second light-emitting devices can each be fitted with an MML structure. Since MML devices can be manufactured without using a metal mask, they can exceed the upper limit of resolution imposed by the alignment accuracy of the metal mask. Furthermore, MML devices eliminate the need for equipment and metal mask cleaning processes associated with manufacturing metal masks. In addition, MML devices can be manufactured at a low cost, making them suitable for mass production.

[0063] The insulating layer is located between the first pixel electrode and the second pixel electrode, filling the space between them. The first and second pixel electrodes are insulated from each other by the insulating layer, which preferably has a resin component. The edges of the first conductive layer and the edges of the second conductive layer overlap with the insulating layer. The first and second conductive layers are separated on the insulating layer.

[0064] The edge of the first EL layer coincides with or approximately coincides with the edge of the first conductive layer. The edge of the second EL layer coincides with or approximately coincides with the edge of the second conductive layer. Alternatively, the edge of the first EL layer overlaps with the first conductive layer. The edge of the second EL layer overlaps with the second conductive layer.

[0065] By providing an insulating layer between the first and second pixel electrodes, the surfaces of the layers (e.g., the first conductive layer, the second conductive layer, the first EL layer, and the second EL layer) provided on the first and second pixel electrodes can be made flatter. This improves the coverage of the layers and suppresses the occurrence of defects such as step breaks or porosity. Therefore, the manufacturing yield of the display device can be increased.

[0066] An insulating layer is formed between the first pixel electrode and the second pixel electrode. Conductive films, which will become the first conductive layer and the second conductive layer, are formed on the first pixel electrode, the second pixel electrode, and the insulating layer. The first EL layer and the second EL layer can then be formed after the conductive film has been formed, or after the conductive film has been processed to form the first and second conductive layers. The conductive film, or the first and second conductive layers, functions as an etching stopper when forming the first and second EL layers.

[0067] An etching stopper is formed on the first pixel electrode, the second pixel electrode, and the insulating layer, and a first film, which will become the first EL layer, is deposited on the etching stopper. Then, the first film can be processed by photolithography to form island-shaped first EL layers. Subsequently, a second film, which will become the second EL layer, is deposited on the etching stopper, and the second film can be processed by photolithography to form island-shaped second EL layers. By forming the first and second EL layers using photolithography, a display device with high resolution can be made.

[0068] By providing an etching stopper on the insulating layer, etching of the insulating layer and subsequent thinning of the insulating layer during the formation of the first EL layer can be suppressed. This improves the coverage of the subsequently formed layer (e.g., the second film) and suppresses the occurrence of defects such as step breaks or porosity in that layer. Therefore, the manufacturing yield of the display device can be increased.

[0069] It is preferable that the first and second pixel electrodes are made of materials that are reflective to visible light. It is preferable that the first and second conductive layers are made of materials that are transparent to visible light. It is preferable that the first and second conductive layers each have a metal oxide.

[0070] In the following section, a more specific configuration example of a display device according to one aspect of the present invention will be described with reference to the drawings.

[0071] Figure 1A shows a top view (also called a plan view) of a display device 100 according to one embodiment of the present invention. The display device 100 has a display unit on which a plurality of pixels 110 are arranged, and a connection unit 140 on the outside of the display unit. A plurality of subpixels are arranged in a matrix on the display unit. In Figure 1A, subpixels in 2 rows and 6 columns are shown, and these constitute a 2 row and 2 column pixel 110. The connection unit 140 can also be called a cathode contact unit.

[0072] The top surface shape of the subpixel shown in Figure 1A corresponds to the top surface shape of the light-emitting region.

[0073] Examples of the top surface shape of a sub-pixel include polygons such as triangles, quadrilaterals (including rectangles and squares), pentagons, polygons with rounded corners, ellipses, or circles.

[0074] The circuit layout constituting the subpixel is not limited to the subpixel range shown in Figure 1A, but can be arranged outside of it. For example, the transistors in subpixel 11R can be located within the range of subpixel 11G shown in Figure 1A, and some or all of them can be located outside the range of subpixel 11R.

[0075] In Figure 1A, the areas of the light-emitting regions of sub-pixels 11R, 11G, and 11B are shown to be equal or approximately equal, and their aperture ratios are shown to be equal or approximately equal; however, one aspect of the present invention is not limited thereto. The aperture ratios of sub-pixels 11R, 11G, and 11B can be determined as appropriate. The aperture ratios of sub-pixels 11R, 11G, and 11B can be different. Alternatively, two or more of sub-pixels 11R, 11G, and 11B can be equal or approximately equal.

[0076] A stripe array is applied to the pixel 110 shown in Figure 1A. The pixel 110 shown in Figure 1A is composed of three subpixels: subpixel 11R, subpixel 11G, and subpixel 11B. Subpixels 11R, 11G, and 11B each have light-emitting devices with different emission colors. Examples of subpixels 11R, 11G, and 11B include subpixels of three colors: red (R), green (G), and blue (B); and subpixels of three colors: yellow (Y), cyan (C), and magenta (M). Furthermore, the number of subpixel types is not limited to three, but can be four or more. Examples of four subpixels include subpixels of four colors: R, G, B, and white (W); subpixels of four colors: R, G, B, and Y; and subpixels of four colors: R, G, B, and infrared (IR).

[0077] In this specification, the row direction is sometimes referred to as the X direction, and the column direction as the Y direction. The X and Y directions intersect, for example, perpendicularly (see Figure 1A). Figure 1A shows an example where subpixels of different colors are arranged in the X direction, and subpixels of the same color are arranged in the Y direction.

[0078] Figure 1A shows an example where the connecting portion 140 is located on one side of the display portion in a top view (also called a plan view), but it is not particularly limited. The connecting portion 140 can be provided at least one location on the top, right, left, or bottom of the display portion in a top view, and can, for example, be provided so as to surround all four sides of the display portion. The top shape of the connecting portion 140 can be a strip, L-shape, U-shape, or frame shape, etc. Also, there can be one or more connecting portions 140.

[0079] <Configuration Example 1> Figure 1B shows a cross-sectional view between the dashed line X1 and X2 in Figure 1A. Figure 2A shows an enlarged view of a part of the cross-sectional view shown in Figure 1B.

[0080] The display device 100 has light-emitting devices 130R, 130G, and 130B between the substrate 103 and the substrate 120. Light-emitting device 130R is a display element of the sub-pixel 11R, light-emitting device 130G is a display element of the sub-pixel 11G, and light-emitting device 130B is a display element of the sub-pixel 11B. For example, light-emitting device 130R emits red (R) light, light-emitting device 130G emits green (G) light, and light-emitting device 130B emits blue (B) light.

[0081] Light-emitting devices 130R, 130G, and 130B are provided on the substrate 103, and a protective layer 131 is provided so as to cover light-emitting devices 130R, 130G, and 130B. The substrate 120 is bonded to the protective layer 131 by a resin layer 122. In addition, an insulating layer 125 and an insulating layer 127 on the insulating layer 125 are provided in the region between adjacent light-emitting devices.

[0082] A display device according to one aspect of the present invention can be a top-emission type that emits light in the direction opposite to the substrate on which the light-emitting device is formed, a bottom-emission type that emits light toward the substrate on which the light-emitting device is formed, or a dual-emission type that emits light on both sides.

[0083] Examples of light-emitting devices include self-emissive light-emitting elements such as LEDs (Light Emitting Diodes), OLEDs (Organic LEDs), and semiconductor lasers. For example, mini-LEDs and micro-LEDs can be used as LEDs.

[0084] The light-emitting device can emit light in the following colors: infrared, red, green, blue, cyan, magenta, yellow, or white. Furthermore, the color purity can be improved by adding a microcavity structure to the light-emitting device.

[0085] The light-emitting device 130R includes a pixel electrode 111R, a conductive layer 137R on the pixel electrode 111R, an island-shaped layer 113R on the conductive layer 137R, a common layer 114 on the layer 113R, and a common electrode 115 on the common layer 114. In the light-emitting device 130R, the layer 113R and the common layer 114 can be collectively called the EL layer.

[0086] The light-emitting device 130G includes a pixel electrode 111G, a conductive layer 137G on the pixel electrode 111G, an island-shaped layer 113G on the conductive layer 137G, a common layer 114 on the layer 113G, and a common electrode 115 on the common layer 114. In the light-emitting device 130G, the layer 113G and the common layer 114 can be collectively called the EL layer.

[0087] The light-emitting device 130B includes a pixel electrode 111B, a conductive layer 137B on the pixel electrode 111B, an island-shaped layer 113B on the conductive layer 137B, a common layer 114 on the layer 113B, and a common electrode 115 on the common layer 114. In the light-emitting device 130B, the layer 113B and the common layer 114 can be collectively called the EL layer.

[0088] In this specification, among the EL layers of a light-emitting device, layers provided in an island-like manner for each light-emitting device are referred to as layer 113B, layer 113G, or layer 113R, and layers shared by multiple light-emitting devices are referred to as the common layer 114. In this specification, the common layer 114 may be omitted, and layers 113R, 113G, and 113B may be referred to as island-like EL layers or EL layers formed in an island-like manner.

[0089] Layers 113R, 113G, and 113B are separated from each other. By providing the EL layers in an island-like configuration for each light-emitting device, leakage current between adjacent light-emitting devices can be suppressed. This prevents unintended light emission caused by crosstalk, enabling the realization of a display device with extremely high contrast. In particular, it enables the realization of a display device with high current efficiency at low brightness levels.

[0090] The island-like layers 113R, 113G, and 113B can each be formed, for example, by photolithography without using a fine metal mask. A film to become layer 113R can be formed, and the film can be processed by photolithography to create the island-like layer 113R. The same applies to layers 113G and 113B. This makes it possible to form layers 113R, 113G, and 113B of a fine size, resulting in a high-resolution display device. As a display device according to one aspect of the present invention, for example, the resolution can be 2000 ppi or more, preferably 3000 ppi or more, more preferably 5000 ppi or more, and even more preferably 6000 ppi or more, and can be 20000 ppi or less, or 30000 ppi or less.

[0091] When using a fine metal mask, it is difficult to reduce the spacing between adjacent light-emitting devices to less than 10 μm. However, by using photolithography, in a process on a glass substrate, the spacing between adjacent light-emitting devices, adjacent EL layers, or adjacent pixel electrodes can be reduced to less than 10 μm, 5 μm or less, 3 μm or less, 2 μm or less, 1.5 μm or less, 1 μm or less, or 0.5 μm or less. Furthermore, by using an exposure system for LSIs, for example, in a process on a Si wafer, the spacing between adjacent light-emitting devices, adjacent EL layers, or adjacent pixel electrodes can be reduced to, for example, 500 nm or less, 200 nm or less, 100 nm or less, or even 50 nm or less. This significantly reduces the area of ​​the non-emitting region that may exist between two light-emitting devices, making it possible to approach 100% aperture ratio. For example, in a display device according to one aspect of the present invention, the aperture ratio can be 40% or more, 50% or more, 60% or more, 70% or more, 80% or more, and even 90% or more, while achieving less than 100%.

[0092] Furthermore, increasing the aperture ratio of a display device can improve its reliability. More specifically, using an organic EL device, if the lifespan of a display device with an aperture ratio of 10% is used as a baseline, the lifespan of a display device with an aperture ratio of 20% (i.e., twice the aperture ratio of the baseline) is approximately 3.25 times longer, and the lifespan of a display device with an aperture ratio of 40% (i.e., four times the aperture ratio of the baseline) is approximately 10.6 times longer. Thus, as the aperture ratio is increased, the current density flowing through the organic EL device required to obtain the same display can be reduced, making it possible to improve the lifespan of the display device. In one embodiment of the present invention, since the aperture ratio can be increased, the display quality of the display device can be improved. Moreover, as the aperture ratio of the display device is increased, the reliability (especially the lifespan) of the display device is significantly improved, which is an excellent effect.

[0093] In the pixel electrodes (pixel electrodes 111R, 111G, and 111B) and common electrode 115, which function as a pair of electrodes in the light-emitting device, it is preferable to use a conductive film that transmits visible light for the electrode that extracts light and a conductive film that reflects visible light for the electrode that does not extract light. Alternatively, a semi-transparent / semi-reflective electrode can be used as the electrode that extracts light. The pixel electrodes 111 and common electrode 115 can be made of metals, alloys, electrically conductive compounds, and mixtures thereof as appropriate. Specifically, examples of such materials include metals such as aluminum, magnesium, titanium, chromium, manganese, iron, cobalt, nickel, copper, gallium, zinc, indium, tin, molybdenum, tantalum, tungsten, palladium, gold, platinum, silver, yttrium, and neodymium, and alloys containing one or more of the aforementioned elements. In addition, conductive metal oxides (hereinafter also referred to as oxide conductors) can be used as such materials. Examples of metal oxides include indium oxide, zinc oxide, indium tin oxide (In-Sn oxide, also written as ITO), indium zinc oxide (In-Zn oxide), In-W oxide, In-W-Zn oxide, In-Ti oxide, In-Ti-Sn oxide, In-Sn-Si oxide (also written as ITSO), zinc oxide with added gallium, In-Ga-Zn oxide (also written as IGZO), and In-Sn-Zn oxide (also written as ITZO®). Oxide conductors containing indium are particularly preferred due to their high conductivity. Other examples of such materials include aluminum alloys such as aluminum-nickel-lanthanum alloys (Al-Ni-La), silver-magnesium alloys, and silver-containing alloys such as silver-palladium-copper alloys (Ag-Pd-Cu, also written as APC). Other materials include elements belonging to Group 1 or Group 2 of the periodic table not exemplified above (e.g., lithium, cesium, calcium, strontium), rare earth metals such as europium and ytterbium, alloys containing these in appropriate combinations, graphene, and the like. The pixel electrode 111R, pixel electrode 111G, pixel electrode 111B, and common electrode 115 can each be a single-layer structure or a multi-layer structure.

[0094] In a light-emitting device, one electrode functions as the anode and the other as the cathode. In the following explanation, we may use the example where the pixel electrode functions as the anode and the common electrode functions as the cathode.

[0095] Pixel electrodes 111R, 111G, and 111B can be formed, for example, in the same process. In the following, pixel electrodes 111R, 111G, and 111B may be collectively referred to as pixel electrode 111.

[0096] An insulating layer 109 is provided between adjacent pixel electrodes 111. The insulating layer 109 is provided, for example, between pixel electrode 111R and pixel electrode 111G, and between pixel electrode 111G and pixel electrode 111B.

[0097] It is preferable that the conductive layer 137R, conductive layer 137G, and conductive layer 137B each have a region that is in contact with the upper surface of the insulating layer 109. That is, it is preferable that the conductive layer 137R has a region that is in contact with the upper surface of the pixel electrode 111R and the upper surface of the insulating layer 109. Similarly, it is preferable that the conductive layer 137G has a region that is in contact with the upper surface of the pixel electrode 111G and the upper surface of the insulating layer 109. It is preferable that the conductive layer 137B has a region that is in contact with the upper surface of the pixel electrode 111B and the upper surface of the insulating layer 109. Furthermore, it is preferable that the ends of the conductive layer 137R, the ends of the conductive layer 137G, and the ends of the conductive layer 137B each overlap with the insulating layer 109. The ends of the conductive layer 137R, the ends of the conductive layer 137G, and the ends of the conductive layer 137B each lie on the insulating layer 109. The edges of conductive layer 137R, conductive layer 137G, and conductive layer 137B can be said to be in contact with the upper surface of the insulating layer 109. Furthermore, conductive layer 137R, conductive layer 137G, and conductive layer 137B are separated from each other on the insulating layer 109.

[0098] The conductive layers 137R, 137G, and 137B can be made from the materials listed for the pixel electrode 111 and the common electrode 115. Each of the conductive layers 137R, 137G, and 137B can be a single layer or a multilayer structure.

[0099] The conductive layers 137R, 137G, and 137B can be formed, for example, in the same process. In the following, the conductive layers 137R, 137G, and 137B may be collectively referred to as conductive layer 137.

[0100] It is preferable that conductive layers 137R, 137G, and 137B be made of materials that are transparent to visible light. Conductive layers 137R, 137G, and 137B function as transparent electrodes. It is preferable that pixel electrodes 111R, 111G, and 111B be made of materials that are reflective to visible light. Pixel electrodes 111R, 111G, and 111B function as reflective electrodes. In addition, a semi-transparent / semi-reflective electrode is used as the common electrode 115. This allows the light-emitting device to have a microcavity structure, causing the light from the light-emitting layer to resonate between the two electrodes and intensifying the light emitted from the light-emitting device. Furthermore, conductive layers 137R, 137G, and 137B function as optical adjustment layers. In this case, it is preferable to set the thickness of these conductive layers so that the optical path length is such that the light emitted by layers 113R, 113G, and 113B is intensified. Furthermore, it can be said that conductive layers 137R, 137G, and 137B (optical adjustment layer) also function as pixel electrodes.

[0101] It is preferable to use materials with high reflectivity for the pixel electrodes 111R, 111G, and 111B. By using materials with high reflectivity for the pixel electrodes 111R, 111G, and 111B, the light extraction efficiency of the light-emitting device can be increased. Examples of materials with high reflectivity include metals such as aluminum, titanium, chromium, iron, cobalt, nickel, copper, molybdenum, tungsten, palladium, gold, platinum, and silver, as well as alloys containing one or more of the aforementioned elements.

[0102] The conductive layers 137R, 137G, and 137B can preferably be made of metal oxides. Metal oxides containing indium are particularly preferred due to their high conductivity. For example, one or more of the following can preferably be used for the conductive layers 137R, 137G, and 137B: In-Sn-Zn oxide, ITO, ITSO, In-Zn oxide, IGZO, and In-Sn-Zn oxide.

[0103] For example, the pixel electrodes 111R, 111G, and 111B can each have a laminated structure consisting of a first titanium film, an aluminum film on the first titanium film, and a second titanium film on the aluminum film. The conductive layers 137R, 137G, and 137B can each have a single-layer structure of an ITO film or an ITSO film. The aluminum film has a high light reflectivity and is suitable as a reflective electrode. On the other hand, if the aluminum film and the oxide conductive film (for example, the ITSO film) come into contact, there is a risk of galvanic corrosion. Therefore, it is preferable to provide a titanium film between the aluminum film and the oxide conductive film.

[0104] By providing an insulating layer 109 between adjacent pixel electrodes 111, the surfaces of the layers (for example, conductive layer 137R, conductive layer 137G, conductive layer 137B, layer 113R, layer 113G, and layer 113B) provided on the pixel electrodes 111 and the insulating layer 109 can be made flatter. Therefore, the coverage of the layers can be improved, and the occurrence of defects such as step breaks or porosity can be suppressed.

[0105] As the insulating layer 109, either an organic insulating layer or an inorganic insulating layer, or both, can be used. The insulating layer 109 can have a single-layer structure or a multi-layer structure.

[0106] It is preferable to use a photosensitive resin as the organic insulating layer. Acrylic resins, polyimide resins, epoxy resins, imide resins, polyamide resins, polyimidoamide resins, silicone resins, siloxane resins, benzocyclobutene resins, phenolic resins, and precursors of these resins can also be used as the organic insulating layer. Furthermore, polyvinyl alcohol (PVA), polyvinyl butyral, polyvinylpyrrolidone, polyethylene glycol, polyglycerin, pullulan, water-soluble cellulose, or alcohol-soluble polyamide resins can be used as the organic insulating layer. Photoresist can also be used as the photosensitive resin. Positive or negative materials can be used as the photosensitive resin. In this specification, the term "acrylic resin" may refer not only to polymethacrylate esters or methacrylic resins, but also to acrylic polymers in a broad sense.

[0107] Examples of materials that can be used for the inorganic insulating layer include oxides, nitrides, oxidized nitrides, and nitride oxides. Examples of oxides include silicon oxide, aluminum oxide, magnesium oxide, gallium oxide, germanium oxide, yttrium oxide, zirconium oxide, lanthanum oxide, neodymium oxide, hafnium oxide, tantalum oxide, cerium oxide, zinc gallium oxide, and hafnium aluminate. Examples of nitrides include silicon nitride and aluminum nitride. Examples of oxidized nitrides include silicon oxidized nitride, aluminum oxidized nitride, gallium oxidized nitride, yttrium oxidized nitride, and hafnium oxidized nitride. Examples of nitride oxides include silicon nitride and aluminum nitride.

[0108] In this specification, the term "oxidogenic nitride" refers to a material whose composition contains more oxygen than nitrogen. The term "nitride oxide" refers to a material whose composition contains more nitrogen than oxygen.

[0109] It is preferable to use an organic insulating layer as the insulating layer 109 that fills the space between adjacent pixel electrodes 111. It is preferable that the insulating layer 109 has a resin. For example, polyimide resin can be suitably used for the insulating layer 109.

[0110] A material with low light transmittance can also be used for the insulating layer 109. This allows the insulating layer 109 to function as a light-shielding layer. Note that low light transmittance is sometimes referred to as high light-shielding properties. The insulating layer 109 can be made of a material that does not easily transmit light. The insulating layer 109 can be made of one or more materials with high light absorption, high light reflectance, or high light absorption and reflectance.

[0111] When the insulating layer 109 is to function as a light-shielding layer, the insulating layer 109 can be made of one or more of the following materials: a material containing a pigment, a material containing a dye, a light-absorbing resin (e.g., polyimide resin), and a resin that can be used for color filters (hereinafter also referred to as color filter material). For example, carbon black can be used as a pigment. The insulating layer 109 can preferably be made of a colored resin; for example, a red, brown, or black resin can preferably be used. Furthermore, it is preferable to use a resin in which two or more color filter materials are laminated or mixed to enhance the light-shielding properties of the insulating layer 109. In particular, by mixing three or more color filter materials, a black or near-black resin can be obtained.

[0112] When the insulating layer 109 functions as a light-shielding layer, it is particularly preferable that the insulating layer 109 has low transmittance of light with energy higher than the band gap of the semiconductor material of the semiconductor layer of the transistor provided in the display device, i.e., light with a shorter wavelength. This effectively suppresses fluctuations in the electrical characteristics of the transistor, resulting in a highly reliable display device.

[0113] By providing a light-shielding layer, it is possible to suppress the incidence of light from ambient light and light-emitting devices onto the transistors. This suppresses fluctuations in the electrical characteristics of the transistors due to light, resulting in a highly reliable display device. Furthermore, since the incidence of light onto the layer containing the transistors is suppressed, the generation of stray light due to wiring and other elements in that layer can be suppressed. This results in a display device with high contrast and high visibility.

[0114] Figure 2A shows an example configuration in which the upper surface of the insulating layer 109 is flat, but the present invention is not limited to this. The upper surface of the insulating layer 109 can also be configured to have a convex portion, a convex curved surface, a concave curved surface, or a recess. Figure 2B shows an example configuration in which the upper surface of the insulating layer 109 is a concave curved surface. It is preferable that the upper surface of the insulating layer 109 be flat or has a large radius of curvature. This improves the coverage of the layers provided on the pixel electrode 111 and the insulating layer 109 (for example, the conductive layer 137R and layer 113R), and suppresses the occurrence of step breaks in these layers. Therefore, the manufacturing yield of the display device can be improved.

[0115] Conductive films that will become conductive layers 137R, 137G, and 137B can be formed on the pixel electrode 111 and the insulating layer 109, and layers 113R, 113G, and 113B can be formed on these conductive films. Preferably, these conductive films function as etching stoppers when forming layers 113R, 113G, and 113B. Hereinafter, the conductive films that will become conductive layers 137R, 137G, and 137B may be referred to as the first etching stopper. For example, the first etching stopper can be formed on the insulating layer 109, the pixel electrode 111R, the pixel electrode 111G, and the pixel electrode 111B. A film that will become layer 113R can be formed on the first etching stopper, and the film can be processed using photolithography to form layer 113R. When forming layer 113R, the insulating layer 109 is covered by the first etching stopper, which prevents the insulating layer 109 from being etched and its thickness from decreasing. Therefore, the coverage of the subsequent layers (for example, the film that will become layer 113G and the film that will become layer 113B) can be improved. This improves the coverage of the layers and suppresses the occurrence of defects such as step breaks or porosity. Consequently, the manufacturing yield of the display device can be improved.

[0116] A layer 113R is provided on the conductive layer 137R, a layer 113G is provided on the conductive layer 137G, and a layer 113B is provided on the conductive layer 137B. Furthermore, the conductive layer 137R is located between the insulating layer 109 and layer 113R, the conductive layer 137G is located between the insulating layer 109 and layer 113G, and the conductive layer 137B is located between the insulating layer 109 and layer 113B. It is preferable that the conductive layers 137R, 137G, and 137B function as barrier layers. By providing barrier layers between layers 113R, 113G, and 113B and the insulating layer 109, it is possible to suppress the diffusion of components contained in the insulating layer 109 (e.g., water) into layers 113R, 113G, and 113B. This can improve the reliability of the light-emitting device. It can also improve the manufacturing yield of the light-emitting device.

[0117] In this specification, a barrier layer refers to a layer that has barrier properties. In this specification, barrier properties refer to a function that makes it difficult for a target substance to diffuse, thereby suppressing the permeation of the substance through the film (also referred to as low permeability). Alternatively, it refers to a function that captures or fixes a target substance (also referred to as gettering).

[0118] Figure 1B shows a configuration in which a mask layer 118R is located on layer 113R, a mask layer 118G is located on layer 113G, and a mask layer 118B is located on layer 113B. Mask layer 118R is a portion of the mask layer that remained after being provided in contact with the upper surface of layer 113R when layer 113R was formed. Similarly, mask layer 118G is a portion of the mask layer that remained after being provided when layer 113G was formed, and mask layer 118B is a portion of the mask layer that remained after being provided when layer 113B was formed. Thus, a display device according to one embodiment of the present invention can be configured such that a portion of the mask layer used to protect the EL layer remains after being manufactured. Two or all of the mask layers 118R, 118G, and 118B can be made of the same material, or different materials can be used for each other. In the following, mask layers 118R, 118G, and 118B may be collectively referred to as mask layer 118.

[0119] In this specification, "different materials" means materials in which some or all of the constituent elements are different, or materials in which the constituent elements are the same but the composition is different.

[0120] One end of the mask layer 118R (the end opposite to the light-emitting region, the outer end) is aligned with or approximately aligned with the end of layer 113R, and the other end of the mask layer 118R is located on layer 113R. Here, it is preferable that the other end of the mask layer 118R (the end on the light-emitting region side, the inner end) overlaps with the region where the conductive layer 137R and the pixel electrode 111R are in contact. In this case, the other end of the mask layer 118R is more likely to be formed on the approximately flat surface of layer 113R. The same applies to mask layers 118G and 118B. Furthermore, the mask layer 118 is located, for example, between the upper surface of an island-shaped EL layer (layer 113R, layer 113G, or layer 113B) and the insulating layer 125. The mask layer will be described in detail in Embodiment 2.

[0121] In forming layer 113R, mask layer 118R, layer 113G, mask layer 118G, layer 113B, and mask layer 118B, it is preferable to set the thickness of conductive layers 137R, 137G, and 137B so that the first etching stopper (later conductive layers 137R, 137B, and 137B) covers the insulating layer 109 and the insulating layer 109 is not exposed. If the thickness of conductive layers 137R, 137G, and 137B is too thin, their function as etching stoppers will be reduced, and if they are too thick, the productivity of the display device may be reduced. Furthermore, when applying a microcavity structure to the light-emitting device, it is preferable that the thickness of conductive layers 137R, 137G, and 137B each function as an optical adjustment layer. As shown in Figure 2A, the thickness T137 of the conductive layer 137R can be the shortest distance between the surface on which the conductive layer 137R is formed in a cross-sectional view (here, the upper surface of the pixel electrode 111R in the region where the conductive layer 137R and the pixel electrode 111R are in contact) and the upper surface of the conductive layer 137R. The thickness T137 is preferably 5 nm to 100 nm, more preferably 10 nm to 100 nm, more preferably 10 nm to 60 nm, more preferably 20 nm to 60 nm, and more preferably 20 nm to 40 nm. By setting the thickness T137 within the above range, it is possible to suppress the thinning of the insulating layer 109 and to increase the productivity of the display device. Note that the thickness T137 is not limited to the above range.

[0122] After forming layers 113R, mask layer 118R, 113G, mask layer 118G, layer 113B, and mask layer 118B on the first etching stopper, the first etching stopper can be processed using these as masks to form conductive layers 137R, 137G, and 137B. This allows the edge of conductive layer 137R to coincide with or approximately coincide with the edge of layer 113R. Similarly, the edge of conductive layer 137G can coincide with or approximately coincide with the edge of layer 113G. The edge of conductive layer 137B can coincide with or approximately coincide with the edge of layer 113B. However, it is also possible to configure conductive layers 137R, 137G, and 137B so that their edges do not coincide with the edges of layers 113R, 113G, and 113B.

[0123] For conductive layers 137R, 137G, and 137B, it is preferable to use materials that have high resistance in the formation of layers 113R, 113G, and 113B, specifically materials with a high selectivity ratio for etching with layers 113R, 113G, and 113B. Dry etching or wet etching can be used to form layers 113R, 113G, and 113B. In particular, anisotropic dry etching can be suitably used. When processing the first etching stopper, a portion of the insulating layer 109 in a region that does not overlap with any of layers 113R, mask layer 118R, 113G, mask layer 118G, layer 113B, and mask layer 118B may be removed. As a result, as shown in Figure 3, the insulating layer 109 may have recesses in areas that do not overlap with any of the layers 113R, mask layer 118R, layer 113G, mask layer 118G, layer 113B, mask layer 118B, conductive layer 137R, conductive layer 137G, and conductive layer 137B.

[0124] Each side of layer 113R, layer 113G, and layer 113B is covered by an insulating layer 125. The insulating layer 127 faces each side of layer 113R, layer 113G, and layer 113B via the insulating layer 125.

[0125] By covering a portion of the upper surface and sides of layers 113R, 113G, and 113B with at least one of the insulating layer 125, insulating layer 127, and mask layer 118, contact between the common layer 114 (or common electrode 115) and the sides of layers 113R, 113G, and 113B is suppressed, thereby preventing a short circuit in the light-emitting device. This improves the reliability of the light-emitting device.

[0126] Preferably, the EL layer has a first region which is a light-emitting region (also called a light-emitting area) and a second region located outside the first region. The second region can also be called a dummy region or dummy area. The first region is located between the pixel electrode and the common electrode. The first region is covered by the mask layer during the manufacturing process of the display device, and is therefore subjected to very little damage. As a result, a light-emitting device with high luminous efficiency and a long lifespan can be realized. On the other hand, the second region includes the edge of the EL layer and its vicinity, and may be damaged by exposure to plasma during the manufacturing process of the display device. By not using the second region as a light-emitting region, variations in the characteristics of the light-emitting device can be suppressed. For example, by providing the EL layer on the insulating layer 109 as well, the region overlapping with the insulating layer 109 is included in the second region. This suppresses variations in the characteristics of the light-emitting device.

[0127] Here, a configuration for forming island-like layers 113R, 113G, and 113B using photolithography is shown, but the present invention is not limited to this. For example, island-like layers 113R, 113G, and 113B can also be formed using a fine metal mask.

[0128] In Figure 1B, layers 113R, 113G, and 113B are shown to have the same thickness, but the present invention is not limited to this. The thicknesses of layers 113R, 113G, and 113B can also be different. For example, it is preferable to set the thicknesses so that the optical path length is such that the light emitted by each of layers 113R, 113G, and 113B is intensified. This makes it possible to realize a microcavity structure and improve the color purity of each light-emitting device.

[0129] The insulating layer 125 has regions that are in contact with the sides of the conductive layer 137R, the sides of the conductive layer 137G, the sides of the conductive layer 137B, the sides of the layer 113R, the sides of the layer 113G, the sides of the layer 113B, the sides and top of the mask layer 118R, the sides and top of the mask layer 118G, the sides and top of the mask layer 118B, and the top surface of the insulating layer 109.

[0130] In cross-sectional views such as Figure 1B, multiple insulating layers 125 and insulating layers 127 are shown, but when the display device 100 is viewed from above, the insulating layers 125 and insulating layers 127 are connected as one unit each. It can also be said that the insulating layers 125 and insulating layers 127 are continuous. In other words, the display device 100 can be configured to have one insulating layer 125 and one insulating layer 127. Furthermore, the display device 100 can be configured to have multiple insulating layers 125 that are separated from each other, and multiple insulating layers 127 that are separated from each other.

[0131] The insulating layer 125 preferably contacts the respective sides of layers 113R, 113G, and 113B (see the dashed areas at the ends of layer 113R and layer 113G and their vicinity shown in Figures 2A and 2B). By configuring the insulating layer 125 to contact layers 113R, 113G, and 113B, peeling of the layers 113R, 113G, and 113B can be prevented. The close contact between the insulating layer 125 and layers 113B, 113G, or 113R provides the effect of fixing or bonding adjacent layers 113B, etc., to the insulating layer 125. This can improve the reliability of the light-emitting device. It can also improve the manufacturing yield of the light-emitting device.

[0132] As shown in Figure 1B, the insulating layers 125 and 127 cover both a portion of the upper surface and the sides of layers 113R, 113G, and 113B, thereby further preventing delamination of the EL layer and improving the reliability of the light-emitting device. Furthermore, it is possible to increase the manufacturing yield of the light-emitting device.

[0133] The insulating layer 127 is provided on the insulating layer 125 so as to fill the recesses in the insulating layer 125. The insulating layer 127 can be configured to face a portion of the upper surface and side surfaces of layers 113R, 113G, and 113B, respectively, via the insulating layer 125. Preferably, the insulating layer 127 covers at least a portion of the side surfaces of the insulating layer 125.

[0134] By providing insulating layers 125 and 127, the gaps between adjacent island-shaped layers can be filled, thereby reducing the large height differences and irregularities on the formed surface of layers (e.g., carrier injection layers and common electrodes) on the island-shaped layers, making it flatter. Consequently, the coverage of the carrier injection layers and common electrodes can be improved.

[0135] The common layer 114 and common electrode 115 are provided on layers 113R, 113G, 113B, mask layer 118, insulating layer 125, and insulating layer 127. Before the insulating layers 125 and 127 are provided, a step difference occurs due to the region where the pixel electrode and island-shaped EL layer are provided and the region where the pixel electrode and island-shaped EL layer are not provided (the region between light-emitting devices). In one embodiment of the present invention, the presence of the insulating layers 125 and 127 can flatten this step difference and improve the coverage of the common layer 114 and common electrode 115. Therefore, connection failures due to step breaks in the common layer 114 and common electrode 115 can be suppressed. In addition, it is possible to suppress the localized thinning of the thickness of the common electrode 115 due to the step difference and the resulting increase in electrical resistance.

[0136] The upper surface of the insulating layer 127 preferably has a highly flat shape, but it can also have a configuration with convex portions, convex curved surfaces, concave curved surfaces, or recesses. For example, the upper surface of the insulating layer 127 preferably has a highly flat, convex curved shape with a large radius of curvature.

[0137] As shown in Figure 3, the recesses in the insulating layer 109 are filled with the insulating layer 127. This improves the coverage of the common layer 114 and the common electrode 115 even on these recesses. Therefore, connection failures due to stepped breaks in the common layer 114 and the common electrode 115 can be suppressed.

[0138] Next, examples of materials for the insulating layer 125 and insulating layer 127 will be described.

[0139] An inorganic insulating layer can be used as the insulating layer 125. The insulating layer 125 can have a single-layer structure or a multi-layer structure. Examples of oxides that can be used for the inorganic insulating layer include silicon oxide, aluminum oxide, magnesium oxide, indium gallium zinc oxide, gallium oxide, germanium oxide, yttrium oxide, zirconium oxide, lanthanum oxide, neodymium oxide, hafnium oxide, and tantalum oxide. Examples of nitrides include silicon nitride and aluminum nitride. Examples of oxidized nitrides include silicon oxidized nitride and aluminum oxidized nitride. Examples of nitride oxides include silicon oxide nitride and aluminum oxide nitride. In particular, aluminum oxide is preferred because it has a high selectivity ratio with the EL layer during etching and has the function of protecting the EL layer during the formation of the insulating layer 127, which will be described later. In particular, by applying an inorganic insulating layer such as an aluminum oxide film, a hafnium oxide film, or a silicon oxide film formed by atomic layer deposition (ALD) to the insulating layer 125, it is possible to form an insulating layer 125 with fewer pinholes and excellent protection for the EL layer. Furthermore, the insulating layer 125 can have a laminated structure of a film formed by the ALD method and a film formed by the sputtering method. For example, the insulating layer 125 can have a laminated structure of an aluminum oxide film formed by the ALD method and a silicon nitride film formed by the sputtering method.

[0140] Preferably, the insulating layer 125 functions as a barrier layer against at least one of water and oxygen. Furthermore, preferably, the insulating layer 125 has the function of suppressing the diffusion of at least one of water and oxygen. Also, preferably, the insulating layer 125 has the function of capturing or fixing (also known as gettering) at least one of water and oxygen.

[0141] The insulating layer 125 has a barrier layer function or a gettering function, which suppresses the intrusion of impurities (typically at least one of water and oxygen) that could diffuse from the outside into each light-emitting device. This configuration makes it possible to provide a highly reliable light-emitting device and, furthermore, a highly reliable display device.

[0142] Furthermore, the same material can be used for the insulating layer 125 and the mask layers 118B, 118G, and 118R. In this case, the boundary between any of the mask layers 118B, 118G, and 118R and the insulating layer 125 may become unclear and indistinguishable. Therefore, the insulating layer 125 may be identified as a single layer with any of the mask layers 118B, 118G, and 118R. In other words, it may be observed that a single layer is provided in contact with a part of the upper surface and side surface of each of the layers 113R, 113G, and 113B, and that the insulating layer 127 covers at least a part of the side surface of the single layer.

[0143] The insulating layer 127, provided on the insulating layer 125, has the function of flattening the large height differences and irregularities in the insulating layer 125 formed between adjacent light-emitting devices. In other words, the presence of the insulating layer 127 has the effect of improving the flatness of the surface forming the common electrode 115.

[0144] The insulating layer 127 can be made from the materials listed for the insulating layer 109. It is preferable to use an organic insulating layer for the insulating layer 127. It is preferable to use a photosensitive resin for the organic insulating layer. For example, acrylic resin can be suitably used for the insulating layer 127.

[0145] A material with low light transmittance can also be used for the insulating layer 127. For example, a material that absorbs visible light can be used for the insulating layer 127. By absorbing the light emitted from the light-emitting device, the insulating layer 127 can suppress light leakage from the light-emitting device to adjacent light-emitting devices through the insulating layer 127. This improves the display quality of the display device. Furthermore, since the display quality can be improved without using a polarizing plate in the display device, the display device can be made lighter and thinner. In addition, by making the insulating layer 127 function as a light-shielding layer, it is possible to suppress ambient light and light emitted from the light-emitting device from entering the transistors of the display device. This suppresses fluctuations in the electrical characteristics of the transistors due to light, resulting in a highly reliable display device. For materials with low light transmittance, refer to the description related to the insulating layer 109.

[0146] A mask layer 118R is provided in contact with a portion of the upper surface of layer 113R, a mask layer 118G is provided in contact with a portion of the upper surface of layer 113G, and a mask layer 118B is provided in contact with a portion of the upper surface of layer 113B. An insulating layer 125 is provided in contact with the upper and side surfaces of mask layer 118R, the upper and side surfaces of mask layer 118G, the upper and side surfaces of mask layer 118B, and the upper surface of insulating layer 109. An insulating layer 127 is provided in contact with the upper and side surfaces of insulating layer 125. In addition, insulating layer 127 faces a portion of the upper and side surfaces of layer 113R, a portion of the upper and side surfaces of layer 113G, and a portion of the upper and side surfaces of layer 113B via insulating layer 125. A common layer 114 is provided covering layer 113R, mask layer 118R, layer 113G, mask layer 118G, layer 113B, mask layer 118B, insulating layer 125, and insulating layer 127, and a common electrode 115 is provided on the common layer 114.

[0147] The insulating layer 127 is formed in the region between the two island-shaped EL layers (for example, the region between layer 113R and layer 113G). At this time, at least a portion of the insulating layer 127 is located between adjacent EL layers. By providing the insulating layer 127, the coverage of the island-shaped EL layers and the common layer 114 and common electrode 115 formed on the insulating layer 127 is improved, thereby preventing the formation of divisions in these layers and localized areas of thinness.

[0148] In cross-sectional view, the upper surface of the insulating layer 127 is preferably a convex curved shape. The convex curved shape of the upper surface of the insulating layer 127 is preferably a shape that bulges gently towards the center. Furthermore, it is preferable that the convex curved portion in the central part of the upper surface of the insulating layer 127 is continuously connected toward the edges. By making the insulating layer 127 such a shape, the common layer 114 and the common electrode 115 can be formed on the entire insulating layer 127 with high coverage.

[0149] By providing insulating layers 127 and 125, the common layer 114 and common electrode 115 can be formed with high coverage. This prevents the formation of divided areas and locally thin areas in the common layer 114 and common electrode 115. Therefore, connection failures caused by divided areas and increases in electrical resistance caused by locally thin areas can be suppressed between each light-emitting device in the common layer 114 and common electrode 115. As a result, the display device according to one aspect of the present invention can improve display quality.

[0150] In Figure 1B, there is no insulating layer (also called a partition, bank, or spacer) between the pixel electrode 111R and layer 113R that covers the upper edge of the pixel electrode 111R. Similarly, there is no insulating layer between the pixel electrode 111G and layer 113G that covers the upper edge of the pixel electrode 111G. As a result, the spacing between adjacent light-emitting devices can be made extremely narrow. Consequently, a high-definition or high-resolution display device can be made. Furthermore, a mask for forming the insulating layer is unnecessary, which can reduce the manufacturing cost of the display device.

[0151] By omitting an insulating layer covering the edges of the pixel electrodes between the pixel electrodes and the EL layer, or in other words, by omitting an insulating layer between the pixel electrodes and the EL layer, light emission from the EL layer can be efficiently extracted. Furthermore, a display device according to one aspect of the present invention can achieve extremely low viewing angle dependence. By reducing viewing angle dependence, the visibility of images in the display device can be improved. For example, in a display device according to one aspect of the present invention, the viewing angle (the maximum angle at which a constant contrast ratio is maintained when viewing the screen from an oblique direction) can be set to a range of 100° or more and less than 180°, preferably 150° or more and 170° or less. The above viewing angle can be applied to both vertical and horizontal viewing angles.

[0152] Figure 1B and others show a configuration in which the edges of conductive layers 137R, 137G, and 137B coincide with the edges of layers 113R, 113G, and 113B, but the present invention is not limited to this. An example of a configuration different from that of Figure 1B is shown in Figure 4A. Figure 4B shows an enlarged view of a part of the cross-sectional view shown in Figure 4A. The configuration shown in Figure 4A differs from the configuration shown in Figure 1B mainly in that the edges of conductive layers 137R, 137G, and 137B do not coincide with the edges of layers 113R, 113G, and 113B.

[0153] The conductive layer 137R has a region that protrudes beyond the edge of layer 113R. Similarly, the conductive layer 137G has a region that protrudes beyond the edge of layer 113G. The conductive layer 137B has a region that protrudes beyond the edge of layer 113B. The edge of layer 113R overlaps with the conductive layer 137R, the edge of layer 113G overlaps with the conductive layer 137G, and the edge of layer 113B overlaps with the conductive layer 137B. The edge of layer 113R is located on the conductive layer 137R, the edge of layer 113G is located on the conductive layer 137G, and the edge of layer 113B is located on the conductive layer 137B. It can also be said that the edge of layer 113R is in contact with the upper surface of the conductive layer 137R, the edge of layer 113G is in contact with the upper surface of the conductive layer 137G, and the edge of layer 113B is in contact with the upper surface of the conductive layer 137B. For example, after forming conductive layer 137R, conductive layer 137G, and conductive layer 137B, layers 113R, 113G, and 113B can be formed.

[0154] A film that will become layer 113R can be formed on conductive layers 137R, 137G, and 137B, and this film can be processed by photolithography to form island-like layers 113R. The same applies to layers 113G and 113B. Conductive layers 137R, 137G, and 137B each function as etching stoppers when forming layers 113R, 113G, and 113B, respectively. Therefore, conductive layers 137R, 137G, and 137B can each be called first etching stoppers.

[0155] When processing a conductive film to form conductive layers 137R, 137G, and 137B, the etching gas or etchant used in the processing may damage layers 113R, 113G, and 113B. Furthermore, layers 113R, 113G, and 113B may peel off. In such cases, it is preferable to form conductive layers 137R, 137G, and 137B before forming layers 113R, 113G, and 113B. This suppresses damage to layers 113R, 113G, and 113B, and prevents them from peeling off. Therefore, the reliability of the light-emitting device can be improved, resulting in a highly reliable display device. Additionally, the manufacturing yield of the display device can be increased.

[0156] The insulating layer 125 has regions that are in contact with the side and top surfaces of the conductive layer 137R, the side and top surfaces of the conductive layer 137G, the side and top surfaces of the conductive layer 137B, the side surfaces of layer 113R, the side surfaces of layer 113G, the side surfaces of layer 113B, the side and top surfaces of the mask layer 118R, the side and top surfaces of the mask layer 118G, the side and top surfaces of the mask layer 118B, and the top surface of the insulating layer 109.

[0157] When forming layers 113R, 113G, and 113B, a portion of the insulating layer 109 in areas that do not overlap with conductive layers 137R, 137G, and 137B may be removed. As a result, as shown in Figures 4A and 4B, the insulating layer 109 may have recesses in areas that do not overlap with conductive layers 137R, 137G, and 137B.

[0158] Alternatively, as shown in Figures 5A and 5B, the ends of layer 113R, layer 113G, and layer 113B can be configured to be in contact with the upper surface of the insulating layer 109. In other words, layer 113R has a region that protrudes beyond the end of the conductive layer 137R. Similarly, layer 113G has a region that protrudes beyond the end of the conductive layer 137G. Layer 113B has a region that protrudes beyond the end of the conductive layer 137B.

[0159] For example, layer 113R can be formed by depositing a film to be layer 113R and processing the film so that layer 113R has a region that protrudes beyond the edge of the conductive layer 137R. The same applies to the formation of layers 113G and 113B. In addition, when forming layers 113R, 113G and 113B, a portion of the insulating layer 109 in a region that does not overlap with any of layers 113R, 113G and 113B may be removed. As a result, as shown in Figures 5A and 5B, the insulating layer 109 may have a recess in a region that does not overlap with any of layers 113R, 113G and 113B.

[0160] Figure 1B shows a configuration in which conductive layers 105R, 105G, and 105B are provided on layer 101, layers 107R, 107G, and 107B are provided on conductive layers 105R, 105G, and 105B, and light-emitting devices 130R, 130G, and 130B are provided on layers 107R, 107G, and 107B.

[0161] Layer 101 has one or more transistors, capacitive elements, and wiring. Layer 101 can be provided with pixel circuits that control the driving of light-emitting devices 130R, 130G, and 130B. Light-emitting devices 130R, 130G, and 130B are each connected to one or more transistors, capacitive elements, and wiring of layer 101.

[0162] Figure 1B shows a configuration in which layer 101 has a substrate 103, an insulating layer 104, a conductive layer 250R, a conductive layer 250G, and a conductive layer 250B. The conductive layers 250R, 250G, and 250B are provided on the substrate 103. The conductive layers 250R, 250G, and 250B correspond to the electrodes of a transistor, the electrodes of a capacitive element, or wiring, respectively.

[0163] The conductive layers 250R, 250G, and 250B can be formed, for example, in the same process. In the following, the conductive layers 250R, 250G, and 250B may be collectively referred to as the conductive layer 250.

[0164] An insulating layer 104 is provided on the conductive layer 250R, conductive layer 250G, and conductive layer 250B. The insulating layer 104 can have a single-layer structure or a laminated structure. The insulating layer 104 has openings 257R that reach the conductive layer 250R, openings 257G that reach the conductive layer 250G, and openings 257B that reach the conductive layer 250B.

[0165] A conductive layer 105R is provided so as to cover the opening 257R. The conductive layer 105R is in contact with the conductive layer 250R at the opening 257R and is connected to the conductive layer 250R. A conductive layer 105G is provided so as to cover the opening 257G. The conductive layer 105G is in contact with the conductive layer 250G at the opening 257G and is connected to the conductive layer 250G. A conductive layer 105B is provided so as to cover the opening 257B. The conductive layer 105B is in contact with the conductive layer 250B at the opening 257B and is connected to the conductive layer 250B.

[0166] As the insulating layer 104, either or both of an inorganic insulating layer and an organic insulating layer can be used. For details on the inorganic insulating layer and the organic insulating layer, please refer to the above description.

[0167] A material with low light transmittance can also be used for the insulating layer 104, or for one or more layers of the insulating layer 104. By having a light-shielding layer in the insulating layer 104, it is possible to suppress the incidence of ambient light and light emitted from light-emitting devices onto the transistors of the display device. This suppresses fluctuations in the electrical characteristics of the transistors due to light, resulting in a highly reliable display device. In particular, it is preferable that one or more layers provided above the semiconductor layer of the transistor function as a light-shielding layer. For materials with low light transmittance, refer to the description relating to the insulating layer 109.

[0168] Layer 107R has a region in contact with the upper surface of the conductive layer 105R. The pixel electrode 111R has a region in contact with the upper and side surfaces of layer 107R, as well as the upper surface of the conductive layer 105R. The pixel electrode 111R is connected to the conductive layer 105R. Furthermore, it is preferable that the insulating layer 109 has a region facing the side surface of layer 107R via the pixel electrode 111R.

[0169] The layer 107G has a region that is in contact with the upper surface of the conductive layer 105G. The pixel electrode 111G has a region that is in contact with the upper and side surfaces of the layer 107G, as well as the upper surface of the conductive layer 105G. The pixel electrode 111G is connected to the conductive layer 105G. Furthermore, it is preferable that the insulating layer 109 has a region that faces the side surface of the layer 107G via the pixel electrode 111G.

[0170] Layer 107B has a region in contact with the upper surface of the conductive layer 105B. The pixel electrode 111B has a region in contact with the upper and side surfaces of layer 107B, as well as the upper surface of the conductive layer 105B. The pixel electrode 111B is also connected to the conductive layer 105B. Preferably, the insulating layer 109 has a region facing the side surface of layer 107B via the pixel electrode 111B.

[0171] The conductive layers 105R, 105G, and 105B can be formed, for example, in the same process. In the following, the conductive layers 105R, 105G, and 105B may be collectively referred to as conductive layer 105. Similarly, layers 107R, 107G, and 107B can be formed, for example, in the same process. In addition, layers 107R, 107G, and 107B may be collectively referred to as layer 107.

[0172] The conductive layers 105R, 105G, and 105B can each be a single-layer structure or a laminated structure of two or more layers. Materials that can be used for these include, for example, one or more of the following: chromium, copper, aluminum, gold, silver, zinc, tantalum, titanium, tungsten, manganese, nickel, iron, cobalt, molybdenum, and niobium, as well as alloys comprising one or more of the aforementioned metals. Conductive materials with low electrical resistivity, containing one or more of copper, silver, gold, and aluminum, can be suitably used for the conductive layers 105R, 105G, and 105B, respectively. Copper or aluminum are particularly preferred due to their excellent mass-producibility. Furthermore, oxide conductors can be used for the conductive layers 105R, 105G, and 105B, respectively.

[0173] The conductive layers 105R, 105G, and 105B can each have a laminated structure consisting of a conductive film containing the aforementioned oxide conductor and a conductive film containing a metal or alloy. By using a conductive film containing a metal or alloy, the wiring resistance can be reduced.

[0174] The conductive layers 105R, 105G, and 105B can each be made of a Cu-X alloy film (where X is Mn, Ni, Cr, Fe, Co, Mo, Ta, or Ti). Using a Cu-X alloy film allows for processing by wet etching, thus reducing manufacturing costs.

[0175] Figure 6A shows top views of the opening 257R, opening 257G, opening 257B, conductive layer 105R, conductive layer 105G, and conductive layer 105B. As shown in Figure 6A, in a top view, it is preferable that conductive layer 105R encompasses opening 257R, conductive layer 105G encompasses opening 257G, and conductive layer 105B encompasses opening 257B.

[0176] Figure 6B shows a top view of Figure 6A with layers 107R, 107G, and 107B added. As shown in Figure 6B, in a top view, it is preferable that layer 107R encompasses the opening 257R, layer 107G encompasses the opening 257G, and layer 107B encompasses the opening 257B. As shown in Figure 1B, conductive layer 105R has a recess in a position overlapping with the opening 257R, and this recess is filled with layer 107R. Similarly, conductive layer 105G has a recess in a position overlapping with the opening 257G, and this recess is filled with layer 107G. Conductive layer 105B has a recess in a position overlapping with the opening 257B, and this recess is filled with layer 107B.

[0177] By filling the recesses caused by the openings 257R, 257G, and 257B with layers 107R, 107G, and 107B, the upper surfaces of the pixel electrodes 111R, 111G, and 111B provided on these recesses can be made flatter. As a result, the areas overlapping with the openings 257R, 257G, and 257B can also be used as the light-emitting area of ​​the light-emitting device. Therefore, the area of ​​the light-emitting area of ​​the light-emitting device can be increased, resulting in a display device with a high aperture ratio.

[0178] It is preferable that layer 107R be provided not only in the region overlapping with the opening 257R on the conductive layer 105R, but also in the region that does not overlap with the opening 257R on the conductive layer 105R. This improves the flatness of the upper surface of layer 107R. By improving the flatness of the upper surface of layer 107R, which is the surface on which the light-emitting device 130R is formed, unevenness in brightness is reduced, and a display device with high display quality can be obtained. The same applies to layers 107G and 107B.

[0179] As shown in Figure 6B, in a top view, it is preferable that the conductive layer 105R encompasses layer 107R, the conductive layer 105G encompasses layer 107G, and the conductive layer 105B encompasses layer 107B.

[0180] The conductivity of layers 107R, 107G, and 107B is not particularly limited and can be, for example, an insulating layer, a semiconductor layer, or a conductive layer. One or more inorganic and organic materials can be used for layers 107R, 107G, and 107B.

[0181] Layers 107R, 107G, and 107B can be made from the materials listed for insulating layer 109. It is preferable to use an organic insulating layer for layers 107R, 107G, and 107B. It is preferable to use a photosensitive resin for the organic insulating layer. For example, polyimide resin can be suitably used for layers 107R, 107G, and 107B.

[0182] Figure 6C shows a top view of Figure 6B with pixel electrodes 111R, 111G, and 111B added. As shown in Figure 6C, in a top view, it is preferable that the pixel electrode 111R encompasses layer 107R. Layer 107R is enclosed by the pixel electrode 111R and the conductive layer 105R. Furthermore, both the pixel electrode 111R and the conductive layer 105R have regions that protrude from the edges of layer 107R. This increases the contact area between the pixel electrode 111R and the conductive layer 105R, and reduces the contact resistance between the pixel electrode 111R and the conductive layer 105R. Similarly, in a top view, it is preferable that the pixel electrode 111G encompasses layer 107G. Layer 107G is enclosed by the pixel electrode 111G and the conductive layer 105G. Furthermore, both the pixel electrode 111G and the conductive layer 105G have regions that protrude from the edges of layer 107G. This increases the contact area between the pixel electrode 111G and the conductive layer 105G, thereby lowering the contact resistance between the pixel electrode 111G and the conductive layer 105G. In a top view, it is preferable that the pixel electrode 111B encompasses the layer 107B. The layer 107B is enclosed by the pixel electrode 111B and the conductive layer 105B. Furthermore, the pixel electrode 111B and the conductive layer 105B each have a region that protrudes from the edge of the layer 107B. This increases the contact area between the pixel electrode 111B and the conductive layer 105B, thereby lowering the contact resistance between the pixel electrode 111B and the conductive layer 105B.

[0183] The end of the pixel electrode 111R can coincide with or roughly coincide with the end of the conductive layer 105R, the end of the pixel electrode 111G can coincide with or roughly coincide with the end of the conductive layer 105G, and the end of the pixel electrode 111B can coincide with or roughly coincide with the end of the conductive layer 105B. For example, a first conductive film, which will become the conductive layer 105R, conductive layer 105G, and conductive layer 105B, is formed on the insulating layer 104. Layers 107R, 107G, and 107B are formed on the first conductive film. A second conductive film, which will become the pixel electrode 111R, pixel electrode 111G, and pixel electrode 111B, is formed on the first conductive film, layer 107R, layer 107G, and layer 107B. Then, the first conductive film and the second conductive film can be processed to form conductive layer 105R, conductive layer 105G, conductive layer 105B, pixel electrode 111R, pixel electrode 111G, and pixel electrode 111B. This allows the edges of conductive layer 105R, conductive layer 105G, and conductive layer 105B to coincide with or approximately coincide with the edges of pixel electrode 111R, pixel electrode 111G, and pixel electrode 111B. By processing the first conductive film and the second conductive film in the same process, the productivity of the display device can be increased and manufacturing costs can be reduced. However, it is also possible to have a configuration in which the edges of conductive layer 105R, conductive layer 105G, and conductive layer 105B do not coincide with the edges of pixel electrode 111R, pixel electrode 111G, and pixel electrode 111B.

[0184] Furthermore, the conductive layer 105R and the pixel electrode 111R can preferably be made of the same material. Alternatively, if the pixel electrode 111R has a laminated structure, the same material as one or more of the layers can preferably be used for the conductive layer 105R. This allows the conductive layer 105R and the pixel electrode 111R to be formed in the same process, thereby increasing productivity. For example, the pixel electrode 111R can have a laminated structure of a first titanium film, an aluminum film on the first titanium film, and a second titanium film on the aluminum film. The conductive layer 105R can then have a single-layer structure of a third titanium film. The same applies to the conductive layer 105G, conductive layer 105B, pixel electrode 111G, and pixel electrode 111B.

[0185] Figure 6D shows a top view of Figure 6C with the insulating layer 109 added. As shown in Figure 6D, the insulating layer 109 is provided between adjacent pixel electrodes 111. The insulating layer 109 is provided, for example, between pixel electrode 111R and pixel electrode 111G, and between pixel electrode 111G and pixel electrode 111B. The insulating layer 109 is provided in areas where none of layers 107R, 107G, and 107B are provided. It is also possible to configure the insulating layer 109 to have an area that overlaps with a part of layers 107R, 107G, and 107B. Furthermore, the insulating layer 109 is provided so as to cover a part of pixel electrode 111R, a part of pixel electrode 111G, and a part of pixel electrode 111B. The insulating layer 109 has an area that overlaps with a part of pixel electrode 111R, a part of pixel electrode 111G, and a part of pixel electrode 111B. As shown in Figure 2A, the insulating layer 109 overlaps with, for example, the region in contact with the conductive layer 105R of the pixel electrode 111R. It can also be said that the insulating layer 109 overlaps with the region of the pixel electrode 111R that protrudes from the edge of layer 107R.

[0186] In cross-sectional views such as Figure 1B, multiple insulating layers 109 are shown, but when the display device 100 is viewed from above, the insulating layer 109 is connected as one (see Figure 6D). It can also be said that the insulating layer 109 is continuous. In other words, the display device 100 can be configured to have only one insulating layer 109. However, the display device 100 can also be configured to have multiple insulating layers 109 that are separated from each other.

[0187] The insulating layer 109 is provided on the insulating layer 104. Between the light-emitting device 130R and the light-emitting device 130G, the insulating layer 109 is located between the conductive layer 105R, layer 107R and the pixel electrode 111R, and between the conductive layer 105G, layer 107G and the pixel electrode 111G. The insulating layer 109 is in contact with the upper surface of the insulating layer 104, the side surface of the conductive layer 105R, the side surface of the region of the pixel electrode 111R that is in contact with the conductive layer 105R, the side surface of the conductive layer 105G, the side surface of the pixel electrode 111G that is in contact with the conductive layer 105G, and the upper surface of the region of the pixel electrode 111G that is in contact with the conductive layer 105G. The same applies between other light-emitting devices.

[0188] It is preferable not to provide an insulating layer 109 in the region along the upper surface of the layer 107 of the pixel electrode 111. This increases the contact area between the pixel electrode 111 and the conductive layer 137, thereby increasing the area of ​​the light-emitting region of the light-emitting device. Consequently, a display device with a high aperture ratio can be obtained.

[0189] As shown in Figure 2A, in a cross-sectional view, it is preferable that the height H111 of the upper surface of the pixel electrode 111 coincides with or approximately coincides with the height H109 of the upper surface of the insulating layer 109. This improves the coverage of the layers (for example, the conductive layer 137R and layer 113R) provided on the pixel electrode 111 and the insulating layer 109. In Figure 2A, the height H111 is shown from the surface on which the conductive layer 105R is formed (here, the upper surface of the insulating layer 104 in the region where the conductive layer 105R and the insulating layer 104 are in contact) to the upper surface of the highest position of the pixel electrode 111R, and the height H109 is shown to the upper surface of the highest position of the insulating layer 109. Alternatively, as shown in Figure 2B, it is preferable that the height H111 is higher than the height H109. In this case, it is preferable that the conductive layer 137 has a region in contact with a part of the side surface of the pixel electrode 111. As shown in Figures 2A and 2B, by making the height H111 the same as or higher than the height H109, ​​the insulating layer 109 is not provided in the region along the upper surface of the layer 107 of the pixel electrode 111, and the contact area between the pixel electrode 111 and the conductive layer 137 can be increased. It is also possible to have a configuration in which the insulating layer 109 has a region located higher than the upper surface of the pixel electrode 111.

[0190] Figure 1B and other figures show a configuration in which the pixel electrode 111 is in contact with the side surface of the layer 107, but the present invention is not limited to this. The configuration of the pixel electrode 111 and the layer 107 is not particularly limited. Furthermore, a configuration without the layer 107 is also possible.

[0191] The light-emitting device of this embodiment can be a single structure (a structure having only one light-emitting unit) or a tandem structure (a structure having multiple light-emitting units). The light-emitting unit has at least one light-emitting layer.

[0192] Layers 113R, 113G, and 113B each have at least an emissive layer. Layer 113R has an emissive layer that emits red light, layer 113G has an emissive layer that emits green light, and layer 113B has an emissive layer that emits blue light. In other words, layer 113R has an emissive material that emits red light, layer 113G has an emissive material that emits green light, and layer 113B has an emissive material that emits blue light.

[0193] When using a tandem light-emitting device, it is preferable that layer 113R has a structure having multiple light-emitting units that emit red light, layer 113G has a structure having multiple light-emitting units that emit green light, and layer 113B has a structure having multiple light-emitting units that emit blue light. It is preferable to provide a charge generation layer between the light-emitting units of each light-emitting device.

[0194] Each of layers 113R, 113G, and 113B may each have one or more of the following: a hole injection layer, a hole transport layer, a hole blocking layer, a charge generation layer, an electron blocking layer, an electron transport layer, and an electron injection layer.

[0195] For example, layers 113R, 113G, and 113B may each have a hole injection layer, a hole transport layer, an emissive layer, and an electron transport layer in that order. An electron blocking layer may also be present between the hole transport layer and the emissive layer. Furthermore, a hole blocking layer may be present between the electron transport layer and the emissive layer. Additionally, an electron injection layer may be present on the electron transport layer.

[0196] For example, layers 113R, 113G, and 113B may each have an electron injection layer, an electron transport layer, an emissive layer, and a hole transport layer in that order. Alternatively, a hole blocking layer may be present between the electron transport layer and the emissive layer. Furthermore, an electron blocking layer may be present between the hole transport layer and the emissive layer. Additionally, a hole injection layer may be present on the hole transport layer.

[0197] Thus, it is preferable that each of layers 113R, 113G, and 113B has an emissive layer and a carrier transport layer (electron transport layer or hole transport layer) on the emissive layer. Alternatively, it is preferable that each of layers 113R, 113G, and 113B has an emissive layer and a carrier block layer (hole block layer or electron block layer) on the emissive layer. Alternatively, it is preferable that each of layers 113R, 113G, and 113B has an emissive layer, a carrier block layer on the emissive layer, and a carrier transport layer on the carrier block layer. When the surfaces of layers 113R, 113G, and 113B are exposed to the atmosphere during the manufacturing process of the display device, by providing one or both of the carrier transport layer and the carrier block layer on the emissive layer, the emissive layer is not exposed to the outermost surface, thus suppressing exposure of the emissive layer to the atmosphere. This reduces damage to the emissive layer and improves the reliability of the light-emitting device.

[0198] The heat resistance temperature of the compounds contained in layers 113R, 113G, and 113B is preferably 100°C to 180°C, preferably 120°C to 180°C, and more preferably 140°C to 180°C. For example, the glass transition temperature (Tg) of these compounds is preferably 100°C to 180°C, preferably 120°C to 180°C, and more preferably 140°C to 180°C.

[0199] In particular, it is preferable that the heat resistance temperature of the functional layer provided on the light-emitting layer is high. Furthermore, it is even more preferable that the heat resistance temperature of the functional layer provided in contact with the light-emitting layer is high. The high heat resistance of the functional layer makes it possible to effectively protect the light-emitting layer and reduce the damage to the light-emitting layer.

[0200] It is preferable that the heat-resistant temperature of the light-emitting layer be high. This helps to prevent damage to the light-emitting layer due to heat, which can reduce luminous efficiency and shorten its lifespan.

[0201] The light-emitting layer comprises a light-emitting substance (also called a light-emitting material, light-emitting compound, guest material, etc.) and a substance other than the light-emitting substance (for example, a host material). Since the light-emitting layer contains a larger amount of host material than light-emitting substance, the glass transition temperature (Tg) of the host material can be used as an indicator of the heat resistance temperature of the light-emitting layer.

[0202] Layers 113R, 113G, and 113B may, for example, include a first light-emitting unit, a charge-generating layer on the first light-emitting unit, and a second light-emitting unit on the charge-generating layer.

[0203] The second light-emitting unit preferably has a light-emitting layer and a carrier transport layer (electron transport layer or hole transport layer) on the light-emitting layer. Alternatively, the second light-emitting unit preferably has a light-emitting layer and a carrier block layer (hole block layer or electron block layer) on the light-emitting layer. Alternatively, the second light-emitting unit preferably has a light-emitting layer, a carrier block layer on the light-emitting layer, and a carrier transport layer on the carrier block layer. If the surface of the second light-emitting unit is exposed to the atmosphere during the manufacturing process of the display device, by providing one or both of the carrier transport layer and the carrier block layer on the light-emitting layer, the light-emitting layer is not exposed to the outermost surface, thus suppressing exposure of the light-emitting layer to the atmosphere. This reduces damage to the light-emitting layer and improves the reliability of the light-emitting device. If there are three or more light-emitting units, it is preferable that the uppermost light-emitting unit has a light-emitting layer and one or both of the carrier transport layer and the carrier block layer on the light-emitting layer.

[0204] The common layer 114 may have, for example, an electron injection layer or a hole injection layer. Alternatively, the common layer 114 may have an electron transport layer and an electron injection layer laminated together, or a hole transport layer and a hole injection layer laminated together. The common layer 114 is shared by the light-emitting device 130R, light-emitting device 130G, and light-emitting device 130B.

[0205] It is preferable that the light-emitting devices 130R, 130G, and 130B have a protective layer 131. Providing the protective layer 131 can improve the reliability of the light-emitting devices. The protective layer 131 can be a single layer or a multilayer structure.

[0206] The conductivity of the protective layer 131 is not required. At least one of an insulating film, a semiconductor film, and a conductive film can be used as the protective layer 131.

[0207] The presence of an inorganic film in the protective layer 131 prevents oxidation of the common electrode 115 and suppresses the intrusion of impurities (such as moisture and oxygen) into the light-emitting device, thereby suppressing degradation of the light-emitting device and improving the reliability of the display device.

[0208] For example, an inorganic insulating layer can be used for the protective layer 131. Examples of materials that can be used for the inorganic insulating layer include oxides, nitrides, oxidized nitrides, and nitride oxides. Specific examples of inorganic insulating layers are as described in the description of the insulating layer 125. In particular, the protective layer 131 preferably has a nitride or nitride oxide, and more preferably has a nitride.

[0209] The protective layer 131 may also be an inorganic film containing ITO, In-Zn oxide, Ga-Zn oxide, Al-Zn oxide, or IGZO. The inorganic film is preferably highly resistive, and more specifically, it is preferably more resistive than the common electrode 115. The inorganic film may further contain nitrogen.

[0210] When the light emitted from a light-emitting device is extracted via a protective layer 131, it is preferable that the protective layer 131 has high transmittance to visible light. For example, ITO, IGZO, and aluminum oxide are preferred because they are inorganic materials with high transmittance to visible light.

[0211] As the protective layer 131, for example, a laminated structure of an aluminum oxide film and a silicon nitride film on the aluminum oxide film, or a laminated structure of an aluminum oxide film and an IGZO film on the aluminum oxide film can be used. By using such a laminated structure, it is possible to suppress the penetration of impurities (water, oxygen, etc.) into the EL layer.

[0212] Furthermore, the protective layer 131 may have an organic film. For example, the protective layer 131 may have both an organic film and an inorganic film. Examples of organic materials that can be used for the protective layer 131 include organic insulating materials that can be used for the insulating layer 127.

[0213] The protective layer 131 may have a two-layer structure formed using different film deposition methods. Specifically, the first layer of the protective layer 131 may be formed using the ALD method, and the second layer of the protective layer 131 may be formed using the sputtering method.

[0214] A light-shielding layer may be provided on the surface of the substrate 120 facing the resin layer 122. Various optical components can also be placed on the outside of the substrate 120. Examples of optical components include polarizing plates, phase difference plates, light diffusion layers (such as diffusion films), anti-reflective layers, and light-collecting films. Furthermore, surface protection layers such as an antistatic film to suppress dust adhesion, a water-repellent film to prevent dirt from adhering, a hard coat film to suppress scratches during use, and an impact-absorbing layer may be placed on the outside of the substrate 120. For example, a glass layer or a silica layer (SiO₂) may be used as the surface protection layer. ｘ Providing a protective layer is preferable as it can suppress surface contamination and scratching. Alternatively, DLC (diamond-like carbon), aluminum oxide, polyester-based materials, or polycarbonate-based materials may be used as the surface protective layer. It is preferable to use a material with high transmittance to visible light for the surface protective layer. Furthermore, it is preferable to use a material with high hardness for the surface protective layer.

[0215] The substrates 103 and 120 can be made of glass, quartz, ceramics, sapphire, resin, metal, alloy, semiconductor, etc. The substrate on the side that extracts light from the light-emitting device should be made of a material that transmits the light. Using flexible materials for substrates 103 and 120 can increase the flexibility of the display device and realize a flexible display. A polarizing plate may also be used as at least one of substrates 103 and 120.

[0216] As substrates 103 and 120, the following can be used: polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyacrylonitrile resin, acrylic resin, polyimide resin, polymethyl methacrylate resin, polycarbonate (PC) resin, polyethersulfone (PES) resin, polyamide resin (nylon, aramid, etc.), polysiloxane resin, cycloolefin resin, polystyrene resin, polyamide-imide resin, polyurethane resin, polyvinyl chloride resin, polyvinylidene chloride resin, polypropylene resin, polytetrafluoroethylene (PTFE) resin, ABS resin, cellulose nanofiber, etc. At least one of substrates 103 and 120 may be made of glass of a thickness sufficient to provide flexibility.

[0217] Furthermore, when a circular polarizing plate is superimposed on a display device, it is preferable to use a substrate with high optical isotropy for the substrate of the display device. A substrate with high optical isotropy has low birefringence (or a small amount of birefringence).

[0218] For substrates with high optical isotropy, the absolute value of the retardation (phase difference) is preferably 30 nm or less, more preferably 20 nm or less, and even more preferably 10 nm or less.

[0219] Examples of films with high optical isotropy include triacetylcellulose (TAC, also known as cellulose triacetate) film, cycloolefin polymer (COP) film, cycloolefin copolymer (COC) film, and acrylic film.

[0220] When a film is used as the substrate, the film may absorb water, which could cause changes in the shape of the display device, such as wrinkles. Therefore, it is preferable to use a film with a low water absorption rate as the substrate. For example, it is preferable to use a film with a water absorption rate of 1% or less, more preferable to use a film with a water absorption rate of 0.1% or less, and even more preferable to use a film with a water absorption rate of 0.01% or less.

[0221] Various types of curing adhesives can be used as the resin layer 122, including UV-curing adhesives, reaction-curing adhesives, thermosetting adhesives, and anaerobic adhesives. Examples of these adhesives include epoxy resins, acrylic resins, silicone resins, phenolic resins, polyimide resins, imide resins, PVC (polyvinyl chloride) resins, PVB (polyvinyl butyral) resins, and EVA (ethylene vinyl acetate) resins. Materials with low moisture permeability, such as epoxy resins, are particularly preferred. Two-component mixed resins may also be used. Adhesive sheets may also be used.

[0222] Figures 7A to 7C show a cross-sectional view between the dashed line Y1 and Y2 in Figure 1A. Figures 7A to 7C show the connection portion 140 and its vicinity. The common electrode 115 is shared by the light-emitting devices 130R, 130G, and 130B. The common electrode 115, which is shared by multiple light-emitting devices, is connected to a conductive layer 123 provided on the connection portion 140. The conductive layer 123 can be formed, for example, in the same process as the pixel electrode 111R, pixel electrode 111G, and pixel electrode 111B.

[0223] A conductive layer 105p is provided on the insulating layer 104. The conductive layer 105p can be formed, for example, in the same process as conductive layer 105R, conductive layer 105G, and conductive layer 105B. A conductive layer 123 is provided on the conductive layer 105p. A layer 107p is provided between the conductive layer 105p and the conductive layer 123. The layer 107p can be formed, for example, in the same process as layer 107R, layer 107G, and layer 107B. The conductive layer 123 is provided so as to cover the conductive layers 105p and 107p and has a region in contact with the conductive layer 105p.

[0224] In areas where transistors are not provided, the insulating layer 109 may be omitted. For example, if transistors are not provided in the area overlapping with the connection portion 140 of layer 101 and its vicinity, the insulating layer 109 may be omitted from the connection portion 140 and its vicinity. Figure 7A shows a configuration in which the insulating layer 109 is provided in the display area (the area on the left in Figure 7A), and the insulating layer 109 is not provided in the connection portion 140 and its vicinity (the area on the right in Figure 7A).

[0225] Figure 7A shows an example in which a conductive layer 137p is provided on a conductive layer 123, a common layer 114 is provided on the conductive layer 137p, and the conductive layer 123 and the common electrode 115 are connected via the conductive layer 137p and the common layer 114. Preferably, the connection portion 140 has a region in which the conductive layer 105p, conductive layer 123, conductive layer 137p, common layer 114, and common electrode 115 overlap in this order without any other layer (for example, layer 107p) in between. By increasing the area in which these conductive layers are in contact with each other, the electrical resistance of the connection portion 140 can be lowered.

[0226] The insulating layer 104 has an opening 257p that reaches the conductive layer 250p. The conductive layer 105p is provided so as to cover the opening 257p. At the opening 257p, the conductive layer 105p is in contact with the conductive layer 250p and is connected to the conductive layer 250p. In other words, the conductive layer 250p is connected to the conductive layer 123 via the conductive layer 105p. The conductive layer 250p corresponds, for example, to the wiring of layer 101. Note that a configuration without the conductive layer 250p is also possible.

[0227] As shown in Figure 7B, the connection portion 140 can be configured without a common layer 114. Preferably, the connection portion 140 has a region in which the conductive layer 105p, conductive layer 123, conductive layer 137p, and common electrode 115 overlap in this order, without any other layer (for example, layer 107p) in between. By increasing the area in which these conductive layers are in contact with each other, the electrical resistance of the connection portion 140 can be lowered. For example, by using a mask for defining the film deposition area (also called an area mask or rough metal mask, to distinguish it from a fine metal mask), the areas in which the common layer 114 and the common electrode 115 are film-deposited can be changed. The conductive layer 123 is connected to the common electrode 115 via the conductive layer 137p.

[0228] As shown in Figure 7C, the connection portion 140 can also be configured without a common layer 114 and a conductive layer 137p. Preferably, the connection portion 140 has a region in which the conductive layer 105p, conductive layer 123, and common electrode 115 overlap in this order without any other layers in between. For example, after forming conductive films that will become conductive layers 137R, 137G, and 137B, the conductive films on the connection portion 140 can be removed. If the electrical resistivity of the material used for conductive layer 137p is higher than that of the materials used for conductive layers 105p and 123, it is preferable to omit the conductive layer 137p from the connection portion 140, as this can lower the electrical resistance at the connection portion 140. The conductive layer 123 is in contact with the common electrode 115 and is connected to the common electrode 115.

[0229] <Configuration Example 2> A configuration example different from the one shown in Figure 1B is shown in Figure 8A. A top view of the display device can be found in Figure 1A. Figure 8A is a cross-sectional view between the dashed lines X1 and X2 in Figure 1A. An enlarged view of a part of the cross-sectional view shown in Figure 8A is shown in Figure 8B. The configuration shown in Figure 8A differs from the configuration shown in Figure 1B mainly in that the display device has conductive layers 135R, 135G, and 135B.

[0230] The light-emitting device 130R has a conductive layer 135R between the pixel electrode 111R and the conductive layer 137R. The light-emitting device 130R includes the pixel electrode 111R, the conductive layer 135R on the pixel electrode 111R, the conductive layer 137R on the conductive layer 135R, the island-shaped layer 113R on the conductive layer 137R, the common layer 114 on the layer 113R, and the common electrode 115 on the common layer 114.

[0231] The light-emitting device 130G has a conductive layer 135G between the pixel electrode 111G and the conductive layer 137G. The light-emitting device 130G includes the pixel electrode 111G, the conductive layer 135G on the pixel electrode 111G, the conductive layer 137G on the conductive layer 135G, the island-shaped layer 113G on the conductive layer 137G, the common layer 114 on the layer 113G, and the common electrode 115 on the common layer 114.

[0232] The light-emitting device 130B has a conductive layer 135B between the pixel electrode 111B and the conductive layer 137B. The light-emitting device 130B includes the pixel electrode 111B, the conductive layer 135B on the pixel electrode 111B, the conductive layer 137B on the conductive layer 135B, the island-shaped layer 113B on the conductive layer 137B, the common layer 114 on the layer 113B, and the common electrode 115 on the common layer 114.

[0233] The conductive layer 135R, conductive layer 135G, and conductive layer 135B can be formed, for example, in the same process. In the following, the conductive layer 135R, conductive layer 135G, and conductive layer 135B may be collectively referred to as conductive layer 135.

[0234] The conductive layer 135R is provided so as to cover the pixel electrode 111R and has regions that are in contact with the upper and side surfaces of the pixel electrode 111R. Similarly, the conductive layer 135G is provided so as to cover the pixel electrode 111G and has regions that are in contact with the upper and side surfaces of the pixel electrode 111G. The conductive layer 135B is provided so as to cover the pixel electrode 111B and has regions that are in contact with the upper and side surfaces of the pixel electrode 111B. In addition, the insulating layer 109 is provided so as to cover a part of the conductive layer 135R, a part of the conductive layer 135G, and a part of the conductive layer 135B. The insulating layer 109 has regions that overlap with a part of the conductive layer 135R, a part of the conductive layer 135G, and a part of the conductive layer 135B.

[0235] It is preferable not to provide the insulating layer 109 in the region of the conductive layer 135R that is provided along the upper surface of layer 107R. In other words, in a cross-sectional view, it is preferable that the height H135 of the upper surface of the conductive layer 135R is higher than the height H109 of the upper surface of the insulating layer 109. Figure 8B shows the height H135 from the surface of the conductive layer 105R to which it is formed (here, the upper surface of the insulating layer 104 in the region where the conductive layer 105R and the insulating layer 104 are in contact) to the upper surface of the highest point of the conductive layer 135R, and the height H109 to the upper surface of the highest point of the insulating layer 109. By making the height H135 higher than the height H109, ​​the insulating layer 109 is not provided in the region of the conductive layer 135R that is provided along the upper surface of layer 107R, and the contact area between the conductive layer 135R and layer 113R can be increased. The same applies to the conductive layer 135G and the conductive layer 135B. This allows for a larger area of ​​the light-emitting region of the light-emitting device, resulting in a display device with a high aperture ratio.

[0236] The conductive layers 135R, 135G, and 135B function as etching stoppers when forming the insulating layer 109. Note that the conductive layers 135R, 135G, and 135B may also be referred to as second etching stoppers. For example, conductive layers 135R, 135G, and 135B are formed on the pixel electrodes 111R, 111G, and 111B. A film that will become the insulating layer 109 is formed on the pixel electrodes 111R, 111G, 111B, conductive layers 135R, 135G, and 135B. Then, the film is processed to expose the conductive layers 135R, 135G, and 135B, thereby forming the insulating layer 109. When forming the insulating layer 109, the pixel electrodes 111R, 111G, and 111B are covered by the second etching stopper, which prevents the pixel electrodes 111R, 111G, and 111B from being etched and their thickness from decreasing. This prevents the electrical resistance of the pixel electrodes from increasing. Furthermore, it prevents damage to the pixel electrodes 111R, 111G, and 111B from occurring during the formation of the insulating layer 109.

[0237] For the second etching stopper, it is preferable to use a material that has high resistance in forming the insulating layer 109, specifically a material with a high selectivity ratio for etching with the insulating layer 109. For forming the insulating layer 109, a dry etching method or a chemical mechanical polishing (CMP) method can be used. In particular, an anisotropic dry etching method can be preferably used.

[0238] In forming the insulating layer 109, it is preferable to set the thickness of the conductive layers 135R, 135G, and 135B so that the second etching stopper (later conductive layers 135R, 135G, and 135B) covers the pixel electrodes 111R, 111G, and 111B, and these pixel electrodes are not exposed. If the thickness of the conductive layers 135R, 135G, and 135B is too thin, their function as etching stoppers will be reduced, and if they are too thick, the productivity of the display device may be reduced. As shown in Figure 8B, the thickness T135 of the conductive layer 135R can be set to the shortest distance between the surface of the conductive layer 135R being formed in cross-sectional view (here, the upper surface of the pixel electrode 111R in the region where the conductive layer 135R and the pixel electrode 111R are in contact) and the upper surface of the conductive layer 135R. The thickness T135 is preferably 5 nm to 100 nm, more preferably 10 nm to 100 nm, more preferably 10 nm to 60 nm, more preferably 20 nm to 60 nm, and more preferably 20 nm to 40 nm. By setting the thickness T135 within the above range, it is possible to suppress the thinning of the pixel electrodes 111R, 111G, and 111B, and to increase the productivity of the display device. Furthermore, it is possible to suppress damage to the pixel electrodes 111R, 111G, and 111B. Note that the thickness T135 is not limited to the above range.

[0239] The conductive layers 135R, 135G, and 135B can be, for example, oxide conductors. The conductive layers 135R, 135G, and 135B can be made of the same materials that can be used for the conductive layers 137R, 137G, and 137B. The conductive layers 135R, 135G, and 135B can preferably be made of one or more of the following materials: ITO, ITSO, In-Zn oxide (IZO®), IGZO, and In-Sn-Zn oxide. The conductive layers 135R, 135G, and 135B can each be made into a single-layer structure or a laminated structure.

[0240] Furthermore, the same material can be used for conductive layers 137R, 137G, and 137B as can be used for conductive layers 135R, 135G, and 135B. By using the same material for these layers, the equipment used for formation can be common, thereby increasing productivity and lowering manufacturing costs. Also, for example, by using the same material for conductive layers 135R and 137R, the refractive indices of these conductive layers can be made the same or approximately the same. This reduces the effects of refraction and reflection in conductive layers 135R and 137R, thereby increasing the light extraction efficiency of the light-emitting device. For example, ITSO can be used for conductive layers 135R, 135G, 135B, 137R, 137G, and 137B. Alternatively, different materials can be used for conductive layers 135R, 135G, and 135B than those used for conductive layers 137R, 137G, and 137B.

[0241] It is preferable that conductive layers 135R, 135G, 135B, 137R, 137G, and 137B be made of materials that are transparent to visible light. Conductive layers 135R, 135G, 135B, 137R, 137G, and 137B function as transparent electrodes. It is preferable that pixel electrodes 111R, 111G, and 111B be made of materials that are reflective to visible light. Pixel electrodes 111R, 111G, and 111B function as reflective electrodes. In addition, a semi-transparent / semi-reflective electrode is used as the common electrode 115. This allows the light-emitting device to have a microcavity structure, causing the light from the light-emitting layer to resonate between the two electrodes and intensifying the light emitted from the light-emitting device. The conductive layers 135R, 135G, 135B, 137R, 137G, and 137B can be said to function as optical adjustment layers. In this case, it is preferable to set the thickness of these conductive layers so that the optical path length is such that the light emitted by layers 113R, 113G, and 113B is intensified. For the thickness T135, refer to the above description. The thickness T137 is preferably 5 nm to 100 nm, more preferably 5 nm to 60 nm, and more preferably 5 nm to 40 nm. Note that the thickness T137 is not limited to the above range.

[0242] For example, the pixel electrodes 111R, 111G, and 111B can each be a laminated structure of a first titanium film, an aluminum film on the first titanium film, and a second titanium film on the aluminum film. The conductive layers 135R, 135G, 135B, 137R, 137G, and 137B can each be a single-layer structure of an ITSO film.

[0243] In Figure 8A, the thicknesses of conductive layers 135R, 135G, and 135B are all shown to be the same, but the present invention is not limited to this. The thicknesses of conductive layers 135R, 135G, and 135B can also be different. For example, it is preferable to set the thicknesses so that the optical path length is such that the light emitted by layers 113R, 113G, and 113B is intensified. This makes it possible to realize a microcavity structure and improve the color purity in each light-emitting device.

[0244] Figures 8A and 8B show a configuration in which the edges of conductive layer 137R, conductive layer 137G, and conductive layer 137B coincide with the edges of layer 113R, layer 113G, and layer 113B, but the present invention is not limited to this. As shown in Figures 9A and 9B, the edges of conductive layer 137R, conductive layer 137G, and conductive layer 137B can also be configured not to coincide with the edges of layer 113R, layer 113G, and layer 113B.

[0245] Figures 8A and 9A show a configuration in which the edge of the conductive layer 135R does not coincide with the edge of the pixel electrode 111R, and the pixel electrode 111R has a region that protrudes more than the edge of the conductive layer 135R. The present invention is not limited to this, and the edge of the conductive layer 135R can coincide with or substantially coincide with the edge of the pixel electrode 111R. The same applies to the conductive layer 135G and the pixel electrode 111G, and the conductive layer 135B and the pixel electrode 111B.

[0246] Figures 8A and 8B show a configuration in which the insulating layer 109 has regions in contact with the pixel electrode 111R, pixel electrode 111G, pixel electrode 111B, conductive layer 105R, conductive layer 105G, and conductive layer 105B, but the present invention is not limited to this. As shown in Figures 10A and 10B, the insulating layer 109 can also be configured not to be in contact with the pixel electrode 111R, pixel electrode 111G, pixel electrode 111B, conductive layer 105R, conductive layer 105G, and conductive layer 105B.

[0247] The conductive layer 135R covers the entire pixel electrode 111R and the conductive layer 105R, and the edge of the conductive layer 135R overlaps with the insulating layer 104. Similarly, the conductive layer 135G covers the entire pixel electrode 111G and the conductive layer 105G, and the edge of the conductive layer 135G overlaps with the insulating layer 104. The conductive layer 135B covers the entire pixel electrode 111B and the conductive layer 105B, and the edge of the conductive layer 135B overlaps with the insulating layer 104. The edges of the conductive layer 135R, the edges of the conductive layer 135G, and the edges of the conductive layer 135B are each located on the insulating layer 104. It can also be said that the edges of the conductive layer 135R, the edges of the conductive layer 135G, and the edges of the conductive layer 135B are each in contact with the upper surface of the insulating layer 104. A conductive layer 135R is provided between the pixel electrode 111R and conductive layer 105R and the insulating layer 109, a conductive layer 135G is provided between the pixel electrode 111G and conductive layer 105G and the insulating layer 109, and a conductive layer 135B is provided between the pixel electrode 111B and conductive layer 105B and the insulating layer 109.

[0248] Depending on the material used for the insulating layer 109, the adhesion between the insulating layer 109 and the layers on the surface to which it is formed (for example, the pixel electrode 111 and the conductive layer 105) may be low, potentially causing the insulating layer 109 to peel off. By using materials with high adhesion to the insulating layer 109 for the conductive layers 135R, 135G, and 135B, and covering the pixel electrode 111R, 111G, 111B, conductive layer 105R, 105G, and 105B with these conductive layers, the peeling of the insulating layer 109 can be suppressed.

[0249] Figures 11A and 11B show cross-sectional views between the dashed-dotted line Y1 and Y2 in Figure 1A. As shown in Figure 11A, a conductive layer 105p is provided on the insulating layer 104, a conductive layer 123 is provided on the conductive layer 105p, a conductive layer 135p is provided on the conductive layer 123, a conductive layer 137p is provided on the conductive layer 135p, a common layer 114 is provided on the conductive layer 137p, and a common electrode 115 is provided on the common layer 114. The conductive layer 135p can be formed, for example, in the same process as conductive layer 135R, conductive layer 135G, and conductive layer 135B. Preferably, the connection portion 140 has a region in which the conductive layer 105p, conductive layer 123, conductive layer 135p, conductive layer 137p, common layer 114, and common electrode 115 overlap in this order without any other layer (for example, layer 107p) in between. By increasing the area in which these conductive layers are in contact with each other, the electrical resistance of the connection portion 140 can be reduced.

[0250] As shown in Figure 11B, the connection portion 140 can be configured without a common layer 114. Preferably, the connection portion 140 has a region in which the conductive layer 105p, conductive layer 123, conductive layer 135p, conductive layer 137p and common electrode 115 overlap in this order, without any other layer (for example, layer 107p) in between. By increasing the area in which these conductive layers are in contact with each other, the electrical resistance of the connection portion 140 can be lowered.

[0251] As shown in Figure 11C, the connection portion 140 can be configured without a common layer 114 and a conductive layer 137p. Preferably, the connection portion 140 has a region in which the conductive layer 105p, conductive layer 123, conductive layer 135p and common electrode 115 overlap in this order without any other layer (for example, layer 107p) in between. For example, after forming conductive films that will become conductive layers 137R, 137G, and 137B, the conductive films on the connection portion 140 can be removed. If the electrical resistivity of the material used for conductive layer 137p is higher than that of the material used for conductive layers 105p and 123, it is preferable to omit the conductive layer 137p from the connection portion 140, as this can lower the electrical resistance at the connection portion 140.

[0252] It is also possible to omit the conductive layer 135p from the connection portion 140 (see Figure 7A). It is also possible to omit the common layer 114 and the conductive layer 135p from the connection portion 140 (see Figure 7B). Alternatively, it is possible to omit the common layer 114, the conductive layer 135p, and the conductive layer 137p from the connection portion 140 (see Figure 7C). For example, the configurations of the connection portion 140 shown in Figures 7A, 7B, 7C, 11A, 11B, and 11C can be combined with the configuration shown in Figure 1B, etc.

[0253] <Configuration Example 3> A configuration example different from the one shown in Figure 1B is shown in Figure 12A. A top view of the display device can be found in Figure 1A. Figure 12A is a cross-sectional view between the dashed lines X1 and X2 in Figure 1A. An enlarged view of a part of the cross-sectional view shown in Figure 12A is shown in Figure 12B. The configuration shown in Figure 12A differs from the configuration shown in Figure 1B mainly in that the display device has conductive layers 180R, 180G, and 180B.

[0254] The light-emitting device 130R has a conductive layer 180R between the pixel electrode 111R and the conductive layer 137R. The light-emitting device 130R includes the pixel electrode 111R, the conductive layer 180R on the pixel electrode 111R, the conductive layer 137R on the conductive layer 180R, the island-shaped layer 113R on the conductive layer 137R, the common layer 114 on the layer 113R, and the common electrode 115 on the common layer 114.

[0255] The light-emitting device 130G has a conductive layer 180G between the pixel electrode 111G and the conductive layer 137G. The light-emitting device 130G includes the pixel electrode 111G, the conductive layer 180G on the pixel electrode 111G, the conductive layer 137G on the conductive layer 180G, the island-shaped layer 113G on the conductive layer 137G, the common layer 114 on the layer 113G, and the common electrode 115 on the common layer 114.

[0256] The light-emitting device 130B has a conductive layer 180B between the pixel electrode 111B and the conductive layer 137B. The light-emitting device 130B includes the pixel electrode 111B, the conductive layer 180B on the pixel electrode 111B, the conductive layer 137B on the conductive layer 180B, the island-shaped layer 113B on the conductive layer 137B, the common layer 114 on the layer 113B, and the common electrode 115 on the common layer 114.

[0257] The conductive layers 180R, 180G, and 180B can be formed, for example, in the same process. In the following, the conductive layers 180R, 180G, and 180B may be collectively referred to as conductive layer 180.

[0258] The conductive layer 180R, conductive layer 180G, and conductive layer 180B can be made from the materials listed for the pixel electrode 111. The conductive layer 180R, conductive layer 180G, and conductive layer 180B can each be made from a single layer or a multilayer structure.

[0259] In the following explanation, the pixel electrode 111R, conductive layer 180R, conductive layer 137R, and layer 107R will be used as examples, and the explanations of the pixel electrode 111G, conductive layer 180G, conductive layer 137G, and layer 107G, as well as the pixel electrode 111B, conductive layer 180B, conductive layer 137B, and layer 107B, may be omitted. For the pixel electrode 111G, conductive layer 180G, conductive layer 137G, and layer 107G, as well as the pixel electrode 111B, conductive layer 180B, conductive layer 137B, and layer 107B, refer to the description relating to the pixel electrode 111R, conductive layer 180R, conductive layer 137R, and layer 107R.

[0260] It is preferable that conductive layers 137R, 137G, and 137B be made of materials that are transparent to visible light. Conductive layers 137R, 137G, and 137B function as transparent electrodes. It is preferable that conductive layers 180R, 180G, 180B, pixel electrodes 111R, 111G, and 111B be made of materials that are reflective to visible light. Conductive layers 180R, 180G, 180B, pixel electrodes 111R, 111G, and 111B function as reflective electrodes.

[0261] It is preferable to use materials with high reflectivity for conductive layers 180R, 180G, and 180B. For materials with high reflectivity, please refer to the above description. Silver and materials containing silver (e.g., silver-containing alloys) have high reflectivity to visible light and can improve the light extraction efficiency of the light-emitting device. Conductive layers 180R, 180G, and 180B can preferably be made of silver or APC.

[0262] The conductive layer 105R, the conductive layer 180R, and the pixel electrode 111R can be formed, for example, using the same resist mask. Using the same resist mask simplifies the process.

[0263] For example, a first conductive film is formed to form conductive layers 105R, 105G, and 105B, and layers 107R, 107G, and 107B are formed on the first conductive film. A second conductive film is formed to form pixel electrodes 111R, 111G, and 111B on the first conductive film, layers 107R, 107G, and 107B, and a third conductive film is formed to form conductive layers 180R, 180G, and 180B on the second conductive film. A first resist mask, a second resist mask, and a third resist mask are formed on the third conductive film. The first resist mask is formed at the positions where conductive layer 105R, pixel electrode 111R, and conductive layer 180R are provided. The second resist mask is formed at the positions where conductive layer 105G, pixel electrode 111G, and conductive layer 180G are provided. The third resist mask is formed at the positions where the conductive layer 105B, the pixel electrode 111B, and the conductive layer 180B are provided. Then, by processing the first conductive film, the second conductive film, and the third conductive film using the first resist mask, the second resist mask, and the third resist mask as masks, the conductive layer 105R, the pixel electrode 111R, the conductive layer 180R, the conductive layer 105G, the pixel electrode 111G, the conductive layer 180G, the conductive layer 105B, the pixel electrode 111B, and the conductive layer 180B can be formed.

[0264] The first conductive film, the second conductive film, and the third conductive film can each be processed using either a dry etching method or a wet etching method, or both. When a material that is difficult to process by dry etching (hereinafter also referred to as a difficult-to-etch material) is used for the conductive film, the wet etching method can be suitably used for processing the conductive film. Examples of difficult-to-etch materials include silver and APC. When a difficult-to-etch material is used for the third conductive film, the wet etching method can be suitably used for processing the third conductive film. Furthermore, the first conductive film and the second conductive film can each be suitably processed using a dry etching method.

[0265] In contrast to dry etching, wet etching tends to proceed isotropically, and therefore, due to side etching, the edges of the processed layer may be located inside the edges of the resist mask. On the other hand, in dry etching, the edges of the processed layer may coincide with or roughly coincide with the edges of the resist mask. Therefore, even when using the same resist mask, the edges of the layer formed by wet etching may be located inside the edges of the layer formed by dry etching.

[0266] For example, a difficult-to-etch material can be used for the third conductive film, a wet etching method can be used for processing the third conductive film, and a dry etching method can be used for processing the first and second conductive films, respectively. This allows for a configuration where, as shown in Figures 12A and 12B, the end of the pixel electrode 111R coincides with or roughly coincides with the end of the conductive layer 105R, and the end of the conductive layer 180R is located inward from the ends of the pixel electrode 111R and the ends of the conductive layer 105R. Also, as shown in Figures 12A and 12B, the end of the conductive layer 180R may face the side surface of layer 107R via the pixel electrode 111R. Preferably, the conductive layer 180R is provided in a region along the upper surface of layer 107R of the pixel electrode 111R. This can improve the light extraction efficiency of the light-emitting device.

[0267] When using the wet etching method, side etching can cause the width of the processed layer to become smaller than the width of the resist mask, making it difficult to control the layer width. On the other hand, in the region of the conductive layer 180R that is provided along the side surface of layer 107R, etching proceeds in the vertical direction (from bottom to top in Figure 12B), making it easier to control the width of the conductive layer 180R compared to when etching proceeds in the horizontal direction. Therefore, it is possible to form a conductive layer 180R of a fine size, and a display device with high resolution can be realized.

[0268] In this example, the conductive layer 105R, the conductive layer 180R, and the pixel electrode 111R are formed using the same resist mask, but the present invention is not limited to this configuration. The conductive layer 105R, the conductive layer 180R, and the pixel electrode 111R can also be formed using different resist masks.

[0269] Figure 13A shows an example of a configuration different from the one shown in Figure 12A. A top view of the display device can be found in Figure 1A. Figure 13A is a cross-sectional view between the dashed lines X1 and X2 in Figure 1A. Figure 13B shows an enlarged view of a part of the cross-sectional view shown in Figure 13A. The configuration shown in Figure 13A differs from the configuration shown in Figure 1B mainly in that the display device has conductive layers 135R, 135G, and 135B.

[0270] The light-emitting device 130R has a conductive layer 135R between a conductive layer 180R and a conductive layer 137R. The light-emitting device 130R includes a pixel electrode 111R, a conductive layer 180R on the pixel electrode 111R, a conductive layer 135R on the conductive layer 180R, a conductive layer 137R on the conductive layer 135R, an island-shaped layer 113R on the conductive layer 137R, a common layer 114 on the layer 113R, and a common electrode 115 on the common layer 114.

[0271] The light-emitting device 130G has a conductive layer 135G between a conductive layer 180G and a conductive layer 137G. The light-emitting device 130G includes a pixel electrode 111G, a conductive layer 180G on the pixel electrode 111G, a conductive layer 135G on the conductive layer 180G, a conductive layer 137G on the conductive layer 135G, an island-shaped layer 113G on the conductive layer 137G, a common layer 114 on the layer 113G, and a common electrode 115 on the common layer 114.

[0272] The light-emitting device 130B has a conductive layer 135B between a conductive layer 180B and a conductive layer 137B. The light-emitting device 130B includes a pixel electrode 111B, a conductive layer 180B on the pixel electrode 111B, a conductive layer 135B on the conductive layer 180B, a conductive layer 137B on the conductive layer 135B, an island-shaped layer 113B on the conductive layer 137B, a common layer 114 on the layer 113B, and a common electrode 115 on the common layer 114.

[0273] The conductive layer 135R is provided so as to cover the conductive layer 180R and the pixel electrode 111R, and has regions that are in contact with the upper and side surfaces of the conductive layer 180R, and the upper and side surfaces of the pixel electrode 111R. Similarly, the conductive layer 135G is provided so as to cover the conductive layer 180G and the pixel electrode 111G, and has regions that are in contact with the upper and side surfaces of the conductive layer 180G, and the upper and side surfaces of the pixel electrode 111G. The conductive layer 135B is provided so as to cover the conductive layer 180B and the pixel electrode 111B, and has regions that are in contact with the upper and side surfaces of the conductive layer 180B, and the upper and side surfaces of the pixel electrode 111B. Although Figures 13A and 13B show a configuration in which the conductive layer 135R is also in contact with the lower surface of the conductive layer 180R, the present invention is not limited to this. The conductive layer 135R can also be configured so that it is not in contact with a part of the lower surface of the conductive layer 180R. The same applies to conductive layer 135G and conductive layer 135B.

[0274] Conductive layers 135R, 135G, and 135B, which function as second etching stoppers, are provided on conductive layers 180R, 180G, and 180B. Here, when forming the insulating layer 109, conductive layers 180R, 180G, and 180B may be oxidized, causing their electrical resistance to increase. Also, oxidation may cause their reflectivity to decrease. By providing second etching stoppers on conductive layers 180R, 180G, and 180B, it is possible to suppress the increase in electrical resistance and decrease in reflectivity of conductive layers 180R, 180G, and 180B. For conductive layers 135R, 135G, and 135B, please refer to the above description.

[0275] <Configuration Example 4> A configuration example different from the one shown in Figure 1B is shown in Figure 14A. A top view of the display device can be found in Figure 1A. Figure 14A is a cross-sectional view between the dashed lines X1 and X2 in Figure 1A. An enlarged view of a part of the cross-sectional view shown in Figure 14A is shown in Figure 14B. The configuration shown in Figure 14A differs from the configuration shown in Figure 1B mainly in that the display device has an insulating layer 147 instead of conductive layers 137R, 137G, and 137B.

[0276] The light-emitting device 130R includes a pixel electrode 111R, an island-shaped layer 113R on the pixel electrode 111R, a common layer 114 on the layer 113R, and a common electrode 115 on the common layer 114.

[0277] The light-emitting device 130G includes a pixel electrode 111G, an island-shaped layer 113G on the pixel electrode 111G, a common layer 114 on the layer 113G, and a common electrode 115 on the common layer 114.

[0278] The light-emitting device 130B includes a pixel electrode 111B, an island-shaped layer 113B on the pixel electrode 111B, a common layer 114 on the layer 113B, and a common electrode 115 on the common layer 114.

[0279] The insulating layer 147 is provided between layers 113R, 113G, and 113B and the insulating layer 109. Preferably, the insulating layer 147 covers at least the upper surface of the insulating layer 109. Preferably, the insulating layer 147 has regions that are in contact with the pixel electrodes 111R, 111G, and 111B. The insulating layer 147 has an opening 149R that reaches the pixel electrode 111R, an opening 149G that reaches the pixel electrode 111G, and an opening 149B that reaches the pixel electrode 111B. Layer 113R is in contact with the pixel electrode 111R at the opening 149R. Layer 113G is in contact with the pixel electrode 111G at the opening 149G. Layer 113B is in contact with the pixel electrode 111B at the opening 149B.

[0280] Layers 113R, 113G, and 113B can be formed on the insulating layer 147. Preferably, the insulating layer 147 functions as an etching stopper when forming layers 113R, 113G, and 113B. Hereinafter, the insulating layer 147 may be referred to as the first etching stopper. For example, an insulating film that will become the insulating layer 147 is formed on the insulating layer 109, the pixel electrode 111R, the pixel electrode 111G, and the pixel electrode 111B. The insulating film is processed to form an insulating layer 147 having openings 149R, 149G, and 149B. Then, a film that will become layer 113R is formed on the first etching stopper (in this case, the insulating layer 147), and layer 113R can be formed by processing the film using photolithography. When forming layer 113R, the insulating layer 109 is covered by the first etching stopper, which prevents the insulating layer 109 from being etched and its thickness from decreasing. Therefore, the coverage of the layers to be formed afterward (for example, the film that will become layer 113G and the film that will become layer 113B) can be improved.

[0281] The insulating layer 147 can be made from the materials listed for insulating layer 109. The insulating layer 147 can be a single layer or a laminated layer. It is preferable to use an inorganic insulating layer as the insulating layer 147. It is preferable to use a material for insulating layer 147 that has high resistance in the formation of layers 113R, 113G, and 113B, specifically a material with a high selectivity ratio for etching with layers 113R, 113G, and 113B. For example, one or more of silicon oxynitride, silicon oxide nitride, and aluminum oxide can be suitably used for the insulating layer 147. Typically, the insulating layer 147 can be made from a single layer of silicon oxynitride film, or from a laminated layer in which a silicon nitride film and a silicon oxynitride film are laminated in that order.

[0282] The insulating layer 147 is located between layers 113R, 113G, and 113B and the insulating layer 109. Preferably, the insulating layer 147 functions as a barrier layer. By providing a barrier layer between layers 113R, 113G, and 113B and the insulating layer 109, the diffusion of components contained in the insulating layer 109 (e.g., water) into layers 113R, 113G, and 113B can be suppressed. This can improve the reliability of the light-emitting device. It can also improve the manufacturing yield of the light-emitting device.

[0283] Although multiple insulating layers 147 are shown in cross-sectional views such as Figure 14A, when the display device 100 is viewed from above, the insulating layer 147 is connected as a single unit. It can also be said that the insulating layer 147 is continuous. In other words, the display device 100 can be configured to have only one insulating layer 147. However, the display device 100 can also be configured to have multiple insulating layers 147 that are separated from each other.

[0284] Figure 15A shows an example of a configuration different from that shown in Figure 14A. A top view of the display device can be found in Figure 1A. Figure 15A is a cross-sectional view between the dashed lines X1 and X2 in Figure 1A. Figure 15B shows an enlarged view of a part of the cross-sectional view shown in Figure 15A. The configuration shown in Figure 15A differs from the configuration shown in Figure 14A mainly in that the display device has conductive layers 137R, 137G, and 137B.

[0285] The conductive layer 137R is provided between the pixel electrode 111R and the insulating layer 147 and the layer 113R. The conductive layer 137R is in contact with the pixel electrode 111R at the opening 149R and is connected to the pixel electrode 111R. The same applies to the conductive layer 137G and the conductive layer 137B.

[0286] <Configuration Example 5> Figure 16A shows a top view of a display device 100 different from that shown in Figure 1A. The pixel 110 shown in Figure 16A is composed of four types of subpixels: subpixel 11R, subpixel 11G, subpixel 11B, and subpixel 11S.

[0287] The sub-pixels 11R, 11G, 11B, and 11S can each be configured to have light-emitting devices with different emission colors. For example, the sub-pixels 11R, 11G, 11B, and 11S could be sub-pixels of four colors R, G, B, and W, sub-pixels of four colors R, G, B, and Y, and sub-pixels of four colors R, G, B, and IR.

[0288] A display device according to one aspect of the present invention may have a light-receiving device in each pixel.

[0289] Of the four subpixels of the pixel 110 shown in Figure 16A, three can be configured to have light-emitting devices and the remaining one to have a light-receiving device.

[0290] For example, a pn-type or PIN-type photodiode can be used as the light-receiving device. The light-receiving device functions as a photoelectric conversion device (also called a photoelectric conversion element) that detects light incident on it and generates an electric charge. The amount of charge generated from the light-receiving device is determined based on the amount of light incident on it.

[0291] The light-receiving device can detect either visible light or infrared light, or both. When detecting visible light, it can detect one or more of the following colors, for example, blue, violet, blue-violet, green, yellow-green, yellow, orange, and red. When detecting infrared light, it is preferable because it enables the detection of objects even in dark places.

[0292] In particular, it is preferable to use an organic photodiode having a layer containing an organic compound as the light-receiving device. Organic photodiodes can be easily made thinner, lighter, and larger in area, and because they offer a high degree of freedom in shape and design, they can be applied to various display devices.

[0293] In one aspect of the present invention, an organic EL device is used as the light-emitting device, and an organic photodiode is used as the light-receiving device. The organic EL device and the organic photodiode can be formed on the same substrate. Therefore, an organic photodiode can be incorporated into a display device using an organic EL device.

[0294] A light-receiving device can detect light incident on it, generate an electric charge, and extract it as an electric current by driving it with a reverse bias applied between the pixel electrode and the common electrode.

[0295] The same manufacturing methods as for light-emitting devices can be applied to light-receiving devices. The island-shaped active layer (also called the photoelectric conversion layer) of the light-receiving device is not formed using a fine metal mask, but rather by depositing a film that will become the active layer onto one surface and then processing that film. This allows for the formation of island-shaped active layers with a uniform thickness. Furthermore, by providing a mask layer on the active layer, damage to the active layer during the manufacturing process of the display device can be reduced, thereby improving the reliability of the light-receiving device.

[0296] For the configuration and materials of the light-receiving device, refer to Embodiment 7.

[0297] Figure 16B shows a cross-sectional view between the dashed lines X3 and X4 in Figure 16A. Note that the cross-sectional view between the dashed lines X1 and X2 in Figure 16A can be found in Figure 1B, and the cross-sectional view between the dashed lines Y1 and Y2 can be found in Figures 7A to 7C.

[0298] As shown in Figure 16B, the display device 100 has a light-emitting device 130R and a light-receiving device 150 on a layer 101, a protective layer 131 covering the light-emitting device and the light-receiving device, and a substrate 120 bonded to it by a resin layer 122. In addition, an insulating layer 125 and an insulating layer 127 on the insulating layer 125 are provided in the region between adjacent light-emitting devices and light-receiving devices.

[0299] Figure 16B shows an example where the light-emitting device 130R emits light towards the substrate 120, and light is incident on the light-receiving device 150 from the substrate 120 side (see Optical Lem and Optical Lin).

[0300] The configuration of the light-emitting device 130R is as described above.

[0301] The light-receiving device 150 includes a pixel electrode 111S, a conductive layer 137S on the pixel electrode 111S, a layer 113S on the conductive layer 137S, a common layer 114 on the layer 113S, and a common electrode 115 on the common layer 114. The layer 113S includes at least an active layer.

[0302] A conductive layer 105S is provided on layer 101, a layer 107S is provided on the conductive layer 105S, and a pixel electrode 111S is provided on layer 107S. The pixel electrode 111S is provided so as to cover the conductive layer 105S and layer 107S. The pixel electrode 111S is in contact with and connected to the conductive layer 105S. A pixel circuit that controls the driving of the light receiving device 150 can be provided on layer 101. A conductive layer 250S is provided on layer 101. The conductive layer 250S corresponds to the electrodes of the transistor, electrodes of the capacitive element, or wiring of layer 101.

[0303] An insulating layer 104 is provided on the conductive layer 250, and the insulating layer 104 has an opening 257S that reaches the conductive layer 250S. The conductive layer 105S is provided so as to cover the opening 257S. The conductive layer 105S is in contact with the conductive layer 250S at the opening 257S and is connected to the conductive layer 250S.

[0304] The conductive layer 250S can be formed in the same process as conductive layers 250R, 250G, and 250B. The opening 257S can be formed in the same process as openings 257R, 257G, and 257B. The conductive layer 105S can be formed in the same process as conductive layers 105R, 105G, and 105B. Layer 107S can be formed in the same process as layers 107R, 107G, and 107B. The pixel electrode 111S can be formed in the same process as pixel electrode 111R, 111G, and 111B. The conductive layer 137S can be formed in the same process as conductive layers 137R, 137G, and 137B.

[0305] Layer 113S includes at least an active layer and preferably has a plurality of functional layers. For example, functional layers include carrier transport layers (hole transport layers and electron transport layers) and carrier block layers (hole block layers and electron block layers). It is also preferable to have one or more layers on the active layer. By having other layers between the active layer and the mask layer, it is possible to suppress the exposure of the active layer to the outermost surface during the manufacturing process of the display device and reduce damage to the active layer. This can improve the reliability of the light receiving device 150. Therefore, it is preferable that layer 113S includes an active layer and a carrier block layer (hole block layer or electron block layer) or a carrier transport layer (electron transport layer or hole transport layer) on the active layer.

[0306] Layer 113S is provided on the light-receiving device 150 but not on the light-emitting device. However, functional layers other than the active layer included in layer 113S may have the same material as functional layers other than the light-emitting layer included in layers 113R, 113G, and 113B. On the other hand, the common layer 114 is a continuous layer shared by the light-emitting device and the light-receiving device.

[0307] Here, layers common to both the light-receiving and light-emitting devices may have different functions in the light-emitting device and the light-receiving device. In this specification, components may be referred to based on their function in the light-emitting device. For example, a hole injection layer functions as a hole injection layer in the light-emitting device and as a hole transport layer in the light-receiving device. Similarly, an electron injection layer functions as an electron injection layer in the light-emitting device and as an electron transport layer in the light-receiving device. Furthermore, layers common to both the light-receiving and light-emitting devices may have the same function in the light-emitting device and the light-receiving device. For example, a hole transport layer functions as a hole transport layer in both the light-emitting and light-receiving devices, and an electron transport layer functions as an electron transport layer in both the light-emitting and light-receiving devices.

[0308] A mask layer 118R is located between layer 113R and the insulating layer 125, and a mask layer 118S is located between layer 113S and the insulating layer 125. Mask layer 118R is a portion of the mask layer that remained after processing layer 113R. Mask layer 118S is a portion of the mask layer that remained after processing layer 113S, which is a layer containing the active layer, by being in contact with the upper surface of layer 113S. Mask layer 118R and mask layer 118S may be made of the same material or different materials.

[0309] Figure 16A shows an example in which the aperture ratio (size, also known as the size of the light-emitting or light-receiving area) of sub-pixel 11S is larger than that of sub-pixels 11R, 11G, and 11B, but the present invention is not limited to this. The aperture ratios of sub-pixels 11R, 11G, 11B, and 11S can be determined as appropriate. The aperture ratios of sub-pixels 11R, 11G, 11B, and 11S can be different, or two or more of sub-pixels 11R, 11G, 11B, and 11S can be equal or substantially equal.

[0310] The sub-pixel 11S may have a higher aperture ratio than at least one of the sub-pixels 11R, 11G, and 11B. A larger light-receiving area for the sub-pixel 11S may make it easier to detect objects. For example, depending on the resolution of the display device and the circuit configuration of the sub-pixels, the aperture ratio of the sub-pixel 11S may be higher than that of the other sub-pixels.

[0311] The sub-pixel 11S may have a lower aperture ratio than at least one of the sub-pixels 11R, 11G, and 11B. A smaller light-receiving area for the sub-pixel 11S results in a narrower imaging range, which helps suppress blurring in the image and improves resolution. This allows for high-definition or high-resolution imaging, which is preferable.

[0312] In this way, the sub-pixel 11S can have a detection wavelength, resolution, and aperture ratio that are suitable for the application.

[0313] This embodiment can be combined with other embodiments as appropriate. Furthermore, if multiple configuration examples are shown within a single embodiment in this specification, these configuration examples can be combined as appropriate.

[0314] (Embodiment 2) This embodiment describes a method for manufacturing a display device according to one aspect of the present invention. Note that descriptions of the materials and formation methods of each element may be omitted if they are the same as those described in Embodiment 1. Furthermore, the details of the configuration of the light-emitting device will be described in Embodiment 6.

[0315] Thin films (insulating films, semiconductor films, and conductive films, etc.) that constitute display devices can be formed using sputtering, chemical vapor deposition (CVD), vacuum deposition, pulsed laser deposition (PLD), atomic layer deposition (ALD), and other methods. CVD methods include plasma enhanced CVD (PECVD) and thermal CVD. One type of thermal CVD is metal-organic CVD (MOCVD).

[0316] Thin films (insulating films, semiconductor films, conductive films, etc.) that constitute a display device can be formed by wet film deposition methods such as spin coating, dip coating, spray coating, inkjet printing, dispensing, screen printing, offset printing, doctor knife method, slit coating, roll coating, curtain coating, or knife coating.

[0317] In particular, vacuum processes such as vapor deposition and solution processes such as spin coating and inkjet can be used to fabricate light-emitting devices. Examples of vapor deposition methods include physical vapor deposition (PVD) methods such as sputtering, ion plating, ion beam deposition, molecular beam deposition, and vacuum deposition, as well as chemical vapor deposition (CVD). Functional layers included in the EL layer (hole injection layer, hole transport layer, hole blocking layer, light-emitting layer, electron blocking layer, electron transport layer, electron injection layer, charge generation layer, etc.) can be formed by vapor deposition (vacuum deposition, etc.), coating methods (dip coating, die coating, bar coating, spin coating, spray coating, etc.), and printing methods (inkjet, screen printing, offset printing, flexographic printing, gravure, or microcontact printing, etc.).

[0318] When processing the thin films that constitute the display device, photolithography or similar methods can be used. Alternatively, thin films can be processed by nanoimprint lithography, sandblasting, lift-off methods, etc. Furthermore, island-shaped thin films can be directly formed using a film deposition method that utilizes a shielding mask such as a metal mask.

[0319] There are two main methods of photolithography. One method involves forming a resist mask on the thin film to be processed, then processing the thin film by etching or other means, and finally removing the resist mask. The other method involves forming a photosensitive thin film, then exposing and developing it to process the thin film into the desired shape.

[0320] In photolithography, the light used for exposure can be, for example, i-line (wavelength 365 nm), g-line (wavelength 436 nm), h-line (wavelength 405 nm), or a mixture thereof. Other light sources such as ultraviolet light, KrF laser light, or ArF laser light can also be used. Exposure can also be performed using immersion lithography. Furthermore, extreme ultraviolet (EUV) light or X-rays can be used as the light source for exposure. An electron beam can also be used instead of light for exposure. Using extreme ultraviolet light, X-rays, or an electron beam is preferable because it allows for extremely fine processing. Note that a photomask is not required when exposure is performed by scanning a beam such as an electron beam.

[0321] For etching thin films, methods such as dry etching, wet etching, and sandblasting can be used.

[0322] <Example of Manufacturing Method 1> Here, an example of a manufacturing method for the display device shown in Figures 8A and 11B will be explained using Figures 17A to 29B. Figures 17A to 29B show side by side the cross-sectional view between the dashed-dotted lines X1 and X2 shown in Figure 1A, and the cross-sectional view between the dashed-dotted lines Y1 and Y2.

[0323] First, a conductive film is formed on the substrate 103, and this is processed to form conductive layers 250R, 250G, 250B, and 250p. Sputtering is preferably used to form the conductive film.

[0324] Next, an insulating film that will become an insulating layer 104 is formed on the substrate 103, conductive layer 250R, conductive layer 250G, conductive layer 250B, and conductive layer 250p. The insulating film can be formed using sputtering or PECVD. The insulating layer 104 is formed by creating openings 257R reaching the conductive layer 250R, 257G reaching the conductive layer 250G, 257B reaching the conductive layer 250B, and 257p reaching the conductive layer 250p in the insulating film (Figure 17A).

[0325] Next, conductive films 105f, consisting of conductive layers 105R, 105G, 105B, and 105p, are formed on the insulating layer 104, conductive layer 250R, conductive layer 250G, conductive layer 250B, and conductive layer 250p. Sputtering is preferably used to form the conductive films 105f.

[0326] Next, layers 107R, 107G, 107B, and 107p are formed on the conductive film 105f (Figure 17B). It is preferable that the film 107f is not provided on the connection portion 140. In particular, it is preferable that the film 107f is not provided in the region where the conductive film 105f and the conductive layer 250p are in contact.

[0327] Next, a mask film 193f is formed on the conductive film 105f and film 107f, and a resist mask 195R, resist mask 195G, resist mask 195B, and resist mask 195p are formed on the mask film 193f (Figure 17C). The resist masks 195R, 195G, 195B, and 195p are provided in the regions where layers 107R, 107G, 107B, and 107p are provided.

[0328] A mask film 193f is processed using resist masks 195R, 195G, 195B, and 195p as masks to form mask layers 193R, 193G, 193B, and 193p. In the following, mask layers 193R, 193G, 193B, and 193p may be collectively referred to as mask layer 193.

[0329] Next, resist masks 195R, 195G, 195B, and 195p are removed (Figure 18A).

[0330] Next, the mask layers 193R, 193G, 193B, and 193p are used as a mask to process the film 107f, forming layers 107R, 107G, 107B, and 107p (Figure 18B).

[0331] Mask layers 193R, 193G, 193B, and 193p function as hard masks when forming layers 107R, 107G, 107B, and 107p. The conductivity of mask layers 193R, 193G, 193B, and 193p is not particularly limited. It is preferable to use materials that have high resistance in the formation of layers 107R, 107G, 107B, and 107p for mask layers 193R, 193G, 193B, and 193p, specifically materials with a high selectivity ratio for etching with layers 107R, 107G, 107B, and 107p.

[0332] When resin is used for layers 107R, 107G, 107B, and 107p, a dry etching method using a gas containing chlorine and / or fluorine can be suitably used for their formation. Oxygen gas can be mixed with the aforementioned gas. For processing film 107f, for example, CF ４ Gas and oxygen gas can be suitably used. Furthermore, it is preferable that the mask layers 193R, 193G, 193B, and 193p have a slow etching rate in the dry etching method using a gas containing one or both of chlorine and fluorine. For example, one or more of ITO, ITSO, In-Zn oxide, IGZO, and In-Sn-Zn oxide can be suitably used for the mask layers 193R, 193G, 193B, and 193p. Alternatively, a dry etching method using an oxygen-containing gas can be suitably used for the formation of layers 107R, 107G, 107B, and 107p. For example, one or more of molybdenum, tungsten, titanium, and aluminum can be suitably used for the mask layers 193R, 193G, 193B, and 193p.

[0333] Next, mask layers 193R, 193G, 193B, and 193p are removed (Figure 18C). Wet etching is preferably used to remove mask layers 193R, 193G, 193B, and 193p.

[0334] By forming layers 107R, 107G, 107B, and 107p using a hard mask, the spacing between adjacent layers 107 can be reduced, and thus the spacing between adjacent light-emitting devices can be reduced. However, layers 107R, 107G, 107B, and 107p can be formed without using a hard mask. For example, when using a photosensitive resin for layers 107R, 107G, 107B, and 107p, layers 107R, 107G, 107B, and 107p can be formed by exposing and developing the film 107f.

[0335] Next, conductive film 111f, which will become the pixel electrode 111R, pixel electrode 111G, pixel electrode 111B, and conductive layer 123, is formed on conductive film 105f, layer 107R, layer 107G, layer 107B, and layer 107p (Figure 19A). The conductive film 111f can be formed by, for example, sputtering or vacuum deposition.

[0336] Next, the conductive films 105f and 111f are processed to form the conductive layer 105R, conductive layer 105G, conductive layer 105B, conductive layer 105p, pixel electrode 111R, pixel electrode 111G, pixel electrode 111B, and conductive layer 123 (Figure 19B). Dry etching is suitably used to form these conductive layers. By processing the conductive films 105f and 111f in the same process, the productivity of the display device can be increased and manufacturing costs can be reduced. Furthermore, the edges of conductive layer 105R and the pixel electrode 111R can be aligned or approximately aligned, the edges of conductive layer 105G and the pixel electrode 111G can be aligned or approximately aligned, the edges of conductive layer 105B and the pixel electrode 111B can be aligned or approximately aligned, and the edges of conductive layer 105p and the conductive layer 123 can be aligned or approximately aligned.

[0337] The conductive layers 105R, 105G, 105B, and 105p can also be formed using different processes than the pixel electrodes 111R, 111G, 111B, and 123. By forming them using different processes, different materials can be used for the conductive layers 105R, 105G, 105B, and 105p and for the pixel electrodes 111R, 111G, 111B, and 123, thereby broadening the range of material choices.

[0338] Next, a conductive film is formed on the pixel electrode 111R, pixel electrode 111G, pixel electrode 111B and conductive layer 123, and the conductive film is processed to form conductive layers 135R, 135G, 135B, and 135p (Figure 19C). Sputtering can be suitably used to form the conductive film.

[0339] Here, an example is shown in which the pixel electrode 111R, pixel electrode 111G, pixel electrode 111B and conductive layer 123 are formed first, and then the conductive layer 135R, conductive layer 135G, conductive layer 135B and conductive layer 135p are formed. However, the present invention is not limited to this example. For example, layers 107R, 107G, 107B and 107p are formed on the conductive film 105f, and the conductive film 111f is formed on the conductive film 105f, layers 107R, 107G, 107B and 107p. Conductive films that become conductive layers 135R, 135G, 135B and 135p are formed on the conductive film 111f. Then, by processing the conductive film, conductive film 111f, and conductive film 105f, conductive layer 135R, conductive layer 135G, conductive layer 135B, conductive layer 135p, pixel electrode 111R, pixel electrode 111G, pixel electrode 111B, conductive layer 123, conductive layer 105R, conductive layer 105G, conductive layer 105B, and conductive layer 105p can be formed. At this time, the edges of these layers can be aligned or approximately aligned. By processing these conductive films in the same process, the productivity of the display device can be increased and manufacturing costs can be reduced.

[0340] Next, an insulating film 109f, which will become the insulating layer 109, is formed on the insulating layer 104, conductive layer 135R, conductive layer 135G, conductive layer 135B, and conductive layer 135p (Figure 20A). It is preferable that the insulating film 109f is not provided at the connection portion 140. In particular, it is preferable that the insulating film 109f is not provided in the region where the conductive layer 105p and the conductive layer 250p are in contact.

[0341] Next, a portion of the insulating film 109f is removed to expose the conductive layer 135R, conductive layer 135G, conductive layer 135B, and conductive layer 135p, and the insulating layer 109 is formed (Figure 20B). The insulating layer 109 can be formed by dry etching or chemical mechanical polishing (CMP).

[0342] The conductive layers 135R, 135G, and 135B not only function as etching stoppers when forming the insulating layer 109, but also function as optical adjustment layers. It is preferable to use materials that have high resistance in the formation of the insulating layer 109, specifically materials with a high selectivity ratio for etching with the insulating layer 109, for the conductive layers 135R, 135G, 135B, and 135p.

[0343] When resin is used for the insulating layer 109, a dry etching method using a gas containing chlorine and / or fluorine can be suitably used for processing the insulating film 109f. Oxygen gas can be mixed with the aforementioned gas. For processing the insulating film 109f, for example, SF ６ Gas and oxygen gas can be suitably used. Furthermore, it is preferable that conductive layers 135R, 135G, 135B, and 135p have a slow etching rate in the dry etching method using a gas containing one or both of chlorine and fluorine. The materials that can be used for conductive layers 135R, 135G, 135B, and 135p are as described above.

[0344] Next, conductive films 137f, which will become conductive layers 137R, 137G, 137B, and 137p, are formed on the insulating layer 109, conductive layer 135R, conductive layer 135G, conductive layer 135B, and conductive layer 135p (Figure 20C).

[0345] Next, a film 113b which will become layer 113B, a mask film 118b which will become mask layer 118B, and a mask film 119b are formed on the conductive film 137f (Figure 21A). Film 113b contains a light-emitting material that emits blue light.

[0346] It is preferable that the film 113b is not provided on the connection portion 140. In particular, it is preferable that the film 113b is not provided in the region where the conductive layer 105p and the conductive layer 250p are in contact. For example, by using an area mask, the film 113b can be formed only in the desired region. By employing a film formation process using an area mask and a processing process using a resist mask, a light-emitting device can be manufactured using a relatively simple process.

[0347] As described above, in one embodiment of the present invention, a heat-resistant material is used for the light-emitting device. Specifically, the heat resistance temperature of the compounds contained in the film 113b is preferably 100°C to 180°C, preferably 120°C to 180°C, and more preferably 140°C to 180°C. This improves the reliability of the light-emitting device. It also allows for an increase in the upper limit of the temperature that can be applied during the manufacturing process of the display device. Therefore, the range of materials and forming methods used in the display device can be broadened, leading to improved manufacturing yield and reliability.

[0348] The film 113b can be formed, for example, by a vapor deposition method, specifically by a vacuum deposition method. Alternatively, the film 113b can be formed by methods such as a transfer method, a printing method, an inkjet method, or a coating method.

[0349] In this embodiment, an example is shown in which the mask film has a two-layer structure consisting of mask film 118b and mask film 119b, but the mask film can have a single-layer structure or a laminated structure of three or more layers.

[0350] By providing a mask layer on the film 113b, damage to the film 113b during the manufacturing process of the display device can be reduced, thereby improving the reliability of the light-emitting device.

[0351] For the mask film 118b, a film with high resistance to the processing conditions of film 113b is used, specifically a film with a high etching selectivity ratio with film 113b. For the mask film 119b, a film with a high etching selectivity ratio with mask film 118b is used.

[0352] The mask films 118b and 119b are formed at a temperature lower than the heat resistance temperature of film 113b. The substrate temperature when forming the mask films 118b and 119b is typically 200°C or lower, preferably 150°C or lower, more preferably 120°C or lower, more preferably 100°C or lower, and even more preferably 80°C or lower.

[0353] Examples of indicators for heat resistance temperature include the glass transition temperature (Tg), softening point, melting point, thermal decomposition temperature, and 5% weight loss temperature. For example, the glass transition temperature (Tg) of the material in each layer constituting the EL layer can be used as an indicator for heat resistance temperature. In the case of a mixed layer consisting of multiple materials, for example, the glass transition temperature of the most abundant material can be used. Alternatively, the lowest glass transition temperature among the multiple materials can be used.

[0354] As described above, in one embodiment of the present invention, a heat-resistant material is used for the light-emitting device. Therefore, the substrate temperature when forming the mask film can be set to 100°C or higher, 120°C or higher, or 140°C or higher. For example, the inorganic insulating layer can be made denser and have higher barrier properties the higher the film formation temperature. Therefore, by forming the mask film at such temperatures, damage to the film 113b can be further reduced, and the reliability of the light-emitting device can be improved.

[0355] It is preferable to use mask films 118b and 119b that can be removed by a wet etching method. By using a wet etching method, the damage to film 113b during processing of mask films 118b and 119b can be reduced compared to when a dry etching method is used.

[0356] For the formation of the mask films 118b and 119b, for example, sputtering, ALD (including thermal ALD and PEALD), CVD, and vacuum deposition can be used. Alternatively, they can be formed using the wet film formation method described above.

[0357] Furthermore, it is preferable that the mask film 118b, which is formed in contact with the film 113b, is formed using a method that causes less damage to the film 113b than the mask film 119b. For example, it is preferable to form the mask film 118b using the ALD method or vacuum deposition method rather than the sputtering method.

[0358] For the mask film 118b and mask film 119b, one or more types can be used, for example, from among metal films, alloy films, metal oxide films, semiconductor films, organic insulating films, and inorganic insulating films.

[0359] The mask films 118b and 119b can be made of metallic materials such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, titanium, aluminum, yttrium, zirconium, and tantalum, or alloy materials containing such metallic materials. In particular, it is preferable to use low-melting-point materials such as aluminum or silver. It is preferable to use a metallic material capable of shielding ultraviolet rays in one or both of the mask films 118b and 119b, as this can suppress the irradiation of film 113b with ultraviolet rays and thus suppress the deterioration of film 113b.

[0360] Using a metal film or alloy film for one or both of the mask films 118b and 119b is preferable because it can suppress plasma damage to film 113b and thus suppress deterioration of film 113b. Specifically, it is possible to suppress plasma damage to film 113b in processes such as dry etching and ashing. In particular, it is preferable to use a metal film such as a tungsten film or an alloy film as the mask film 119b.

[0361] For mask films 118b and 119b, metal oxides such as In-Ga-Zn oxide, indium oxide, In-Zn oxide, In-Sn oxide, indium titanium oxide (In-Ti oxide), indium tin zinc oxide (In-Sn-Zn oxide), indium titanium zinc oxide (In-Ti-Zn oxide), indium gallium tin zinc oxide (In-Ga-Sn-Zn oxide), and silicon-containing indium tin oxide can be used, respectively.

[0362] In addition, 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) can be used instead of gallium.

[0363] As the mask film, a film containing a material that has light-shielding properties against light, especially ultraviolet light, can be used. For example, a film that reflects ultraviolet light or a film that absorbs ultraviolet light can be used. Various materials can be used as the light-shielding material, such as metals, insulators, semiconductors, and metalloids that have light-shielding properties against ultraviolet light. However, since part or all of the mask film will be removed in a later process, it is preferable that the film be processable by etching, and in particular, that it has good processability.

[0364] For example, semiconductor materials such as silicon or germanium can be used as materials with high affinity to semiconductor manufacturing processes. Alternatively, oxides or nitrides of the above semiconductor materials can be used. Alternatively, nonmetallic materials such as carbon, or compounds thereof, can be used. Alternatively, metals such as titanium, tantalum, tungsten, chromium, and aluminum, or alloys containing one or more of these, can be used. Alternatively, oxides containing the above metals such as titanium oxide or chromium oxide, or nitrides such as titanium nitride, chromium nitride, or tantalum nitride can be used.

[0365] By using a mask film containing a material that has light-shielding properties against ultraviolet light, it is possible to suppress the irradiation of the EL layer with ultraviolet light during the exposure process. By suppressing damage to the EL layer from ultraviolet light, the reliability of the light-emitting device can be improved.

[0366] Furthermore, a film containing a material that has light-shielding properties against ultraviolet rays can be used as the material for the insulating film 125f described later to achieve the same effect.

[0367] Various inorganic insulating films that can be used in the protective layer 131 can be used as mask films 118b and 119b, respectively. In particular, oxide insulating films are preferred because they have higher adhesion to film 113b compared to nitride insulating films. For example, inorganic insulating materials such as aluminum oxide, hafnium oxide, and silicon oxide can be used as mask films 118b and 119b, respectively. For mask films 118b and 119b, aluminum oxide films can be formed, for example, using the ALD method. Using the ALD method is preferred because it reduces damage to the substrate (especially the EL layer).

[0368] For example, an inorganic insulating film (e.g., an aluminum oxide film) formed using the ALD method can be used as the mask film 118b, and an inorganic film (e.g., an In-Ga-Zn oxide film, a silicon film, or a tungsten film) formed using the sputtering method can be used as the mask film 119b.

[0369] Furthermore, the same inorganic insulating film can be used for both the mask film 118b and the insulating layer 125 that is formed later. For example, an aluminum oxide film formed using the ALD method can be used for both the mask film 118b and the insulating layer 125. Here, the same film formation conditions can be applied to the mask film 118b and the insulating layer 125. Alternatively, different film formation conditions can be applied to each other. For example, by forming the mask film 118b under the same conditions as the insulating layer 125, the mask film 118b can be made into an insulating layer with high barrier properties against at least one of water and oxygen. On the other hand, since the mask film 118b is a layer that is mostly or completely removed in a later process, it is preferable that it be easy to process. Therefore, it is preferable to form the mask film 118b under conditions where the substrate temperature during film formation is lower than that of the insulating layer 125.

[0370] Organic materials can be used in either or both of the mask films 118b and 119b. For example, as the organic material, a material that is soluble in a chemically stable solvent for at least the uppermost film of film 113b can be used. Materials that are soluble in water or alcohol are particularly suitable. When forming such a film, it is preferable to dissolve the material in a solvent such as water or alcohol, apply it using a wet film formation method, 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 film 113b.

[0371] As the mask membrane 118b, a material with higher water solubility than the membrane 113b can be used. For example, a material that dissolves in an aqueous solution containing hydrofluoric acid (HF) can be used as the mask membrane 118b. Alternatively, a material that dissolves in an aqueous solution containing tetramethylammonium hydroxide (abbreviated as TMAH) can be used as the mask membrane 118b.

[0372] Specifically, tris(8-quinolinolato)aluminum(III) (abbreviation: Alq ３ ), bis(10-hydroxybenzo[h]quinolinato)beryllium(II) (abbreviation: BeBq) ２Metal complexes such as bis(2-methyl-8-quinolinolato)(4-phenylphenololato)aluminum(III) (abbreviated as BAlq), bis(8-quinolinolato)zinc(II) (abbreviated as Znq), bis[2-(2-benzoxazollyl)phenololato]zinc(II) (abbreviated as ZnPBO), and bis[2-(2-benzothiazolyl)phenololato]zinc(II) (abbreviated as ZnBTZ) can be used in the mask film 118b.

[0373] It is preferable to use a water-soluble material for the mask film 118b and an inorganic film for the mask film 119b.

[0374] For example, as the mask film 118b, Alq ３ A film can be used, and as the mask film 119b, an In-Ga-Zn oxide film, a silicon film, or a tungsten film can be used.

[0375] By forming a water-soluble material as a mask film 118b on the film 113b, for example, even if the properties of the mask film 118b change during the manufacturing process, the mask film 118b can be removed from the film 113b to form the light-emitting device 130B. Furthermore, the mask film 118b that has been exposed to plasma or the like during the manufacturing process can be removed. In addition, the mask film 118b can mitigate the influence of plasma or the like on components located on the layer 101 side of the mask film 118b during the manufacturing process. Furthermore, it can protect the film 113b from damage incurred during the manufacturing process. As a result, a novel display device with superior convenience, usefulness, and reliability can be provided.

[0376] The mask films 118b and 119b can be made from resins such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinylpyrrolidone, polyethylene glycol, polyglycerin, pullulan, water-soluble cellulose, alcohol-soluble polyamide resin, or fluororesin such as perfluoropolymer, respectively.

[0377] For example, as the mask film 118b, an organic film (for example, a PVA film) formed using either vapor deposition or the above-described wet film formation method can be used, and as the mask film 119b, an inorganic film (for example, a silicon nitride film) formed using sputtering can be used.

[0378] As described in Embodiment 1, in the display device of one aspect of the present invention, a part of the mask film may remain as a mask layer.

[0379] Subsequently, a resist mask 190B is formed on the mask film 119b (FIG. 21B). The resist mask 190B can be formed by applying a photosensitive resin (photoresist) and performing exposure and development.

[0380] For the resist mask 190B, a positive resist material or a negative resist material can be used.

[0381] The resist mask 190B is provided at a position overlapping the pixel electrode 111B. The resist mask 190B is preferably also provided at a position overlapping the conductive layer 123. Thereby, it is possible to suppress damage to the conductive layer 123 during the manufacturing process of the display device. Note that the resist mask 190B may not be provided on the conductive layer 123.

[0382] Subsequently, a part of the mask film 119b is removed using the resist mask 190B as a mask to form a mask layer ll9B (FIG. 22A). The mask layer 119B remains on the pixel electrode 111B and on the conductive layer 123.

[0383] Subsequently, the resist mask 190B is removed (FIG. 22B). The resist mask 190B can be removed, for example, by ashing using oxygen plasma. Or, oxygen gas and CF ４ , C ４ F ８ , SF ６ , CHF ３ , Cl ２ , H ２ , O, BCl ３Alternatively, noble gases such as He can be used. Alternatively, the resist mask 190B can be removed by wet etching. At this time, since the mask film 118b is located on the outermost surface and the film 113b is not exposed, damage to the film 113b can be suppressed in the process of removing the resist mask 190B. In addition, the range of selection of the method for removing the resist mask 190B can be widened.

[0384] Subsequently, using the mask layer 119B as a mask, a part of the mask film 118b and the film 113b is removed to form the mask layer 118B and the layer 113B (FIG. 23A).

[0385] The mask film 118b and the mask film 119b can each be processed by a wet etching method or a dry etching method. The processing of the mask film 118b and the mask film 119b is preferably performed by anisotropic etching.

[0386] By using the wet etching method, the damage applied to the film 113b during the processing of the mask film 118b and the mask film 119b can be reduced as compared with the case of using the dry etching method. When using the wet etching method, for example, it is preferable to use a developer, an aqueous solution of tetramethylammonium hydroxide (TMAH), dilute hydrofluoric acid, oxalic acid, phosphoric acid, acetic acid, nitric acid, or a mixed solution containing two or more of these.

[0387] In the processing of the mask film 119b, since the film 113b is not exposed, the range of selection of the processing method is wider than that of the mask film 118b. Specifically, when using a gas containing oxygen in the etching gas during the processing of the mask film 119b, deterioration of the film 113b can be further suppressed.

[0388] When using the dry etching method for the processing of the mask film 118b, deterioration of the film 113b can be suppressed by not using a gas containing oxygen in the etching gas. When using the dry etching method, for example, CF ４ 、C ４ F ８ 、SF ６ 、CHF ３ 、Cl ２ 、H２ O, BCl ３ It is preferable to use a gas containing noble gases such as He as the etching gas.

[0389] For example, when using an aluminum oxide film formed using the ALD method as the mask film 118b, CHF ３ and He, or CHF ３ and He and CH ４ Using this method, the mask film 118b can be processed by dry etching. Furthermore, when an In-Ga-Zn oxide film formed by sputtering is used as the mask film 119b, the mask film 119b can be processed by wet etching using diluted phosphoric acid. Alternatively, CH ４ It can be processed by dry etching using Ar. Alternatively, the mask film 119b can be processed by wet etching using diluted phosphoric acid. Furthermore, when a tungsten film formed by sputtering is used as the mask film 119b, SF ６ CF ４ and O ２ , or CF ４ and Cl ２ and O ２ Using this method, the mask film 119b can be processed by dry etching.

[0390] As a result, as shown in Figure 23A, the laminated structure of layer 113B, mask layer 118B, and mask layer 119B remains on the conductive film 137f. In addition, a portion of the conductive film 137f is exposed.

[0391] The conductive film 137f (later conductive layers 137R, 137G, and 135B) functions not only as an etching stopper when forming layer 113B, but also as an optical adjustment layer. It is preferable to use a material for the conductive film 137f that has high resistance in the formation of layer 113B, specifically a material with a high selectivity ratio for etching with layer 113B. When processing film 113b, the insulating layer 109 is covered by the conductive film 137f, and the surface of the insulating layer 109 is not exposed to etching gas or etching solution. This prevents the thickness of the insulating layer 109 from becoming thinner. The materials that can be used for the conductive film 137f are as described above.

[0392] The film 113b is preferably processed using an anisotropic etching method. In particular, an anisotropic dry etching method is preferred. Alternatively, a wet etching method may also be used.

[0393] When processing the film 113b using the dry etching method, the surface of the display device being manufactured is exposed to plasma. It is preferable to use a metal film or alloy film for one or both of the mask layer 118B and the mask layer 119B, as this can suppress plasma damage to the remaining region of the film 113b (the region that becomes layer 113B) and thus suppress the deterioration of layer 113B. In particular, it is preferable to use a metal film or alloy film for the mask layer 119B, and a tungsten film or a molybdenum film can be suitably used.

[0394] When using a dry etching method to process the film 113b, the degradation of the film 113b can be suppressed by not using an oxygen-containing gas as the etching gas.

[0395] It is also possible to use an etching gas containing oxygen. By using an etching gas containing oxygen, the etching rate can be increased. Therefore, etching can be performed under low power conditions while maintaining a sufficiently fast etching rate. This suppresses damage to the film 113b. Furthermore, it suppresses problems such as the adhesion of reaction products generated during etching.

[0396] When using the dry etching method, for example, H２ CF ４ , C ４ F ８ SF ６ CHF ３ , Cl ２ H ２ O, BCl ３ It is preferable to use a gas containing one or more of the noble gases such as He, Ar, etc., as the etching gas. Alternatively, it is preferable to use a gas containing one or more of these and oxygen as the etching gas. Alternatively, oxygen gas can be used as the etching gas. Specifically, for example, H ２ and Ar-containing gas, or CF ４ A gas containing He can be used as an etching gas. Also, for example, CF ４ Gases containing , He, and oxygen can be used as etching gases. Also, for example, H ２ Gases containing Ar and gases containing oxygen can be used as etching gases.

[0397] As a dry etching apparatus, a dry etching apparatus having a high-density plasma source can be used. A dry etching apparatus having a high-density plasma source can be, for example, an inductively coupled plasma (ICP) etching apparatus. Alternatively, a capacitively coupled plasma (CCP) etching apparatus having parallel plate electrodes can be used. A capacitively coupled plasma etching apparatus having parallel plate electrodes can be configured to apply a high-frequency voltage to one electrode of the parallel plate electrodes. Alternatively, it can be configured to apply multiple different high-frequency voltages to one electrode of the parallel plate electrodes. Alternatively, it can be configured to apply a high-frequency voltage of the same frequency to each of the parallel plate electrodes. Alternatively, it can be configured to apply high-frequency voltages of different frequencies to each of the parallel plate electrodes.

[0398] By covering the pixel electrodes 111R, 111G, and 111B with the conductive film 137f, subsequent processes can be carried out without exposing the pixel electrodes 111R, 111G, and 111B. If the ends of the pixel electrodes 111R, 111G, and 111B are exposed, corrosion may occur during etching processes. Products generated by the corrosion of the pixel electrodes 111R, 111G, and 111B may be unstable; for example, in the case of wet etching, they may dissolve in the solution, and in the case of dry etching, there is a concern that they may scatter into the atmosphere. Dissolution of the products into the solution or scattering into the atmosphere may cause the products to adhere to the processed surface and the sides of layer 113B, for example, adversely affecting the characteristics of the light-emitting device or potentially forming leak paths between multiple light-emitting devices. Furthermore, in areas where the edges of the pixel electrode 111B are exposed, the adhesion between the layers in contact with each other decreases, which may make the layer 113B or the pixel electrode 111B more prone to peeling. Therefore, by configuring the conductive film 137f to cover the pixel electrode 111R, pixel electrode 111G, and pixel electrode 111B, for example, the yield and characteristics of the light-emitting device can be improved.

[0399] At the connection point 140 and its vicinity, the laminated structure of the mask layer 118B and the mask layer 119B remains on the conductive layer 123.

[0400] As described above, in one aspect of the present invention, a resist mask 190B is formed on the mask film 119b, and a mask layer 119B is formed by removing a portion of the mask film 119b using the resist mask 190B. Subsequently, a layer 113B is formed by removing a portion of the film 113b using the mask layer 119B as a hard mask. Thus, it can be said that a layer 113B is formed by processing the film 113b using a photolithography method. Note that a portion of the film 113b can be removed using the resist mask 190B. Subsequently, the resist mask 190B can be removed.

[0401] Next, a film 113g, which will become layer 113G, a mask film 118g, which will become mask layer 118G, and a mask film 119g are deposited on the conductive film 137f. Film 113g contains a light-emitting material that emits green light.

[0402] Next, a resist mask 190G is formed on the mask film 119g (Figure 23B).

[0403] Film 113g can be formed in the same manner as the method used to form film 113b. The materials and formation methods for mask films 118g and 119g are the same as those applicable to mask films 118b and 119b. The materials and formation methods for resist mask 190G are the same as those applicable to resist mask 190B. The resist mask 190G is placed in a position that overlaps with the pixel electrode 111G.

[0404] Next, a portion of the mask film 119g is removed using the resist mask 190G to form a mask layer 119G.

[0405] Next, remove the resist mask 190G (Figure 24A).

[0406] Next, the mask layer 119G is used as a mask, and a portion of the mask film 118g and film 113g are removed to form the mask layer 118G and layer 113G (Figure 24B).

[0407] Here, when processing the film 113g, the insulating layer 109 is covered with the conductive film 137f, and the surface of the insulating layer 109 is not exposed to etching gas or etching solution. This prevents the thickness of the insulating layer 109 from decreasing.

[0408] When processing film 113g using a dry etching method, the surface of the display device being manufactured is exposed to plasma. It is preferable to use a metal film or alloy film for one or both of the mask layer 118B and mask layer 119B, as this can suppress plasma damage to layer 113B and thus suppress deterioration of layer 113B. It is also preferable to use a metal film or alloy film for one or both of the mask layer 118G and mask layer 119G, as this can suppress plasma damage to the remaining region of film 113g (the region that becomes layer 113G) and thus suppress deterioration of layer 113G. In particular, it is preferable to use a metal film or alloy film as the mask layer 119G, and a tungsten film or a molybdenum film can be suitably used.

[0409] As a result, as shown in Figure 24B, a laminated structure of layer 113G, mask layer 118G, and mask layer 119G remains on the conductive film 137f.

[0410] Next, a film 113r which will become layer 113R, a mask film 118r which will become mask layer 118R, and a mask film 119r are formed on the conductive film 137f (film 113r contains a light-emitting material that emits red light).

[0411] Next, a resist mask 190R is formed on the mask film 119r (Figure 25A).

[0412] The film 113r can be formed in the same manner as the method used to form the film 113b. The materials and formation methods for the mask film 118r and mask film 119r are the same as the conditions applicable to the mask film 118b and mask film 119b. The materials and formation methods for the resist mask 190R are the same as the conditions applicable to the resist mask 190B. The resist mask 190R is provided in a position that overlaps with the pixel electrode 111R.

[0413] Next, a portion of the mask film 119r is removed using the resist mask 190R to form a mask layer 119R.

[0414] Next, remove the resist mask 190R (Figure 25B).

[0415] Next, using the mask layer 119R as a mask, a part of the mask film 118r and the film 113r is removed to form the mask layer 118R and the layer 113R (FIG. 26A).

[0416] When processing the film 113r using a dry etching method, the surface of the display device being manufactured is exposed to plasma. By using a metal film or an alloy film for one or both of the mask layer 118B and the mask layer 119B, and one or both of the mask layer 118G and the mask layer 119G, respectively, it is possible to suppress damage to the layers 113B and 113G caused by plasma, and thus suppress deterioration of the layers 113B and 113G, which is preferable. Also, by using a metal film or an alloy film for one or both of the mask layer 118R and the mask layer 119R, it is possible to suppress damage to the region where the film 113r remains (the region that becomes the layer 113R) caused by plasma, and thus suppress deterioration of the layer 113R, which is preferable. In particular, it is preferable to use a metal film or an alloy film for the mask layer 119R, and a tungsten film or a molybdenum film can be preferably used.

[0417] As a result, as shown in FIG. 26A, a laminated structure of the layer 113R, the mask layer 118R, and the mask layer 119R remains on the conductive film 137f.

[0418] Note that it is preferable that the side surfaces of the layers 113B, 113G, and 113R are perpendicular or substantially perpendicular to the formation surface (here, the upper surface of the conductive film 137f). For example, it is preferable that the angle formed by the formation surface and these side surfaces is 60 degrees or more and 90 degrees or less.

[0419] As described above, the distance between two adjacent ones of the layers 113B, layer 113G, and layer 113R formed using the photolithography method can be narrowed to 8 μm or less, 5 μm or less, 3 μm or less, 2 μm or less, or 1 μm or less. Here, the distance can be defined, for example, as the distance between two opposing end portions of two adjacent ones among the layers 113B, layer 113G, and layer 113R. By narrowing the distance between the island-shaped EL layers in this way, it is possible to provide a display device having high fineness and a large aperture ratio.<了

[0420] Next, it is preferable to remove the mask layer 119B, mask layer 119G, and mask layer 119R (Figure 26B). Depending on the subsequent process, some of the mask layer 118B, mask layer 118G, mask layer 118R, mask layer 119B, mask layer 119G, and mask layer 119R may remain in the display device. By removing the mask layer 119B, mask layer 119G, and mask layer 119R at this stage, it is possible to create a configuration in which the mask layer 119B, mask layer 119G, and mask layer 119R do not remain in the display device. For example, when conductive materials are used for the mask layer 119B, mask layer 119G, and mask layer 119R, removing the mask layer 119B, mask layer 119G, and mask layer 119R can suppress the generation of leakage current and the formation of capacitance due to the remaining mask layer 119B, mask layer 119G, and mask layer 119R.

[0421] Here, a manufacturing method in which mask layers 119B, 119G, and 119R are removed will be described as an example, but it is possible to leave a portion of mask layers 119B, 119G, and 119R intact. For example, if mask layers 119B, 119G, and 119R contain a material that has light-shielding properties against ultraviolet light, it is preferable to proceed to the next step without removing them, as this protects the island-shaped EL layer from ultraviolet light.

[0422] The removal of mask layers 119B, 119G, and 119R can be performed using the same method as for the formation of mask layers 119B, 119G, and 119R. In particular, by using a wet etching method, the damage to layers 113B, 113G, and 113R when removing mask layers 119B, 119G, and 119R can be reduced compared to when using a dry etching method.

[0423] When a metal film or alloy film is used for mask layers 119B, 119G, and 119R, the presence of mask layers 119B, 119G, and 119R can suppress plasma damage to the EL layer. Therefore, in the process up to the removal of mask layers 119B, 119G, and 119R, the film can be processed using a dry etching method. On the other hand, in the process of removing mask layers 119B, 119G, and 119R, and in the processes after their removal, the film that suppresses plasma damage to the EL layer is gone, so it is preferable to process the film using a method that does not use plasma, such as a wet etching method.

[0424] The mask layer 119B, mask layer 119G, and mask layer 119R can be removed by dissolving them in a solvent such as water or alcohol. Examples of alcohols include ethyl alcohol, methyl alcohol, isopropyl alcohol (IPA), or glycerin.

[0425] Next, a portion of the conductive film 137f is removed using mask layers 118B, 118G, and 118R as masks to form conductive layers 137R, 137G, 137B, and 137p (Figure 27A). The formation of conductive layers 137R, 137G, 137B, and 137p can preferably be done using a wet etching method. By using a wet etching method, the damage to layers 113B, 113G, and 113R during the formation of conductive layers 137R, 137G, 137B, and 137p can be reduced compared to when using a dry etching method.

[0426] After forming conductive layers 137R, 137G, 137B, and 137p, a drying treatment can be performed to remove water contained in layers 113B, 113G, and 113R, and water adsorbed on the surfaces of layers 113B, 113G, and 113R. For example, a heat treatment can be performed in an inert gas atmosphere such as a nitrogen atmosphere or a reduced pressure atmosphere. The heat treatment can be performed at a substrate temperature of 50°C to 200°C, preferably 60°C to 150°C, and more preferably 70°C to 120°C. A reduced pressure atmosphere is preferable because it allows drying at a lower temperature.

[0427] Next, an insulating film 125f, which will become the insulating layer 125, is formed so as to cover the insulating layer 109, conductive layer 137G, conductive layer 137B, conductive layer 137R, conductive layer 137p, layer 113B, layer 113G, layer 113R, mask layer 118B, mask layer 118G, and mask layer 118R (Figure 27B).

[0428] Subsequently, an insulating film 127f is formed in contact with the upper surface of the insulating film 125f, becoming the insulating layer 127. For this reason, it is preferable that the upper surface of the insulating film 125f has high adhesion to the resin composition used for the insulating film 127f (for example, a photosensitive resin composition containing acrylic resin). To improve this adhesion, it is preferable to perform a surface treatment to make the upper surface of the insulating film 125f hydrophobic (or to increase its hydrophobicity). For example, it is preferable to perform the treatment using a silylation agent such as hexamethyldisilazane (HMDS). By making the upper surface of the insulating film 125f hydrophobic in this way, the insulating film 127f can be formed with high adhesion.

[0429] Next, an insulating film 127f is formed on the insulating film 125f (Figure 28A).

[0430] It is preferable that the insulating film 125f and insulating film 127f are formed using a method that causes minimal damage to layers 113B, 113G, and 113R. In particular, since insulating film 125f is formed in contact with the sides of layers 113B, 113G, and 113R, it is preferable that it be formed using a method that causes less damage to layers 113B, 113G, and 113R than insulating film 127f.

[0431] The insulating film 125f and insulating film 127f are formed at a temperature lower than the heat resistance temperature of layers 113B, 113G, and 113R, respectively. Furthermore, by increasing the substrate temperature during film formation of insulating film 125f, it is possible to create a film with a low impurity concentration and high barrier properties against at least one of water and oxygen, even if the film is thin.

[0432] The substrate temperature when forming insulating film 125f and insulating film 127f is preferably 60°C or higher, 80°C or higher, 100°C or higher, or 120°C or higher, and 200°C or lower, 180°C or lower, 160°C or lower, 150°C or lower, or 140°C or lower, respectively.

[0433] As described above, in one embodiment of the present invention, a heat-resistant material is used for the light-emitting device. Therefore, the substrate temperature when forming the insulating film 125f and insulating film 127f can be set to 100°C or higher, 120°C or higher, or 140°C or higher, respectively. For example, the higher the deposition temperature of the inorganic insulating film, the denser and more barrier-oriented the film can be. Therefore, by depositing the insulating film 125f at such a temperature, the damage to layers 113B, 113G, and 113R can be further reduced, and the reliability of the light-emitting device can be improved.

[0434] It is preferable to deposit an insulating film 125f with a thickness of 3 nm or more, 5 nm or more, or 10 nm or more, and a thickness of 200 nm or less, 150 nm or less, 100 nm or less, or 50 nm or less, within the above substrate temperature range.

[0435] The insulating film 125f is preferably formed using, for example, the ALD method. The ALD method is preferable because it can reduce film formation damage and allow for the formation of a film with high coverage. For example, it is preferable to form an aluminum oxide film as the insulating film 125f using the ALD method.

[0436] The insulating film 125f can also be formed using sputtering, CVD, or PECVD methods, which have faster deposition rates than the ALD method. This allows for the highly productive manufacture of reliable display devices.

[0437] The insulating film 127f is preferably formed using the wet film formation method described above. The insulating film 127f is preferably formed using a photosensitive resin, for example, by spin coating, and more specifically, it is preferably formed using a photosensitive resin composition containing an acrylic resin.

[0438] It is preferable to perform a heat treatment (also called pre-baking) after the formation of the insulating film 127f. The temperature of the heat treatment is lower than the heat resistance temperature of layers 113B, 113G, and 113R. The substrate temperature during the heat treatment is preferably 50°C to 200°C, more preferably 60°C to 150°C, and even more preferably 70°C to 120°C. This makes it possible to remove the solvent contained in the insulating film 127f.

[0439] Next, visible light or ultraviolet light is irradiated onto a portion of the insulating film 127f to expose that portion of the insulating film 127f. For example, when a positive-type photosensitive resin composition containing acrylic resin is used for the insulating film 127f, visible light or ultraviolet light is irradiated onto a region where the insulating layer 127 will not be formed in a later step. The width of the insulating layer 127 can be controlled by the region that is exposed at this stage.

[0440] The light used for exposure preferably includes the i-line (wavelength 365 nm). Furthermore, the light used for exposure may also include at least one of the g-line (wavelength 436 nm) and the h-line (wavelength 405 nm).

[0441] Next, development is performed to form an insulating layer 127 (Figure 28B). The insulating layer 127 is formed in the region surrounding layer 113R, the region surrounding layer 113G, and the region surrounding layer 113B. When acrylic resin is used for the insulating film 127f, it is preferable to use an alkaline solution as the developer, for example, an aqueous solution of tetramethylammonium hydroxide (TMAH) can be used.

[0442] Furthermore, after development, a process can be carried out to remove the residue (so-called scum) from the development process. For example, the residue can be removed by ashing using oxygen plasma. After each of the development processes described below, a process to remove the residue can also be carried out.

[0443] Furthermore, etching can be performed to adjust the surface height of the insulating layer 127. The insulating layer 127 can be processed, for example, by ashing using oxygen plasma.

[0444] It is preferable to perform a heat treatment (also called post-bake) after development. By performing the heat treatment, the side surface of the insulating layer 127 can be made tapered. The heat treatment should be performed at a temperature lower than the heat resistance temperature of the EL layer. The heat treatment can be performed at a substrate temperature of 50°C to 200°C, preferably 60°C to 150°C, and more preferably 70°C to 130°C. The heating atmosphere can be, for example, an atmospheric atmosphere or an inert gas atmosphere. Alternatively, the heating atmosphere can be an atmospheric pressure atmosphere or a reduced pressure atmosphere. A reduced pressure atmosphere is preferable because it allows drying at a lower temperature. It is preferable to use a higher substrate temperature for the heat treatment in this step than for the heat treatment (pre-bake) after the formation of the insulating film 127f. This improves the adhesion between the insulating layer 127 and the insulating layer 125, and also improves the corrosion resistance of the insulating layer 127.

[0445] Next, the insulating layer 127 is used as a mask to remove a portion of the insulating film 125f, mask layer 118B, mask layer 118G, and mask layer 118R. As a result, the insulating layer 125 is formed, and openings are created in each of the mask layers 118B, mask layer 118G, and mask layer 118R, exposing the upper surfaces of layers 113G, 113G, 113R, and the conductive layer 137p (Figure 29A).

[0446] The insulating film 125f, mask layer 118B, mask layer 118G, and mask layer 118R can be processed using either a dry etching method or a wet etching method. It is preferable to use the same material for the insulating film 125f as for the mask layers 118B, 118G, and 118R, as this allows the processing to be performed in a single step.

[0447] When using the dry etching method, it is preferable to use a chlorine-based gas. As a chlorine-based gas, Cl ２ , BCl ３ SiCl４ , and CCl ４ These can be used individually or in mixtures of two or more gases. In addition, oxygen gas, hydrogen gas, helium gas, and argon gas can be used individually or in mixtures of two or more gases with the chlorine-based gas. By using dry etching, thin areas of the mask layers 118B, 118G, and 118R can be formed with good in-plane uniformity.

[0448] When using the dry etching method, by-products generated during dry etching may accumulate on the upper and side surfaces of the insulating layer 127. As a result, components contained in the etching gas, components contained in the insulating film 125f, and components contained in the mask layer 118B, mask layer 118G, and mask layer 118R may be present in the insulating layer 127.

[0449] It is preferable to use a wet etching method for processing the insulating film 125f, mask layer 118B, mask layer 118G, and mask layer 118R. By using a wet etching method, damage to layers 113B, 113G, and 113R can be reduced compared to when a dry etching method is used. For example, an alkaline solution can be used as the etchant for wet etching. For example, an aqueous solution of tetramethylammonium hydroxide (TMAH), which is an alkaline solution, can be suitably used for wet etching of an aluminum oxide film.

[0450] As described above, by providing insulating layer 127, insulating layer 125, mask layer 118B, mask layer 118G, and mask layer 118R, connection failures caused by the divided portion and increases in electrical resistance caused by locally thinner portions can be suppressed between each light-emitting device in the common layer 114 and common electrode 115. As a result, a display device according to one embodiment of the present invention can improve display quality.

[0451] After exposing a portion of layers 113B, 113G, and 113R, further heat treatment can be performed. This heat treatment can remove water contained in the EL layer and water adsorbed on the surface of the EL layer. In addition, this heat treatment may change the shape of the insulating layer 127. Specifically, the insulating layer 127 may spread to cover at least one of the following: the edge of the insulating layer 125, the edges of the mask layers 118B, 118G, and 118R, and the upper surfaces of layers 113B, 113G, and 113R. For example, the heat treatment can be performed in an inert gas atmosphere or a reduced pressure atmosphere. The heat treatment can be performed at a substrate temperature of 50°C to 200°C, preferably 60°C to 150°C, and more preferably 70°C to 120°C. A reduced pressure atmosphere is preferable because it allows for dehydration at a lower temperature. However, it is preferable to appropriately set the temperature range for the above heat treatment, taking into consideration the heat resistance temperature of the EL layer. Furthermore, considering the heat resistance temperature of the EL layer, a temperature range of 70°C to 120°C is particularly preferred within the above temperature range.

[0452] If the etching process for the insulating layer 125 and the mask layer is performed all at once after post-baking, side etching may cause the insulating layer 125 and the mask layer beneath the edges of the insulating layer 127 to disappear, forming a cavity. This cavity can cause unevenness on the surface forming the common layer 114 and the common electrode 115, making it easier for the common layer 114 and the common electrode 115 to break down. Therefore, it is preferable to perform the etching process for the insulating layer 125 and the mask layer separately, before and after post-baking.

[0453] Next, a common layer 114 and a common electrode 115 are formed in this order on the insulating layer 127, layer 113B, layer 113G, and layer 113R, and then a protective layer 131 is formed (Figure 29B).

[0454] The common layer 114 can be formed by, for example, a vapor deposition method (including vacuum deposition), a transfer method, a printing method, an inkjet method, or a coating method.

[0455] The common electrode 115 can be formed, for example, by sputtering or vacuum deposition. Alternatively, a film formed by deposition and a film formed by sputtering can be laminated together.

[0456] The protective layer 131 can be formed by, for example, vacuum deposition, sputtering, CVD, or ALD.

[0457] Next, the display device can be manufactured by bonding the substrate 120 onto the protective layer 131 using the resin layer 122 (Figures 8A and 11B).

[0458] As described above, in the method for manufacturing the display device of this embodiment, the island-shaped layers 113B, 113G, and 113R are not formed using a fine metal mask, but rather by depositing a film on one surface and processing the film. Therefore, the island-shaped layers can be formed with a uniform thickness. This makes it possible to realize a high-definition display device or a display device with a high aperture ratio. Furthermore, even if the resolution or aperture ratio is high and the distance between subpixels is extremely short, it is possible to suppress contact between layers 113B, 113G, and 113R in adjacent subpixels. Therefore, it is possible to suppress the generation of leakage current between subpixels. This prevents unintended light emission caused by crosstalk, and makes it possible to realize a display device with extremely high contrast.

[0459] In this explanation, we have described an example in which layers 113B, 113G, and 113R are formed in that order, but the order of formation is not particularly limited.

[0460] By providing an insulating layer 127 having a tapered shape at its end between adjacent island-shaped EL layers, it is possible to suppress the occurrence of step breaks during the formation of the common electrode 115 and to prevent the formation of locally thin areas in the common electrode 115. This suppresses connection failures caused by the divided areas and increases in electrical resistance caused by locally thin areas in the common layer 114 and the common electrode 115. Therefore, a display device according to one aspect of the present invention can achieve both high resolution and high display quality.

[0461] <Example of Manufacturing Method 2> Here, an example of a manufacturing method for the display device shown in Figures 9A and 11B will be explained using Figures 30A to 33B. Figures 30A to 33B show side by side the cross-sectional view between the dashed-dotted lines X1 and X2 shown in Figure 9A, and the cross-sectional view between the dashed-dotted lines Y1 and Y2. Note that explanations of parts that overlap with the aforementioned Example of Manufacturing Method 1 may be omitted.

[0462] First, the conductive film 137f is formed in the same manner as in example 1 of the manufacturing method (Figure 20C).

[0463] Next, the conductive film 137f is processed to form conductive layers 137R, 137G, 137B, and 137p (Figure 30A).

[0464] Next, film 113b, mask film 118b, and mask film 119b are formed on the insulating layer 109, conductive layer 137R, conductive layer 137G, conductive layer 137B, and conductive layer 137p. Then, a resist mask 190B is formed on the mask film 119b (Figure 30B).

[0465] Next, the mask film 119b is processed using the resist mask 190B as a mask to form the mask layer 119B. Then, the resist mask 190B is removed. Then, using the mask layer 119B as a mask, a portion of the mask film 118b and film 113b is removed to form the mask layer 118B and layer 113B (Figure 31A). When processing the mask film 118b and film 113b, a portion of the insulating layer 109 in a region that does not overlap with any of the conductive layers 137R, 137G, 137B, and 137p is removed, which may form a recess in the insulating layer 109.

[0466] Next, film 113g, mask film 118g, and mask film 119g are deposited. Then, a resist mask 190G is formed on mask film 119g (Figure 31B).

[0467] Next, the mask film 119g is processed using the resist mask 190G as a mask to form the mask layer 119G. Then, the resist mask 190G is removed. Then, using the mask layer 119G as a mask, a portion of the mask film 118g and film 113g is removed to form the mask layer 118G and layer 113G (Figure 32A). When processing the mask film 118g and film 113g, a portion of the insulating layer 109 in a region that does not overlap with any of the conductive layers 137R, 137G, 137B, and 137p is removed, which may form a recess in the insulating layer 109. Alternatively, the depth of the recess formed when processing the mask film 118b and film 113b may increase.

[0468] Next, film 113r, mask film 118r, and mask film 119r are deposited. Then, a resist mask 190R is formed on the mask film 119r (Figure 32B).

[0469] Next, the mask film 119r is processed using the resist mask 190R as a mask to form the mask layer 119R. Then, the resist mask 190R is removed. Then, a portion of the mask film 118r and film 113r is removed using the mask layer 119R as a mask to form the mask layer 118R and layer 113R (Figure 33A). When processing the mask film 118r and film 113r, a portion of the insulating layer 109 in a region that does not overlap with any of the conductive layers 137R, 137G, 137B, and 137p is removed, which may form a recess in the insulating layer 109. Alternatively, the depth of the recess formed when processing the mask film 118b and film 113b, and the mask film 118g and film 113g may increase.

[0470] Next, it is preferable to remove the mask layer 119B, mask layer 119G, and mask layer 119R (Figure 33B).

[0471] Next, an insulating film 125f, which will become the insulating layer 125, is formed so as to cover the insulating layer 109, conductive layer 137G, conductive layer 137B, conductive layer 137R, conductive layer 137p, layer 113B, layer 113G, layer 113R, mask layer 118B, mask layer 118G, and mask layer 118R. After the formation of the insulating film 125f, refer to the description in Figures 27B to 29B.

[0472] This allows for the fabrication of a display device (Figures 9A and 11B).

[0473] This embodiment can be combined with other embodiments as appropriate.

[0474] (Embodiment 3) In this embodiment, a display device according to one aspect of the present invention will be described with reference to Figures 34A and 35K.

[0475] This embodiment primarily describes a pixel layout different from that shown in Figure 1A. There are no particular limitations on the arrangement of subpixels, and various methods can be applied. Examples of subpixel arrangements include stripe arrangements, S-stripe arrangements, matrix arrangements, delta arrangements, Bayer arrangements, and pentile arrangements.

[0476] In this embodiment, the top surface shape of the subpixel shown in the figure corresponds to the top surface shape of the light-emitting region (or light-receiving region).

[0477] The top surface shape of the sub-pixels may include, for example, polygons such as triangles, quadrilaterals (including rectangles and squares), pentagons, polygons with rounded corners, ellipses, or circles.

[0478] The circuit layout that constitutes the subpixel is not limited to the subpixel area shown in the figure, but can also be arranged outside of it.

[0479] The pixel 110 shown in Figure 34A has an S-stripe array applied to it. The pixel 110 shown in Figure 34A is composed of three subpixels: subpixel 110a, subpixel 110b, and subpixel 110c.

[0480] The pixel 110 shown in Figure 34B includes a sub-pixel 110a having a roughly trapezoidal or triangular top surface shape with rounded corners, a sub-pixel 110b having a roughly trapezoidal or triangular top surface shape with rounded corners, and a sub-pixel 110c having a roughly square or hexagonal top surface shape with rounded corners. Furthermore, sub-pixel 110b has a larger light-emitting area than sub-pixel 110a. In this way, the shape and size of each sub-pixel can be determined independently. For example, the size of a sub-pixel can be reduced to a level that provides a more reliable light-emitting device.

[0481] A pentile array is applied to pixels 124a and 124b shown in Figure 34C. Figure 34C shows an example in which pixels 124a having sub-pixels 110a and 110b, and pixels 124b having sub-pixels 110b and 110c are arranged alternately.

[0482] Pixels 124a and 124b shown in Figures 34D to 34F utilize a delta array. Pixel 124a has two subpixels (subpixels 110a and 110b) in the top row (1st row) and one subpixel (subpixel 110c) in the bottom row (2nd row). Pixel 124b has one subpixel (subpixel 110c) in the top row (1st row) and two subpixels (subpixels 110a and 110b) in the bottom row (2nd row).

[0483] Figure 34D shows an example where each subpixel has a roughly square top shape with rounded corners, Figure 34E shows an example where each subpixel has a circular top shape, and Figure 34F shows an example where each subpixel has a roughly hexagonal top shape with rounded corners.

[0484] In Figure 34F, each subpixel is located inside a densely arranged hexagonal region. When focusing on one subpixel, it is arranged so that it is surrounded by six other subpixels. Furthermore, subpixels that emit light of the same color are not adjacent to each other. For example, when focusing on subpixel 110a, three subpixels 110b and three subpixels 110c are arranged alternately around it.

[0485] Figure 34G shows an example where the subpixels of each color are arranged in a zigzag pattern. Specifically, in a top view, the upper edges of two subpixels aligned in the row direction (for example, subpixel 110a and subpixel 110b, or subpixel 110b and subpixel 110c) are offset.

[0486] In each pixel shown in Figures 34A to 34G, it is preferable, for example, that sub-pixel 110a be sub-pixel R that emits red light, sub-pixel 110b be sub-pixel G that emits green light, and sub-pixel 110c be sub-pixel B that emits blue light. However, the configuration of the sub-pixels is not limited to this, and the colors emitted by the sub-pixels and their order can be determined as appropriate. For example, sub-pixel 110b can be sub-pixel R that emits red light, and sub-pixel 110a can be sub-pixel G that emits green light.

[0487] In photolithography, the finer the pattern being processed, the more significant the effects of light diffraction become. This compromises the fidelity of the transfer of the photomask pattern through exposure, making it difficult to process the resist mask into the desired shape. Therefore, even if the photomask pattern is rectangular, patterns with rounded corners are likely to be formed. Consequently, the top surface shape of subpixels may be a polygon with rounded corners, an ellipse, or a circle.

[0488] Furthermore, in a method for manufacturing a display device according to one aspect of the present invention, the EL layer is processed into an island shape using a resist mask. The resist film formed on the EL layer needs to be cured at a temperature lower than the heat resistance temperature of the EL layer. Therefore, depending on the heat resistance temperature of the EL layer material and the curing temperature of the resist material, the curing of the resist film may be insufficient. A resist film that is not sufficiently cured may take a shape that deviates from the desired shape during processing. As a result, the top surface shape of the EL layer may become a polygon with rounded corners, an ellipse, or a circle. For example, if an attempt is made to form a resist mask with a square top surface, a resist mask with a circular top surface may be formed, resulting in a circular top surface shape for the EL layer.

[0489] Furthermore, in order to achieve the desired shape of the upper surface of the EL layer, a technique (OPC (Optical Proximity Correction) technique) can be used to pre-correct the mask pattern so that the design pattern and the transferred pattern match. Specifically, in the OPC technique, a correction pattern is added to the corners of the shape on the mask pattern.

[0490] As shown in Figures 35A to 35I, a pixel can be configured to have four types of subpixels.

[0491] The pixels 110 shown in Figures 35A to 35C are arranged in a stripe pattern.

[0492] Figure 35A shows an example where each subpixel has a rectangular top surface shape, Figure 35B shows an example where each subpixel has a top surface shape formed by connecting two semicircles and a rectangle, and Figure 35C shows an example where each subpixel has an elliptical top surface shape.

[0493] The pixels 110 shown in Figures 35D to 35F are arranged in a matrix array.

[0494] Figure 35D shows an example where each subpixel has a square top surface shape, Figure 35E shows an example where each subpixel has a roughly square top surface shape with rounded corners, and Figure 35F shows an example where each subpixel has a circular top surface shape.

[0495] Figures 35G and 35H show an example in which one pixel 110 is composed of 2 rows and 3 columns.

[0496] The pixel 110 shown in Figure 35G has three subpixels (subpixels 110a, 110b, and 110c) in the top row (1st row) and one subpixel (subpixel 110d) in the bottom row (2nd row). In other words, pixel 110 has subpixel 110a in the left column (1st column), subpixel 110b in the middle column (2nd column), subpixel 110c in the right column (3rd column), and subpixel 110d extending across these three columns.

[0497] The pixel 110 shown in Figure 35H has three subpixels (subpixels 110a, 110b, and 110c) in the top row (1st row) and three subpixels 110d in the bottom row (2nd row). In other words, the pixel 110 has subpixels 110a and 110d in the left column (1st column), subpixels 110b and 110d in the middle column (2nd column), and subpixels 110c and 110d in the right column (3rd column). As shown in Figure 35H, by aligning the arrangement of subpixels in the top row and the bottom row, it becomes possible to efficiently remove dust and other debris that may occur during the manufacturing process. Therefore, a display device with high display quality can be provided.

[0498] Figure 35I shows an example where one pixel 110 is composed of 3 rows and 2 columns.

[0499] The pixel 110 shown in Figure 35I has a sub-pixel 110a in the top row (1st row), a sub-pixel 110b in the middle row (2nd row), a sub-pixel 110c spanning from the 1st to the 2nd row, and one sub-pixel (sub-pixel 110d) in the bottom row (3rd row). In other words, the pixel 110 has sub-pixels 110a and 110b in the left column (1st column), a sub-pixel 110c in the right column (2nd column), and a sub-pixel 110d spanning these two columns.

[0500] The pixel 110 shown in Figures 35A to 35I is composed of four subpixels: subpixel 110a, subpixel 110b, subpixel 110c, and subpixel 110d.

[0501] Sub-pixels 110a, 110b, 110c, and 110d can each be configured to have a light-emitting device with a different emission color. Examples of sub-pixels 110a, 110b, 110c, and 110d include sub-pixels of four colors: R, G, B, and white (W); sub-pixels of four colors: R, G, B, and Y; or sub-pixels of R, G, B, and infrared (IR).

[0502] In each pixel 110 shown in Figures 35A to 35I, it is preferable, for example, that sub-pixel 110a be a sub-pixel R that emits red light, sub-pixel 110b be a sub-pixel G that emits green light, sub-pixel 110c be a sub-pixel B that emits blue light, and sub-pixel 110d be one of the following: sub-pixel W that emits white light, sub-pixel Y that emits yellow light, or sub-pixel IR that emits near-infrared light. With such a configuration, in the pixels 110 shown in Figures 35G and 35H, the layout of R, G, and B becomes a stripe arrangement, which can improve the display quality. Also, in the pixels 110 shown in Figure 35I, the layout of R, G, and B becomes a so-called S-stripe arrangement, which can improve the display quality.

[0503] Pixel 110 may have subpixels that have light-receiving devices.

[0504] In each pixel 110 shown in Figures 35A to 35I, one of the sub-pixels 110a to 110d can be a sub-pixel having a light-receiving device.

[0505] In each pixel 110 shown in Figures 35A to 35I, it is preferable, for example, that sub-pixel 110a be a sub-pixel R that emits red light, sub-pixel 110b be a sub-pixel G that emits green light, sub-pixel 110c be a sub-pixel B that emits blue light, and sub-pixel 110d be a sub-pixel S having a light-receiving device. With such a configuration, in the pixels 110 shown in Figures 35G and 35H, the layout of R, G, and B becomes a stripe arrangement, which can improve the display quality. Also, in the pixels 110 shown in Figure 35I, the layout of R, G, and B becomes a so-called S-stripe arrangement, which can improve the display quality.

[0506] The wavelength of light detected by the sub-pixel S, which has a light-receiving device, is not particularly limited. The sub-pixel S can be configured to detect either visible light or infrared light, or both.

[0507] As shown in Figures 35J and 35K, a pixel can be configured to have five types of subpixels.

[0508] Figure 35J shows an example where one pixel 110 is composed of two rows and three columns.

[0509] The pixel 110 shown in Figure 35J has three subpixels (subpixel 110a, subpixel 110b, and subpixel 110c) in the top row (1st row) and two subpixels (subpixel 110d and subpixel 110e) in the bottom row (2nd row). In other words, pixel 110 has subpixels 110a and 110d in the left column (1st column), subpixel 110b in the middle column (2nd column), subpixel 110c in the right column (3rd column), and subpixel 110e extending from the 2nd to the 3rd column.

[0510] Figure 35K shows an example where one pixel 110 is composed of 3 rows and 2 columns.

[0511] The pixel 110 shown in Figure 35K has a sub-pixel 110a in the top row (1st row), a sub-pixel 110b in the middle row (2nd row), a sub-pixel 110c spanning from the 1st to the 2nd row, and two sub-pixels (sub-pixels 110d and 110e) in the bottom row (3rd row). In other words, the pixel 110 has sub-pixels 110a, 110b, and 110d in the left column (1st column), and sub-pixels 110c and 110e in the right column (2nd column).

[0512] In each pixel 110 shown in Figures 35J and 35K, it is preferable, for example, that sub-pixel 110a be sub-pixel R that emits red light, sub-pixel 110b be sub-pixel G that emits green light, and sub-pixel 110c be sub-pixel B that emits blue light. With such a configuration, in the pixel 110 shown in Figure 35J, the layout of R, G, and B becomes a stripe arrangement, which can improve the display quality. Also, in the pixel 110 shown in Figure 35K, the layout of R, G, and B becomes a so-called S-stripe arrangement, which can improve the display quality.

[0513] In each pixel 110 shown in Figures 35J and 35K, it is preferable to apply a sub-pixel S having a light-receiving device to at least one of the sub-pixels 110d and 110e. When light-receiving devices are used for both sub-pixels 110d and 110e, the configurations of the light-receiving devices can be made different from each other. For example, the wavelength ranges of the light they detect can be made at least partially different. Specifically, one of the sub-pixels 110d and 110e can have a light-receiving device that mainly detects visible light, and the other can have a light-receiving device that mainly detects infrared light.

[0514] In each pixel 110 shown in Figures 35J and 35K, it is preferable to apply a sub-pixel S having a light-receiving device to one of the sub-pixels 110d and 110e, and a sub-pixel having a light-emitting device that can be used as a light source to the other. For example, it is preferable that one of the sub-pixels 110d and 110e is a sub-pixel IR that emits infrared light, and the other is a sub-pixel S having a light-receiving device that detects infrared light.

[0515] In a pixel having sub-pixels R, G, B, IR, and S, an image can be displayed using sub-pixels R, G, and B, while sub-pixel IR is used as a light source to detect the reflected infrared light emitted by sub-pixel IR at sub-pixel S.

[0516] As described above, in one aspect of the present invention, a display device can be configured to have pixels having subpixels with light-emitting devices, and various layouts can be applied to these pixels. Furthermore, in one aspect of the present invention, a display device can be configured to have pixels having both light-emitting devices and light-receiving devices. In this case as well, various layouts can be applied.

[0517] This embodiment can be combined with other embodiments as appropriate.

[0518] (Embodiment 4) In this embodiment, a display device according to one aspect of the present invention will be described with reference to Figures 36A to 41B.

[0519] The display device of this embodiment can be a high-definition display device or a large-screen display device. Therefore, the display device of this embodiment can be used in electronic devices with relatively large screens, such as television equipment, desktop or notebook personal computers, computer monitors, digital signage, and large game machines such as pachinko machines, as well as in the display units of digital cameras, digital video cameras, digital photo frames, mobile phones, portable game consoles, personal information terminals, and audio playback devices.

[0520] The display device of this embodiment can be used, for example, as a display unit for information terminals (wearable devices) such as wristwatches and bracelets, as well as as a display unit for wearable devices that can be worn on the head, such as VR devices like head-mounted displays (HMDs) and AR devices like glasses.

[0521] Figure 36A shows a top view of the display device 100A.

[0522] The display device 100A has a configuration in which substrate 152 and substrate 151 are bonded together by a sealing material 712.

[0523] The display device 100A includes a display unit 162, a connection unit 140, a circuit 164, a circuit 704, wiring 165, an FPC terminal unit 708, etc. Figure 36A shows an example in which IC 173 and FPC 172 are mounted on the display device 100A. Therefore, the configuration shown in Figure 36A can also be described as a display module having the display device 100A, an IC, and an FPC.

[0524] The connection portion 140 is provided on the outside of the display portion 162. The connection portion 140 can be provided along one or more sides of the display portion 162. There can be one or more connection portions 140. Figure 36A shows an example in which the connection portion 140 is provided so as to surround all four sides of the display portion. The connection portion 140 connects the common electrode of the light-emitting device to the conductive layer, and can supply potential to the common electrode.

[0525] Circuit 164 functions, for example, as a scan line driving circuit. Similarly, circuit 704 functions, for example, as a signal line driving circuit.

[0526] Signals and power are supplied to the display unit 162, circuit 164, and circuit 704, respectively, via the FPC 172 and wiring 165. These signals and power are input to the FPC 172 from an external source or from IC 173.

[0527] Figure 36A shows an example in which IC 173 is provided on the substrate 151 using a COG (Chip On Glass) method or a COF (Chip On Film) method, etc. IC 173 can be an IC having, for example, a scan line drive circuit or a signal line drive circuit. When IC 173 functions as a signal line drive circuit, circuit 704 can be configured to include at least one of the following: a protection circuit, a buffer circuit, a demultiplexer circuit, etc.

[0528] Furthermore, the display device 100A and the display module can be configured without an IC. Alternatively, the IC can be mounted on the FPC using a COF (Core-on-Fiber) method or the like.

[0529] The display device 100B shown in Figure 36B has a flexible resin layer 743 applied in place of the substrate 151. The display device 100B can be used as a flexible display.

[0530] In Figure 36B, the display device 100B has pixel sections 702 that are not rectangular in shape, but have arc-shaped corners. A pair of circuits 164 can function as gate driver circuits and are provided on both sides of the display section 162. The circuits 164 are also provided along the arc-shaped contours at the corners of the display section 162.

[0531] In Figure 36B, the resin layer 743 has a shape in which the area where the FPC 172 is provided protrudes. In addition, a part of the resin layer 743, including the FPC terminal portion 708, can be folded back to the other side in area P2. By folding the resin layer 743 back to the other side, the display device 100B can be mounted on an electronic device with the FPC 172 placed on top of the back of the display unit 162, making it possible to create a compact electronic device.

[0532] <Cross-sectional configuration example 1> Figure 37A shows an example of a cross-section when a portion of the area including the FPC 172, a portion of the circuit 164, a portion of the display unit 162, a portion of the connection portion 140, and a portion of the area including the end portion of the display device 100A are cut.

[0533] The display device 100A shown in Figure 37A has a transistor 201, a transistor 205, a light-emitting device 130R, a light-emitting device 130G, and a light-emitting device 130B, etc., between the substrate 151 and the substrate 152.

[0534] Figure 37A shows an example in which the configuration of pixel electrode 111R, pixel electrode 111G, pixel electrode 111B, conductive layer 105R, conductive layer 105G, conductive layer 105B, layer 107R, layer 107G, layer 107B, conductive layer 135R, conductive layer 135G, conductive layer 135B, conductive layer 137R, conductive layer 137G, and conductive layer 137B shown in Figure 8A is applied.

[0535] The conductive layer 105R contacts and connects with the conductive layer 222b of the transistor 205 at openings provided in the insulating layers 214, 215, and 213. Layer 107R is provided on the conductive layer 105R, and the pixel electrode 111R is provided so as to cover the conductive layer 105R and layer 107R. The conductive layer 105R is provided so as to cover the opening and has a recess. This recess is filled with layer 107R. The same applies to the pixel electrode 111G, conductive layer 105G and layer 107G, and the pixel electrode 111B, conductive layer 105B and layer 107B, so a detailed explanation is omitted.

[0536] The upper surfaces and sides of layers 113B, 113G, and 113R are covered by insulating layers 125 and 127, respectively. A mask layer 118B is located between layer 113B and insulating layer 125. A mask layer 118G is located between layer 113G and insulating layer 125, and a mask layer 118R is located between layer 113R and insulating layer 125. A common layer 114 is provided on layers 113B, 113G, 113R, and insulating layers 125 and 127, and a common electrode 115 is provided on the common layer 114. The common layer 114 and the common electrode 115 are each a continuous film provided in common to multiple light-emitting devices.

[0537] A protective layer 131 is provided on the light-emitting devices 130R, 130G, and 130B. The protective layer 131 and the substrate 152 are bonded via an adhesive layer 142. A light-shielding layer 117 is provided on the substrate 152. For sealing the light-emitting devices, a solid sealing structure or a hollow sealing structure can be applied. In Figure 37A, the space between the substrate 152 and the substrate 151 is filled with the adhesive layer 142, and a solid sealing structure is applied. Alternatively, the space can be filled with an inert gas (such as nitrogen or argon), and a hollow sealing structure can be applied. In this case, the adhesive layer 142 may be provided so as not to overlap with the light-emitting devices. Furthermore, the space may be filled with a resin different from the adhesive layer 142, which is provided in a frame shape.

[0538] A connection portion 204 is provided in the region of substrate 151 where substrate 152 does not overlap. At the connection portion 204, wiring 165 is connected to FPC 172 via conductive layer 105q, conductive layer 166, conductive layer 135q, conductive layer 137q and connection layer 242. Conductive layer 105q can be formed in the same process as conductive layer 105R, conductive layer 105G and conductive layer 105B, for example. Conductive layer 166 can be formed in the same process as pixel electrode 111R, pixel electrode 111G and pixel electrode 111B, for example. Layer 107q is provided between conductive layer 105q and conductive layer 166. Layer 107q can be formed in the same process as layer 107R, layer 107G and layer 107B, for example. Conductive layer 166 can be formed in the same process as pixel electrode 111R, pixel electrode 111G and pixel electrode 111B, for example. The conductive layer 135q can be formed, for example, in the same process as conductive layer 135R, conductive layer 135G, and conductive layer 135B. The conductive layer 137q can be formed, for example, in the same process as conductive layer 137R, conductive layer 137G, and conductive layer 137B. The conductive layer 137q is exposed on the upper surface of the connection portion 204. This allows the connection portion 204 and the FPC 172 to be connected via the connection layer 242.

[0539] The protective layer 131 is provided at least on the display unit 162, and preferably so as to cover the entire display unit 162. Preferably, the protective layer 131 is provided so as to cover not only the display unit 162, but also the connection unit 140 and the circuit 164. Furthermore, it is preferable that the protective layer 131 extends to the end of the display device 100A. On the other hand, in the connection unit 204, there is an area where the protective layer 131 is not provided in order to connect the FPC 172 and the conductive layer 166.

[0540] For example, after forming the protective layer 131 over the entire surface of the display device 100A, the conductive layer 137q can be exposed by removing the area of ​​the protective layer 131 that overlaps with the conductive layer 137q using a mask.

[0541] A laminated structure of at least one organic layer and a conductive layer may be provided on the conductive layer 137q, and a protective layer 131 may be provided on the laminated structure. Then, a starting point for peeling (a portion that triggers peeling) may be formed on the laminated structure using a laser or a sharp blade (e.g., a needle or cutter), and the laminated structure and the protective layer 131 on it may be selectively removed, exposing the conductive layer 137q. For example, the protective layer 131 can be selectively removed by pressing an adhesive roller against the substrate 151 and moving the roller relatively while rotating it. Alternatively, an adhesive tape may be attached to the substrate 151 and peeled off. Due to the low adhesion between the organic layer and the conductive layer, or the low adhesion between the organic layers themselves, separation occurs at the interface between the organic layer and the conductive layer, or within the organic layer. This allows for the selective removal of the region of the protective layer 131 that overlaps with the conductive layer 137q. If any organic layer remains on the conductive layer 137q, it can be removed with an organic solvent or the like.

[0542] As the organic layer, for example, at least one organic layer (a layer that functions as a light-emitting layer, a carrier block layer, a carrier transport layer, or a carrier implantation layer) can be used in any of layers 113B, 113G, and 113R. The organic layer may be formed during the deposition of any of layers 113B, 113G, and 113R, or it may be provided separately. The conductive layer can be formed using the same process and materials as the common electrode 115. For example, it is preferable to form an ITO film as both the common electrode 115 and the conductive layer. When a laminated structure is used for the common electrode 115, at least one layer from among the layers constituting the common electrode 115 is provided as the conductive layer.

[0543] The upper surface of the conductive layer 137q may be covered with a mask to prevent the protective layer 131 from being formed on the conductive layer 137q. As the mask, for example, a metal mask (area metal mask) may be used, or an adhesive or suction tape or film may be used. By forming the protective layer 131 with the mask in place and then removing the mask, the conductive layer 137q can be kept exposed even after the protective layer 131 has been formed.

[0544] Using this method, a region is formed in the connection portion 204 where the protective layer 131 is not provided, and in that region, the conductive layer 137q and the FPC 172 can be connected via the connecting layer 242.

[0545] In this example, a configuration in which conductive layers 135q and 137q are provided on the connection portion 204 is shown, but the present invention is not limited to this. The connection portion 204 may also be configured without one or both of the conductive layers 135q and 137q. If neither the conductive layer 135q nor the conductive layer 137q is provided on the connection portion 204, the conductive layer 166 will be exposed on the upper surface of the connection portion 204, and the conductive layer 166 will be in contact with the connection layer 242.

[0546] The display device 100A is a top-emission type. The light emitted by the light-emitting device is emitted towards the substrate 152. It is preferable to use a material with high transmittance to visible light for the substrate 152. The pixel electrodes contain a material that reflects visible light, and the counter electrodes (common electrodes 115) contain a material that transmits visible light.

[0547] The laminated structure from the substrate 151 to the insulating layer 214 corresponds to layer 101 in Embodiment 1.

[0548] Both transistors 201 and 205 are formed on the substrate 151. These transistors can be formed by the same process.

[0549] On the substrate 151, insulating layers 211, 213, 215, and 214 are provided in this order. A portion of insulating layer 211 functions as a gate insulating layer for each transistor. A portion of insulating layer 213 functions as a gate insulating layer for each transistor. Insulating layer 215 is provided covering the transistors. Insulating layer 214 is provided covering the transistors and functions as a planarization layer. The number of gate insulating layers and insulating layers covering the transistors are not limited and can be a single layer or two or more layers, respectively.

[0550] It is preferable to use a material that does not easily allow impurities such as water and hydrogen to diffuse into at least one layer of the insulating layer covering the transistor. This allows the insulating layer to function as a barrier layer. With such a configuration, the diffusion of impurities from the outside into the transistor can be effectively suppressed, thereby improving the reliability of the display device.

[0551] It is preferable to use inorganic insulating layers as insulating layers 211, 213, and 215, respectively. Examples of inorganic insulating layers that can be used include silicon nitride film, silicon oxynitride film, silicon oxide film, silicon nitride oxide film, aluminum oxide film, aluminum nitride film, etc. Alternatively, hafnium oxide film, yttrium oxide film, zirconium oxide film, gallium oxide film, tantalum oxide film, magnesium oxide film, lanthanum oxide film, cerium oxide film, and neodymium oxide film can be used. Furthermore, two or more of the above insulating films can be laminated and used.

[0552] An organic insulating layer is preferred for the insulating layer 214, which functions as a planarizing layer. For materials that can be used for the organic insulating layer, please refer to the above description. Alternatively, the insulating layer 214 can be a laminated structure of an organic insulating layer and an inorganic insulating layer. The outermost layer of the insulating layer 214 preferably functions as an etching protection layer. This suppresses the formation of recesses in the insulating layer 214 when forming the conductive layer 105R, pixel electrode 111R, or conductive layer 135R. Alternatively, recesses may be provided in the insulating layer 214 when processing the conductive layer 105R, pixel electrode 111R, or conductive layer 135R.

[0553] A material with low light transmittance can be used for one or more layers above the transistor, particularly above the semiconductor layer of the transistor. For example, by having a light-shielding layer in the insulating layer 214, it is possible to suppress the incidence of ambient light and light emitted from light-emitting devices onto the transistors of the display device. This suppresses fluctuations in the electrical characteristics of the transistors due to light, resulting in a highly reliable display device. For materials with low light transmittance, refer to the description relating to the insulating layer 109.

[0554] Transistors 201 and 205 have a conductive layer 221 that functions as a gate, an insulating layer 211 that functions as a gate insulating layer, conductive layers 222a and 222b that function as source and drain, a semiconductor layer 231, an insulating layer 213 that functions as a gate insulating layer, and a conductive layer 223 that functions as a gate. Here, the same hatching pattern is applied to multiple layers obtained by processing the same conductive film. The insulating layer 211 is located between the conductive layer 221 and the semiconductor layer 231. The insulating layer 213 is located between the conductive layer 223 and the semiconductor layer 231.

[0555] The transistor structure of the display device of this embodiment is not particularly limited. For example, planar transistors, staggered transistors, inverse staggered transistors, etc., can be used. Furthermore, either a top-gate or bottom-gate transistor structure may be used. Alternatively, gates may be provided above and below the semiconductor layer in which the channel is formed.

[0556] Transistors 201 and 205 employ a configuration in which a semiconductor layer on which a channel is formed is sandwiched between two gates. The transistors can be driven by connecting the two gates and supplying them with the same signal. Alternatively, the threshold voltage of the transistors can be controlled by applying a potential to control the threshold voltage to one of the two gates and a potential to drive the other gate.

[0557] The display device may also use transistors with different structures. The transistors in circuit 164 and the transistors in display unit 162 may have the same structure or different structures. The structures of the multiple transistors in circuit 164 may all be the same or there may be two or more different structures. Similarly, the structures of the multiple transistors in display unit 162 may all be the same or there may be two or more different structures.

[0558] This section describes materials that can be used in the semiconductor layer of a transistor.

[0559] The semiconductor material is not particularly limited. For example, semiconductors made of elemental materials or compound semiconductors can be used. Examples of semiconductors made of elemental materials include silicon and germanium. Examples of compound semiconductors include gallium arsenide and silicon germanium. Other examples of compound semiconductors include organic semiconductors, nitride semiconductors, and oxide semiconductors (OS). These semiconductor materials may contain impurities as dopants.

[0560] The crystallinity of the semiconductor material is not particularly limited, 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) can be used. Using a single-crystal semiconductor or a semiconductor having crystalline properties is preferable because it can suppress the degradation of transistor characteristics.

[0561] The semiconductor layer can be made of, for example, silicon. Examples of silicon include single-crystal silicon, polycrystalline silicon, microcrystalline silicon, and amorphous silicon. An example of polycrystalline silicon is low-temperature polysilicon (LTPS). Transistors using amorphous silicon for the channel formation region can be formed on large glass substrates and can be manufactured at low cost. Transistors using polycrystalline silicon for the channel formation region have high field-effect mobility and can operate at high speeds. Transistors using microcrystalline silicon for the channel formation region have higher field-effect mobility than transistors using amorphous silicon and can operate at high speeds. Note that transistors using silicon for the channel formation region are sometimes referred to as Si transistors, and transistors using LTPS for the channel formation region are sometimes referred to as LTPS transistors.

[0562] It is preferable to use a metal oxide (hereinafter also referred to as an oxide semiconductor) that exhibits semiconductor properties for the semiconductor layer. Transistors using oxide semiconductors (hereinafter also referred to as OS transistors) have extremely high field-effect mobility compared to transistors using amorphous silicon. Furthermore, OS transistors have a remarkably low off-current and can retain the charge stored in a capacitor connected in series with the transistor for a long period of time. In addition, by applying OS transistors, the power consumption of the display device can be reduced. When a metal oxide is used for the semiconductor layer, the semiconductor layer can be called a metal oxide layer or a metal oxide film.

[0563] To increase the luminescence brightness of a light-emitting device included in a pixel circuit, it is necessary to increase the amount of current flowing through the light-emitting device. To achieve this, the source-drain voltage of the drive transistor included in the pixel circuit must be increased. Compared to Si transistors, OS transistors have a higher breakdown voltage between their source and drain, allowing a higher voltage to be applied to the source-drain of an OS transistor. Therefore, by using an OS transistor as the drive transistor in the pixel circuit, the amount of current flowing through the light-emitting device can be increased, thereby increasing the luminescence brightness of the light-emitting device.

[0564] When a transistor operates in the saturation region, an OS transistor exhibits a smaller change in source-drain current in response to a change in gate-source voltage than a Si transistor. Therefore, by using an OS transistor as the driving transistor in a pixel circuit, the current flowing between the source and drain can be precisely controlled by the change in gate-source voltage, thereby controlling the amount of current flowing to the light-emitting device. This allows for an increase in the number of grayscale levels in the pixel circuit.

[0565] In terms of the saturation of the current flowing when a transistor operates in the saturation region, OS transistors can supply a more stable current (saturation current) than Si transistors, even when the source-drain voltage gradually increases. Therefore, by using OS transistors as driving transistors, a stable current can be supplied to the light-emitting device even if there are variations in the current-voltage characteristics of the EL device. In other words, when operating in the saturation region, OS transistors can stabilize the luminescence brightness of the light-emitting device because the change in source-drain current is small even when the source-drain voltage is high.

[0566] As described above, by using OS transistors in the drive transistors included in the pixel circuit, it is possible to achieve "suppression of black level floating," "increase in luminescence brightness," "multi-gradation," and "suppression of variations in light-emitting devices."

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

[0568] For example, by using both an LTPS transistor and an OS transistor in the display unit 162, a display device with low power consumption and high driving capability can be realized. Furthermore, a configuration combining an LTPS transistor and an OS transistor is sometimes referred to as LTPO. As a more preferable example, it is preferable to apply an OS transistor to a transistor that functions as a switch for controlling conduction and non-conduction between wires, and an LTPS transistor to a transistor that controls current.

[0569] For example, one of the transistors in the display unit 162 functions as a transistor for controlling the current flowing to the light-emitting device, and can also be called a drive transistor. One of the source and drain of the drive transistor is connected to the pixel electrode of the light-emitting device. It is preferable to use an LTPS transistor for the drive transistor. This makes it possible to increase the current flowing to the light-emitting device in the pixel circuit.

[0570] On the other hand, the other transistor in the display unit 162 functions as a switch for controlling the selection and deselection of pixels, and can also be called a selection transistor. The gate of the selection transistor is connected to the gate line, and one of the source and drain is connected to the source line (signal line). It is preferable to use an OS transistor for the selection transistor. This makes it possible to maintain the gradation of pixels even when the frame frequency is significantly low (for example, 1 fps or less), and thus power consumption can be reduced by stopping the driver when displaying a still image.

[0571] Thus, a display device according to one aspect of the present invention can combine a high aperture ratio, high resolution, high display quality, and low power consumption.

[0572] One embodiment of the present invention is a display device having an OS transistor and an MML (metal maskless) structured light-emitting device. This configuration makes it possible to extremely reduce the leakage current that can flow through the transistor and the leakage current that can flow between adjacent light-emitting devices (also called lateral leakage current or side leakage current). Furthermore, with this configuration, when an image is displayed on the display device, the observer can observe one or more of the following: image sharpness, image clarity, high saturation, and high contrast ratio. Moreover, by having an extremely low leakage current that can flow through the transistor and lateral leakage current between light-emitting devices, it is possible to achieve a display with minimal light leakage (so-called black level floating) that may occur when displaying black.

[0573] In particular, even among MML-structured light-emitting devices, applying the aforementioned SBS structure results in a configuration where the layers between light-emitting devices (for example, an organic layer used in common between light-emitting devices, also called a common layer) are separated, thus eliminating or significantly reducing side leakage. Furthermore, since the SBS structure allows for the optimization of materials and configurations for each light-emitting element, the range of material and configuration selection is broadened, making it easier to improve brightness and reliability.

[0574] This section describes metal oxides that can be used in semiconductor layers.

[0575] The metal oxide used in the semiconductor layer preferably contains indium. For example, indium oxide can be suitably used as the metal oxide. Alternatively, for example, gallium oxide or zinc oxide can be used as the metal oxide. Alternatively, the metal oxide preferably contains one or both of indium and zinc. Alternatively, the metal oxide preferably has one or more elements selected from indium, element M, and zinc. Element M is a metal element or metalloid with a high bond energy with oxygen, for example, a metal element or metalloid with a higher bond energy with oxygen than indium. Specific examples of element M include aluminum, gallium, tin, yttrium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, zirconium, molybdenum, hafnium, tantalum, tungsten, lanthanum, cerium, neodymium, magnesium, calcium, strontium, barium, boron, silicon, germanium, and antimony. The element M present in the metal oxide is preferably one or more of the above elements, more preferably one or more selected from gallium, aluminum, tin, and yttrium, and even more preferably one or more of gallium, aluminum, and tin. These elements are more preferred because they have high bonding energy with oxygen and their ionic radii are similar to those of indium or zinc. Furthermore, tin is more preferred because its tetravalent state can increase carrier mobility. In this specification, metallic elements and metalloid elements are sometimes collectively referred to as "metallic elements," and the "metallic elements" described in this specification may include metalloid elements.

[0576] Examples of metal oxides include In-Zn oxide, ITO, indium titanium oxide (In-Ti oxide), indium gallium oxide (In-Ga oxide), indium tungsten oxide (In-W oxide, also written as IWO), indium gallium aluminum oxide (In-Ga-Al oxide), indium gallium tin oxide (In-Ga-Sn oxide, also written as IGTO), gallium zinc oxide (Ga-Zn oxide, also written as GZO), and aluminum zinc oxide (Al- Other suitable materials include Zn oxide (also written as AZO), indium aluminum zinc oxide (In-Al-Zn oxide, also written as IAZO), In-Sn-Zn oxide, indium titanium zinc oxide (In-Ti-Zn oxide), IGZO, indium gallium tin zinc oxide (In-Ga-Sn-Zn oxide, also written as IGZTO), and indium gallium aluminum zinc oxide (In-Ga-Al-Zn oxide, also written as IGAZO, IGZAO, or IAGZO). Alternatively, ITSO, gallium tin oxide (Ga-Sn oxide), aluminum tin oxide (Al-Sn oxide), etc., can be used.

[0577] Furthermore, the metal oxide can be composed of one or more metal elements with high periodic numbers in the periodic table, either in place of indium or in addition to indium. The greater the overlap of the metal element orbitals, the greater the carrier conduction in the metal oxide tends to be. Therefore, by including metal elements with high periodic numbers, the field-effect mobility of the transistor can be increased. Examples of metal elements with high periodic numbers include those belonging to the 5th period and those belonging to the 6th period. Specifically, these metal elements include yttrium, zirconium, silver, cadmium, tin, antimony, barium, lead, bismuth, lanthanum, cerium, praseodymium, neodymium, promethium, samarium, and europium. Lanthanum, cerium, praseodymium, neodymium, promethium, samarium, and europium are called light rare earth elements.

[0578] Metal oxides may contain one or more nonmetallic elements. The presence of nonmetallic elements in metal oxides can increase carrier concentration or reduce the band gap, potentially improving the field-effect mobility of transistors. Examples of nonmetallic elements include carbon, nitrogen, phosphorus, sulfur, selenium, fluorine, chlorine, bromine, and hydrogen.

[0579] By increasing the ratio of indium atoms to the sum of all metal element atoms in the metal oxide, the field-effect mobility of the transistor can be increased. Furthermore, this allows for a transistor with a high on-current, resulting in a transistor that operates at high speed.

[0580] In this specification, the ratio of the number of indium atoms to the sum of the total number of atoms of all contained metal elements may be referred to as the indium content. The same applies to other metal elements. If element M contains multiple elements, the sum of the ratios of the number of atoms of element M to the sum of the total number of atoms of all contained metal elements may be referred to as the element M content.

[0581] Transistors using metal oxides with a high indium content in their semiconductor layer have high field-effect mobility, allowing them to achieve a large on-current even with a small channel width. Therefore, the transistor's footprint can be reduced. By using metal oxides with a high indium content in the semiconductor layer of the pixel circuit, the footprint of the pixel circuit can be reduced, enabling a high-resolution display device. Furthermore, by using metal oxides with a high indium content in the semiconductor layer of the drive circuit (scan line drive circuit and signal line drive circuit), the footprint of the drive circuit can be reduced, enabling a narrow-bezel display device.

[0582] By increasing the zinc content in a metal oxide, a highly crystalline metal oxide is obtained, which suppresses the diffusion of impurities within the metal oxide. Therefore, fluctuations in the electrical characteristics of the transistor are suppressed, and its reliability can be improved.

[0583] By increasing the content of element M in the metal oxide, a metal oxide with a large band gap can be produced. This allows for the formation of oxygen vacancies (V) in the metal oxide. Ｏ The formation of oxygen deficiency (V) is suppressed, and oxygen deficiency (V) is inhibited. Ｏ Carrier generation caused by ) is suppressed. Therefore, the shift in the transistor's threshold voltage is suppressed, and the drain current (hereinafter also referred to as the cutoff current) that flows when the gate voltage (Vg) is 0V can be reduced, making it possible to create a normally-off transistor. In addition, it is possible to create a transistor with a small off current. Furthermore, fluctuations in the transistor's electrical characteristics are suppressed, and reliability can be improved.

[0584] By using a metal oxide with a large band gap in the semiconductor layer, oxygen vacancies (V) can be created in the semiconductor layer by light. Ｏ The formation of ) is suppressed, and the shift in the transistor's threshold voltage can be suppressed. Therefore, a transistor with high reliability against light can be made. A metal oxide having element M can be suitably used in the semiconductor layer of a transistor provided in a region where light can be incident (for example, a display unit).

[0585] Here, in metal oxides, oxygen deficiency (V Ｏ A defect in which hydrogen has entered (hereinafter referred to as V Ｏ The H (denoted as H) functions as a donor, and electrons, which are carriers, may be generated. When a metal oxide is used in the semiconductor layer, the V of the channel formation region Ｏ It is preferable to reduce H as much as possible and make it high-purity intrinsic or substantially high-purity intrinsic. In this way, V Ｏ To obtain a metal oxide with sufficiently reduced H content, impurities such as water and hydrogen must be removed from the metal oxide (sometimes referred to as dehydration and dehydrogenation treatment), and oxygen must be supplied to the metal oxide to eliminate oxygen deficiency (V). Ｏ It is important to repair ). Ｏ By using a metal oxide with sufficiently reduced impurities such as H in the channel formation region, a transistor with stable electrical characteristics can be produced.

[0586] It is preferable to use a crystalline metal oxide for the semiconductor layer. Examples of crystalline metal oxide structures include single-crystal structures, polycrystalline structures, CAAC (c-axis aligned crystal) structures, and microcrystalline (nc: nano-crystal) structures. By using a crystalline metal oxide, the defect level density in the semiconductor layer can be reduced, enabling the realization of a highly reliable transistor. On the other hand, by using a metal oxide with low crystallinity, it is possible to realize a transistor that can carry a large current.

[0587] The semiconductor layer preferably has high crystallinity, and is preferably polycrystalline or monocrystalline. A polycrystalline indium oxide film is preferably used as the semiconductor layer, and a monocrystalline indium oxide film is more preferably used.

[0588] The crystallinity of a semiconductor layer can be analyzed, for example, by X-ray diffraction (XRD), transmission electron microscopy (TEM), or electron diffraction (ED). Alternatively, a combination of these methods can be used for analysis.

[0589] Single-crystal films are particularly preferred because they do not have grain boundaries, thus suppressing carrier scattering at grain boundaries and enabling transistors with high field-effect mobility. Compared to microcrystalline and amorphous films, polycrystalline films can reduce carrier scattering and enable transistors with high field-effect mobility. When using a polycrystalline film as the semiconductor layer, it is preferable that the grain size of the crystals contained in the semiconductor layer is large. By using a polycrystalline film with large grain size, the number of crystal grain boundaries located in the channel formation region can be reduced, and the length of the crystal grain boundaries located in the channel formation region can be shortened, thus enabling transistors with high field-effect mobility. Furthermore, it is preferable to have a small number of crystal grain boundaries that intersect with the direction of drain current flow (also known as the channel length direction) in the channel formation region. Note that even with a polycrystalline film, if there are no crystal grain boundaries located in the channel formation region, the same effects as a single-crystal film can be achieved.

[0590] The grain size and grain boundaries of the crystal grains contained in the semiconductor layer can be analyzed, for example, by TEM, scanning transmission electron microscopy (STEM), or electron backscatter diffraction (EBSD or EBSP). Alternatively, a combination of these methods can be used for analysis.

[0591] In this specification, a grain boundary refers to, for example, the boundary between adjacent grains with different crystal orientations. Therefore, in this specification, boundaries between adjacent grains with the same crystal orientation are not included in grain boundaries. For example, even if a boundary is observed between two grains in a TEM image, if the crystal orientations of those two grains are the same or nearly the same, the boundary may not be called a grain boundary. Also, in EBSD, if the difference in crystal orientation between adjacent measurement points is small (for example, if the difference in crystal orientation is less than 5 degrees), these measurement points can be considered to belong to the same grain.

[0592] Furthermore, when the semiconductor layer is thin, it may be difficult to evaluate its crystallinity and grain size.

[0593] It is preferable to use CAAC-OS or nc-OS for the semiconductor layer.

[0594] CAAC-OS has multiple layered crystals. The c-axis of these crystals is oriented in the direction normal to the surface to be formed. Preferably, the semiconductor layer has layered crystals that are parallel or approximately parallel to the surface to be formed. As a result, the layered crystals of the semiconductor layer are formed parallel or approximately parallel to the channel length direction of the transistor, making it possible to create a transistor with a large on-current.

[0595] By using a highly crystalline metal oxide in the semiconductor layer, the defect level density in the semiconductor layer can be reduced. On the other hand, by using a less crystalline metal oxide, it is possible to realize a transistor that can conduct large currents.

[0596] The semiconductor layer can also utilize a layered material that functions as a semiconductor. A layered material is a general term for a group of materials having a layered crystalline structure. Layered materials have high electrical conductivity within a single layer, i.e., high two-dimensional electrical conductivity. By using a material that functions as a semiconductor and has high two-dimensional electrical conductivity in the channel formation region, a transistor with a large on-current can be provided.

[0597] Examples of the above-mentioned layered materials include graphene, silicene, and chalcogenides. Chalcogenides are compounds containing chalcogens (elements belonging to Group 16). Examples of chalcogenides include transition metal chalcogenides and Group 13 chalcogenides. Specifically, a transition metal chalcogenide applicable as a channel formation region in transistors is molybdenum sulfide (typically MoS ２ ), molybdenum selenide (typically MoSe ２ ), molybdenum tellurium (typically MoTe ２ ), tungsten sulfide (typically WS ２ ), tungsten selenide (typically WSe ２ ), tungsten tellurium (typically WTe ２), hafnium sulfide (typically HfS ２ ), hafnium selenide (typically HfSe ２ ), zirconium sulfide (typically ZrS ２ ), zirconium selenide (typically ZrSe ２ ) are some examples.

[0598] Figures 37B to 37D show other examples of transistor configurations.

[0599] Transistors 209 and 210 each have a conductive layer 221 that functions as a gate, an insulating layer 211 that functions as a gate insulating layer, a semiconductor layer 231 having a channel forming region 231i and a pair of low-resistance regions 231n, a conductive layer 222a connected to one of the pair of low-resistance regions 231n, a conductive layer 222b connected to the other of the pair of low-resistance regions 231n, an insulating layer 225 that functions as a gate insulating layer, a conductive layer 223 that functions as a gate, and an insulating layer 215 covering the conductive layer 223. The insulating layer 211 is located between the conductive layer 221 and the channel forming region 231i. The insulating layer 225 is located at least between the conductive layer 223 and the channel forming region 231i. Furthermore, an insulating layer 218 covering the transistor may be provided.

[0600] In the transistor 209 shown in Figure 37B, an example is shown in which the insulating layer 225 covers the top and side surfaces of the semiconductor layer 231. The conductive layers 222a and 222b are in contact with and connected to the low-resistance region 231n at openings provided in the insulating layer 225 and insulating layer 215, respectively. Of the conductive layers 222a and 222b, one functions as a source and the other functions as a drain.

[0601] In the transistor 210 shown in Figure 37C, the insulating layer 225 overlaps with the channel formation region 231i of the semiconductor layer 231, but does not overlap with the low-resistance region 231n. For example, the structure shown in Figure 37C can be fabricated by processing the insulating layer 225 using the conductive layer 223 as a mask. An insulating layer 215 is provided covering the insulating layer 225 and the conductive layer 223, and at the opening of the insulating layer 215, the conductive layer 222a and the conductive layer 222b are in contact with the low-resistance region 231n, thus connecting the conductive layer 222a and the conductive layer 222b with the low-resistance region 231n.

[0602] In the transistor 210 shown in Figure 37D, the semiconductor layer 231 has a region 231m that does not overlap with the conductive layer 223 but overlaps with the insulating layer 225. The insulating layer 225 has a region that protrudes beyond the edge of the conductive layer 223. In the transistor 210, region 231m functions as an LDD (Lightly Doped Drain) region. By providing an LDD region, a transistor with a high drain breakdown voltage can be made.

[0603] It is preferable to provide a light-shielding layer 117 on the surface of the substrate 152 that faces the substrate 151. The light-shielding layer 117 can be provided between adjacent light-emitting devices, at connection points 140, and in circuits 164, etc. In addition, various optical components can be arranged on the outside of the substrate 152.

[0604] Substrates 151 and 152 can each be made of materials that can be used for substrate 120.

[0605] The adhesive layer 142 can be made of a material that can be used for the resin layer 122.

[0606] The connecting layer 242 can be made of an anisotropic conductive film (ACF), an anisotropic conductive paste (ACP), or the like.

[0607] Figure 38A shows an example of a transistor configuration different from those shown in Figures 37A to 37D.

[0608] The transistors 201V and 205V shown in Figure 38A have a conductive layer 221 that functions as a gate, an insulating layer 211 that functions as a gate insulating layer, a semiconductor layer 231, a conductive layer 222a, and a conductive layer 222b. The conductive layer 222a functions as one of the source and drain, and the conductive layer 222b functions as the other of the source and drain.

[0609] An insulating layer 160 is provided on the conductive layer 222a, and a conductive layer 222b is provided on the insulating layer 160. The conductive layer 222b and the insulating layer 160 have openings that reach the conductive layer 222a. The semiconductor layer 231 is provided so as to cover the openings and is in contact with the conductive layer 222a at the openings. The semiconductor layer 231 is also in contact with the side surfaces of the insulating layer 160 and the conductive layer 222b. Preferably, the semiconductor layer 231 is in contact not only with the side surfaces of the conductive layer 222b but also with the upper surface of the conductive layer 222b. The region of the semiconductor layer 231 in contac...

Claims

1. A display device comprising a first light-emitting device, a second light-emitting device, and an insulating layer, wherein the first light-emitting device comprises a first pixel electrode, a first conductive layer on the first pixel electrode, a first EL layer on the first conductive layer, and a common electrode on the first EL layer, and the second light-emitting device comprises a second pixel electrode, a second conductive layer on the second pixel electrode, a second EL layer on the second conductive layer, and the common electrode on the second EL layer, wherein the insulating layer is located between the first pixel electrode and the second pixel electrode, the end of the first conductive layer overlaps with the insulating layer, the end of the second conductive layer overlaps with the insulating layer, the end of the first EL layer overlaps with the first conductive layer, and the end of the second EL layer overlaps with the second conductive layer.

2. The display device according to claim 1, wherein the first conductive layer and the second conductive layer are separated on the insulating layer.

3. A display device according to claim 1, wherein the first conductive layer and the second conductive layer each have a metal oxide.

4. A display device according to any one of claims 1 to 3, wherein the height of the upper surface of the first pixel electrode is greater than the height of the upper surface of the insulating layer, and the height of the upper surface of the second pixel electrode is greater than the height of the upper surface of the insulating layer.

5. A display device according to any one of claims 1 to 3, wherein the insulating layer is made of resin.

6. A display device according to any one of claims 1 to 3, comprising a third conductive layer, a fourth conductive layer, a first layer, and a second layer, wherein the first layer is located on the third conductive layer, the first pixel electrode is in contact with the upper surface and side surface of the first layer and the upper surface of the third conductive layer, and the second layer is located on the second conductive layer, the second pixel electrode is in contact with the upper surface and side surface of the second layer and the upper surface of the fourth conductive layer.

7. The display device according to claim 6, wherein the insulating layer has a region facing the side surface of the first layer via the first pixel electrode, and the insulating layer has a region facing the side surface of the second layer via the second pixel electrode.

8. The display device according to claim 6, wherein the first layer and the second layer each have a resin.

9. A method for manufacturing a display device, comprising: forming a first pixel electrode and a second pixel electrode; forming an insulating layer between the first pixel electrode and the second pixel electrode; depositing a conductive film on the first pixel electrode, the second pixel electrode and the insulating layer; processing the conductive film to form a first conductive layer in contact with the upper surface of the first pixel electrode and a second conductive layer in contact with the upper surface of the second pixel electrode; depositing a first film on the first conductive layer, the second conductive layer and the insulating layer; processing the first film to form a first EL layer in contact with the upper surface of the first conductive layer; depositing a second film on the first EL layer, the second conductive layer and the insulating layer; and processing the second film to form a second EL layer in contact with the upper surface of the second conductive layer.

10. A method for manufacturing a display device, wherein the first conductive layer and the second conductive layer each have a metal oxide, according to claim 9.

11. A method for manufacturing a display device, wherein the insulating layer is made of resin, according to claim 9 or claim 10.

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