Display device

Abstract

Provided is a highly reliable display device. Provided is a display device with high contrast. Provided is a display device with high visibility. Provided is a display device with high brightness. Provided is a high-definition display device. Provided is a high-resolution display device. The display device has a first insulating layer above a first conductive layer, and has a second conductive layer on and in contact with the first insulating layer. An upper surface and a lateral surface of the second conductive layer are covered by a first electrode of a first light-emitting device. The second conductive layer is electrically connected to the first conductive layer via the first insulating layer. The first insulating layer and the second conductive layer have the same lateral surface, and the first electrode of the first light-emitting device covers the same lateral surface.

Description

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 highly reliable display device. 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 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 novel display device.

[0010] One aspect of the present invention aims to provide a method for manufacturing a display device with a high yield. Furthermore, it aims to provide a display device with high resolution manufactured by applying this manufacturing method.

[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] (1) One aspect of the present invention is a display device having a first insulating layer on a first conductive layer, a second conductive layer in contact with the upper surface of the first insulating layer, a first electrode of a first light-emitting device covering the upper and side surfaces of the second conductive layer, the second conductive layer being electrically connected to the first conductive layer, the first insulating layer and the second conductive layer having a first side surface having the same surface, and the first electrode covering the first side surface.

[0013] (2) Or, a display device having a first insulating layer on a first conductive layer and a third conductive layer, a second conductive layer and a fourth conductive layer in contact with the first insulating layer, a first electrode of a first light-emitting device covering the top and side surfaces of the second conductive layer, the second conductive layer being electrically connected to the first conductive layer via the first insulating layer, a first electrode of a second light-emitting device covering the top and side surfaces of the fourth conductive layer, the fourth conductive layer being electrically connected to the third conductive layer via the first insulating layer, the first insulating layer and the second conductive layer having a first side surface having the same surface, the first insulating layer and the fourth conductive layer having a second side surface having the same surface, the first electrode of the first light-emitting device covering the first side surface, the first electrode of the second light-emitting device covering the second side surface, and the first insulating layer having a trench between the first light-emitting device and the second light-emitting device.

[0014] (3) In addition, in (2) above, it is preferable that the width of the trench in the first insulating layer is wider than the distance between the side surface of the second conductive layer and the side surface of the fourth conductive layer.

[0015] (4) In addition, in (2) above, it is preferable that the first insulating layer has a trench between the first light-emitting device and the second light-emitting device that is deeper than the thickness of the first electrode.

[0016] (5) In addition, in (2) above, it is preferable that the bottom surface of the trench is located between the upper surfaces of the first conductive layer and the third conductive layer and the lower ends of the first electrodes of the first light-emitting device and the second light-emitting device.

[0017] (6) In addition, in (2) or (5) above, it is preferable that the trench has a second insulating layer, and the second insulating layer is in contact with the side surface of the first electrode of the first light-emitting device, the side surface of the first electrode of the second light-emitting device, the side surface of the first insulating layer, and the bottom surface of the first insulating layer.

[0018] (7) In addition, in (6) above, it is preferable that a third insulating layer is provided on a part of the first electrode of the first light-emitting device, a part of the first electrode of the second light-emitting device, and the second insulating layer.

[0019] (8) In addition, it is preferable that the second insulating layer, the second conductive layer, and the first electrode of the first light-emitting device overlap in the region described in (6) above.

[0020] (9) In addition, in (2) above, it is preferable that the first electrode of the first light-emitting device includes one or more selected from silver, a silver-magnesium alloy, and an Ag-Pd-Cu alloy.

[0021] (10) In addition, in (2) above, it is preferable that the first electrode of the first light-emitting device includes one or more selected from silver, palladium, and copper, and one or more selected from indium, zinc, tin, tungsten, titanium, silicon, gallium, and oxygen.

[0022] (11) In addition, in (10) above, the first electrode of the first light-emitting device has a structure in which a first layer, a second layer, and a third layer are stacked in order, and the first layer and the third layer preferably contain one or more selected from indium, zinc, tin, tungsten, titanium, silicon, and gallium oxides, and the second layer preferably contains one or more selected from silver, palladium, and copper.

[0023] (12) In addition, in (2) above, it is preferable that the second conductive layer contains one or more selected from aluminum, chromium, tantalum, titanium, molybdenum, and tungsten.

[0024] (13) Or, having a first insulating layer on a first conductive layer and a third conductive layer, a second conductive layer and a fourth conductive layer in contact with the first insulating layer, having a first electrode of the first light-emitting device covering the top and side surfaces of the second conductive layer, the second conductive layer being electrically connected to the first conductive layer via the first insulating layer, and having a first electrode of the second light-emitting device covering the top and side surfaces of the fourth conductive layer, the fourth conductive layer is the first A display device in which a third conductive layer is electrically connected to a first conductive layer via an insulating layer, the second conductive layer has a first bottom surface, the fourth conductive layer has a second bottom surface, the first insulating layer has a trench between the first and second light-emitting devices, the second insulating layer has a trench, and the second insulating layer is in contact with the first insulating layer, the first electrode of the first light-emitting device, the first electrode of the second light-emitting device, the first bottom surface, and the second bottom surface.

[0025] 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 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 display device with high detail can be provided. According to one aspect of the present invention, a display device with high resolution can be provided. According to one aspect of the present invention, a novel display device can be provided.

[0026] According to one aspect of the present invention, a method for manufacturing a display device with a high yield can be provided. Furthermore, a display device with high resolution can be provided by applying this manufacturing method.

[0027] 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.

[0028] Figure 1A is a plan view showing an example of a display device. Figure 1B is a cross-sectional view showing an example of a display device. Figure 2A is a cross-sectional view showing an example of a display device. Figures 2B, 2C, and 2D are plan views showing an example of a display device. Figures 3A and 3B are cross-sectional views showing an example of a display device. Figure 4 is a cross-sectional view showing an example of a display device. Figures 5A, 5B, and 5C are cross-sectional views showing an example of a display device. Figures 6A, 6B, and 6C are cross-sectional views showing an example of a display device. Figures 7A and 7B 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 and 11B 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. Figure 13 is a cross-sectional view 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 16 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 display device. Figures 18A and 18B are cross-sectional views showing an example of 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, 21B, and 21C 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, 23B, and 23C are cross-sectional views showing an example of a method for manufacturing a display device. Figures 24A, 24B, and 24C are cross-sectional views showing an example of a method for manufacturing a display device. Figures 25A, 25B, and 25C are cross-sectional views showing an example of a method for manufacturing a display device. Figures 26A, 26B, and 26C 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, 28B, 28C, 28D, 28E, 28F, and 28G are diagrams showing an example of a pixel.Figures 29A, 29B, 29C, 29D, 29E, 29F, 29G, 29H, 29I, 29J, and 29K are diagrams showing examples of pixels. Figure 30A is a plan view showing an example of a transistor. Figures 30B, 30C, and 30D are cross-sectional views showing an example of a transistor. Figure 31 is a cross-sectional view showing an example of a transistor. Figure 32 is a cross-sectional view showing an example of a transistor. Figures 33A and 33B are cross-sectional views showing an example of a transistor. Figure 34A is a cross-sectional view showing an example of a transistor. Figures 34B and 34C are perspective views showing an example of a transistor. Figures 35A and 35B are perspective views showing an example of a display device. Figure 36 is a cross-sectional view showing an example of a display device. Figure 37 is a cross-sectional view showing an example of a display device. Figure 38 is a cross-sectional view showing an example of a display device. 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. Figure 41 is a cross-sectional view showing an example of a display device. Figure 42 is a cross-sectional view showing an example of a display device. Figures 43A and 43B illustrate the carrier concentration dependence of Hall mobility. Figure 43C is a cross-sectional view illustrating an indium oxide film. Figures 44A, 44B, 44C, 44D, 44E, and 44F show examples of light-emitting device configurations. Figures 45A and 45B show examples of light-receiving device configurations. Figures 45C, 45D, and 45E show examples of display device configurations. Figures 46A, 46B, 46C, 46D, and 46E show examples of electronic equipment. Figures 47A, 47B, 47C, and 47D show examples of electronic equipment. Figures 48A, 48B, 48C, 48D, 48E, and 48F show examples of electronic equipment. Figures 49A, 49B, 49C, 49D, 49E, 49F, and 49G show examples of electronic equipment.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] In this specification, the ordinal numbers "first," "second," etc., are used for convenience only and do not limit the number of components or the order of components (for example, process order or stacking order). Furthermore, the ordinal numbers used for components in one part of this specification may not be the same as those used for the same components in other parts of this specification or in the claims.

[0033] 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.

[0034] 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."

[0035] 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).

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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."

[0040] 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."

[0041] 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.

[0042] In this specification, unless otherwise specified, on-current refers to the drain current (also written as Id) when the transistor is in the ON state (also called the conducting state). Unless otherwise specified, the ON state refers to the state in an n-channel transistor where the voltage between the gate and source (also written as Vg) is equal to or greater than the threshold voltage (also written as Vth), and in a p-channel transistor where it is less than or equal to the threshold voltage.

[0043] 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.

[0044] 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.

[0045] 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."

[0046] In this specification, the top surface shape of a component refers to the contour shape of that component in a plan view. A plan view refers to a view 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.

[0047] In the following, expressions indicating direction, such as "up" and "down," will generally be used in accordance with the orientation shown in the drawings. However, for the purpose of simplifying explanations, the direction referred to by "up" or "down" in the specification may not coincide with that of the drawings. For example, when explaining the stacking order (or formation order) of a laminate, even if the side on which the laminate is provided (the surface to be formed, the support surface, the adhesive surface, the flat surface, etc.) is located above the laminate in the drawing, it may be expressed as the surface to be formed being below, or the laminate being above.

[0048] 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. For example, a shape is called a forward tapered shape when the angle between the inclined side surface and the substrate surface or the surface to be formed (hereinafter sometimes referred to as the tapered angle) is less than 90 degrees, and a shape is called a reverse tapered shape when it exceeds 90 degrees.

[0049] 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).

[0050] In this specification, devices manufactured using a metal mask or FMM (Fine Metal Mask, high-resolution metal mask) may be referred to as MM (metal mask) structured devices. Furthermore, in this specification, devices manufactured without using a metal mask or FMM may be referred to as MML (metal maskless) structured devices. Since MML structured 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. Additionally, MML structured devices eliminate the need for equipment and metal mask cleaning processes associated with metal mask manufacturing. Moreover, MML structured devices are suitable for mass production because their manufacturing costs can be kept low.

[0051] 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. Because the SBS structure allows for the optimization of materials and configurations for each light-emitting element, it broadens the range of material and configuration choices, making it easier to improve brightness and reliability.

[0052] In this specification, holes or electrons may be referred to as "carriers." Specifically, 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." It should be noted 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.

[0053] 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.

[0054] In this specification, a photodetector (also called a photodetector) has an active layer that functions as a photoelectric conversion layer between a pair of electrodes.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] Furthermore, 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 on the circuit board using a COG (Chip On Glass) method, may be referred to as a display panel module, display module, or simply a display panel.

[0059] In this specification, a touch panel, which is one form of a display device, has the function of displaying images, etc., on its display surface, and the function of a touch sensor that detects when a detectable object such as a finger or stylus touches, presses, or approaches the display surface. Therefore, a touch panel is one form of an input / output device.

[0060] A touch panel can also be called, for example, a display panel (or display device) with a touch sensor, or a display panel (or display device) with touch sensor functionality. A touch panel can also have a configuration comprising a display panel and a touch sensor panel. Alternatively, the display panel may have a touch sensor function located inside or on its surface.

[0061] Furthermore, in this specification, a touch panel circuit board on which, for example, connectors and ICs are mounted may be referred to as a touch panel module, display module, or simply a touch panel.

[0062] (Embodiment 1) This embodiment describes a display device according to one aspect of the present invention.

[0063] One aspect of the present invention is a display device having a first insulating layer, a first conductive layer, a second conductive layer, and a light-emitting device.

[0064] The light-emitting device is provided on a first layer. The first layer is, for example, a layer containing a transistor. The light-emitting device includes a first electrode, a light-emitting layer on the first electrode, and a second electrode on the light-emitting layer.

[0065] The first conductive layer is a conductive layer of the first layer. The first conductive layer functions, for example, as an electrode of a transistor, an electrode of a capacitive element, or wiring. A display device according to one aspect of the present invention has a first insulating layer on the first conductive layer, a second conductive layer in contact with the upper surface of the first insulating layer, and a first electrode of a light-emitting device covering the upper and side surfaces of the second conductive layer. The second conductive layer is electrically connected to the first conductive layer. The first insulating layer and the second conductive layer have the same side surface. The first electrode covers the same side surface of the first.

[0066] By using a highly reflective material for the first electrode of a light-emitting device, it is possible to give it the function of a reflective electrode. This can improve the light extraction efficiency of the display device, resulting in a display device with high brightness.

[0067] Alloys containing silver have high reflectivity and are suitable as materials for pixel electrodes. When using silver-containing alloys for pixel electrodes, patterns are formed by wet etching. By incorporating a structure that reduces variations in pixel electrode width due to side etching, dimensional errors during pattern formation can be minimized. Furthermore, using materials that can be processed by dry etching allows for miniaturization of wiring. However, electrolytic corrosion may occur between the pixel electrode and the conductive layer to which it connects. By positioning the pixel electrode to cover the conductive layer, electrolytic corrosion can be prevented between the pixel electrode and the conductive layer, allowing the use of highly reflective materials.

[0068] The pixel electrode pattern can be formed by etching a mask onto the conductive film that will serve as the pixel electrode. For example, by using a material that can be processed by dry etching, a fine pixel electrode pattern can be formed. On the other hand, if the material is difficult to process by dry etching, the pattern can be formed using wet etching.

[0069] When pattern formation is performed by wet etching, etching tends to proceed isotropically, which can lead to etching extending inward beyond the edges of the mask film formed on the conductive film. This results in the processing extending further inward than the desired pattern shape dimensions. Furthermore, the effect of variations in processing dimensions becomes greater as the pixel electrode pattern becomes finer. For this reason, pattern formation using wet etching has been difficult in the fabrication of high-resolution display devices.

[0070] In a method for manufacturing a display device according to one aspect of the present invention, the conductive film forming the pixel electrodes has a portion formed along the side surface of a trench provided in the insulating layer. This makes it possible to suppress variations in the electrode width of the pixel electrodes even when side etching progresses inward beyond the mask film.

[0071] Furthermore, if the pixel electrode and the conductive layer connected to the pixel electrode are made of different conductive materials, galvanic corrosion may occur between the pixel electrode and the conductive layer during processing using wet etching. For example, if a silver-containing alloy is used for the pixel electrode and aluminum is used for the conductive layer, galvanic corrosion may occur between the pixel electrode and the conductive layer. In such cases, galvanic corrosion between the pixel electrode and the conductive layer can be prevented by creating a structure in which the conductive layer in contact with the pixel electrode is not exposed on the processed surface.

[0072] In a method for manufacturing a display device according to one aspect of the present invention, a conductive layer is provided on an insulating layer, and the sides and top surface of the conductive layer are covered with pixel electrodes, thereby suppressing the effects of electrolytic corrosion during wet etching.

[0073] Furthermore, when forming conductive films that serve as pixel electrodes using the sputtering method, creating steps on the surface where the conductive film is formed allows for the formation of non-uniform film thickness. In particular, sputtering, when performed under high vacuum, can produce films with high anisotropy. As a result, in some cases, little to no film may be formed in areas that are in shadow of the surface from which the sputtered particles are flying.

[0074] In a method for manufacturing a display device according to one aspect of the present invention, by providing a region with a wider trench in the insulating layer on a part of the side surface of the insulating layer, the conductive film that will become the pixel electrode is stepped between the bottom surface of the trench in the insulating layer and the side surface of the trench in the insulating layer, thereby forming a pixel electrode pattern by self-alignment. Since the conductive layer that will form the pixel electrode and the conductive layer that is not needed for the pixel electrode are separated, there is no need to use wet etching to form the pixel electrode pattern. Therefore, there is no need to consider side etching by wet etching, variations in processing dimensions can be suppressed, and it becomes possible to form finer pixel electrode patterns.

[0075] Figure 1A shows a plan view (also called a top 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 provided on the outside of the display unit. Each pixel 110 has a plurality of subpixels. Figure 1A shows an example in which the pixel 110 has subpixels 11R, subpixels 11G, and subpixels 11B. The plurality of subpixels are arranged in a matrix on the display unit. Figure 1A shows subpixels in 2 rows and 6 columns, which together constitute a pixel 110 in 2 rows and 2 columns. The connection unit 140 can also be called a cathode contact unit.

[0076] The top surface shape of the subpixel shown in Figure 1A corresponds to the top surface shape of the light-emitting region.

[0077] 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.

[0078] 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.

[0079] 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. For example, 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.

[0080] 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. Each of the subpixels 11R, subpixel 11G, and subpixel 11B has a light-emitting device with a different emission color. For example, three subpixels of red (R), green (G), and blue (B) can be used as subpixels 11R, subpixel 11G, and subpixel 11B. Alternatively, three subpixels of yellow (Y), cyan (C), and magenta (M) can also be used. Furthermore, the number of subpixel types is not limited to three, but can be four or more. For example, four subpixels can be of four colors: R, G, B, and white (W); four subpixels of R, G, B, and Y; and four subpixels of R, G, B, and infrared (IR).

[0081] 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.

[0082] 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, and bottom sides 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.

[0083] [Configuration Example 1] Figure 1B shows a cross-sectional view between the dashed line X1 and X2 shown in Figure 1A. Figure 2A shows an enlarged view of a part of the cross-sectional view shown in Figure 1B.

[0084] In Figure 1B, the display device 100 includes light-emitting devices 130R, 130G, and 130B. Light-emitting devices 130R, 130G, and 130B are display elements of sub-pixels 11R, 11G, and 11B, respectively. 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.

[0085] The configuration shown in Figure 1B is such that layer 101 comprises a substrate 103, conductive layers 250R, 250G, 250B, and an insulating layer 191 on the substrate 103. An insulating layer 188 is provided on layer 101, and an insulating layer 192 is provided on insulating layer 188. Plugs 170R, 170G, and 170B are embedded in insulating layers 188 and 192. A conductive layer 111R is provided on insulating layer 192 and plug 170R, a conductive layer 111G is provided on insulating layer 192 and plug 170G, and a conductive layer 111B is provided on insulating layer 192 and plug 170B. A light-emitting device 130R is provided on conductive layer 111R, a light-emitting device 130G is provided on conductive layer 111G, and a light-emitting device 130 is provided on conductive layer 111B. A protective layer 128 is provided to cover the light-emitting devices 130R, 130G, and 130B. An insulating layer 122 is provided on the protective layer 128. The substrate 120 is bonded to the insulating layer 122 via an adhesive layer 129. The insulating layer 192 also has trenches (sometimes called grooves) formed along island-like shapes.

[0086] In this specification, the conductive layers 250R, 250G, and 250B may be collectively referred to as conductive layer 250. Similarly, plugs 170R, 170G, and 170B may be collectively referred to as plug 170. Furthermore, conductive layers 111R, 111G, and 111B may be collectively referred to as conductive layer 111. Additionally, light-emitting devices 130R, 130G, and 130B may be collectively referred to as light-emitting device 130. Furthermore, for other components distinguished by letters, when explaining matters common to these components, the letters may be omitted and symbols used instead.

[0087] 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 electrically connected to one or more transistors, capacitive elements, and wiring of layer 101. As shown in Figure 1B, conductive layers 250R, 250G, and 250B are provided on the substrate 103. Conductive layers 250R, 250G, and 250B correspond to the electrodes of the transistors, electrodes of the capacitive elements, or wiring, respectively. An insulating layer 188 is provided on conductive layers 250R, 250G, and 250B. In addition, an insulating layer 191 is provided between the conductive layers 250.

[0088] [Insulating Layer 192] In cross-sectional views such as Figure 1B, multiple insulating layers 192 are shown, but when the display device 100 is viewed from above, as shown in Figure 2B, the insulating layer 192 is connected as one. In other words, the display device 100 can be configured to have only one insulating layer 192. The display device 100 can also be configured to have multiple insulating layers 192 that are separated from each other. The same configuration can be applied to insulating layer 188 and insulating layer 191.

[0089] Plan views of the insulating layer 192 are shown in Figures 2B and 2C. Figure 2B is a plan view corresponding to the dashed line A1-A2 shown in Figure 2A. In a top view, the plug 170R is provided so as to be embedded in the insulating layer 192. Although not shown in Figure 2B, similarly, in a top view, the plugs 170G and 170B are provided so as to be embedded in the insulating layer 192.

[0090] It is preferable that the height of the upper surface of the insulating layer 192 in the region in contact with the conductive layer 111R matches or approximately matches the height of the upper surface of the plug 170R. Similarly, it is preferable that the height of the upper surface of the insulating layer 192 in the region in contact with the conductive layer 111G matches or approximately matches the height of the upper surface of the plug 170G. It is preferable that the height of the upper surface of the insulating layer 192 in the region in contact with the conductive layer 111B matches or approximately matches the height of the upper surface of the plug 170B. This increases the flatness of the formed surfaces of the conductive layer 111R, conductive layer 111G, and conductive layer 111B. As a result, brightness unevenness is reduced, and a display device with high display quality can be obtained.

[0091] The insulating layer 192 can be one or more of the following: an insulating layer having an inorganic material (hereinafter also referred to as an inorganic insulating layer) and an insulating layer having an organic material (hereinafter also referred to as an organic insulating layer). As the inorganic insulating layer, for example, an inorganic insulating film such as an oxide insulating film, a nitride insulating film, an oxidized nitride insulating film, and an oxidized nitride insulating film can be used. 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. Examples of materials that can be used for the organic insulating layer include acrylic resin and polyimide resin.

[0092] For forming the insulating layer 192, for example, sputtering, ALD (including thermal ALD and PEALD), chemical vapor deposition (CVD), or vacuum deposition can be used. Alternatively, a wet film formation method can be used.

[0093] When flattening the upper surface of the insulating layer 192 using the CMP (Chemichl Mechanical Polishing) method, an inorganic insulating layer can be suitably used for the insulating layer 192.

[0094] The insulating layer 192 can preferably be made of an inorganic material having silicon, for example. Preferably, the insulating layer 192 contains silicon and oxygen. For example, silicon oxide can preferably be used for the insulating layer 192.

[0095] The insulating layer 192 can be a single-layer structure or a laminated structure. When the insulating layer 192 is a laminated structure, it is preferable to have one or more inorganic insulating layers. The insulating layer 192 can also be a laminated structure of an inorganic insulating layer and an organic insulating layer. For example, the insulating layer 192 can be a laminated structure of an organic insulating layer and an inorganic insulating layer on the organic insulating layer. When the upper surface of the insulating layer 192 is made flat using the CMP method, an inorganic insulating layer can preferably be used as the uppermost layer of the insulating layer 192. The uppermost layer of the insulating layer 192 can also be an organic insulating layer.

[0096] 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.

[0097] [Plug 170] Plan views of plug 170R are shown in Figures 2B and 2C. Figure 2B is a plan view corresponding to the dashed line A1-A2 shown in Figure 2A. Figure 2C is a plan view corresponding to the dashed line A3-A4 shown in Figure 2A. As shown in Figures 1B, 2B, and 2C, plug 170R is provided so as to be embedded in the insulating layer 188 and the insulating layer 192. It is preferable that plug 170R is provided so as to be in contact with the upper surface of the conductive layer 250R. The conductive layer 111R is located on the insulating layer 192. It is preferable that the conductive layer 111R is provided so as to be in contact with plug 170R. The conductive layer 250R and the conductive layer 111R are electrically connected via plug 170R. This configuration is the same for plug 170G and plug 170B.

[0098] The plugs 170R, 170G, and 170B, which function as plugs, are preferably made of a metallic element selected from aluminum, chromium, copper, silver, gold, platinum, zinc, tantalum, nickel, titanium, iron, cobalt, molybdenum, tungsten, hafnium, vanadium, niobium, manganese, magnesium, zirconium, beryllium, indium, ruthenium, iridium, strontium, lanthanum, etc., or an alloy containing the aforementioned metallic elements, or an alloy combining the aforementioned metallic elements. As alloys containing the aforementioned metallic elements, nitrides of the alloy or oxides of the alloy can be used. For example, it is preferable to use tantalum nitride, titanium nitride, nitrides containing titanium and aluminum, nitrides containing tantalum and aluminum, ruthenium oxide, ruthenium nitride, oxides containing strontium and ruthenium, oxides containing lanthanum and nickel, etc. In addition, polycrystalline silicon containing impurity elements such as phosphorus, or silicide (e.g., nickel silicide) can also be used.

[0099] Conductive materials containing nitrogen, such as nitrides containing tantalum, nitrides containing titanium, nitrides containing molybdenum, nitrides containing tungsten, nitrides containing ruthenium, nitrides containing tantalum and aluminum, or nitrides containing titanium and aluminum; conductive materials containing oxygen, such as oxides containing ruthenium oxide, strontium and ruthenium, or oxides containing lanthanum and nickel; and materials containing metallic elements such as titanium, tantalum, or ruthenium are preferred because they are conductive materials that are resistant to oxidation, conductive materials that have the function of suppressing oxygen diffusion, or materials that maintain low electrical resistance even when absorbing oxygen. Examples of conductive materials containing oxygen include indium oxide, zinc oxide, In-Sn oxide, In-Zn oxide, In-W oxide, In-W-Zn oxide, In-Ti oxide, In-Ti-Sn oxide, and In-Sn-Si oxide (also called In-Sn oxide containing silicon).

[0100] Conductive materials primarily composed of tungsten, copper, or aluminum are preferred due to their high conductivity.

[0101] Plugs 170R, 170G, and 170B can have a single-layer or multi-layer structure. For example, a multi-layer structure can be formed by combining the aforementioned metal element material with an oxygen-containing conductive material. Alternatively, a multi-layer structure can be formed by combining the aforementioned metal element material with a nitrogen-containing conductive material. Furthermore, a multi-layer structure can be formed by combining the aforementioned metal element material with an oxygen-containing conductive material and a nitrogen-containing conductive material.

[0102] [Conductive layer 111] A plan view of the conductive layer 111R is shown in Figure 2D. Figure 2D is a plan view corresponding to the dashed line A5-A6 shown in Figure 2A. In a top view, it is preferable that the conductive layer 111R encompasses the plug 170R. Although not shown in Figure 2D, similarly, in a top view, it is preferable that the conductive layer 111G encompasses the plug 170G and the conductive layer 111B encompasses the plug 170B.

[0103] Furthermore, as shown in Figure 2D, the side surface of the conductive layer 111R is covered by the pixel electrode 199R. Although not shown in Figure 2D, similarly, the side surface of the conductive layer 111G is covered by the pixel electrode 199G, and the side surface of the conductive layer 111B is covered by the pixel electrode 199B.

[0104] Furthermore, in a top view, the top surface shape of the conductive layer 111R shown in Figure 2D is provided to roughly coincide with the top surface shape of the insulating layer 192 shown in Figure 2C. Although not shown in Figure 2C, similarly, the top surface shape of the insulating layer 192 in the plan view corresponding to the dashed lines A3-A4 and the top surfaces of the conductive layer 111G and conductive layer 111B in the plan view corresponding to the dashed lines A5-A6 are provided to roughly coincide.

[0105] Furthermore, as shown in Figure 2A, in a cross-sectional view, the conductive layer 111R and the insulating layer 192 have sides with the same surface. This is because the conductive layer 111R functions as a hard mask when processing the trench in the insulating layer 192. Although not shown in Figure 2A, similarly, the conductive layer 111G and the insulating layer 192 form sides with the same surface, and the conductive layer 111B and the insulating layer 192 form sides with the same surface.

[0106] It is preferable to process the trenches in the insulating layer 192 using dry etching. By processing under appropriate dry etching conditions, the conductive layer 111 and the insulating layer 192 can form sides having the same surface.

[0107] Furthermore, as shown in Figures 3A and 3B, depending on the dry etching conditions, the shape of the side surface of the insulating layer 192 in contact with the lower end of the conductive layer 111 can be tapered or inversely tapered. By covering both the side surface of the insulating layer 192 and the side surface of the conductive layer 111 with the pixel electrode 199, peeling of the conductive layer 111 can be further prevented, thereby improving the reliability of the display device. In addition, the manufacturing yield of the display device can be further improved.

[0108] Furthermore, as shown in Figure 4, the left and right ends of the insulating layer 192 in contact with the lower end of the conductive layer 111 can be formed to be located inward from the position of the side ends of the conductive layer 111. Because the sides of the insulating layer 192 are located inward, a region where the lower surface of the conductive layer 111 is exposed may be formed between the lower left and lower right ends of the conductive layer 111 and the sides of the insulating layer 192. In this case, the region of the bottom surface of the conductive layer 111 is a shaded region with respect to the surface from which sputtered particles fly, and pixel electrodes 199 may hardly be formed. In this case, the resist mask covers the region of the bottom surface of the conductive layer 111 where the conductive film that will become the pixel electrode 199 is not formed. This creates a structure in which wet etching progressing from the bottom surface along the sides of the insulating layer 192 is blocked by the resist mask. With this configuration, pixel electrodes 199 that are not affected by wet etching can be formed on the upper and side surfaces of the conductive layer 111. The influence of wet etching conditions on the pattern of the pixel electrode 199 can be reduced, and the variation in the width Wa of the pixel electrode 199 can be reduced. This makes it possible to further improve the manufacturing yield of the display device. In order to form a structure in which the pixel electrode 199 is stepped, the insulating layer 192 has a so-called overhang shape in which some of its sides extend inward beyond the left and right ends of the conductive layer 111, and can have trenches deeper than the thickness of the pixel electrode 199.

[0109] The conductive layer 111R is provided on the plug 170R and the insulating layer 192. The conductive layer 111R has a region in contact with the upper surface of the plug 170R and a region in contact with the upper surface of the insulating layer 192. The upper and side surfaces of the conductive layer 111R are covered by the pixel electrode 199R. This configuration is the same for the conductive layer 111R and the conductive layer 111B.

[0110] Figure 2D shows a plan view including the conductive layer 111R, a portion of the conductive layer 111G, the pixel electrode 199R, and a portion of the pixel electrode 199G. As shown in Figure 2D, in a top view, it is preferable that the conductive layer 111R encompasses the plug 170R. Although not shown in Figure 2D, similarly, it is preferable that the conductive layer 111G encompasses the plug 170G, and the conductive layer 111B encompasses the plug 170B.

[0111] Preferably, at least one of the conductive layer 111 and the pixel electrode 199 has a conductive layer with high reflectivity, and in particular, the pixel electrode 199 is preferably a conductive layer with high reflectivity. For example, a metal or alloy can be used as the conductive layer with high reflectivity. More specifically, for example, metals such as silver, aluminum, gold, platinum, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, and titanium, or alloys containing these metals, can be used.

[0112] When aluminum is used as the conductive layer 111, it is preferable to have a laminated structure with a conductive layer such as titanium or titanium nitride in the lower or upper layer of the aluminum layer. For example, a three-layer laminated structure of titanium, aluminum on titanium, and titanium on aluminum is preferable. As the conductive layer 111, for example, the metals, metal nitrides, alloys, etc. mentioned above can be used as appropriate. For example, titanium, tungsten, tantalum, aluminum, molybdenum, titanium nitride, tantalum nitride, etc. can be used. It is also possible to laminate two or more of these conductive layers.

[0113] Furthermore, conductive layers 111R, 111G, and 111B can each have a tapered shape at their ends. This can improve the coverage of the layers provided on conductive layers 111R, 111G, and 111B (for example, pixel electrodes 199R, 199G, and 199B), and may suppress the occurrence of porosity in these layers.

[0114] Furthermore, the conductive layer 111 may be configured such that one or more of its sides are vertical.

[0115] [Pixel electrode 199] The pixel electrode 199 covers the upper and side surfaces of the conductive layer 111 and a portion of the side surfaces of the insulating layer 192. Preferably, the lower end of the pixel electrode 199 is located below the lower surface of the conductive layer 111.

[0116] For example, a highly reflective conductive layer can be used as the pixel electrode 199R, pixel electrode 199G, and pixel electrode 199B. Furthermore, a highly conductive layer can be used as the conductive layer 111R, conductive layer 111G, and conductive layer 111B.

[0117] In the following, pixel electrodes 199R, 199G, and 199B may be collectively referred to as pixel electrode 199.

[0118] The pixel electrodes 199R, 199G, and 199B are made of a material that can be processed using wet etching, for example. The pixel electrodes 199R, 199G, and 199B can be formed by wet etching of the conductive film. The ends of the pixel electrodes 199R, 199G, and 199B may have a tapered shape, an inverse tapered shape, or a shape perpendicular to the side surface.

[0119] The configuration in which the lower end of the pixel electrode 199 is located below the lower surface of the conductive layer 111 will be described below. The conductive layer 111 is provided so as to be in contact with and covering the upper surface of the insulating layer 192. The conductive layer 111 has an island-like pattern. Trenches are formed in the insulating layer 192. Since the island-like conductive layer 111 functions as a hard mask when forming the trenches, the conductive layer 111 and the insulating layer 192 have sides that share the same surface. The pixel electrode 199 is provided in contact with and covering the conductive layer 111 and the insulating layer 192. Since the pixel electrode 199 located below the lower surface of the conductive layer 111 is removed by wet etching, the lower end of the pixel electrode 199 formed in the trenches of the insulating layer 192 is located between the lower and upper surfaces of the insulating layer 192.

[0120] Furthermore, depending on the dry etching conditions, a tapered shape or an inverse tapered shape can be formed on the side surface of the insulating layer 192. In this case, the position of the side edge of the conductive layer 111R can be made to coincide with the positions of the left and right edges of the side surface of the insulating layer 192. Alternatively, the left and right edges of the insulating layer 192 can be formed to be located inward relative to the position of the side edge of the conductive layer 111R. In this case, a region where the lower surface of the conductive layer 111R is exposed may be formed between the lower left and lower right edges of the conductive layer 111R and the side surface of the insulating layer 192. With this configuration, the pixel electrode 199 can cover part of the side and bottom surfaces of the conductive layer 111 and part of the side surface of the insulating layer 192.

[0121] The pixel electrode 199, which functions as one of a pair of electrodes in a light-emitting device, can be made of metal, alloy, electrically conductive compound, or mixtures thereof as appropriate.

[0122] Examples of metals and alloys include aluminum, magnesium, titanium, chromium, manganese, iron, cobalt, nickel, copper, gallium, zinc, indium, tin, molybdenum, tantalum, tungsten, palladium, gold, platinum, silver, yttrium, neodymium, and alloys containing these metals in appropriate combinations. More specifically, examples of alloys include aluminum alloys such as aluminum, nickel, and lanthanum alloys (Al-Ni-Lai-La alloys), as well as silver alloys of silver and magnesium, and silver alloys such as silver, palladium, and copper alloys (Ag-Pd-Cu alloys, also written as APC).

[0123] Furthermore, elements belonging to Group 1 or Group 2 of the periodic table not exemplified above (for example, lithium, cesium, calcium, strontium), rare earth metals such as europium and ytterbium, and alloys containing these in appropriate combinations can also be used.

[0124] Examples of electrically conductive compounds include nitrides of metals or alloys, and oxides of metals or alloys (specifically, for example, oxide conductors described later).

[0125] Furthermore, examples of electrically conductive compounds include silicides such as nickel silicide.

[0126] Graphene may also be used as the electrode for the light-emitting device.

[0127] Preferably, at least one of the pixel electrode 199 and the conductive layer 111 has a conductive layer with high reflectivity, and in particular, the pixel electrode 199 is preferably a conductive layer with high reflectivity. For example, a metal or alloy can be used as the conductive layer with high reflectivity. More specifically, for example, metals such as silver, aluminum, gold, platinum, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, and titanium, or alloys containing these metals, can be used.

[0128] A silver-containing alloy can be used as the pixel electrode 199. Silver-containing alloys have a high reflectivity for visible light, which can suitably improve the light extraction efficiency of the light-emitting device. It is particularly preferable to use an alloy of silver (Ag), palladium (Pd), and copper (Cu) (Ag-Pd-Cu alloy (APC)) as the pixel electrode 199.

[0129] When a silver-containing alloy is used as the pixel electrode 199, the pattern is formed using wet etching. A display device according to one aspect of the present invention (typically shown in Figure 1B) has a structure that can reduce variations in the width Wa of the pixel electrode 199 due to side etching. This makes it possible to reduce the dimensional error of the pattern during wet etching, and to achieve fine pattern formation of the pixel electrode 199 even when using wet etching.

[0130] Furthermore, a conductive layer having high reflectivity may be used as the conductive layer 111. Also, by using a material that can be dry-etched as the conductive layer 111, miniaturization of the wiring can be achieved.

[0131] Aluminum has high reflectivity and can be suitably used as the pixel electrode 199 and the conductive layer 111.

[0132] On the other hand, aluminum may undergo electrolytic corrosion when it comes into contact with metal or alloy oxides, for example during wet etching. Therefore, it is preferable that the pixel electrode 199 is positioned so as to cover the conductive layer 111 so that the conductive layer 111 does not come into contact with the etchant during wet etching of the pixel electrode 199.

[0133] For example, a conductive layer having the function of transmitting light can be used as the pixel electrode 199 and the common electrode 115. As the conductive layer having the function of transmitting light, an oxide conductor can be used.

[0134] Examples of oxide conductors include indium oxide, zinc oxide, In-Sn oxide, In-Zn oxide, In-W oxide, In-W-Zn oxide, In-Ti oxide, In-Ti-Sn oxide, In-Sn-Si oxide (also called silicon-containing In-Sn oxide), zinc oxide with gallium added, In-Ga-Zn oxide, and In-Sn-Zn oxide. Since oxide conductors are not easily oxidized, they can function as oxidation-suppressing layers by covering easily oxidized conductive layers. Specifically, for example, when an easily oxidized conductive layer is used as the pixel electrode 199, the oxide conductor can be provided to cover the pixel electrode 199, thereby suppressing the oxidation of the pixel electrode 199. In particular, it is especially preferable for the pixel electrode 199 to use a three-layer laminated structure consisting of In-Sn oxide, silver or a silver-containing alloy on the In-Sn oxide, and In-Sn oxide on the silver or silver-containing alloy.

[0135] The surface of the pixel electrode 199 is preferably highly flat. This improves the coverage of the layers formed on the pixel electrode 199 (for example, layers 113R, 113G, and 113B), and suppresses the occurrence of defects such as step breaks or porosity in the layers. When using a material with a composition that is prone to forming a polycrystalline structure for the pixel electrode 199, it is preferable to include elements that inhibit crystallization. This suppresses the pixel electrode 199 from forming a polycrystalline structure, and the surface can be made flatter. For example, compared to In-Sn oxide, In-Sn oxide containing silicon is less likely to form a polycrystalline structure and has high surface flatness, making it suitable for use in the pixel electrode 199. When using In-Sn oxide containing silicon, the silicon content (the ratio of the number of silicon atoms to the sum of the ratios of the number of silicon atoms to the sum of the ratios of the number of silicon atoms to the sum of the ratios of the number of tin atoms) is preferably 1% or more and 20% or less, more preferably 3% or more and 20% or less, more preferably 3% or more and 15% or less, and more preferably 5% or more and 15% or less.

[0136] It is more preferable that the pixel electrode 199 uses a structure in which a material that is transparent to visible light and a material that is reflective to visible light are stacked. As an example, the pixel electrode 199 can be provided with a structure in which, from the bottom layer upwards, a first layer that functions as a transparent electrode using a material that is transparent to visible light, a second layer that functions as a reflective electrode using a material that is reflective to visible light, and a third layer that functions as a transparent electrode using a material that is transparent to visible light are stacked.

[0137] Furthermore, by using a material that is transparent to visible light for the common electrode 115, the common electrode 115 can function as a transparent electrode. Alternatively, it is preferable that the common electrode 115 functions as an electrode that is both transparent and reflective. 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. When a transparent electrode is used for the pixel electrode 199 in contact with the light-emitting device, the thickness of the transparent electrode can be said to function as an optical adjustment layer. In this case, it is preferable to set the thickness of these conductive layers such that the optical path length becomes such that the light emitted by each of layers 113R, 113G, and 113B is intensified. In this specification, a reflective electrode may be referred to as a pixel electrode or a common electrode, and a transparent electrode may be referred to as an optical adjustment layer. However, a transparent electrode (optical adjustment layer) can also function as a pixel electrode or a common electrode.

[0138] For example, each pixel electrode 199 can have a laminated structure consisting of a conductive film having a first In-Sn oxide, a conductive film having silver or a silver-containing alloy on the first In-Sn oxide film, and a conductive film having a second In-Sn oxide on the conductive film having silver or a silver-containing alloy. The conductive film having silver or a silver-containing alloy has a high light reflectivity and high silver conductivity, making it suitable as a reflective electrode.

[0139] In conductive films using silver or silver-containing alloys, the silver can be oxidized by the intrusion of oxidizing impurities such as oxygen and water, potentially degrading conductivity and reflectivity. By sandwiching a silver-containing conductive film between conductive layers containing In-Sn oxide, the intrusion of impurities that contribute to degradation from the outside can be prevented. Such a layered structure is preferable because it allows for the acquisition of pixel electrodes that maintain conductivity and reflectivity.

[0140] The conductive layer 250R, conductive layer 250G, and conductive layer 250B can be formed, for example, in the same process. Similarly, the plugs 170R, plugs 170G, and plugs 170B can be formed, for example, in the same process. Similarly, the conductive layer 111R, conductive layer 111G, and conductive layer 111B can be formed, for example, in the same process. Similarly, the pixel electrodes 199R, pixel electrodes 199G, and pixel electrodes 199B can be formed, for example, in the same process.

[0141] [Light-emitting device 130] Of the pair of electrodes in the light-emitting device, one electrode functions as the anode and the other electrode functions as the cathode. In the following explanation, the case in which the pixel electrode functions as the anode and the common electrode functions as the cathode may be used as an example.

[0142] In addition, in the stacked structure of the conductive layer 111R and the pixel electrode 199R, the pixel electrode 199R may mainly function as the anode, and the conductive layer 111R may mainly function as a conductive layer to enhance conductivity. Furthermore, in the stacked structure of the conductive layer 111G and the pixel electrode 199G, the pixel electrode 199G may mainly function as the anode, and the conductive layer 111G may mainly function as a conductive layer to enhance conductivity. Furthermore, in the stacked structure of the conductive layer 111B and the pixel electrode 199B, the pixel electrode 199B may mainly function as the anode, and the conductive layer 111B may mainly function as a conductive layer to enhance conductivity.

[0143] The stacked structure of conductive layer 111R and pixel electrode 199R, the stacked structure of conductive layer 111G and pixel electrode 199G, and the stacked structure of conductive layer 111B and pixel electrode 199B can function as the lower electrode of a light-emitting device.

[0144] Alternatively, in the stacked structure of conductive layer 111R and pixel electrode 199R, only the pixel electrode 199R may be referred to as the lower electrode. Also, in the stacked structure of conductive layer 111G and pixel electrode 199G, only the pixel electrode 199G may be referred to as the lower electrode. Furthermore, in the stacked structure of conductive layer 111B and pixel electrode 199B, only the pixel electrode 199B may be referred to as the lower electrode.

[0145] In the light-emitting device 130R, the pixel electrode 199R is provided so as to cover the top and side surfaces of the conductive layer 111R and a portion of the side surfaces of the insulating layer 192. This suppresses variations in electrode width during etching when forming the pixel electrode 199R, thereby improving the quality of the display device. The variation in electrode width and its suppression will be described later in Figures 5 and 6. Similarly, in the light-emitting device 130G, the pixel electrode 199G is provided so as to cover the top and side surfaces of the conductive layer 111G and a portion of the side surfaces of the insulating layer 192. Similarly, in the light-emitting device 130B, the pixel electrode 199B is provided so as to cover the top and side surfaces of the conductive layer 111B and a portion of the side surfaces of the insulating layer 192. This suppresses side etching during the formation of the pixel electrode 199G and pixel electrode 199B, thereby improving the quality of the display device.

[0146] The light-emitting device 130R includes a pixel electrode 199R on a conductive layer 111R, an island-shaped layer 113R on the pixel electrode 199R, a common layer 114 on the layer 113R, and a common electrode 115 on the common layer 114. The pixel electrode 199R is a conductive layer. The light-emitting devices 130G and 130B have a similar configuration.

[0147] In the light-emitting device 130R, layer 113R and the common layer 114 can be collectively referred to as the EL layer. Similarly, in the light-emitting devices 130G and 130B, layer 113G or layer 113B and the common layer 114 can be collectively referred to as the EL layer.

[0148] In this specification, among the EL layers of a light-emitting device, layers provided in an island-like manner for each light-emitting device may be referred to as layer 113R, layer 113G, or layer 113B, and a layer shared by multiple light-emitting devices may be referred to as the common layer 114. In this specification, layers 113R, layer 113G, and layer 113B may also be referred to as island-like EL layers or island-shaped EL layers, without including the common layer 114.

[0149] [Island-shaped EL layer] Layer 113R has a portion located on the pixel electrode 199R and a portion located on the insulating layer 109. Layer 113G has a portion located on the pixel electrode 199 and a portion located on the insulating layer 109. Layer 113B has a portion located on the pixel electrode 199 and a portion located on the insulating layer 109.

[0150] Layer 113R has a portion that protrudes from the end of the pixel electrode 199R. Layer 113G has a portion that protrudes from the end of the pixel electrode 199G. Layer 113B has a portion that protrudes from the end of the pixel electrode 199B. This makes it possible to increase the area of ​​the light-emitting region of the light-emitting device 130, resulting in a display device with a high aperture ratio.

[0151] Layers 113R, 113G, and 113B are separated from each other. By providing an EL layer in an island-like configuration for each light-emitting device, leakage current between adjacent light-emitting devices is 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.

[0152] In the following, layers 113R, 113G, and 113B may be collectively referred to as layer 113.

[0153] [Insulating layer 109] The insulating layer 109 is provided on the insulating layer 192. The insulating layer 109 is also provided between the conductive layers 111 and between the light-emitting devices 130.

[0154] As shown in Figure 1A, the insulating layer 109 provided between adjacent light-emitting devices 130 is located between adjacent conductive layers 111 and between adjacent pixel electrodes 199.

[0155] It is preferable to use either an organic insulating layer or an inorganic insulating layer, or both, for the insulating layer 109. The insulating layer 109 has the function of suppressing leakage current between adjacent pixel electrodes of light-emitting devices. Furthermore, by embedding the insulating layer 109 in trenches provided in the insulating layer 192, the difference between the upper surface of the pixel electrode 199 and the upper surface of the insulating layer 109 can be reduced. By providing the insulating layer 109, the unevenness of the surface to which the layer to be formed, which is provided above the pixel electrode 199, can be reduced. Therefore, the coverage of the layer to be provided above the pixel electrode 199 can be improved. Improved coverage prevents, for example, the common electrode 115 from being cut or thinned due to large unevenness on the surface to which it is formed.

[0156] Furthermore, the insulating layer 109 can have a single-layer structure or a multi-layer structure.

[0157] It is preferable to use a photosensitive resin as the organic material. Suitable organic materials include 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. Alternatively, organic materials such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinylpyrrolidone, polyethylene glycol, polyglycerin, pullulan, water-soluble cellulose, or alcohol-soluble polyamide resins can be used. Furthermore, a photoresist can be used as the photosensitive resin. Positive or negative photosensitive resins can be used. 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.

[0158] Furthermore, inorganic materials include, for example, 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.

[0159] In this specification, "oxidogenic nitride" refers to a material in which the oxygen atom content is greater than the nitrogen atom content. "Nitride oxide" refers to a material in which the nitrogen atom content is greater than the oxygen atom content.

[0160] Next, the configuration of the pixel electrodes of the display device will be explained using Figures 5A to 5C.

[0161] Figure 5A shows an example configuration in which a pixel electrode 199RX is formed on a flat surface using a mask MSK_a.

[0162] In the display device shown in Figure 5A, layer 101 comprises a substrate 103, a conductive layer 250R on the substrate 103, and an insulating layer 191. An insulating layer 188 is provided on layer 101, and an insulating layer 192X is provided on the insulating layer 188. Plugs 170R are embedded in the insulating layer 188 and the insulating layer 192X. The upper surfaces of the insulating layer 192X and the plugs 170R are flat. Pixel electrodes 199RX are formed from the conductive film formed on the insulating layer 192X and the plugs 170R by etching using a mask MSK_a.

[0163] Furthermore, the ends of the pixel electrode 199RX are located inward from the left and right ends of the mask MSK_a, respectively. That is, during the etching process, as shown by the arrow in Figure 5A, the ends of the pixel electrode 199RX may extend inward from the ends of the mask MSK_a. This type of lateral etching is called side etching. In wet etching, isotropic etching tends to occur, and side etching may occur during the formation of the pixel electrode 199RX.

[0164] When side etching occurs, the width Wa of the pixel electrode 199RX changes depending on the amount of etching that progresses laterally during side etching, resulting in variations in width Wa. The aperture ratio of the pixel decreases as the width Wa is reduced. In particular, when manufacturing a display device with high resolution, it is preferable to keep the dimensional error of the pattern to a minimum. Therefore, in one embodiment of this invention, a configuration in which trenches are formed to reduce the dimensional error of the pattern is described below.

[0165] [Formation of Trench] Unlike Figure 5A, Figure 5B shows a structure in which the surface to be formed on the pixel electrode 199R is convex, a so-called trench structure. A conductive film that will become the conductive layer 111R is formed on the insulating layer 192, and the conductive film is patterned into island-shaped conductive layers 111R. The conductive layers 111R are used as a hard mask to form trenches in the insulating layer 192, thereby forming the convex structure. In other words, the surface to be formed on the pixel electrode 199R has a convex structure.

[0166] As shown in Figure 5B, by providing trenches in the insulating layer 192, variations in the width Wa of the pixel electrode 199R due to side etching can be reduced. In the configuration of Figure 5B, if etching continues after etching has progressed laterally due to side etching, the etching proceeds upward along the side surface of the insulating layer 192 of the pixel electrode 199R, as shown by the arrow in Figure 5B. In this case, the width Wa of the pixel electrode 199R does not depend on the amount of etching, so variations in width Wa can be reduced.

[0167] In Figure 5B, the bottom surface of the conductive layer 111R is located at a height H111B from the bottom surface of the trench in the insulating layer 192. The height H111B can be appropriately rephrased as the height of the trench in the insulating layer 192, or the depth of the trench in the insulating layer 192, etc. Etching of the pixel electrode 199R proceeds from the bottom surface of the trench in the insulating layer 192 to a height H199E. In this case, if the height H199E is higher than the height H111B, the conductive layer 111R will also come into contact with the etchant during wet etching, similar to the pixel electrode 199R. As a result, electrolytic corrosion may occur between the conductive layer 111R and the pixel electrode 199R. Therefore, to avoid electrolytic corrosion, it is preferable that the lower end of the pixel electrode 199R be lower than the height H111B. It can also be expressed that the end of the pixel electrode 199R is located between the bottom surface of the trench in the insulating layer 192 and the bottom surface of the conductive layer 111R.

[0168] Furthermore, if etching during the formation of the pixel electrode 199R progresses not only along the side surface of the conductive layer 111R but also along the upper surface of the conductive layer 111R, then, as in Figure 5A, variations in the width Wa due to etching will occur. Therefore, it is preferable that the height of the lower end of the pixel electrode 199R is lower than the lower surface of the conductive layer 111R.

[0169] Furthermore, when forming the pixel electrode 199R, a portion of the insulating layer 192 can be removed. In this case, the side surface of the insulating layer 192 can be positioned inward from the side surface of the conductive layer 111R. Additionally, the width of the trench provided in the insulating layer 192 can be increased.

[0170] Figure 5C shows an example of a structure having a trench, similar to Figure 5B, but with different configurations for the plug 170R and the conductive layer 111R. In Figure 5C, the plug 170R has a laminated structure with the conductive layer 259R on the plug 170R, and the conductive layer 111R has a laminated structure with the conductive layer 260R and the conductive layer 111R on the conductive layer 260R. Here, it is preferable that the conductive layer 259R functions as a barrier layer for the plug 170R. It is preferable that the conductive layer 260R functions as a barrier layer for the conductive layer 111R.

[0171] In this specification, a barrier layer refers to a layer having barrier properties. The conductivity of the barrier layer is not particularly limited and can be, for example, an insulating layer, a semiconductor layer, or a conductive layer. In this specification, barrier properties refer to a function that makes it difficult for the target substance to diffuse, thereby suppressing the permeation of the substance through the film (also called low permeability). Alternatively, it refers to a function that captures or fixes the target substance (also called gettering).

[0172] The conductive layers 260R and 111R, which function as barrier layers, can each be alloys composed of metallic elements, such as nitrides or oxides of the alloy. For example, it is preferable to use tantalum nitride, titanium nitride, nitrides containing titanium and aluminum, nitrides containing tantalum and aluminum, ruthenium oxide, ruthenium nitride, oxides containing strontium and ruthenium, or oxides containing lanthanum and nickel. Alternatively, polycrystalline silicon containing impurity elements such as phosphorus, or silicides (e.g., nickel silicide) can also be used.

[0173] In Figure 5C, it is preferable to prevent the conductive layer 111R from being affected by wet etching during etching of the pixel electrode 199R. For this reason, it is preferable that the end of the pixel electrode 199R is lower than the height H260B. Alternatively, it can be said that the end of the pixel electrode 199R is located between the lower surface of the trench in the insulating layer 192 and the lower surface of the conductive layer 260R. This configuration makes it possible to reduce variations in the width Wa of the pixel electrode 199R due to side etching.

[0174] As shown in Figure 5B, height H111B represents the height from the trench bottom surface of the insulating layer 192 to the bottom surface of the conductive layer 111R, and height H199B represents the height from the trench bottom surface of the insulating layer 192 to the top surface of the conductive layer 111R. It is preferable that the height H199E of the end of the pixel electrode 199R is lower than the height H111B. On the side surface of the insulating layer 192, the pixel electrode 199R covers the area higher than the height H199E and does not cover the area lower than the height H199E.

[0175] Furthermore, as shown in Figure 5C, height H260B represents the height from the trench bottom surface of the insulating layer 192 to the bottom surface of the conductive layer 260R, and height H199B represents the height from the trench bottom surface of the insulating layer 192 to the top surface of the conductive layer 111R. It is preferable that the height H199E of the end of the pixel electrode 199R is lower than the height H260B. On the side surface of the insulating layer 192, the pixel electrode 199R covers the area higher than the height H199E, but does not cover the area lower than the height H199E.

[0176] In Figure 5B, the height H111B can also be said to be the thickness of the trench in the insulating layer 192. Similarly, in Figure 5C, the height H260B can also be said to be the thickness of the trench in the insulating layer 192. The height H111B is, for example, a trench deeper than the thickness of the pixel electrode 199, and is 10 nm or more, preferably 100 nm or more, and more preferably 1000 nm or more.

[0177] Figures 6A to 6C show an example of forming a pixel electrode 199R using the mask MSK_b. Figures 6A to 6C show an example in which the configuration of the insulating layer 192 differs from that of Figures 5A to 5C. With this configuration, a canopy structure can be formed on the side surface of the insulating layer 192. This allows the pixel electrode 199R to be stepped. In addition, a portion of the pixel electrode 199R formed on the bottom surface of the insulating layer 192 can be removed by wet etching. With this configuration, the pixel electrode 199R can be formed on the side surface of the insulating layer 192, the side surface of the conductive layer 111R, and the top surface. In this way, variations in the width Wa of the pixel electrode 199R due to etching can be avoided.

[0178] The process of forming an overhang structure on the insulating layer 192 will now be described. An insulating layer 192 is provided on layer 101, in which insulating layer 192a, insulating layer 192b, and insulating layer 192c are sequentially laminated. It is preferable to use materials for insulating layers 192a to 192c that can be patterned by dry etching.

[0179] The insulating layers 192b and 192c are patterned in an island-like manner by dry etching. On the other hand, a portion of the insulating layer 192a is etched. In this case, it can also be said that trenches are formed in the insulating layer 192a.

[0180] Furthermore, it is preferable to use different materials for insulating layer 192a and insulating layer 192c than for insulating layer 192b. In particular, materials with different wet etching selectivity ratios are preferred. For example, by using silicon oxide films for insulating layer 192a and insulating layer 192c, and silicon nitride films for insulating layer 192b, a selectivity ratio for wet etching can be obtained.

[0181] After processing insulating layers 192a to 192c by dry etching, selectively wet etching insulating layer 192b allows the left and right edges of insulating layer 192b to be set back further inward than the left and right edges of insulating layer 192c, as shown in Figure 6A. This makes it possible to form an overhang structure on the side surface of the trench of insulating layer 192.

[0182] Next, the process of forming the pixel electrode 199R will be explained. After forming a canopy structure on the insulating layer 192, a conductive film that will become the pixel electrode 199R is formed by sputtering. As shown in the schematic cross-sectional view in Figure 6A, almost no conductive film that will become the pixel electrode 199R is formed on the upper surface of the canopy formed on the insulating layer 192. This is because, in the highly anisotropic sputtering method, due to the effect of shadowing, almost no film is formed on surfaces that are in shadow relative to the incident surface of the sputtered particles. As a result, a conductive film that will become the pixel electrode 199R is formed on the conductive layer 111R. In addition, a conductive film 199f is formed on the trench bottom surface of the insulating layer 192 as the same film as the conductive film that will become the pixel electrode 199R. The conductive film 199f can be said to be a conductive film separated from the pixel electrode 199R on the conductive layer 111R by the canopy structure formed on the side wall of the insulating layer 192. In this way, the pixel electrode 199R and the conductive film 199f are formed separately, allowing the pixel electrode 199R to be formed on the conductive layer 111R in a self-aligned manner.

[0183] Furthermore, in order to separate the pixel electrode 199R from the conductive film 199f, the insulating layer 192 needs to form a trench that is at least deeper than the thickness of the pixel electrode 199R.

[0184] Figure 6B is a schematic cross-sectional view showing a mask MSK_b formed on the pixel electrode 199R. The pixel electrode 199R is located inside the left and right edges of the mask MSK_b. The mask MSK_b fills the space between the conductive film 199f formed on the trench bottom surface of the insulating layer 192 and the pixel electrode 199R formed on the sides of the insulating layer 192, the conductive layer 260R, the conductive layer 111R, and the upper surface of the conductive layer 111R.

[0185] In the etching process of the pixel electrode 199R, the pixel electrode 199R not covered by the mask MSK_b is removed by wet etching as shown by the arrow in Figure 6C. On the other hand, the pixel electrode 199R covered by the mask MSK_b is not etched. Unlike the structures shown in Figures 5B and 5C, the structure in Figure 6C is preferable because it prevents side etching of the pixel electrode 199R regardless of the position of the edge of the pixel electrode 199R.

[0186] In Figure 6A, the height H111B is preferably a thickness that allows the pixel electrode 199R to be stepped. The thickness of the trench in the insulating layer 192 is preferably at least greater than the film thickness of the pixel electrode 199R formed on the upper surface of the conductive layer 111R.

[0187] In the above descriptions relating to Figures 5A to 5C and Figures 6A to 6C, the descriptions relating to the pixel electrode 199R, conductive layer 111R, conductive layer 259R, and conductive layer 260R can be replaced with the pixel electrode 199G, conductive layer 111G, conductive layer 259G, and conductive layer 260G, or the pixel electrode 199B, conductive layer 111B, conductive layer 259B, and conductive layer 260B.

[0188] [Common Electrode 115] The common electrode 115 can function as the upper electrode of the light-emitting device. It is preferable to use a light-transmitting conductive film for the electrode that extracts light, and a light-reflecting conductive film for the electrode that does not extract light. Examples of light emitted by the light-emitting device include visible light and infrared light.

[0189] The common electrode 115 can be made of, for example, metals, alloys, electrically conductive compounds, and mixtures thereof, as mentioned for the pixel electrode 199.

[0190] Furthermore, a light-transmitting conductive film can also be used on the electrode that does not extract light. For example, in the light-emitting device shown in Figure 1B, if a light-reflecting conductive film is used on the lower electrode and a light-transmitting conductive film is used on the upper electrode, a light-transmitting conductive film can also be placed between the lower electrode and the EL layer. This allows the lower electrode to function as a semi-transparent and semi-reflective film.

[0191] In Figure 1B and other figures, when a laminated structure composed of a conductive layer 111 and a pixel electrode 199 functions as a reflective electrode, for example, the pixel electrode 199 can be configured to have a conductive layer with high reflectivity. In this case, by configuring the conductive layer 111 to have a conductive layer with high conductivity, a pixel electrode with both high reflectivity and high conductivity can be realized.

[0192] Furthermore, for example, when forming the pixel electrode 199 by wet etching, using a material suitable for microfabrication as the conductive layer 111 and capable of being processed using anisotropic dry etching may enable further improvements in the resolution of the display device.

[0193] [Insulating layer 125, insulating layer 127] An insulating layer 125 and an insulating layer 127 on the insulating layer 125 are provided in the region between adjacent light-emitting devices 130. 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. In other words, the display device can be configured to have one insulating layer 125 and one insulating layer 127. The display device can also be configured to have multiple insulating layers 125 that are separated from each other. Furthermore, the display device can also be configured to have multiple insulating layers 127 that are separated from each other.

[0194] The insulating layer 125 is provided in contact with the insulating layer 109. The insulating layer 125 is also provided in contact with the side surface of layer 113 and has a region that is in contact with the side surface and top surface of the mask layer 118R. The insulating layer 127 is provided in contact with the top surface of the insulating layer 125.

[0195] 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 improve the manufacturing yield of the light-emitting device.

[0196] By using an inorganic insulating film as the insulating layer 125, it can have functions such as a barrier insulating layer against impurities.

[0197] The insulating layer 125 preferably functions as a barrier insulating layer. By providing an insulating layer 125 that functions as a barrier insulating layer, the diffusion of components contained in the insulating layer 127 towards the layer 113 can be suppressed. This suppresses the diffusion of impurities into the light-emitting layer of the light-emitting device 130, thereby improving the reliability of the light-emitting device. Therefore, a highly reliable display device can be made. The insulating layer 125 can be a single-layer structure or a laminated structure. For example, it can be a laminated structure of layers having the aforementioned materials.

[0198] The barrier insulating layer can be, for example, one or more of the following: an oxide having one or both aluminum and hafnium, an oxide having magnesium, an oxide having gallium, a nitride having silicon, and a silicon nitride oxide. Typically, the barrier layer can preferably be one or more of the following: aluminum oxide, hafnium oxide, hafnium aluminate, magnesium oxide, gallium oxide, zinc gallium oxide, silicon nitride, and silicon nitride oxide. For example, a silicon nitride film can preferably be used as the insulating layer 125.

[0199] An organic material can be used as the insulating layer 127. For example, the organic materials listed for the insulating layer 109 can be used.

[0200] The insulating layer 127, provided on the insulating layer 125, has the function of flattening the unevenness of the insulating layer 125 formed between adjacent light-emitting devices, where there is a large difference in height. In other words, the presence of the insulating layer 127 improves the flatness of the surface forming the common electrode 115.

[0201] [Mask layer 118] Mask layer 118R, mask layer 118G, and mask layer 118B are made up of a portion of the mask layer that was provided when forming layers 113R, 113G, and 113B. A display device according to one aspect of the present invention can have a configuration in which a portion of the mask layer used to protect the EL layer during its manufacture remains.

[0202] In the following, mask layer 118R, mask layer 118G, and mask layer 118B may be collectively referred to as mask layer 118.

[0203] [Connection part 140] Figures 7A and 7B show cross-sectional views between the dashed line Y1-Y2 in Figure 1A. Figures 7A and 7B show the connection part 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 the multiple light-emitting devices, is connected to a conductive layer 123 provided in the connection part 140. The conductive layer 123 is provided on the insulating layer 192. The conductive layer 123 can also be formed in the same process as, for example, the conductive layer 111R, the conductive layer 111G, and the conductive layer 111B.

[0204] A conductive layer 250p and an insulating layer 191 are provided on the substrate 103. The conductive layer 250p corresponds, for example, to the wiring of layer 101. An insulating layer 188 is provided on the conductive layer 250p, and an insulating layer 192 is provided on the insulating layer 188. The conductive layer 250p has a region that contacts a plug 170p embedded in the insulating layers 188 and 192, and is connected to the plug 170p. A conductive layer 123 is provided on the plug 170p and the insulating layer 192. The plug 170p has a region that contacts the conductive layer 123, and is connected to the conductive layer 123. Therefore, the conductive layer 123 is connected to the conductive layer 250p via the plug 170p. A common electrode 115 is also provided on the conductive layer 123. Note that a configuration without the plug 170p and conductive layer 250p is also possible.

[0205] As shown in Figure 7A, a common layer 114 is provided on the conductive layer 123, and a common electrode 115 is provided on the common layer 114.

[0206] The connection portion 140 preferably has a region in which the conductive layer 123, the common layer 114, and the common electrode 115 are laminated without any other layers 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.

[0207] Figure 7A shows an example in which the conductive layer 123 and the common electrode 115 are connected via a common layer 114. Note that the common layer 114 can be omitted from the connection portion 140.

[0208] As shown in Figure 7B, the connection portion 140 can have a region where the conductive layer 123 and the common electrode 115 are laminated without any other layers in between. 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 regions where the common layer 114 and the common electrode 115 are film-deposited can be changed.

[0209] Figures 7A to 7B show an example configuration in which the mask layer (here, mask layer 118B) has a region in contact with the conductive layer 123. However, the present invention is not limited to this, and as shown in Figures 8A to 8B, the mask layer may have no region in contact with the conductive layer 123. The insulating layer 125 has a region in contact with the upper surface of the insulating layer 192, the side surface of the conductive layer 123, and a portion of the upper surface of the conductive layer 123. An insulating layer 127 is provided on the insulating layer 125. For the connection between the conductive layer 123 and the common electrode 115 shown in Figure 8A, refer to the description in Figure 7A. Similarly, for the configuration shown in Figure 8B, refer to the description in Figure 7B.

[0210] The configuration of the connection part 140 shown here can also be applied to other configuration examples.

[0211] [Characteristics of the components of the display device] 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.

[0212] 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.

[0213] As the light-emitting device, it is preferable to use, for example, an OLED (Organic Light Emitting Diode) or a QLED (Quantum-dot Light Emitting Diode). Examples of light-emitting materials for the light-emitting device include fluorescent materials, phosphorescent materials, thermally activated delayed fluorescence (TADF) materials, and inorganic compounds (quantum dot materials, etc.). In addition, LEDs such as microLEDs (Light Emitting Diodes) can also be used as the light-emitting device.

[0214] 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.

[0215] In Figure 1B, there is no insulating layer (also called a partition or spacer) between the conductive layer 111R and the pixel electrode 199R and layer 113R that covers the upper edge of the pixel electrode 199R. Similarly, there is no insulating layer between the conductive layer 111G and the pixel electrode 199G and layer 113G that covers the edges of the conductive layer 111G and the pixel electrode 199G. There is no insulating layer between the conductive layer 111B and the pixel electrode 199B and layer 113B that covers the edges of the conductive layer 111G and the pixel electrode 199B. This makes it possible to make the spacing between adjacent light-emitting devices extremely narrow. As a result, a high-definition or high-resolution display device can be made. In addition, a mask for forming the insulating layer is not required, which can reduce the manufacturing cost of the display device.

[0216] 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.

[0217] 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.

[0218] 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.

[0219] 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.

[0220] Each of the layers 113R, 113G, and 113B may 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.

[0221] 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 from the layer 101 side. 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.

[0222] 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 from the layer 101 side. Furthermore, a hole blocking layer may be present between the electron transport layer and the emissive layer. Also, 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.

[0223] 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). 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). Alternatively, it is preferable that each of layers 113R, 113G, and 113B has an emissive layer, a carrier block layer, and a carrier transport layer on the carrier block layer. It is more preferable that the carrier transport layer is provided on the emissive layer. It is more preferable that the carrier block layer is provided on the emissive layer. If the surfaces of layers 113R, 113G, and 113B are exposed to the atmosphere during the manufacturing process of the display device, providing one or both of the carrier transport layer and the carrier block layer on the emissive layer prevents the emissive layer from being exposed to the atmosphere because the emissive layer is not exposed to the outermost surface. This reduces damage to the light-emitting layer and improves the reliability of the light-emitting device.

[0224] 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.

[0225] 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 upper surface of 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.

[0226] 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.

[0227] 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.

[0228] 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.

[0229] 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.

[0230] 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 stacked together, or a hole transport layer and a hole injection layer stacked together. The common layer 114 is shared by the light-emitting device 130R, light-emitting device 130G, and light-emitting device 130B.

[0231] The island-like layers 113R, 113G, and 113B can be formed, for example, by photolithography without using a fine metal mask. A film to become layer 113R can be formed, and this film can be processed by photolithography to form 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.

[0232] 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%.

[0233] 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.

[0234] In Figure 1B, etc., a mask layer 118R is located on layer 113R of the light-emitting device 130R, a mask layer 118G is located on layer 113G of the light-emitting device 130G, and a mask layer 118B is located on layer 113B of the light-emitting device 130B. Mask layer 118B is a portion of the mask layer that remained after being prepared in contact with the upper surface of layer 113B during processing. Similarly, mask layers 118G and 118R are also portions of the mask layers that remained after being prepared during the formation of layers 113G and 113R, respectively. 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 manufacturing. 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 layer 118R, mask layer 118G, and mask layer 118B may be collectively referred to as mask layer 118.

[0235] 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.

[0236] 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. The other end of the mask layer 118R (the end on the light-emitting region side, the inner end) is located on layer 113R. Here, it is preferable that the other end of the mask layer 118R overlaps with the region where layer 113R and the conductive layer 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 remains between the upper surface of the 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.

[0237] Each side of layer 113R, layer 113G, and layer 113B is covered by the insulating layer 125. The insulating layer 127 overlaps with each side of layer 113R, layer 113G, and layer 113B via the insulating layer 125.

[0238] The upper surfaces and sides of layers 113R, 113G, and 113B are covered by at least one of the insulating layer 125, insulating layer 127, and mask layer 118. This prevents the common layer 114 (or common electrode 115) from coming into contact with the sides of layers 113R, 113G, and 113B, thereby suppressing short circuits in the light-emitting device. This improves the reliability of the light-emitting device.

[0239] 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. In Figure 1B, for example, the portion located on the insulating layer 109 is included in the second region of the EL layer.

[0240] In this embodiment, a configuration is shown in which island-like layers 113R, 113G, and 113B are formed using photolithography, 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.

[0241] In Figure 1B, etc., the thicknesses of layers 113R, 113G, and 113B are all the same, but the present invention is not limited to this. The thicknesses of layers 113R, 113G, and 113B may be different. For example, it is preferable to set the thickness of each layer such that the optical path length increases the intensity of the light emitted by each layer. This makes it possible to realize a microcavity structure and improve the color purity of each light-emitting device.

[0242] The insulating layer 125 can be an insulating layer having an inorganic material. For example, inorganic insulating films such as oxide insulating films, nitride insulating films, oxidative nitride insulating films, and nitride oxide insulating films can be used for the insulating layer 125. The insulating layer 125 can have a single-layer structure or a multilayer structure. Examples of oxide insulating films include silicon oxide film, aluminum oxide film, magnesium oxide film, indium gallium zinc oxide film, gallium oxide film, germanium oxide film, yttrium oxide film, zirconium oxide film, lanthanum oxide film, neodymium oxide film, hafnium oxide film, and tantalum oxide film. Examples of nitride insulating films include silicon nitride film and aluminum nitride film. Examples of oxidative nitride insulating films include silicon oxidative nitride film and aluminum oxidative nitride film. Examples of nitride oxide insulating films include silicon nitride film and aluminum nitride film. 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 in the formation of the insulating layer 127 described later. In particular, by applying an inorganic insulating film 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. Alternatively, the insulating layer 125 may 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.

[0243] Preferably, the insulating layer 125 functions as a barrier insulating 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.

[0244] In this specification, a barrier insulating layer refers to an insulating layer having barrier properties. In this specification, barrier properties refer to a function that makes it difficult for the 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 the target substance (also referred to as gettering).

[0245] The insulating layer 125 has the function of a barrier insulating layer or a gettering function, thereby suppressing 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.

[0246] The insulating layer 125 preferably has a low impurity concentration. This prevents impurities from mixing from the insulating layer 125 into the EL layer and degrading the EL layer. Furthermore, by lowering the impurity concentration in the insulating layer 125, the barrier properties against at least one of water and oxygen can be improved. For example, it is desirable that the insulating layer 125 has a sufficiently low hydrogen concentration and a sufficiently low carbon concentration, preferably both.

[0247] 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 difficult to distinguish. 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.

[0248] 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.

[0249] As the insulating layer 127, an insulating layer having an organic material can be suitably used. Preferably, a photosensitive resin is used as the organic material; for example, a photosensitive resin composition containing an acrylic resin is preferred. In this specification, the term "acrylic resin" does not refer only to polymethacrylate esters or methacrylic resins, but may refer to acrylic polymers in a broad sense.

[0250] The insulating layer 127 can also be made of acrylic resin, polyimide resin, epoxy resin, imide resin, polyamide resin, polyimidoamide resin, silicone resin, siloxane resin, benzocyclobutene resin, phenol resin, and precursors of these resins. Alternatively, the insulating layer 127 can be made of organic materials such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinylpyrrolidone, polyethylene glycol, polyglycerin, pullulan, water-soluble cellulose, or alcohol-soluble polyamide resin. Furthermore, a photoresist can be used as the photosensitive resin. The photosensitive resin can be either a positive-type or negative-type material.

[0251] The insulating layer 127 can also be made of a material that absorbs visible light. 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.

[0252] The insulating layer 192 can have a single-layer structure or a multi-layer structure.

[0253] As the insulating layer 192, either an inorganic insulating layer or an organic insulating layer, or both, can be used. Examples of materials that can be used for the organic insulating layer include acrylic resin and polyimide resin. 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.

[0254] 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.

[0255] The insulating layer 188 can be a single-layer structure or a multi-layer structure. The same material as that used for the insulating layer 192 can be used for the insulating layer 188.

[0256] The conductive layer 250 and the plug 170 can be made from the aforementioned metals, alloys, electrically conductive compounds, and mixtures thereof as appropriate.

[0257] The insulating layer 125 is preferably in contact with the respective sides of layers 113R, 113G, and 113B. By configuring the insulating layer 125 to be in contact with layers 113R, 113G, and 113B, peeling of the layers 113R, 113G, and 113B can be prevented. This improves the reliability of the light-emitting device. In addition, by being in close contact with layers 113B, 113G, or 113R, the insulating layer 125 has the effect of fixing or bonding the layer. This improves the manufacturing yield of the light-emitting device.

[0258] As shown in Figure 1B and other figures, 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.

[0259] The insulating layer 127 is provided on the insulating layer 125 so as to fill the recesses formed in the insulating layer 125. The insulating layer 127 can be configured to overlap a portion of the upper surface and side surfaces of layers 113R, 113G, and 113B via the insulating layer 125. It is also preferable that the insulating layer 127 covers at least a portion of the side surfaces of the insulating layer 125.

[0260] By providing insulating layers 125 and 127, the gaps between adjacent island-shaped layers can be filled. This reduces the large height differences and irregularities on the surface of layers formed on the island-shaped layers (e.g., carrier injection layers and common electrodes), making it flatter. As a result, the coverage of the carrier injection layers and common electrodes can be improved.

[0261] The common layer 114 and the 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 exists between 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 allows the step difference to be flattened. This improves the coverage of the common layer 114 and the common electrode 115. Therefore, connection failures due to step breaks can be suppressed. In addition, it is possible to suppress the local thinning of the common electrode 115 due to the step difference, which increases the electrical resistance.

[0262] The upper surface of the insulating layer 127 preferably has a highly flat shape. However, 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.

[0263] 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. Furthermore, the insulating layer 127 overlaps with 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 the 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.

[0264] 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. This prevents the separation of these layers and also prevents the formation of locally thin areas.

[0265] 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 with high coverage over the entire upper surface of the insulating layer 127.

[0266] By providing insulating layers 127 and 125, the common layer 114 and common electrode 115 can be formed with high coverage. This prevents divisions in the common layer 114 and common electrode 115, as well as localized reductions in thickness. Therefore, connection failures due to divisions in the common layer 114 and common electrode 115, and increases in electrical resistance due to localized reductions in thickness, can be suppressed between each light-emitting device. As a result, the display device according to one aspect of the present invention can improve display quality.

[0267] It is preferable that the light-emitting devices 130R, 130G, and 130B have a protective layer 128. The protective layer 128 can be a single layer or a multilayer structure. Providing the protective layer 128 can improve the reliability of the light-emitting devices.

[0268] The conductivity of the protective layer 128 is not required. At least one of an insulating film, a semiconductor film, and a conductive film can be used as the protective layer 128.

[0269] The presence of an inorganic film in the protective layer 128 prevents oxidation of the common electrode 115. It also suppresses the ingress of impurities (such as moisture and oxygen) into the light-emitting device. These effects suppress degradation of the light-emitting device and improve the reliability of the display device.

[0270] For the protective layer 128, inorganic insulating films such as oxide insulating films, nitride insulating films, oxidoxide-nitriding insulating films, and nitride-oxide insulating films can be used. Specific examples of these inorganic insulating films are given in the description of the insulating layer 125. In particular, the protective layer 128 preferably has a nitride insulating film or a nitride-oxide insulating film, and more preferably has a nitride insulating film.

[0271] As the protective layer 128, 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 In-Ga-Zn oxide 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.

[0272] Furthermore, the protective layer 128 may have an organic film. For example, the protective layer 128 may have both an organic film and an inorganic film. Examples of organic materials that can be used for the protective layer 128 include organic insulating materials that can be used for the insulating layer 127.

[0273] The protective layer 128 may have a two-layer structure formed using different film deposition methods. Specifically, the first layer of the protective layer 128 may be formed using the ALD method, and the second layer of the protective layer 128 may be formed using the sputtering method.

[0274] Preferably, the insulating layer 122 has the function of flattening the large height differences and irregularities in the insulating layer 127 formed between adjacent light-emitting devices. Furthermore, it is preferable to thin the insulating layer 122 using the CMP method. This shortens the distance from the light-emitting surface of the light-emitting device on the substrate 103 to the output surface of the display device, thereby suppressing color mixing from adjacent pixels. Examples of organic materials that can be used for the insulating layer 122 include organic insulating materials that can be used for the insulating layer 127.

[0275] A flexible substrate can be used as the substrate 103, and a display device or the like can be formed directly on the flexible substrate. Alternatively, a release layer can be provided between the substrate 103 and the display device or the like. By providing a release layer, part or all of the display device can be formed on it, then separated from the substrate 103 and transferred to another substrate. In this case, the display device or the like can be transferred to a substrate with poor heat resistance or to a flexible substrate.

[0276] As the substrate 103, an insulating layer can also be laminated on the aforementioned substrate.

[0277] A light-shielding layer may be provided on the side of the substrate 120 facing the adhesive layer 129. Various optical components can be placed on the outside of the substrate 120. Examples of optical components include polarizing plates, phase difference plates, light diffusion layers (diffusion films, etc.), anti-reflective layers, and light-gathering films. Surface protection layers such as an antistatic film to suppress the adhesion of dust, a water-repellent film to make it difficult for dirt to adhere, a hard coat film to suppress the occurrence of scratches during use, and an impact absorption layer may also be placed on the outside of the substrate 120. For example, providing a glass layer or a silica layer (SiOx layer) as a surface protection layer is preferable as it can suppress surface contamination and the occurrence of scratches. Alternatively, DLC (diamond-like carbon), aluminum oxide (AlOx), polyester-based materials, or polycarbonate-based materials may be used as the surface protection layer. It is preferable to use a material with high transmittance to visible light for the surface protection layer. It is also preferable to use a material with high hardness for the surface protection layer.

[0278] The substrates 120 and 103 of the display device can be made of glass, quartz, ceramics, sapphire, resin, metal, alloy, semiconductor, or the like.

[0279] The substrate on the side that extracts light from the light-emitting device uses a material that transmits the light. Using a flexible substrate increases the flexibility of the display device, enabling a flexible display. Alternatively, a polarizing plate may be used as the substrate.

[0280] As substrates 120 and 103, 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. may be used. Glass of a thickness sufficient to provide flexibility may also be used for substrate 120.

[0281] 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).

[0282] 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.

[0283] 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.

[0284] When a film is used as a 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 preferably 0.1% or less, and even more preferably 0.01% or less.

[0285] Various types of curing adhesives can be used as the adhesive layer 129, 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.

[0286] [Configuration Example 2] As a configuration of a display device according to one aspect of this embodiment, a modified version of Figure 1B is shown in Figure 9A. A plan view of the display device can be found in Figure 1A. In Figure 9A, a configuration is shown in which the end of layer 113R is in contact with the upper surface of pixel electrode 199R, the end of layer 113G is in contact with the upper surface of pixel electrode 199G, and the end of layer 113B is in contact with the upper surface of pixel electrode 199B. An enlarged view of a part of the cross-sectional view shown in Figure 9A is shown in Figure 9B.

[0287] Figure 1B and others show a configuration in which the insulating layer 109 is provided in contact with the upper surface of the insulating layer 192, but the present invention is not limited to this. In Figure 9A, a configuration can be made in which the insulating layer 109 is not provided in the configuration shown in Configuration Example 1. Furthermore, a configuration is shown in which the end of layer 113R is in contact with the upper surface of the pixel electrode 199R, the end of layer 113G is in contact with the upper surface of the pixel electrode 199G, and the end of layer 113B is in contact with the upper surface of the pixel electrode 199B. An enlarged view of a part of the cross-sectional view shown in Figure 9A is shown in Figure 9B.

[0288] The edges of layer 113R are located inward from the left and right edges of the pixel electrode 199R, respectively. In a top view, the pixel electrode 199R is provided so as to encompass layer 113R. If layer 113R has a portion that protrudes from the edge of the pixel electrode 199R, the step created by the pixel electrode 199R may reduce the coverage of layer 113R, potentially resulting in thin areas in layer 113R. Furthermore, these areas may become leak paths. By providing the pixel electrode 199 so as to encompass layer 113R, the thickness of layer 113R can be made more uniform. This suppresses the occurrence of thin areas in layer 113R, thereby suppressing current leakage and enabling a current-efficient light-emitting device 130R. The same applies to the pixel electrode 199G and layer 113G, and the pixel electrode 199B and layer 113B. Therefore, a display device with high current efficiency can be obtained.

[0289] As shown in Figures 9A and 9B, the insulating layer 125 is provided in the region that is in contact with the trench side and bottom surface of the insulating layer 192 and the side surfaces of the pixel electrode 199R, pixel electrode 199G, and pixel electrode 199B. Furthermore, an insulating layer 127 is provided on top of the insulating layer 125. The insulating layer 127 can also be provided in the region that overlaps with the trench of the insulating layer 192. Here, it is preferable that the end of the insulating layer 127 is located outside the connection between layer 113R and the common layer 114. This reduces the unevenness of the surface to which the common electrode 115 is formed, and improves the coverage of the common electrode 115.

[0290] Furthermore, the configurations of layers 113R, 113G, and 113B shown here can also be applied to other configuration examples.

[0291] For details regarding the connection portion 140, please refer to the description in Figures 8A and 8B.

[0292] [Configuration Example 3] Figure 10A is a modified example of Figure 1A. A plan view of the display device can be found in Figure 1A. Figure 10A shows a configuration in which the display device has an insulating layer 196. Figure 10B shows an enlarged view of a part of the cross-sectional view shown in Figure 10A.

[0293] The insulating layer 196 is provided so as to cover the insulating layer 109 embedded in the trench of the insulating layer 192. The insulating layer 196 is also provided so as to cover the upper shoulder portions of the pixel electrodes 199R, 199G, and 199B. This makes it possible to suppress current leakage between adjacent pixel electrodes 199. It also makes it possible to suppress current leakage between the ends of the pixel electrodes 199 and the layer 113. Even if electric field concentration occurs on the upper shoulder portion of the pixel electrode 199, the insulating layer 196 can increase the distance between the upper shoulder portion of the pixel electrode 199 and the layer 113, thereby suppressing the effects of electric field concentration. In particular, when a tandem structure is used for the light-emitting device 130, the insulating layer 196 can increase the distance between the layer 113 and the upper shoulder portion of the pixel electrode 199, thereby suppressing the occurrence of a leakage path between the charge generation layer and the upper shoulder portion of the pixel electrode 199.

[0294] Furthermore, it is more preferable that the insulating layer 196 functions as a barrier layer. By providing an insulating layer 196 that functions as a barrier layer, the diffusion of components contained in the insulating layer 109 to layers 113R, 113G, and 113B can be suppressed. This improves the reliability of the light-emitting device. Therefore, a highly reliable display device can be made.

[0295] The insulating layer 196 can also be used as an etching stopper when patterning layer 113. In this case, the insulating layer 109 can be made of a material that does not have etching resistance when etching layer 113, and the material for filling the trenches of the insulating layer 192 can be suitably selected.

[0296] [Configuration Example 4] Figure 11A is a modified example of Figure 1A. A plan view of the display device can be found in Figure 1A. Figure 11A shows a configuration having a structure in which insulating layers 192 are stacked (specifically insulating layer 192a, insulating layer 192b, and insulating layer 192c). Furthermore, the width of the trenches in the insulating layer 192 is wider than the width of the adjacent pixel electrodes 199. Figure 11B shows an enlarged view of a part of the cross-sectional view shown in Figure 11A.

[0297] As shown in Figure 11A, the structure has an insulating layer 188 on which insulating layers 192a, 192b, and 192c are sequentially laminated. In this example, insulating layers 192a, 192b, and 192c may be collectively referred to as insulating layer 192.

[0298] As shown in Figure 11A, the left and right ends of the insulating layer 192b are located inward from the left and right ends of the insulating layer 192c, respectively. Also, the left and right ends of the insulating layer 192b are located inward from the left and right ends of the conductive layer 111R, conductive layer 111G, and conductive layer 111B, respectively.

[0299] Furthermore, the surface of the insulating layer 192c on the insulating layer 192b side may be formed at a position higher than the lower end of the pixel electrode 199. Alternatively, it can be said that the surface of the insulating layer 192c exists between the lower end of the pixel electrode 199 and the lower end of the conductive layer 111. By performing wet etching under conditions that allow for a selectivity ratio for the insulating layer 192a and the insulating layer 192c, the shape of the insulating layer 192c shown in Figure 11A can be formed.

[0300] In the etching process that forms the insulating layer 192b, the surface of the insulating layer 192c facing the insulating layer 192b is exposed. Also, under the etching conditions for the insulating layer 192b, a portion of the exposed insulating layer 192c may be etched. In that case, for example as shown in Figure 11A, the thickness of the insulating layer 192c may become thinner compared to the region where the insulating layer 192c is in contact with the insulating layer 192b and the conductive layer 111.

[0301] Furthermore, in the etching process that forms the insulating layer 192b, the exposed insulating layer 192a may also be etched in the same way. By ensuring that the etching rate of the insulating layer 192a is sufficiently lower than that of the insulating layer 192b, the insulating layer 192a can be preserved.

[0302] The pixel electrode 199 shown in Figure 11A can be formed using the structure formed by the insulating layers 192a, 192b, and 192c. The surface of the insulating layer 192c on the insulating layer 192a side is a region that is in shadow with respect to the sputtering irradiation surface (for example, a surface perpendicular to the bottom of Figure 11A). In regions that are in shadow during sputtering, a film may not be formed, or hardly at all, due to the shadowing effect. By providing a region on the surface of the insulating layer 192 where the pixel electrode 199 is not formed, such as the surface of the insulating layer 192c on the insulating layer 192a side, the pixel electrode 199R can be stepped off at the overhang of the insulating layer 192, as shown in Figure 6A. By stepping off the pixel electrode 199, only the pixel electrode 199R formed on the insulating layer 192a can be removed, as shown in Figures 6C and 11A. With this configuration, pixel electrodes 199R can be formed on the side surface of the insulating layer 192, the side surface of the conductive layer 111R, and the top surface.

[0303] Furthermore, an insulating layer 109 is provided on insulating layers 192a, 192b, and 192c. It is preferable to use one or both of an organic insulating layer and an inorganic insulating layer as the insulating layer 109. In particular, it is preferable to provide the insulating layer 109 under film formation conditions that allow for good embedding.

[0304] [Configuration Example 5] As shown in Figures 12A to 13, a lens array 133 can be provided in the display device. The lens array 133 can be mounted on top of the light-emitting device. By providing the lens array 133 in a position that overlaps with the light-emitting device, the light emitted from the light-emitting device can be utilized efficiently. This makes it possible to realize a highly reliable display device.

[0305] Figures 12A and 12B show an example in which the lens array 133 is provided on the light-emitting device 130R, on the light-emitting device 130G, and on the light-emitting device 130B via a protective layer 128. The lens array 133 is formed directly on the substrate on which the light-emitting device is formed. This improves the accuracy of the alignment between the light-emitting device and the lens array.

[0306] Figure 13 shows an example in which a substrate 120 on which a lens array 133 is provided is bonded to an insulating layer 122 by an adhesive layer 129. By providing the lens array 133 on the substrate 120, the temperature of the heat treatment in these formation processes can be increased.

[0307] Figures 12B and 13 show an example in which a layer having a planarization function is used as the insulating layer 122 on the protective layer 128. However, as shown in Figure 12A, a configuration can be used in which a protective layer 128 without a planarization function is provided on the formation surface of the lens array 133. For example, by using an organic film for the insulating layer 122, the upper surface of the insulating layer 122 can be made flat. Also, the protective layer 128 shown in Figures 12A and 13 can be formed by using, for example, an inorganic film.

[0308] The convex surface of the lens array 133 can be configured to face the substrate 120 side. Alternatively, the convex surface of the lens array 133 can be configured to face the light-emitting device side.

[0309] The lens array 133 can be formed using at least one of an inorganic material and an organic material. For example, a material containing resin can be used for the lens. Alternatively, a material containing at least one of an oxide and a sulfide can be used for the lens. As the lens array 133, for example, a microlens array can be used. The lens array 133 can be formed directly on a substrate or on a light-emitting device. Alternatively, a separately formed lens array can be bonded onto the light-emitting device.

[0310] As shown in Figures 14A and 14B, a colored layer can be provided in the display device. For example, a colored layer 132R that transmits red light can be provided in a position overlapping with the red light-emitting device 130R, a colored layer 132G that transmits green light can be provided in a position overlapping with the green light-emitting device 130G, and a colored layer 132B that transmits blue light can be provided in a position overlapping with the blue light-emitting device 130B. For example, unwanted wavelengths of light emitted from the red light-emitting device 130R can be blocked using the colored layer 132R that transmits red light. By using such a configuration, the color purity of the light emitted from each light-emitting device can be further increased. Although the above description refers to a red light-emitting device, similar effects can be obtained with combinations of a green light-emitting device 130G and a colored layer 132G, and with combinations of a blue light-emitting device 130B and a colored layer 132B.

[0311] By layering a colored layer with the light-emitting device, external light reflection can be significantly reduced, which is preferable. Furthermore, if the light-emitting device has a microcavity structure, external light reflection can be further reduced. Thus, by applying at least one, preferably both, of the colored layer and the microcavity structure, external light reflection can be sufficiently suppressed without using optical components such as circular polarizers in the display device. By not using circular polarizers in the display device, attenuation of light emission from the light-emitting device can be suppressed, and the light extraction efficiency of the light-emitting device can be increased. As a result, the power consumption of the display device can be reduced.

[0312] It is preferable that the colored layers of different colors overlap. The overlapping regions of the colored layers can function as a light-shielding layer. This can further reduce external light reflection.

[0313] Figure 14A shows an example in which colored layers 132R, 132G, and 132B are provided on light-emitting devices 130R, 130G, and 130B via a protective layer 128 and an insulating layer 122 on the protective layer 128. By directly forming the colored layers 132R, 132G, and 132B on the substrate on which the light-emitting devices are formed, the accuracy of the alignment between the light-emitting devices and the colored layers can be improved. Furthermore, by reducing the distance between the light-emitting devices and the colored layers, it is possible to suppress color mixing and improve viewing angle characteristics, which is preferable.

[0314] As shown in Figure 14A, the colored layer is preferably provided on an insulating layer 122 having a planarization function. By forming the colored layer on a highly flat surface, it is possible to suppress the formation of irregularities in the colored layer depending on the surface on which it is formed. This suppresses the diffuse reflection of a portion of the light emitted by the light-emitting device due to irregularities in the colored layer, thereby improving the display quality of the display device. For example, it is preferable that the protective layer 128 has an inorganic insulating film on the common electrode 115, and the insulating layer 122 has an organic insulating film on the inorganic insulating film.

[0315] Figure 14B shows an example in which a substrate 120, on which colored layers 132R, 132G, and 132B are provided, is bonded to an insulating layer 122 by an adhesive layer 129. By providing colored layers 132R, 132G, and 132B on the substrate 120, the temperature of the heat treatment in the formation process can be increased.

[0316] As shown in Figures 15A to 16, the display device can be provided with both a colored layer and a lens array.

[0317] Figure 15A shows an example in which a colored layer 132R, a colored layer 132G, and a colored layer 132B are provided on light-emitting devices 130R, 130G, and 130B via an insulating layer 122 having a planarization function, an insulating layer 134 is provided on the colored layers 132R, 132G, and 132B, and a lens array 133 is provided on the insulating layer 134. By directly forming the colored layers 132R, 132G, 132B, and the lens array 133 on the substrate on which the light-emitting devices are formed, the accuracy of the alignment between the light-emitting devices and the colored layers or lens arrays can be improved.

[0318] The insulating layer 134 can be made of either an inorganic insulating film or an organic insulating film, or both. The insulating layer 134 can have a single-layer structure or a multi-layer structure. The insulating layer 134 can be made of materials that can be used for the protective layer 128, for example. Since the light emitted from the light-emitting device is extracted through the insulating layer 134, it is preferable that the insulating layer 134 has high transmittance to visible light.

[0319] In Figure 15A, the light emitted from the light-emitting device passes through the colored layer, then through the lens array 133, and is extracted to the outside of the display device. Bringing the light-emitting device and the colored layer closer together is preferable because it can suppress color mixing and improve viewing angle characteristics. Alternatively, the lens array 133 can be provided on the light-emitting device, and the colored layer can be provided on the lens array 133.

[0320] Figure 15B shows an example in which a substrate 120, on which colored layers 132R, 132G, 132B, and a lens array 133 are provided, is bonded to a protective layer 128 by an adhesive layer 129. By providing the substrate 120 with the colored layers 132R, 132G, 132B, and lens array 133, the heat treatment temperature in the formation process can be increased.

[0321] Figure 15B shows an example in which a colored layer 132R, a colored layer 132G, and a colored layer 132B are provided in contact with the substrate 120, an insulating layer 134 is provided in contact with the colored layers 132R, 132G, and 132B, and a lens array 133 is provided in contact with the insulating layer 134.

[0322] In Figure 15B, the light emitted from the light-emitting device passes through the lens array 133, then through the colored layer, and is extracted to the outside of the display device. Alternatively, the lens array 133 can be provided in contact with the substrate 120, the insulating layer 134 in contact with the lens array 133, and the colored layer in contact with the insulating layer 134. In this case, the light emitted from the light-emitting device passes through the colored layer, then through the lens array 133, and is extracted to the outside of the display device. As shown in Figures 15A and 15B, it is preferable to provide an overlapping region between the lens array 133 and adjacent lens arrays 133 where two colored layers overlap. By providing an overlapping region where colored layers of different colors overlap, color mixing of the light emitted from the light-emitting device can be suppressed.

[0323] Figure 16 shows an example in which a lens array 133 is provided on light-emitting devices 130R, 130G, and 130B via a protective layer 128, and a substrate 120 on which colored layers 132R, 132G, and 132B are provided is bonded to the lens array 133 and the protective layer 128 by an adhesive layer 129.

[0324] Unlike in Figure 16, the lens array 133 can be provided on the substrate 120, and the colored layer can be formed directly on the protective layer 128. In this way, one of the lens array 133 and the colored layer can be provided on the protective layer 128, and the other on the substrate 120.

[0325] Figures 15A and 15B show an example in which a layer with a planarization function is used as the insulating layer 122. However, as shown in Figure 16, it is possible to have a configuration without an insulating layer 122 with a planarization function. For example, by using an organic film for the insulating layer 122, the upper surface of the insulating layer 122 can be made flat. Also, the protective layer 128 shown in Figure 16 can be formed by using, for example, an inorganic film.

[0326] The lens array 133 and colored layer configurations shown here can also be applied to other configurations.

[0327] By using an organic film in the insulating layer 122 which has a planarization function, the upper surface of the insulating layer 122 can be planarized. Furthermore, the upper surface of the insulating layer 122 using the organic film can be planarized using the CMP method. To prevent peeling of the organic film due to CMP, a highly adhesive film can be provided as an underlayer in contact with the lower surface of the organic film. Titanium, silicon, etc., can be used as the underlayer to enhance adhesion with the organic film. In particular, it is preferable to use titanium as the underlayer. Since the light emission of the light-emitting device is extracted through the underlayer, it is preferable to make the thickness of the underlayer sufficiently thin. In this case, the thickness of the underlayer is preferably 20 nm or less, preferably 10 nm or less, and more preferably 5 nm or less.

[0328] [Modification 1] In the configuration example described above, layers 113R, 113G, and 113B in the light-emitting device were shown to be separated from each other. However, it is also possible to have a configuration in which the layers 113 of the light-emitting device are not separated.

[0329] Note that parts similar to those described in Embodiment 1 may be omitted from the diagrams and descriptions.

[0330] The display device shown in Figure 17A differs from that in Figure 9A in that layer 113 is not separated between adjacent light-emitting devices. For the configuration above layer 113 in Figure 17A, please refer to the description in Figure 9A.

[0331] When the distance between adjacent pixel electrodes 199 is sufficiently large, leakage current between adjacent light-emitting devices can be suppressed. This prevents unintended light emission caused by crosstalk without separating the layer 113 for each light-emitting device, enabling the realization of a display device with extremely high contrast.

[0332] The display device shown in Figure 17A differs from that in Figure 1B mainly in that it does not have an insulating layer 109. Also, the absence of the insulating layer 109 results in different shapes for layers 113, 125, and 127.

[0333] [Modification 2] In the configuration example 3 described above, an insulating layer 196 is provided between the lower electrode of the light-emitting device 130R and layer 113R as an insulating layer that covers the upper shoulder portion of the lower electrode. Similarly, an insulating layer 196 is provided between the lower electrode of the light-emitting device 130G and layer 113G that covers the upper shoulder portion of the lower electrode, and an insulating layer 196 is provided between the lower electrode of the light-emitting device 130B and layer 113B that covers the upper shoulder portion of the lower electrode.

[0334] The display device shown in Figure 17B has an insulating layer 196a covering the upper shoulder portion of the lower electrode of the light-emitting device and an insulating layer 196b provided in contact with the upper surface of the insulating layer 196a. The insulating layer 196a has a portion that covers the upper shoulder portion of the pixel electrode 199R, a portion that covers the end of the pixel electrode 199G, and a portion that covers the end of the pixel electrode 199B. The left and right ends of the insulating layer 196b are located outside the left and right ends of the insulating layer 196a, respectively. The left and right ends of the insulating layer 196b have an overhang shape relative to the insulating layer 196a.

[0335] The layer 113 has portions located on the insulating layer 196a and the insulating layer 196b.

[0336] Figure 17B shows an example in which the side surface of the insulating layer 196a is vertical and the insulating layer 196b is tapered, but the shape of the ends of the insulating layer 196a and insulating layer 196b is not particularly limited.

[0337] It is preferable to use films of different materials for the insulating layer 196a and insulating layer 196b. After pattern formation of insulating layer 196a and insulating layer 196b by dry etching, if the etching rate of insulating layer 196b is sufficiently lower than that of insulating layer 196a, insulating layer 196b may remain, resulting in a configuration with an overhang shape. For example, a silicon nitride film can be suitably used as insulating layer 196a. Also, for example, a silicon oxide film can be suitably used as insulating layer 196b.

[0338] If the insulating layer 196a or insulating layer 196b is sufficiently thick compared to the thickness of layer 113, the layer 113 can be stepped by the overhang shape formed by the insulating layers 196a and 196b. In particular, it is preferable that the thickness of the insulating layer 196a is greater than or equal to the thickness of layer 113. By stepping the layer 113 with the structure of the insulating layer 196 located between adjacent light-emitting devices, leakage current between adjacent light-emitting devices can be suppressed. This allows for insulation between adjacent light-emitting devices without separating the layer 113 for each light-emitting device, for example, by photolithography. Even without separating each light-emitting device, unintended light emission due to crosstalk can be prevented, and a display device with extremely high contrast can be realized.

[0339] [Modification 3] In Modification 2 described above, an insulating layer 196a is provided between the lower electrode of the light-emitting device 130R and layer 113 as an insulating layer covering the upper shoulder portion of the lower electrode, and an insulating layer 196b is provided in contact with the upper surface of the insulating layer 196a. Similarly, between the lower electrode of the light-emitting device 130G and layer 113, an insulating layer 196a covering the upper shoulder portion of the lower electrode and an insulating layer 196b on the insulating layer 196a are provided, and between the lower electrode of the light-emitting device 130B and layer 113, an insulating layer 196a covering the upper shoulder portion of the lower electrode and an insulating layer 196b on the insulating layer 196a are provided.

[0340] The display device shown in Figure 17C has an insulating layer 196a covering the upper shoulder portion of the lower electrode of the light-emitting device on the insulating layer 109, an insulating layer 196b provided in contact with the upper surface of the insulating layer 196a, and an insulating layer 196c provided in contact with the upper surface of the insulating layer 196b. The insulating layer 196a has a portion that covers the upper shoulder portion of the pixel electrode 199R, a portion that covers the end of the pixel electrode 199G, and a portion that covers the end of the pixel electrode 199B. The left and right ends of the insulating layer 196b are located inward, respectively, than the left and right ends of the insulating layer 196a. On the other hand, the left and right ends of the insulating layer 196c are located outward, respectively, than the left and right ends of the insulating layer 196b. Because the left and right ends of the insulating layer 196b are located inward from the insulating layers 196a and 196c, the insulating layer 196 has an overhang shape.

[0341] The layer 113 has portions located on the insulating layer 196a, the insulating layer 196b, and the insulating layer 196c.

[0342] Figure 17C shows an example in which insulating layers 196a and 196c have a tapered shape and the side surface of insulating layer 196b has a vertical shape; however, the shape of the ends of insulating layers 196a, 196b, and 196c is not particularly limited.

[0343] It is preferable that insulating layers 196a and 196c use films of the same material, while insulating layer 196b uses a film of a different material than insulating layers 196a and 196c. After pattern formation of insulating layers 196a, 196b, and 196c by dry etching, if the etching rate of insulating layer 196b is sufficiently higher than that of insulating layers 196a and 196c, insulating layer 196c may remain, resulting in a configuration with an overhang shape. For example, a silicon nitride film can be suitably used as insulating layer 196b. Also, for example, a silicon oxide film can be suitably used as insulating layer 196a and insulating layer 196c.

[0344] If the insulating layer 196b is sufficiently thick compared to the thickness of layer 113, the layer 113 can be stepped by utilizing the overhang shape of the insulating layer 196c. In particular, it is preferable that the thickness of the insulating layer 196b is greater than or equal to the thickness of layer 113. By stepping the layer 113 with the insulating layer 196 located between adjacent light-emitting devices, leakage current between adjacent light-emitting devices can be suppressed. This allows for insulation between adjacent light-emitting devices without separating the layer 113 for each light-emitting device, for example, by photolithography. Even without separating each light-emitting device, unintended light emission due to crosstalk can be prevented, and a display device with extremely high contrast can be realized.

[0345] [Modification 4] In Modification 3 described above, an insulating layer 196a, an insulating layer 196b on insulating layer 196a, and an insulating layer 196c on insulating layer 196b are provided between the lower electrode of the light-emitting device 130R and layer 113 as insulating layers covering the upper shoulder portion of the lower electrode. Similarly, between the lower electrode of the light-emitting device 130G and layer 113, an insulating layer 196a, an insulating layer 196b on insulating layer 196a, and an insulating layer 196c on insulating layer 196b are provided as insulating layers covering the upper shoulder portion of the lower electrode. Furthermore, between the lower electrode of the light-emitting device 130B and layer 113, an insulating layer 196a, an insulating layer 196b on insulating layer 196a, and an insulating layer 196c on insulating layer 196b are provided to cover the upper shoulder portion of the lower electrode.

[0346] The display device shown in Figure 18A has an insulating layer 196a covering the upper shoulder portion of the lower electrode of the light-emitting device on the insulating layer 109, a conductive layer 197 provided in contact with the upper surface of the insulating layer 196a, and an insulating layer 196b provided in contact with the upper surface of the conductive layer 197. The insulating layer 196a has a portion that covers the upper shoulder portion of the pixel electrode 199R, a portion that covers the end of the pixel electrode 199G, and a portion that covers the end of the pixel electrode 199B. The left and right ends of the conductive layer 197 are located inward from the left and right ends of the insulating layer 196a, respectively. The left and right ends of the insulating layer 196b are located outward from the left and right ends of the conductive layer 197, respectively. In other words, the left and right ends of the conductive layer 197 are located inward from the insulating layers 196a and 196b, resulting in a configuration with an overhang shape.

[0347] It is preferable that insulating layers 196a and 196b use films of the same material. It is preferable that the conductive layer 197 uses a material that can be processed using dry etching. For example, a silicon oxide film can be suitably used as the insulating layer 196a. Also, for example, a titanium film can be suitably used as the conductive layer 197.

[0348] Figure 18A shows a structure in which layer 113, a common layer 114 on layer 113, and a common electrode 115 on layer 113 are stepped. While layer 113 is isolated for each light-emitting device, the common layer 114 or common electrode 115 is electrically connected between adjacent light-emitting devices via a conductive layer 197. This allows for isolation between adjacent light-emitting devices without separating layer 113 for each light-emitting device, for example, by photolithography. Even without separating each light-emitting device, unintended light emission due to crosstalk can be prevented, and a display device with extremely high contrast can be realized.

[0349] Alternatively, in the light-emitting device to be the light-emitting device 130R, after forming layers 113, a common layer 114, a common electrode 115, and a protective layer 128, the patterns of layers 113, a common layer 114, a common electrode 115, and a protective layer 128 are formed by photolithography. The patterns of layers 113, a common layer 114, and a common electrode 115 are separated for each light-emitting device, but the common electrode 115 is electrically connected between adjacent light-emitting devices via a conductive layer 197. In this way, the light-emitting device 130R is formed. Light-emitting devices 130G and 130B can be formed in the same manner. In this case as well, the common electrode 115 is electrically connected between adjacent light-emitting devices via the conductive layer 197. This makes it possible to increase the luminous efficiency of the light-emitting device, or to increase the color purity.

[0350] [Modification 5] In Modification 4 described above, an insulating layer 196a is provided between the lower electrode of the light-emitting device 130R and layer 113 as an insulating layer covering the upper shoulder portion of the lower electrode. A conductive layer 197 is provided on the insulating layer 196a, and an insulating layer 196b is provided on the conductive layer 197. Similarly, between the lower electrode of the light-emitting device 130G and layer 113, an insulating layer 196a covering the upper shoulder portion of the lower electrode, a conductive layer 197 on the insulating layer 196a, and an insulating layer 196b on the conductive layer 197 are provided. Between the lower electrode of the light-emitting device 130B and layer 113, an insulating layer 196a covering the upper shoulder portion of the lower electrode, a conductive layer 197 on the insulating layer 196a, and an insulating layer 196b on the conductive layer 197 are provided.

[0351] The display device shown in Figure 18B includes an insulating layer 196a covering the upper shoulder portion of the lower electrode of the light-emitting device on the insulating layer 109, an insulating layer 196b provided in contact with the upper surface of the insulating layer 196a, a conductive layer 197 provided in contact with the upper surface of the insulating layer 196b, and an insulating layer 196c provided in contact with the upper surface of the conductive layer 197. Here, the insulating layer 196a has a portion covering the upper shoulder portion of the pixel electrode 199R, a portion covering the end of the pixel electrode 199G, and a portion covering the end of the pixel electrode 199B. The left and right ends of the insulating layer 196b are located outside the insulating layer 196a. On the other hand, the left and right ends of the conductive layer 197 are located inside the left and right ends of the insulating layer 196b, respectively. Furthermore, the left and right ends of the insulating layer 196c are located outside the left and right ends of the conductive layer 197, respectively. In other words, the left and right ends of the insulating layer 196b and insulating layer 196c are located on the outside relative to the insulating layer 196a and conductive layer 197, resulting in a configuration with a two-tiered overhang shape.

[0352] It is preferable that insulating layers 196b and 196c use films of the same material. It is preferable that insulating layer 196a uses a film of a different material than insulating layers 196b and 196c. It is preferable that conductive layer 197 use a material that can be processed using dry etching. For example, a silicon nitride film can be suitably used as insulating layer 196a. Also, for example, a silicon oxide film can be suitably used as insulating layer 196b and insulating layer 196c. A titanium film can be suitably used as conductive layer 197.

[0353] Figure 18B shows a structure in which layer 113, a common layer 114 on layer 113, and a common electrode 115 on layer 113 are stepped. Layer 113 can be separated for each light-emitting device. In addition, the common layer 114 or the common electrode 115 can be electrically connected between adjacent light-emitting devices via a conductive layer 197. This allows for insulation between adjacent light-emitting devices without separating layer 113 for each light-emitting device, for example, by photolithography. Even without separating each light-emitting device, unintended light emission due to crosstalk can be prevented, and a display device with extremely high contrast can be realized.

[0354] Alternatively, in a light-emitting device that will become the light-emitting device 130R, a layer 113, a common layer 114, a common electrode 115, and a protective layer 128 are deposited, and patterns of the layer 113, common layer 114, common electrode 115, and protective layer 128 are formed by photolithography. The patterns of the layer 113, common layer 114, or common electrode 115 are separated for each light-emitting device, but the common electrode 115 is electrically connected between adjacent light-emitting devices via a conductive layer 197. In this way, the light-emitting device 130R can be formed. Similarly, light-emitting devices 130G and 130B can also be formed by photolithography. In this case as well, the common electrode 115 can be electrically connected between adjacent light-emitting devices via the conductive layer 197. This makes it possible to increase the luminous efficiency of the light-emitting device, or to increase the color purity.

[0355] (Embodiment 2) In this embodiment, a method for manufacturing a display device according to one aspect of the present invention will be described with reference to Figures 19A to 27B. Note that the description of the materials and forming methods of each element may be omitted if it is the same as that described in Embodiment 1. Furthermore, the details of the configuration of the light-emitting device will be described in Embodiment 7.

[0356] Thin films (insulating films, semiconductor films, and conductive films, etc.) that constitute display devices can be formed using sputtering, CVD, vacuum deposition, pulsed laser deposition (PLD), atomic layer deposition (ALD), and other methods. Examples of CVD methods include plasma enhanced CVD (PECVD), thermal CVD, and atmospheric pressure CVD (APCVD). One type of thermal CVD method is metal-organic CVD (MOCVD).

[0357] 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.

[0358] 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.).

[0359] When processing the thin film that constitutes the display device, lithography or the like can be used. Alternatively, the thin film may be processed by nanoimprint lithography, sandblasting, lift-off lithography, or the like. Furthermore, island-shaped thin films may be directly formed by a film deposition method using a shielding mask such as a metal mask.

[0360] There are two main lithography methods. 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.

[0361] In lithography, 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 may also be performed using immersion lithography. Furthermore, extreme ultraviolet (EUV) light or X-rays may be used as the light source for exposure. An electron beam can also be used instead of the light source 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.

[0362] For etching thin films, methods such as dry etching, wet etching, and sandblasting can be used.

[0363] [Manufacturing Method] Here, an example of a manufacturing method for the display device shown in Figure 1B will be explained using Figures 19A to 27B. Figures 19A to 27B show the cross-sectional views between the dashed line X1 and X2 shown in Figure 1B.

[0364] First, a conductive layer 250 and an insulating layer 191 between adjacent conductive layers 250 are formed on the substrate 103. The materials that can be used for the substrate 103 are as described above, and as described above, insulating layers can also be laminated on the substrate.

[0365] The conductive layer 250 and the insulating layer 191 can be formed, for example, by the following steps. First, a conductive film that will become the conductive layer 250 is formed on the substrate 103. The conductive film is patterned to form the conductive layer 250. A dry etching method can be used for pattern formation. Then, an insulating film that will become the insulating layer 191 is formed so as to cover the substrate 103 and the conductive layer 250 that have been exposed after the conductive film has been removed. Then, a part of the insulating film is removed to expose the upper surface of the conductive layer 250 and to form the insulating layer 191. It is preferable to use the CMP method to remove the part of the insulating film. By using the CMP method, the upper surfaces of the conductive layer 250 and the insulating layer 191 can be made flat.

[0366] Alternatively, an insulating film to form the insulating layer 191 is formed, and trenches are formed in the insulating film. Subsequently, a conductive film to form the conductive layer 250 is formed so as to fill the trenches in the insulating film to form the insulating layer 191. Then, a portion of the conductive film is removed to expose the upper surface of the insulating layer 191, and the conductive layer 250 is formed. When removing a portion of the conductive film, a portion of the insulating layer 191 may also be removed. The removal of the conductive film can be done by dry etching or CMP. CMP is particularly preferable. By using CMP, the upper surfaces of the conductive layer 250 and the insulating layer 191 can be made flat.

[0367] An insulating film that will become an insulating layer 188 is provided so as to cover the conductive layer 250 and the insulating layer 191, and an insulating film that will become an insulating layer 192 is formed on the insulating film. Then, by forming openings 194R that reach the conductive layer 250R, openings 194G that reach the conductive layer 250G, and openings 194B that reach the conductive layer 250B in the two insulating films, an insulating layer 188 and an interlayer insulating film 192f are obtained (Figure 19A).

[0368] The insulating layer 188 can preferably be made of, for example, silicon nitride. As an example, a laminated structure can be formed consisting of a first silicon nitride film formed by the PECVD method and a second silicon nitride film formed on the first silicon nitride film by the PEALD method.

[0369] The insulating layer 192 can be the inorganic insulating layer described in Embodiment 1.

[0370] Next, a conductive film forming the plug 170 is formed so as to cover the interlayer insulating film 192f, which will become the insulating layer 192, the openings 194R, 194G, and 194B. A portion of the conductive film forming the plug 170 is removed, exposing the upper surfaces of plugs 170R, 170G, and 170B, and the insulating layer 192 is formed (Figure 19B). The removal of the conductive film can be done, for example, by dry etching or CMP. In particular, the CMP method can be preferably used. Figure 19B shows an example in which the upper surface of the plug 170 matches or approximately matches the height of the upper surface of the insulating layer 192.

[0371] In the process of forming the insulating layer 192, a mask film made of a different material from the insulating layer 192 may be used on the insulating layer 192 beforehand. In this case, the mask film is formed, openings 194R, 194G, and 194B are formed, a conductive film that will become the plug 170 is formed, a portion of the conductive film that will become the plug 170 is removed, and then the mask film is removed to form the plug 170 and the insulating layer 192. In this way, the flatness of the formed surfaces of the plug 170 and the insulating layer 192 can be increased.

[0372] Next, a conductive film 111f, which will become the conductive layer 111, is formed on the plug 170 and the insulating layer 192 (Figure 19C). Then, the conductive layer 111R, conductive layer 111G, and conductive layer 111B are formed by processing the conductive film 111f (Figure 20A). For example, the conductive film 111f can be formed by sputtering or vacuum deposition. Note that when processing the conductive film 111f, a part of the insulating layer 192 may be removed, and a recess may be formed in the insulating layer 192.

[0373] Next, trenches are formed in the insulating layer 192 by using the conductive layer 111 as a hard mask (Figure 20B). Because the insulating layer is processed using the conductive layer 111 as a hard mask, the conductive layer 111 and the insulating layer 192 have the same surface and the same side surface. The trenches in the insulating layer 192 can be formed, for example, by dry etching.

[0374] Next, a conductive film 199f is formed on the conductive layer 111 (Figure 20C). The conductive film 199f is formed to cover the top surface of the conductive layer 111, the side surfaces of the conductive layer 111, the side surfaces of the trenches of the insulating layer 192, and the bottom surface of the trenches of the insulating layer 192. Various thin-film formation methods can be used to form the conductive film 199f. For example, a conductive film 199f can be formed by laminating an In-Sn oxide layer, a conductive layer having an Ag-Pd-Cu alloy, and another In-Sn oxide layer using a sputtering method.

[0375] Next, a resist mask MSK1 is formed on the conductive film 199f (Figure 21A).

[0376] Next, the conductive film 199f is processed using the resist mask MSK1 as a mask to form the pixel electrode 199R, pixel electrode 199G, and pixel electrode 199B (Figure 21B).

[0377] Wet etching can be used to process the conductive film 199f. As shown in Figure 21B, wet etching removes the conductive film 199f formed on the bottom surface of the trenches in the insulating layer 192. In addition, the conductive film 199f inside the edge of the resist mask MSK1 and a portion of the conductive film 199f formed on the side surface of the trenches in the insulating layer 192 may also be etched. As previously mentioned in Figures 5A to 5C, wet etching tends to proceed isotropically, and etching may penetrate inward from the edge of the resist mask. In the method for manufacturing a display device according to one embodiment of the present invention, since the conductive film 199f has a portion formed along the side surface of the insulating layer 192, even if etching proceeds inward beyond the edge of the resist mask MSK1, variations in the electrode width of the pixel electrode 199 can be suppressed.

[0378] Next, remove the resist mask MSK1 (Figure 21C).

[0379] Next, an insulating film 109f, which will become the insulating layer 109, is formed on the insulating layer 192 and the pixel electrode 199 (Figure 22A). The insulating film 109f is formed to fill the region between two adjacent conductive layers 111 and the trenches of the insulating layer 192.

[0380] Next, a part of the insulating film 109f is removed to expose the pixel electrode 199, and the insulating layer 109 is formed (FIG. 22B). The insulating layer 109 can be formed using a dry etching method or a CMP method.

[0381] Subsequently, it is preferable to perform a hydrophobization treatment on the pixel electrode 199. By the hydrophobization treatment, the surface of the treatment target changes from hydrophilic to hydrophobic, or the hydrophobicity of the surface of the treatment target is enhanced. By performing the hydrophobization treatment on the pixel electrode 199, the adhesion between the pixel electrode 199 and the film (here, the film 113b) formed in a later process can be enhanced, and film peeling can be suppressed. Note that the hydrophobization treatment may not be performed.

[0382] The hydrophobization treatment can be performed, for example, by fluorine modification of the pixel electrode 199. The fluorine modification can be performed, for example, by treatment with a gas containing fluorine or heat treatment, plasma treatment in an atmosphere of a gas containing fluorine, etc. As the gas containing fluorine, for example, fluorine gas can be used, and for example, fluorocarbon gas can be used. As the fluorocarbon gas, for example, carbon tetrafluoride (CF ８ ) gas, C ４ F ６ gas, C ２ F ６ gas, C ４ F ８ gas, C ５ F ８ and other lower fluorocarbon gases can be used. Also, as the gas containing fluorine, for example, SF ６ gas, NF ３ gas, CHF ３ gas, etc. can be used. Also, helium gas, argon gas, hydrogen gas, etc. can be appropriately added to these gases.

[0383] The surface of the pixel electrode 199 can be made hydrophobic by performing plasma treatment in a gas atmosphere containing a group 18 element such as argon, followed by treatment with a silylation agent. Examples of silylation agents that can be used include hexamethyldisilazane (HMDS) and trimethylsilylimidazole (TMSI). Furthermore, the surface of the pixel electrode 199 can also be made hydrophobic by performing plasma treatment in a gas atmosphere containing a group 18 element such as argon, followed by treatment with a silane coupling agent.

[0384] By performing plasma treatment on the surface of the pixel electrode 199 in a gas atmosphere containing a group 18 element such as argon, damage can be inflicted on the surface of the pixel electrode 199. This makes it easier for methyl groups contained in silylation agents such as HMDS to bond to the surface of the pixel electrode 199. It also makes silane coupling by silane coupling agents easier to occur. Thus, by performing plasma treatment on the surface of the pixel electrode 199 in a gas atmosphere containing a group 18 element such as argon, followed by treatment with a silylation agent or a silane coupling agent, the surface of the pixel electrode 199 can be made hydrophobic.

[0385] Treatment using a silylation agent or silane coupling agent can be carried out by applying the silylation agent or silane coupling agent using, for example, a spin coating method or a dip method. Alternatively, treatment using a silylation agent or silane coupling agent can be carried out by forming a film containing a silylation agent or a film containing a silane coupling agent in contact with the pixel electrode 199 using, for example, a vapor phase method. In the vapor phase method, first, the silylation agent or silane coupling agent is incorporated into the atmosphere by evaporating the material containing the silylation agent or the material containing the silane coupling agent. Subsequently, the substrate on which the pixel electrode 199 is formed is placed in this atmosphere. This allows a film containing a silylation agent or silane coupling agent to be formed in contact with the pixel electrode 199, thereby hydrophobicizing the surface of the pixel electrode 199.

[0386] Subsequently, a film 113b, which will later become the layer 113B, is formed on the pixel electrode 199B (FIG. 23A). The film 113b (the later layer 113B) contains a light-emitting material that emits blue light. That is, in the present embodiment, first, an island-shaped EL layer of a light-emitting device that emits blue light is formed, and then an island-shaped EL layer of a light-emitting device that emits light of other colors is formed.

[0387] As described in Embodiment 1, in a display device according to an aspect of the present invention, a material with high heat resistance is used for the light-emitting device. Specifically, the heat-resistant temperature of the compounds contained in the film 113b is preferably 100°C or higher and 180°C or lower, more preferably 120°C or higher and 180°C or lower, and even more preferably 140°C or higher and 180°C or lower. Thereby, the reliability of the light-emitting device can be enhanced. Also, the upper limit of the temperature allowed in the manufacturing process of the display device can be increased. Therefore, the range of selection of materials and formation methods used for the display device can be widened, and improvements in manufacturing yield and reliability can be achieved.

[0388] The film 113b can be formed, for example, by a vapor deposition method, specifically, a vacuum vapor deposition method. Also, the film 113b may be formed by a method such as a transfer method, a printing method, an inkjet method, or a coating method.

[0389] Subsequently, a mask film 118b that will become the mask layer 118B and a mask film 119b that will become the mask layer 119B are sequentially formed on the film 113b (FIG. 23A). <0~

[0390] In the present embodiment, an example of a two-layer structure of the mask film 118b and the mask film 119b is shown, but the mask film can also have a single-layer structure or a laminated structure of three or more layers.

[0391] By providing a mask layer on the film 113b, damage applied to the film 113b during the manufacturing process of the display device can be reduced, and the reliability of the light-emitting device can be enhanced.

[0392] For the mask film 118b, a film with high resistance to the processing conditions of the film 113b, specifically, a film with a large etching selectivity ratio with respect to the film 113b, is used. For the mask film 119b, a film with a large etching selectivity ratio with respect to the mask film 118b is used.

[0393] The mask films 118b and 119b are formed at a temperature lower than the heat resistance temperature of the film 113b. As the substrate temperature when forming the mask films 118b and 119b, typically, it is 200°C or lower, preferably 150°C or lower, more preferably 120°C or lower, still more preferably 100°C or lower, and even more preferably 80°C or lower, respectively.

[0394] As an index of the heat resistance temperature, for example, the glass transition point, softening point, melting point, thermal decomposition temperature, and 5% weight loss temperature, etc. can be mentioned. As the heat resistance temperature of the film 113b, film 113g, and film 113r (that is, layer 113B, layer 113G, and layer 113R), it can be any of these temperatures serving as the index of the heat resistance temperature, preferably the lowest temperature among them.

[0395] As described above, in the display device according to one aspect of the present invention, a material with high heat resistance is used for the light-emitting device. Therefore, the substrate temperature when forming the mask film can also be 100°C or higher, 120°C or higher, or 140°C or higher. For example, the higher the film formation temperature of the inorganic insulating film, the denser and more barrier - like the film can be. Therefore, by forming the mask film at such a temperature, the damage to the film 113b can be further reduced, and the reliability of the light - emitting device can be enhanced.

[0396] It is preferable to use a film that can be removed by a wet etching method for the mask films 118b and 119b. By using the wet etching method, the damage to the film 113b during the processing of the mask films 118b and 119b can be reduced compared to the case of using the dry etching method.

[0397] For the formation of the mask films 118b and 119b, for example, a sputtering method, an ALD method (including a thermal ALD method and a PEALD method), a CVD method, or a vacuum evaporation method can be used. Also, it may be formed using the above - mentioned wet film - forming method.

[0398] Furthermore, it is preferable to form the mask film 118b, which is formed in contact with the film 113b, using a formation 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.

[0399] For the mask film 118b and the 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.

[0400] 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.

[0401] 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 the film 113b and thus suppress deterioration of the film 113b. Specifically, it is possible to suppress plasma damage to the 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.

[0402] 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.

[0403] 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.

[0404] By using a mask film containing a material that blocks 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 caused by ultraviolet light, the reliability of the light-emitting device can be improved.

[0405] Furthermore, a similar effect can be obtained by using a film containing a material that has light-shielding properties against ultraviolet rays as the material for the insulating film 125f, which will be described later.

[0406] Various inorganic insulating films that can be used in the protective layer 128 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. Furthermore, mask films 118b and 119b can be formed using the ALD method, for example, an aluminum oxide film can be formed. Using the ALD method is preferable because it reduces damage to the substrate (especially the EL layer).

[0407] 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.

[0408] 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 may be applied to the mask film 118b and the insulating layer 125, or different film formation conditions may be applied to each. 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 will be mostly or completely removed in a later process, it is preferable that it be easy to process. For this reason, 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.

[0409] Organic materials may be used in one 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 the film located at least on top of film 113b may be used. Materials that are soluble in water or alcohol are particularly suitable. When forming such a film, it is preferable to apply the material by a wet film formation method while it is dissolved in a solvent such as water or alcohol, and then perform a heat treatment to evaporate the solvent. At this time, performing the heat treatment under a reduced pressure atmosphere is preferable because it allows the solvent to be removed at a low temperature and in a short time, thereby reducing thermal damage to film 113b.

[0410] The mask film 118b and the mask film 119b may each be made of the same organic material that can be used for the insulating layer 127 described above.

[0411] For example, an organic film (e.g., a PVA film) formed using either a vapor deposition method or the wet film formation method described above can be used as the mask film 118b, and an inorganic film (e.g., a silicon nitride film) formed using a sputtering method can be used as the mask film 119b.

[0412] As described in Embodiment 1, in one embodiment of the present invention, a portion of the mask film may remain as a mask layer in the display device.

[0413] Next, a resist mask 190B is formed on the mask film 119b (Figure 23A). The resist mask 190B can be formed by applying a photosensitive resin, followed by exposure and development.

[0414] The resist mask 190B can use either a positive-type resist material or a negative-type resist material.

[0415] The resist mask 190B is positioned to overlap with the pixel electrode 199B.

[0416] Next, a portion of the mask film 119b is removed using the resist mask 190B as a mask, and a mask layer 119B is formed. The mask layer 119B remains on the pixel electrode 199B. Then, the resist mask 190B is removed (Figure 23B).

[0417] Next, using the mask layer 119B as a mask, a portion of the mask film 118b is removed, and the mask layer 118B is formed (Figure 23C). The mask layer 119B can also be said to function as a hard mask.

[0418] Mask films 118b and 119b can be processed by wet etching or dry etching, respectively. It is preferable to use an anisotropic dry etching method for processing mask films 118b and 119b.

[0419] By using the wet etching method, damage to the film 113b during processing of the mask films 118b and 119b can be reduced compared to the dry etching method. In the wet etching method, it is preferable to use, for example, 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.

[0420] In processing the mask film 119b, the film 113b is not exposed, so there is a wider range of processing methods to choose from compared to processing the mask film 118b. Specifically, when processing the mask film 119b, even if an oxygen-containing gas is used as the etching gas, the deterioration of the film 113b can be further suppressed.

[0421] When using a dry etching method for processing the mask film 118b, the degradation of the film 113b can be suppressed by not using an oxygen-containing gas as the etching gas. When using a dry etching method, for example, 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 noble gases such as He as the etching gas.

[0422] For example, when using an aluminum oxide film formed using the ALD method as the mask film 118b, CHF ３ and He, or CHF ３and 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.

[0423] The resist mask 190B can be removed, for example, by ashing using oxygen plasma. Or, O ２ And CF ４ , C ４ F ８ SF ６ CHF ３ , Cl ２ , H ２ O, BCl ３ Alternatively, a noble gas such as He can be used. Or, the resist mask 190B can be removed by wet etching. In this case, since the mask film 118b is located on the outermost surface and film 113b is not exposed, damage to film 113b can be suppressed during the resist mask 190B removal process. In addition, the range of selectable methods for removing the resist mask 190B can be broadened.

[0424] Next, the film 113b is processed to form layer 113B. For example, a portion of the film 113b is removed using mask layers 119B and 118B as masks to form layer 113B (Figure 23C). Mask layers 119B and 118B can also be said to function as hard masks.

[0425] As a result, as shown in FIG. 23C, a laminated structure of the layer 113B, the mask layer 118B, and the mask layer 119B remains on the pixel electrode 199B. The upper surfaces and upper surface shoulders of the pixel electrodes 199R and 199G are exposed.

[0426] Here, when processing the film 113b, the pixel electrodes 199R and 199G are exposed to an etching gas or an etching solution. On the other hand, the pixel electrode 199B is not exposed to an etching gas or an etching solution. In this case, in the light-emitting device of the color formed first, the pixel electrode 199 is not damaged by the etching process, and the state of the interface between the pixel electrode and the EL layer can be kept good.

[0427] The processing of the film 113b is preferably performed by anisotropic etching. In particular, it is preferable to use an anisotropic dry etching method. Alternatively, a wet etching method can also be used.

[0428] When using the dry etching method for processing the film 113b, in the process of manufacturing the display device, the surface of the display device is exposed to plasma in the dry etching apparatus. Here, by using a metal film or an alloy film for one or both of the mask layer 118B and the mask layer 119B, it is possible to suppress damage by plasma being applied to the portion where the film 113b remains (the portion that becomes the layer 113B), and thus it is possible to suppress deterioration of the layer 113B, which is preferable. In particular, it is preferable to use a metal film or an alloy film such as a tungsten film as the mask layer 119B.

[0429] When using the dry etching method, by not using a gas containing O ２ in the etching gas, deterioration of the film 113b can be suppressed.

[0430] A gas containing O ２ can also be used as the etching gas. When the etching gas is O ２By including this, the etching rate can be increased. Therefore, etching can be performed under low power conditions while maintaining a sufficiently fast etching rate. As a result, damage to the film 113b can be suppressed. Furthermore, problems such as the adhesion of reaction products generated during etching can be suppressed.

[0431] When using the dry etching method, for example, H ２ 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 also 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 , He, and O ２ A gas containing H can be used as an etching gas. Also, for example, H ２ Gases containing Ar and gases containing oxygen can be used as etching gases.

[0432] 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.

[0433] Figure 23C shows an example where the edge of layer 113B is located outside the edge of the pixel electrode 199B. This configuration allows for a higher aperture ratio of the pixel. Although not shown in Figure 23C, the etching process may result in the formation of recesses in areas of the insulating layer 109 that do not overlap with layer 113B.

[0434] By having layer 113B cover the top and sides of the pixel electrode 199B, processing can be performed in subsequent steps without exposing the pixel electrode 199B. If the ends of the pixel electrode 199B are exposed, corrosion may occur during etching or other processes. Products generated by the corrosion of the pixel electrode 199B may have unstable properties; for example, in the case of wet etching, they may dissolve in the solution, and in the case of dry etching, 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, potentially adversely affecting the characteristics of the light-emitting device. It may also create leak paths between multiple light-emitting devices. Therefore, by configuring layer 113B to cover the top and sides of the pixel electrode 199B, for example, the yield and characteristics of the light-emitting device can be improved.

[0435] 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 mask. Therefore, it can be said that a layer 113B is formed by processing the film 113b using a photolithography method. Alternatively, a portion of the film 113b can be removed using the resist mask 190B. After that, the resist mask 190B can be removed.

[0436] Next, it is preferable to perform a hydrophobic treatment on the pixel electrode 199. During the processing of the film 113b, the surface state of the pixel electrode 199 may change to hydrophilic. By performing a hydrophobic treatment on the pixel electrode 199, the adhesion between the pixel electrode 199 and the film (in this case, film 113g) formed in a later step can be improved, and film peeling can be suppressed. However, the hydrophobic treatment is not required.

[0437] Next, a film 113g, which will become layer 113G, is formed on the pixel electrode 199R, on the pixel electrode 199G, and on the mask layer 119B (Figure 24A). The film 113g (later layer 113G) contains a light-emitting material that emits green light. In other words, this embodiment shows an example in which an island-shaped EL layer for a light-emitting device that emits green light is formed secondly. However, the present invention is not limited to this, and secondly, an island-shaped EL layer for a light-emitting device that emits red light can also be formed.

[0438] The film 113g can be formed by the same method as that used to form film 113b.

[0439] Next, a mask film 118g, which will become mask layer 118G, and a mask film 119g, which will become mask layer 119G, are formed sequentially on film 113g, after which the resist mask 190G is formed (Figure 24A). The materials and formation methods for mask film 118g and mask film 119g are the same as those applicable to mask film 118b and mask film 119b. The materials and formation methods for resist mask 190G are the same as those applicable to resist mask 190B.

[0440] The resist mask 190G is positioned to overlap with the pixel electrode 199G.

[0441] Next, a portion of the mask film 119g is removed using the resist mask 190G, forming a mask layer 119G. The mask layer 119G remains on the pixel electrode 199G. Subsequently, the resist mask 190G is removed (Figure 24B).

[0442] Next, using mask layer 119G as a mask, a portion of mask film 118g is removed, forming mask layer 118G. Then, film 113g is processed to form layer 113G. For example, using mask layer 119G and mask layer 118G as masks, a portion of film 113g is removed, forming layer 113G (Figure 24C).

[0443] Here, when processing the film 113g, the pixel electrode 199R is exposed to etching gas or etching solution. On the other hand, the pixel electrodes 199G and 199B are not exposed to etching gas or etching solution. In other words, in the second color light-emitting device formed, the surface of the pixel electrode is exposed in one etching step, and in the third color light-emitting device formed, the surface of the pixel electrode is exposed in two etching steps. For this reason, it is preferable to form the island-shaped EL layer earlier for light-emitting devices in which the surface condition of the pixel electrode is more likely to affect the characteristics. This makes it possible to improve the characteristics of each color light-emitting device.

[0444] Using a metal film or alloy film on one or both of the mask layers 118B and 119B is preferable because it suppresses plasma damage to layer 113B when forming layer 113B using the dry etching method, thereby preventing deterioration of layer 113B. Similarly, using a metal film or alloy film on one or both of the mask layers 118G and 119G is also preferable because it suppresses plasma damage to the remaining portion of film 113g (layer 113G), thereby preventing deterioration of layer 113G. In particular, it is preferable to use a metal film or alloy film such as a tungsten film as the mask layer 119G.

[0445] As a result, as shown in Figure 24C, the stacked structure of layer 113G, mask layer 118G, and mask layer 119G remains on the pixel electrode 199G. The upper surface and upper shoulder portion of the pixel electrode 199R are exposed.

[0446] Next, it is preferable to perform a hydrophobic treatment on the pixel electrode 199. The hydrophobic treatment is effective when the surface state of the pixel electrode 199 changes to hydrophilic when processing the film 113g. By performing a hydrophobic treatment on the pixel electrode 199, the adhesion between the pixel electrode 199 and the film (in this case, film 113r) formed in a later step can be improved, and film peeling can be suppressed. However, the hydrophobic treatment is not required.

[0447] Next, the film 113r, which will become layer 113R, is formed on the pixel electrode 199R, the mask layer 119G, and the mask layer 119B (Figure 25A). The film 113r (later layer 113R) contains a light-emitting material that emits red light.

[0448] The film 113r can be formed by the same method as that used to form the film 113b.

[0449] Next, a mask film 118r, which will become the mask layer 118R, and a mask film 119r, which will become the mask layer 119R, are formed sequentially on the film 113r, after which the resist mask 190R is formed (Figure 25A). The materials and formation methods for the mask films 118r and 119r are the same as those applicable to the mask films 118b and 119b. The materials and formation methods for the resist mask 190R are the same as those applicable to the resist mask 190B.

[0450] The resist mask 190R is positioned to overlap with the pixel electrode 199R.

[0451] Next, a portion of the mask film 119r is removed using the resist mask 190R as a mask, and a mask layer 119R is formed. The mask layer 119R remains on the pixel electrode 199R. Then, the resist mask 190R is removed (Figure 25B).

[0452] Next, a portion of the mask film 118r is removed using the mask layer 119R as a mask, and the mask layer 118R is formed. Subsequently, the film 113r is processed to form layer 113R. For example, in the film 113r, a portion is removed using the mask layer 119R and the mask layer 118R as masks, and layer 113R is formed (Figure 25C).

[0453] It is preferable to use a metal film or alloy film for mask layer 118B and / or mask layer 119B, and mask layer 118G and / or mask layer 119G, respectively, as this suppresses plasma damage to layers 113B and 113G and prevents deterioration of layers 113B and 113G. It is also preferable to use a metal film or alloy film for mask layer 118R and / or mask layer 119R, as this suppresses plasma damage to the remaining portion of film 113r (layer 113R) and prevents deterioration of layer 113R. In particular, it is preferable to use a metal film such as a tungsten film or an alloy film as mask layer 119R.

[0454] As a result, as shown in Figure 25C, the stacked structure of layer 113R, mask layer 118R, and mask layer 119R remains on the pixel electrode 199R. In addition, mask layer 119G and mask layer 119B are exposed.

[0455] Furthermore, it is preferable that the sides of layers 113B, 113G, and 113R are perpendicular or approximately perpendicular to the surface to be formed. For example, it is preferable that the angle between the surface to be formed and these sides be 60 degrees or more and 90 degrees or less.

[0456] As described above, the distance between two adjacent layers of layers 113B, 113G, and 113R formed using photolithography 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, this distance refers to, for example, the distance between two adjacent opposing ends of layers 113B, 113G, and 113R. By narrowing the distance between the island-shaped EL layers in this way, a display device with high resolution and a large aperture ratio can be provided.

[0457] Next, it is preferable to remove the mask layer 119B, mask layer 119G, and mask layer 119R (Figure 26A). Depending on the subsequent process, 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 suppress the remaining mask layer 119B, mask layer 119G, and mask layer 119R 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 in advance 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.

[0458] In this embodiment, the case in which mask layers 119B, 119G, and 119R are removed is described as an example, but it is also possible to have a configuration in which mask layers 119B, 119G, and 119R are not removed. For example, if mask layers 119B, 119G, and 119R contain the aforementioned light-shielding material against ultraviolet rays, it is preferable to proceed to the next step without removing them, as this protects the island-shaped EL layer from ultraviolet rays.

[0459] The same method as the mask film processing method can be used for the mask film removal process. In particular, by using a wet etching method, the damage inflicted on layers 113B, 113G, and 113R when removing the mask layer can be reduced compared to when using a dry etching method.

[0460] 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 by dry etching. On the other hand, in the process of removing mask layers 119B, 119G, and 119R, and in the processes after removal, the film that suppresses plasma damage to the EL layer is gone, so it is preferable to process the film by a method that does not use plasma, such as wet etching.

[0461] The mask layer can be removed by dissolving it in a solvent such as water or alcohol. Examples of alcohols include ethyl alcohol, methyl alcohol, isopropyl alcohol (IPA), or glycerin.

[0462] After removing the mask layer, 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 is preferably performed at a substrate temperature of 50°C to 200°C, more preferably at 60°C to 150°C, and even more preferably at 70°C to 120°C. A reduced pressure atmosphere is preferable because it allows drying at a lower temperature.

[0463] Next, an insulating film 125f, which will become the insulating layer 125, is formed so as to cover the pixel electrode 199, layer 113, and mask layer 118 (Figure 26A).

[0464] Next, an insulating layer 127f is formed in contact with the upper surface of the insulating film 125f (Figure 26B). 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 layer 127f (for example, a photosensitive resin composition containing acrylic resin). To improve adhesion, it is preferable to hydrophobize (or increase the hydrophobicity of) the upper surface of the insulating film 125f by performing a surface treatment. For example, it is preferable to perform the treatment using a silylation agent such as hexamethyldisilazane (HMDS). By hydrophobizing the upper surface of the insulating film 125f in this way, the insulating layer 127 can be formed with high adhesion. The aforementioned hydrophobic treatment can also be used as the surface treatment.

[0465] Next, the insulating layer 127f is processed to form the insulating layer 127 (Figure 26C).

[0466] The insulating film 125f and the insulating layer 127 are preferably formed using a method that minimizes damage to layer 113. In particular, since the insulating film 125f is formed in contact with the side surface of layer 113, it is preferable that it be formed using a method that minimizes damage to layer 113 more than the insulating layer 127.

[0467] The insulating film 125f and the insulating layer 127 are each formed at a temperature lower than the heat resistance temperature of layer 113. Furthermore, by increasing the substrate temperature during film formation of the 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.

[0468] Preferably, the substrate temperature when forming the insulating film 125f and the insulating layer 127 is 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.

[0469] 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 the insulating layer 127 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.

[0470] 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.

[0471] In addition, the insulating film 125f may be formed using a sputtering method, CVD method, or PECVD method, which have a faster deposition rate than the ALD method. This makes it possible to manufacture highly reliable display devices with high productivity.

[0472] The insulating layer 127 can be formed, for example, by applying a photosensitive resin and then exposing and developing it. The insulating layer 127 is formed in the region sandwiched between any two of the pixel electrodes 199R, 199G, and 199B.

[0473] Here, the width of the insulating layer 127 can be controlled by adjusting the exposure amount. In this embodiment, the insulating layer 127 is processed so that it has a portion that overlaps with the upper surface of the pixel electrode 199. However, it is also possible to have an insulating layer 127 that does not have a portion that overlaps with the upper surface of the pixel electrode 199.

[0474] Furthermore, etching can be performed to adjust the surface height of the insulating layer 127. The insulating layer 127 can also be processed, for example, by ashing using oxygen plasma.

[0475] Next, the taper angle of the side surface of the insulating layer 127 can be adjusted by performing a heat treatment (hereinafter also referred to as post-bake). Specifically, the taper angle of the side surface of the insulating layer 127 can be made smaller. The temperature of the heat treatment is preferably lower than the heat resistance temperature of the EL layer. The substrate temperature during the heat treatment is 50°C to 200°C, preferably 60°C to 150°C, and more preferably 70°C to 130°C. The heating atmosphere can be an atmospheric atmosphere or an inert gas atmosphere. The heating atmosphere can also be an atmospheric pressure atmosphere or a reduced pressure atmosphere. A reduced pressure atmosphere is preferable because it allows drying at a lower temperature.

[0476] Next, as shown in Figure 27A, the insulating layer 127 is used as a mask, and a portion of the insulating film 125f and the mask layer 118 are removed. As a result, the insulating layer 125 is formed, and openings are created in each of the mask layers 118. Also, the upper surface of layer 113 is exposed.

[0477] The etching process can be carried out by dry etching or wet etching. It is preferable to use the same material for the insulating film 125f as for the mask layer 118, as these can be etched together.

[0478] When performing dry etching, it is preferable to use a chlorine-based gas. Examples of chlorine-based gases include Cl ２ , BCl ３ SiCl ４ , and CCl ４These can be used individually or in combination of two or more gases. In addition, oxygen gas, hydrogen gas, helium gas, and argon gas can be added to the chlorine-based gas as appropriate, individually or in combination of two or more gases. By using dry etching, thin areas of the mask layer 118B, mask layer 118G, and mask layer 118R can be formed with good in-plane uniformity.

[0479] When dry etching is performed, by-products generated during dry etching may accumulate on the upper and side surfaces of the insulating layer 127. Therefore, components contained in the etching gas, components contained in the insulating film 125f, and components contained in the mask layer 118 may be present in the insulating layer 127 after the display device is completed.

[0480] It is preferable to perform the etching process by wet etching. By using the wet etching method, the damage to layer 113 can be reduced compared to when using the dry etching method. For example, wet etching can be performed using an alkaline solution. For example, for wet etching of an aluminum oxide film, it is preferable to use an aqueous solution of tetramethylammonium hydroxide (TMAH), which is an alkaline solution. In this case, wet etching can be performed using a paddle method.

[0481] As described above, by providing the insulating layer 127, insulating layer 125, and mask layer 118, connection failures due to discontinued areas in the common layer 114 and common electrode 115 between each light-emitting device, and increases in electrical resistance due to locally thinner film thicknesses can be suppressed. As a result, a display device according to one embodiment of the present invention can improve display quality.

[0482] After exposing a portion of layer 113, 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 insulating layer 125, the edge of mask layer 118B, the edge of mask layer 118G, the edge of mask layer 118R, and the upper surface of layer 113B, the upper surface of layer 113G, and the upper surface of layer 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.

[0483] Furthermore, the insulating layer 127 can be configured to cover the entire edge of the mask layer 118.

[0484] Next, a common layer 114 and a common electrode 115 are formed on the insulating layer 127 and layer 113 in that order. Furthermore, a protective layer 128 is formed (Figure 27B).

[0485] Next, an insulating layer 122 having a planarization function is formed on the protective layer 128, and then the substrate 120 is bonded to the insulating layer 122 using an adhesive layer 129 to create a display device (Figures 1B and 2A).

[0486] The common layer 114 can be created, for example, by a vapor deposition method (including vacuum deposition), a transfer method, a printing method, an inkjet method, or a coating method.

[0487] For the formation of the common electrode 115, for example, sputtering or vacuum deposition can be used. Alternatively, a film formed by deposition and a film formed by sputtering can be laminated together.

[0488] The protective layer 128 can be formed by, for example, vacuum deposition, sputtering, CVD, or ALD.

[0489] By following the above steps, a display device according to one aspect of the present invention can be manufactured.

[0490] (Embodiment 3) In this embodiment, a display device according to one aspect of the present invention will be described with reference to Figures 28 and 29.

[0491] [Pixel Layout] In this embodiment, a pixel layout different from that shown in Figure 1A will be described. The arrangement of subpixels is not particularly limited, 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.

[0492] 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).

[0493] 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.

[0494] 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.

[0495] The pixel 110 shown in Figure 28A has an S-stripe array applied to it. The pixel 110 shown in Figure 28A is composed of three subpixels: subpixel 110a, subpixel 110b, and subpixel 110c.

[0496] The pixel 110 shown in Figure 28B includes a sub-pixel 110a having a roughly trapezoidal or roughly triangular top surface shape with rounded corners, a sub-pixel 110b having a roughly triangular or roughly triangular top surface shape with rounded corners, and a sub-pixel 110c having a roughly square or roughly 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 size that has a more reliable light-emitting device.

[0497] A pentile array is applied to pixels 124a and 124b shown in Figure 28C. Figure 28C 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.

[0498] Pixels 124a and 124b shown in Figures 28D to 28F 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).

[0499] Figure 28D shows an example where each subpixel has a roughly square top shape with rounded corners, Figure 28E shows an example where each subpixel has a circular top shape, and Figure 28F shows an example where each subpixel has a roughly hexagonal top shape with rounded corners.

[0500] In Figure 28F, 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.

[0501] Figure 28G 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.

[0502] In each pixel shown in Figures 28A to 28G, 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.

[0503] 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.

[0504] 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.

[0505] 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.

[0506] As shown in Figures 29A to 29I, the pixel can be configured to have four types of subpixels.

[0507] The pixels 110 shown in Figures 29A to 29C are arranged in a stripe pattern.

[0508] Figure 29A shows an example where each subpixel has a rectangular top surface shape, Figure 29B shows an example where each subpixel has a top surface shape formed by connecting two semicircles and a rectangle, and Figure 29C shows an example where each subpixel has an elliptical top surface shape.

[0509] The pixels 110 shown in Figures 29D to 29F are arranged in a matrix array.

[0510] Figure 29D shows an example where each subpixel has a square top surface shape, Figure 29E shows an example where each subpixel has a roughly square top surface shape with rounded corners, and Figure 29F shows an example where each subpixel has a circular top surface shape.

[0511] Figures 29G and 29H show an example in which one pixel 110 is composed of 2 rows and 3 columns.

[0512] The pixel 110 shown in Figure 29G 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.

[0513] The pixel 110 shown in Figure 29H 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 29H, 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.

[0514] Figure 29I shows an example where one pixel 110 is composed of 3 rows and 2 columns.

[0515] The pixel 110 shown in Figure 29I 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.

[0516] The pixel 110 shown in Figures 29A to 29I is composed of four subpixels: subpixel 110a, subpixel 110b, subpixel 110c, and subpixel 110d.

[0517] 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).

[0518] In each pixel 110 shown in Figures 29A to 29I, it is preferable, for example, that sub-pixel 110a be sub-pixel R emitting red light, sub-pixel 110b be sub-pixel G emitting green light, sub-pixel 110c be sub-pixel B emitting blue light, and sub-pixel 110d be sub-pixel W emitting white light, sub-pixel Y emitting yellow light, or sub-pixel IR emitting near-infrared light. With such a configuration, in the pixels 110 shown in Figures 29G and 29H, the layout of R, G, and B forms a stripe arrangement, which can improve the display quality. Also, in the pixels 110 shown in Figure 29I, the layout of R, G, and B forms a so-called S-stripe arrangement, which can improve the display quality.

[0519] Pixel 110 may have subpixels that have light-receiving devices.

[0520] In each pixel 110 shown in Figures 29A to 29I, one of the sub-pixels 110a to 110d can be a sub-pixel having a light-receiving device.

[0521] In each pixel 110 shown in Figures 29A to 29I, 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 29G and 29H, 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 29I, the layout of R, G, and B becomes a so-called S-stripe arrangement, which can improve the display quality.

[0522] 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.

[0523] As shown in Figures 29J and 29K, a pixel can be configured to have five types of subpixels.

[0524] Figure 29J shows an example where one pixel 110 is composed of two rows and three columns.

[0525] The pixel 110 shown in Figure 29J 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.

[0526] Figure 29K shows an example where one pixel 110 is composed of 3 rows and 2 columns.

[0527] The pixel 110 shown in Figure 29K 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).

[0528] In each pixel 110 shown in Figures 29J and 29K, 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 29J, 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 29K, the layout of R, G, and B becomes a so-called S-stripe arrangement, which can improve the display quality.

[0529] In each pixel 110 shown in Figures 29J and 29K, 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.

[0530] In each pixel 110 shown in Figures 29J and 29K, 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.

[0531] 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.

[0532] 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.

[0533] This embodiment can be combined with other embodiments as appropriate.

[0534] (Embodiment 4) This embodiment describes an example of the configuration of a semiconductor device according to one aspect of the present invention. Here, a transistor is described as an example of a semiconductor device. The semiconductor layer of the transistor described below can be the semiconductor layer illustrated in Embodiment 4.

[0535] [Example of Semiconductor Device Configuration] Figures 30A to 30D are plan views and cross-sectional views of the transistor 1200. Figure 30A is a plan view of the transistor 1200, and Figures 30B to 30D are schematic cross-sectional views corresponding to the cutting lines A11-A12, A13-A14, and A15-A16 in Figure 30A, respectively. Here, Figure 30B is a cross-section of the transistor 1200 in the channel length direction, and Figures 30C and 30D correspond to cross-sections in the channel width direction, respectively. Figure 31 is an enlarged view of Figure 30B. Note that some components are omitted in Figure 30A.

[0536] The transistor 1200 includes a substrate 1210, an insulating layer 1201 provided on the substrate 1210, a semiconductor layer 1230 provided on the insulating layer 1201, conductive layers 1242a and 1242b provided on the semiconductor layer 1230, an insulating layer 1250 provided on the semiconductor layer 1230, and a conductive layer 1260 provided on the insulating layer 1250. An insulating layer 1275 is provided covering the semiconductor layer 1230, conductive layer 1242a, and conductive layer 1242b, and an insulating layer 1280 is provided on the insulating layer 1275. The insulating layer 1280 and insulating layer 1275 are provided with grooves that reach the semiconductor layer 1230, and the conductive layer 1242a and conductive layer 1242b are separated by these grooves. The insulating layer 1250 is provided within the groove, along the surfaces of the insulating layer 1280, insulating layer 1275, conductive layer 1242a, conductive layer 1242b, and semiconductor layer 1230. The conductive layer 1260 is provided on the insulating layer 1250 so as to fill the groove. In addition, insulating layers 1282 and 1285 are provided in order, covering the insulating layers 1280, insulating layer 1250, and conductive layer 1260.

[0537] The semiconductor layer 1230 functions as the channel formation region of the transistor 1200. The conductive layer 1260 functions as the gate electrode of the transistor 1200. The insulating layer 1250 functions as the gate insulating layer of the transistor 1200. The conductive layer 1242a functions as either the source electrode or the drain electrode of the transistor 1200, and the conductive layer 1242b functions as the other.

[0538] The semiconductor layer 1230 can be made using the semiconductor layer exemplified in this embodiment. Similarly, the insulating layer 1201 can be made using the insulating layer exemplified in this embodiment.

[0539] It is preferable that the conductive layers 1242a and 1242b have a laminated structure. It is preferable to use a conductor that is resistant to oxidation, such as a metal nitride, on the side in contact with the semiconductor layer 1230. This prevents the conductive layers 1242a and 1242b from being excessively oxidized by the oxygen contained in the semiconductor layer 1230. It is also preferable to use a metal or alloy with higher conductivity than the layer in contact with the semiconductor layer 1230 on the side that does not contact the semiconductor layer 1230. This allows the conductive layers 1242a and 1242b to function as highly conductive wiring or electrodes.

[0540] In the conductive layers 1242a and 1242b, it is preferable to use a metal nitride on the side in contact with the semiconductor layer 1230. For example, it is preferable to use a tantalum nitride, a titanium nitride, a molybdenum nitride, a tungsten nitride, a tantalum and aluminum nitride, or a titanium and aluminum nitride. Alternatively, for example, ruthenium, ruthenium oxide, ruthenium nitride, an oxide containing strontium and ruthenium, or an oxide containing lanthanum and nickel may be used. These materials are preferred because they are conductive materials that are resistant to oxidation or maintain conductivity even when absorbing oxygen.

[0541] The insulating layer 1201 is a film that is in contact with the semiconductor layer 1230, and it is preferable to use an oxide insulating film. For example, it is preferable to use silicon oxide or silicon oxynitride as the insulating layer 1201.

[0542] Furthermore, an insulating layer that functions as a barrier layer may be provided between the insulating layer 1201 and the semiconductor layer 1230, or between the insulating layer 1201 and the substrate 1210. Preferably, the insulating layer has barrier properties against hydrogen. Examples of hydrogen barrier layers include oxides such as aluminum oxide, hafnium oxide, and tantalum oxide, and nitrides such as silicon nitride. This makes it possible to keep the hydrogen concentration in the semiconductor layer 1230 low, thereby improving the reliability of the transistor 1200.

[0543] It is preferable to use a metal oxide (hereinafter also referred to as an oxide semiconductor) that functions as a semiconductor for the semiconductor layer 1230.

[0544] The band gap of the metal oxide functioning as a semiconductor is preferably 2 eV or more, and more preferably 2.5 eV or more. By using a metal oxide with a large band gap, the off-current of the transistor can be reduced. A transistor having a metal oxide in the channel formation region in this way is called an OS transistor. Because OS transistors have a small off-current, the power consumption of semiconductor devices can be significantly reduced. In addition, because OS transistors have high frequency characteristics, semiconductor devices can be operated at high speeds.

[0545] It is preferable to use indium oxide as the semiconductor layer 1230. In particular, it is preferable to use a single-crystal indium oxide film. It is preferable to use a crystalline film for the semiconductor layer 1230, and it is particularly preferable to use indium oxide with a single-crystal structure, but it is also possible to use indium oxide with a polycrystalline or microcrystalline structure. By using indium oxide with a single-crystal structure, carrier scattering at the grain boundaries can be suppressed, and a transistor with high field-effect mobility can be realized. Furthermore, a highly reliable transistor can be realized.

[0546] When using indium oxide having a polycrystalline structure, it is preferable that no grain boundaries are observed, at least in the channel-forming region (the region superimposed with the conductive layer 1260). This allows indium oxide having a polycrystalline structure to achieve the same effects as when it has a single-crystal structure.

[0547] The thickness of the semiconductor layer 1230 is more preferably 2 nm to 50 nm, more preferably 2.5 nm to 30 nm, more preferably 2.5 nm to 20 nm, more preferably 5 nm to 20 nm, and even more preferably 5 nm to 10 nm. By setting the thickness of the semiconductor layer 1230 within the above range, the crystallinity of the semiconductor layer 1230 can be improved.

[0548] Among highly crystalline oxide semiconductors, indium oxide is a film in which hydrogen and / or oxygen can move more easily compared to, for example, an IGZO (In-Ga-Zn-O based oxide) film. Therefore, indium oxide can be said to be a film in which hydrogen and / or oxygen can be supplied and expelled more easily compared to, for example, an IGZO film. As a result, excess oxygen or excess hydrogen that can become carriers or fixed charges is less likely to accumulate in the semiconductor layer 1230, making it possible to create a transistor with good electrical characteristics and reliability.

[0549] It is preferable that the semiconductor layer 1230 has a reduced concentration of elements that decrease crystallinity. For example, the concentration of elements such as boron and aluminum is preferably 1 atomic% or less, more preferably 0.1 atomic% or less, and even more preferably 0.01 atomic% (100 ppm) or less.

[0550] Furthermore, because gallium has a tendency to bond with excess oxygen atoms, if a large amount of gallium is present, the fluctuation in the threshold voltage in the PBTS (Positive Bias Temperature Stress) test may increase. For this reason, the gallium concentration in the semiconductor layer 1230 is preferably 1 atomic% or less, more preferably 0.1 atomic% or less, and even more preferably 0.01 atomic% (100 ppm) or less.

[0551] In addition, metal oxides that can be used in the semiconductor layer 1230 include tin oxide, zinc oxide, indium tin oxide, indium titanium oxide, indium gallium oxide, indium gallium aluminum oxide, indium gallium tin oxide, gallium zinc oxide, aluminum zinc oxide, indium aluminum zinc oxide, indium tin zinc oxide, indium titanium zinc oxide, indium gallium zinc oxide, indium gallium tin zinc oxide, and indium gallium aluminum zinc oxide. Alternatively, silicon-containing indium tin oxide, gallium tin oxide, aluminum tin oxide, etc., can also be used. When using these, it is preferable that the film has at least crystalline properties, and more preferably that it has a single-crystal structure.

[0552] The insulating layer 1250, which functions as a gate insulating layer, preferably has the function of capturing and fixing hydrogen. This reduces the hydrogen concentration in the channel formation region of the semiconductor layer 1230. This makes it possible to make the channel formation region i-type or substantially i-type.

[0553] Here, it is preferable that the insulating layer 1250 has a laminated structure consisting of a first layer in contact with the semiconductor layer 1230, a second layer on the first layer, and a third layer on the second layer. In this case, it is preferable that the first layer has the function of capturing hydrogen and fixing hydrogen.

[0554] Examples of insulators having the function of capturing and fixing hydrogen include metal oxides having an amorphous structure. For the first layer, it is preferable to use a metal oxide such as magnesium oxide, or an oxide containing one or both of aluminum and hafnium. In such amorphous metal oxides, oxygen atoms have dangling bonds, and these dangling bonds may have the property of capturing or fixing hydrogen. In other words, amorphous metal oxides have a high ability to capture or fix hydrogen.

[0555] Furthermore, it is preferable to use a high-dielectric constant (high-k) material for the first layer. An example of a high-k material is an oxide containing either or both aluminum and hafnium. By using a high-k material as the first layer, it becomes possible to reduce the gate potential applied during transistor operation while maintaining the physical thickness of the gate insulating layer. Additionally, it becomes possible to thin the equivalent oxide thickness (EOT) of the insulator that functions as the gate insulating layer.

[0556] It is preferable to use an oxide containing one or both of aluminum and hafnium as the first layer, and it is more preferable to use an oxide having an amorphous structure that contains one or both of aluminum and hafnium, and it is even more preferable to use aluminum oxide having an amorphous structure.

[0557] Next, it is preferable to use an insulator with a thermally stable structure, such as silicon oxide or silicon oxide-nitride, for the second layer.

[0558] Alternatively, a structure may be provided in which a fourth layer is placed on top of the second layer. In this case, the fourth layer can be an insulator that can be used for the first layer. For example, hafnium oxide can be used as the fourth layer. By providing the fourth layer between the third layer and the second layer, hydrogen contained in the second layer and the like can be captured and fixed more effectively.

[0559] The third layer preferably has oxygen barrier properties. The third layer is provided between the channel-forming region of the semiconductor layer 1230 and the conductive layer 1260, and between the insulating layer 1280 and the conductive layer 1260. This configuration suppresses the diffusion of oxygen contained in the channel-forming region of the semiconductor layer 1230 into the conductive layer 1260, preventing the formation of oxygen vacancies in the channel-forming region of the semiconductor layer 1230. It also suppresses the diffusion of oxygen contained in the semiconductor layer 1230 and the oxygen contained in the insulating layer 1280 into the conductive layer 1260, preventing oxidation of the conductive layer 1260. The third layer preferably has lower oxygen permeability than at least the insulating layer 1280. For example, it is preferable to use a silicon nitride film as the third layer. In this case, the third layer is an insulator containing at least nitrogen and silicon.

[0560] Furthermore, it is preferable that the third layer has hydrogen barrier properties. This prevents impurities such as hydrogen contained in the conductive layer 1260 from diffusing into the semiconductor layer 1230.

[0561] The insulating layer 1275 preferably has barrier properties against oxygen. The insulating layer 1275 is provided between the insulating layer 1280 and the conductive layer 1242a, and between the insulating layer 1280 and the conductive layer 1242b. This configuration suppresses the diffusion of oxygen contained in the insulating layer 1280 into the conductive layers 1242a and 1242b. Therefore, it is possible to suppress the oxidation of the conductive layers 1242a and 1242b by oxygen contained in the insulating layer 1280, which increases their resistivity and reduces the on-current. The insulating layer 1275 preferably has lower oxygen permeability than at least the insulating layer 1280. For example, it is preferable to use silicon nitride as the insulating layer 1275. In this case, the insulating layer 1275 is an insulator having at least nitrogen and silicon.

[0562] Furthermore, in this embodiment, it is preferable to configure the semiconductor device to suppress the ingress of hydrogen into the transistor 1200, etc., in addition to the above configuration. For example, it is preferable to provide an insulator having the function of suppressing hydrogen diffusion so as to cover the transistor 1200. In the semiconductor device described in this embodiment, the insulator is, for example, an insulating layer 1282 and an insulating layer 1283. Alternatively, a similar film may be provided under the transistor 1200.

[0563] It is preferable that one or more of the insulating layers 1282 and 1283 function as a barrier insulator that suppresses the diffusion of impurities such as water and hydrogen from above the transistor 1200 to the transistor 1200. Therefore, it is preferable that one or more of the insulating layers 1282 and 1283 have an insulating material that has the function of suppressing the diffusion of impurities such as hydrogen atoms, hydrogen molecules, water molecules, nitrogen atoms, nitrogen molecules, nitrogen oxide molecules (N2O, NO, NO2, etc.), and copper atoms (the above impurities are less permeable to them). Alternatively, it is preferable that the insulating material has the function of suppressing the diffusion of oxygen (for example, at least one such as oxygen atoms and oxygen molecules) (the above oxygen is less permeable to them).

[0564] The insulating layer 1282 and insulating layer 1283 preferably have an insulator that has the function of suppressing the diffusion of impurities such as water and hydrogen, and oxygen. For example, aluminum oxide, magnesium oxide, hafnium oxide, gallium oxide, silicon nitride, or silicon nitride oxide can be used. For example, it is preferable to use silicon nitride, which has higher hydrogen barrier properties, as the insulating layer 1283. Also, for example, it is preferable that the insulating layer 1282 has aluminum oxide or magnesium oxide, which have high hydrogen capture and hydrogen fixation functions. This makes it possible to suppress the diffusion of impurities such as water and hydrogen from the interlayer insulating film located outside the insulating layer 1283 to the transistor 1200, etc. Also, it is possible to suppress the diffusion of oxygen contained in the insulating layer 1280, etc., upward from the transistor 1200, etc. via the insulating layer 1282, etc. Furthermore, by providing a film similar to one or both of the insulating layers 1282 and 1283 below the transistor 1200, it is possible to suppress the diffusion of impurities such as water and hydrogen from the substrate side to the transistor 1200.

[0565] The insulating layers 1271a and 1271b are inorganic insulators that function as etching stoppers during processing of the conductive layers 1242a and 1242b, protecting them. Furthermore, since the insulating layers 1271a and 1271b are in contact with the conductive layers 1242a and 1242b, it is preferable that they are inorganic insulators that do not easily oxidize the conductive layers 1242a and 1242b. For example, the insulating layers 1271a and 1271b can be arranged in a laminated structure, with silicon nitride used on the side in contact with the conductive layers 1242a and 1242b, and silicon oxide used on the other sides.

[0566] Insulating layers 1285, 1283, 1282, 1280, 1275, and 1271a have openings that reach the conductive layer 1242a, and the conductive layer 1240a and insulating layer 1241a are provided within these openings. Insulating layer 1241a is provided adjacent to the side wall of the opening, and the conductive layer 1240a is provided inside the insulating layer 1241a. In addition, insulating layers 1285, 1283, 1282, 1280, 1275, and 1271b have openings that reach the conductive layer 1242b, and the conductive layer 1240b and insulating layer 1241b are provided within these openings. Insulating layer 1241b is provided adjacent to the side wall of the opening, and the conductive layer 1240b is provided inside the insulating layer 1241b. The conductive layers 1240a and 1240b function as vias connecting wiring and the like provided on the transistor 1200 to the source or drain of the transistor 1200.

[0567] The conductive layers 1240a and 1240b are preferably made of conductive materials mainly composed of, for example, tungsten, copper, or aluminum. The conductive layers 1240a and 1240b may also be arranged in a laminated structure.

[0568] For example, as shown in Figure 31, the conductive layer 1240a and conductive layer 1240b may be arranged in a two-layer laminated structure. The conductive layer 1240a has a conductive layer 1240a1 formed along the opening and a conductive layer 1240a2 formed inside the conductive layer 1240a1. The conductive layer 1240b has a conductive layer 1240b1 formed along the opening and a conductive layer 1240b2 formed inside the conductive layer 1240b1.

[0569] It is preferable to use conductive materials such as tantalum, tantalum nitride, titanium, titanium nitride, ruthenium, or ruthenium oxide for the conductive layers 1240a1 and 1240b1, which have the function of suppressing the permeation of impurities such as water and hydrogen. Furthermore, the conductive material that has the function of suppressing the permeation of impurities such as water and hydrogen may be used in a single layer or in a laminated form. By providing conductive layers 1240a1 and 1240b1, it is possible to suppress the mixing of impurities such as water and hydrogen into the semiconductor layer 1230 through conductive layers 1240a2 and 1240b2. The conductive layers 1240a2 and 1240b2 may be conductive materials that can be used for the conductive layers 1240a and 1240b described above.

[0570] Furthermore, as shown in Figure 30B, the upper surfaces of the conductive layer 1240a and conductive layer 1240b can be formed to coincide with or substantially coincide with the upper surface of the insulating layer 1285. Also, as shown in Figure 31, the lower part of the conductive layer 1240a may be formed to be embedded in the conductive layer 1242a. Similarly, the lower part of the conductive layer 1240b may be formed to be embedded in the conductive layer 1242b.

[0571] For insulating layers 1241a and 1241b, a barrier insulator that can be used for insulating layer 1275 and the like may be used. For example, silicon nitride may be used for insulating layers 1241a and 1241b. Insulating layers 1241a and 1241b are provided in contact with insulating layers 1285, 1283, 1282, 1275, 1271a, and 1271b. This prevents impurities such as water and hydrogen contained in insulating layer 1280 from mixing into semiconductor layer 1230 through conductive layer 1240a and conductive layer 1240b. Silicon nitride is particularly suitable because it has high blocking properties against hydrogen. In addition, it prevents oxygen contained in insulating layer 1280 from being absorbed by conductive layer 1240a and conductive layer 1240b.

[0572] The conductive layer 1260 functions as the gate electrode of the transistor 1200. Here, it is preferable that the conductive layer 1260 extends in the channel width direction, as shown in Figures 30A and 30C. With this configuration, when multiple transistors are provided, the conductive layer 1260 functions as wiring.

[0573] The conductive layer 1260 may have a laminated structure. Figure 31 shows an example in which the conductive layer 1260 has a conductive layer 1260a located on the side in contact with the insulating layer 1250 and a conductive layer 1260b above it. In this case, it is preferable to use a conductive material that is resistant to oxidation, such as titanium, titanium nitride, tantalum, tantalum nitride, ruthenium, or ruthenium oxide, or a conductive material that has the function of suppressing oxygen diffusion, for the conductive layer 1260a. It is also preferable to use a low-resistance conductive material such as tungsten, copper, or aluminum for the conductive layer 1260b.

[0574] The insulating layer 1280 preferably has a low dielectric constant. By using a material with a low dielectric constant as the interlayer film, parasitic capacitance between wirings can be reduced. For example, the insulating layer 1280 preferably has one or more of the following: silicon oxide, silicon oxynitride, silicon oxide with added fluorine, silicon oxide with added carbon, silicon oxide with added carbon and nitrogen, and silicon oxide with vacancies. Silicon oxide and silicon oxynitride are preferred because they are thermally stable. In particular, materials such as silicon oxide, silicon oxynitride, and silicon oxide with vacancies are preferred because they can easily form regions containing oxygen that is desorbed by heating.

[0575] [Variations] The following describes an example with some configuration differences from the above example. Note that the following explanation omits parts that overlap with the above.

[0576] [Modification 1] Figure 32 shows an example having a conductive layer 1205 that functions as a back gate. The configuration shown in Figure 32 has a conductive layer 1205 and an insulating layer 1202.

[0577] The conductive layer 1205 is provided so as to be embedded in the insulating layer 1202. The insulating layer 1201 is provided so as to cover the insulating layer 1202 and the conductive layer 1205.

[0578] The conductive layer 1205 functions as the second gate (back gate) of the transistor 1200. The conductive layer 1205 is provided in a region that overlaps with the conductive layer 1260 via the semiconductor layer 1230.

[0579] The conductive layer 1205 can be made of a material that can be used for the conductive layer 1260. Furthermore, the conductive layer 1205 may have a laminated structure.

[0580] In this case, the insulating layer 1201 functions as a second gate insulating layer. In this case, it is preferable to have a laminated structure for the insulating layer 1201 and to use a high dielectric constant material such as hafnium oxide, aluminum oxide, or hafnium aluminate in part thereof.

[0581] The insulating layer 1202 can be made of a silicon oxide film. It is preferable to provide an insulating film, such as silicon nitride or aluminum oxide, which has barrier properties against oxygen, between the insulating layer 1202 and the conductive layer 1205, as this can suppress oxidation of the conductive layer 1205.

[0582] [Modification 2] The above described a configuration in which the gate electrode is embedded, but the following describes a transistor with a different configuration.

[0583] Figure 33A shows a cross-sectional view of transistor 1200a in the channel length direction. Transistor 1200a has a semiconductor layer 1230, an insulating layer 1250, a conductive layer 1260, a conductive layer 1242a, and a conductive layer 1242b.

[0584] An insulating layer 1250 is provided covering the semiconductor layer 1230, and a conductive layer 1260 is provided on the insulating layer 1250 in a position overlapping with the semiconductor layer 1230. Furthermore, insulating layers 1281 and 1280 are laminated and provided covering the insulating layer 1250 and the conductive layer 1260. A pair of openings reaching the semiconductor layer 1230 is provided in the insulating layer 1281, insulating layer 1280, and insulating layer 1250, respectively. Conductive layers 1242a and 1242b are provided on the insulating layer 1280 and are in contact with the semiconductor layer 1230 at their respective openings.

[0585] As the insulating layer 1281, an insulator having barrier properties against hydrogen and oxygen, similar to that of the insulating layer 1275, can be used. This makes it possible to suppress the diffusion of impurities contained in the insulating layer 1280 into the semiconductor layer 1230, and the diffusion of oxygen contained in the semiconductor layer 1230 towards the insulating layer 1280.

[0586] The region of the semiconductor layer 1230 that overlaps with the conductive layer 1260 functions as a channel-forming region. Furthermore, a pair of regions 1230n flanking the channel-forming region function as a source region or a drain region. It is preferable that regions 1230n have lower resistance than the channel-forming region.

[0587] For example, region 1230n preferably contains an element that imparts conductivity to the semiconductor layer 1230. Examples of such elements include titanium, aluminum, tantalum, tungsten, tin, silicon, germanium, zirconium, hafnium, antimony, magnesium, hydrogen, boron, and phosphorus. These elements can be introduced into a portion of the semiconductor layer 1230 by methods such as doping, ion implantation, or thermal diffusion. For example, using the conductive layer 1260 as a mask, the above elements can be introduced into a region of the semiconductor layer 1230 that does not overlap with the conductive layer 1260 via the insulating layer 1250 by doping or ion implantation.

[0588] Figure 33B shows an example where the insulating layer 1250 is located only in the region overlapping with the conductive layer 1260 and is not provided on the region 1230n of the semiconductor layer 1230. In this case, by using a film containing the above-mentioned elements for the insulating layer 1281 in contact with region 1230n, the elements can be introduced into region 1230n during the formation of the insulating layer 1281 or by subsequent heat treatment. For example, it is preferable to use silicon nitride containing hydrogen for the insulating layer 1281. Alternatively, oxides of the above-mentioned metal elements may be used.

[0589] [Modification 3] Below, we will describe a vertical transistor in which the source electrode and drain electrode are located at different heights.

[0590] Figure 34A shows a schematic cross-sectional view of transistor 1200b. Transistor 1200b has a semiconductor layer 1230, an insulating layer 1250, a conductive layer 1260, a conductive layer 1245, and a conductive layer 1246. Conductive layer 1245 functions as one of the source electrode and drain electrode, and conductive layer 1246 functions as the other.

[0591] A conductive layer 1245 is provided on an insulating layer 1201, and an insulating layer 1211 is provided covering the conductive layer 1245. A conductive layer 1246 is provided on the insulating layer 1211. The conductive layer 1246 and the insulating layer 1211 are provided with openings that reach the conductive layer 1245. The semiconductor layer 1230 is provided in contact with the upper surface of the conductive layer 1246, the side surface of the conductive layer 1246 at the opening, the side surface of the insulating layer 1211, and the upper surface of the conductive layer 1245. An insulating layer 1250 is provided covering the semiconductor layer 1230 inside the opening, and a conductive layer 1260 is provided covering the insulating layer 1250.

[0592] In transistor 1200b, the source electrode and drain electrode are located at different heights, and current flows in the height direction through the semiconductor layer. That is, the channel length direction has a component in the height direction (vertical direction), so transistor 1200b can be called a VFET (Vertical Field Effect Transistor), vertical transistor, vertical channel transistor, or vertical channel type transistor. In transistor 1200b, two or more of the source electrode, semiconductor, and drain electrode can be stacked, so the occupied area can be significantly reduced compared to a so-called planar type transistor (which can also be called a lateral transistor or LFET (Lateral FET)) in which the semiconductor is arranged on a plane.

[0593] Furthermore, since the channel length of transistor 1200b can be precisely controlled by the thickness of the insulating layer 1211 which functions as a spacer, the variation in channel length can be made extremely small compared to planar transistors. Moreover, by making the insulating layer 1211 thinner, transistors with extremely short channel lengths can also be fabricated. The channel length can be, for example, 2 μm or less, 1 μm or less, 500 nm or less, 300 nm or less, 200 nm or less, 100 nm or less, 50 nm or less, 30 nm or less, or 20 nm or less, and can be 5 nm or more, 7 nm or more, or 10 nm or more. As a result, transistors with extremely small channel lengths that could not be achieved with mass-production exposure equipment can be realized. In addition, transistors with channel lengths of less than 10 nm can be realized without using the extremely expensive exposure equipment used in state-of-the-art LSI technology.

[0594] In transistor 1200b, the shape of the opening provided in the insulating layer 1211 can be of various shapes.

[0595] Figure 34B shows a perspective view with the insulating layer 1211 and the semiconductor layer 1230 extracted. Here, an example is shown in which a cylindrical opening 1290o is provided in the insulating layer 1211. In this case, the semiconductor layer 1230 has a cylindrical portion along the side wall of the opening 1290o and flat portions parallel to the substrate surface at the bottom and top. In the configuration shown in Figure 34B, the channel width of the transistor is approximately equal to the circumference of the cylindrical portion. Therefore, in the configuration shown in Figure 34B, it is easy to make the channel length small and the channel width large, and a transistor capable of carrying extremely large currents can be realized.

[0596] On the other hand, Figure 34C shows an example in which a slit-shaped opening 1290s is provided in the insulating layer 1211. As shown in Figure 34C, multiple semiconductor layers 1230 can be arranged in the opening 1290s, making it suitable for high-density arrangement of transistors. Although not shown here, a conductive layer 1260 that functions as a gate electrode is provided so as to be embedded in the opening 1290s and can be used as wiring extending in the direction of extension of the opening 1290s.

[0597] The above is an explanation of the variations.

[0598] This embodiment can be implemented in appropriate combination with other embodiments described herein, at least in part.

[0599] (Embodiment 5) In this embodiment, a display device according to one aspect of the present invention will be described with reference to Figures 35 to 48.

[0600] The display device of this embodiment can be a high-definition display device. Therefore, the display device of this embodiment can be used, for example, as a display unit for wristwatch-type and bracelet-type information terminals (wearable devices), as well as as a display unit for wearable devices that can be worn on the head, such as VR devices such as head-mounted displays (HMDs) and AR devices such as glasses.

[0601] The display device of this embodiment can be a high-resolution display device or a large-screen display device. Therefore, the display device of this embodiment can be used in electronic devices with relatively large screens, such as television equipment, desktop or notebook 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.

[0602] [Display Module] Figure 35A is a perspective view of the display module 280. The display module 280 includes a display device 100A and an FPC 290. Note that the display device of the display module 280 is not limited to the display device 100A, and the display devices 100B to 100F described later can also be used.

[0603] The display module 280 has substrates 291 and 292. The display module 280 has a display unit 281. The display unit 281 is an area in the display module 280 that displays an image, and is an area in which light from each pixel provided in the pixel unit 284, which will be described later, can be seen.

[0604] Figure 35B shows a schematic perspective view illustrating the configuration of the substrate 291. On the substrate 291, a circuit section 282, a pixel circuit section 283 on the circuit section 282, and a pixel section 284 on the pixel circuit section 283 are stacked. In addition, a terminal section 285 for connecting to the FPC 290 is provided in the portion of the substrate 291 that does not overlap with the pixel section 284. The terminal section 285 and the circuit section 282 are connected by a wiring section 286, which is composed of multiple wires.

[0605] The pixel section 284 has a plurality of pixels 284a arranged periodically. An enlarged view of one pixel 284a is shown on the right side of Figure 35B. Various configurations described in the previous embodiment can be applied to the pixel 284a. Figure 35B shows an example where the pixel has a configuration similar to that of the pixel 110 shown in Figure 1A.

[0606] The pixel circuit section 283 has a plurality of pixel circuits 283a arranged periodically.

[0607] A single pixel circuit 283a is a circuit that controls the driving of multiple elements in a single pixel 284a. A single pixel circuit 283a can be configured to have three circuits that control the light emission of a single light-emitting device. For example, a single pixel circuit 283a can be configured to have at least one selection transistor, one current control transistor (driving transistor), and a capacitor for each light-emitting device. In this case, a gate signal is input to the gate of the selection transistor, and a source signal is input to the source. This realizes an active-matrix type display device.

[0608] The circuit section 282 has circuits for driving each pixel circuit 283a of the pixel circuit section 283. For example, it is preferable to have one or both of a gate line drive circuit and a source line drive circuit. In addition, it is also possible to have a configuration that has at least one of the following: an arithmetic circuit, a memory circuit, and a power supply circuit.

[0609] The FPC290 functions as wiring for supplying video signals or power potential, etc., to the circuit section 282 from an external source. An IC can also be mounted on the FPC290.

[0610] The display module 280 can be configured such that one or both of the pixel circuit section 283 and the circuit section 282 are superimposed on the lower side of the pixel section 284, thereby making the aperture ratio (effective display area ratio) of the display section 281 extremely high. For example, the aperture ratio of the display section 281 can be 40% or more and less than 100%, preferably 50% or more and 95%, and more preferably 60% or more and 95%. Furthermore, it is possible to arrange the pixels 284a at an extremely high density, making the resolution of the display section 281 extremely high. For example, it is preferable that the pixels 284a in the display section 281 are arranged at a density of 2000 ppi or more, preferably 3000 ppi or more, more preferably 5000 ppi or more, and even more preferably 6000 ppi or more, with a resolution of 20000 ppi or less, or 30000 ppi or less.

[0611] Because such a display module 280 is extremely high-resolution, it can be suitably used in VR devices such as HMDs or AR devices such as glasses. For example, even in a configuration where the display part of the display module 280 is viewed through lenses, the display module 280 has an extremely high-resolution display part 281, so even when the display part is magnified with lenses, pixels are not visible, and a highly immersive display can be provided. Furthermore, the display module 280 is not limited to this and can be suitably used in electronic devices having relatively small display parts. For example, it can be suitably used in the display part of wearable electronic devices such as wristwatches.

[0612] [Display device 100A] The display device 100A shown in Figure 36 includes a substrate 103, a light-emitting device 130R, a light-emitting device 130G, a light-emitting device 130B, a capacitor 240, and a transistor 310.

[0613] Substrate 103 corresponds to substrate 291 in Figures 35A and 35B. The laminated structure from substrate 103 to insulating layer 188 corresponds to layer 101 in Embodiment 1.

[0614] The transistor 310 is a transistor having a channel-forming region in the substrate 103. For example, a semiconductor substrate such as a single-crystal silicon substrate can be used as the substrate 103. The transistor 310 comprises a portion of the substrate 103, a conductive layer 311, a low-resistance region 312, an insulating layer 313, and an insulating layer 314. The conductive layer 311 functions as a gate electrode. The insulating layer 313 is located between the substrate 103 and the conductive layer 311 and functions as a gate insulating layer. The low-resistance region 312 is a region of the substrate 103 doped with impurities and functions as either a source or a drain. The insulating layer 314 is provided covering the side surface of the conductive layer 311.

[0615] An element isolation layer 315 is provided between two adjacent transistors 310 so as to be embedded in the substrate 103.

[0616] An insulating layer 261 is provided covering the transistor 310, and a capacitance 240 is provided on the insulating layer 261.

[0617] The capacitor 240 has a conductive layer 241, a conductive layer 245, and an insulating layer 243 located between them. The conductive layer 241 functions as one electrode of the capacitor 240, the conductive layer 245 functions as the other electrode of the capacitor 240, and the insulating layer 243 functions as the dielectric of the capacitor 240.

[0618] By using materials with low light transmittance for conductive layers 241 and 245, the incidence of light on the transistor 310 can be suppressed. Since conductive layers 241 and 245 function as light-shielding layers, fluctuations in the electrical characteristics of the transistor 310 are suppressed, resulting in a highly reliable display device. Furthermore, it is more preferable that one or both of conductive layers 241 and 245 have a region that overlaps with the transistor 310 (particularly the channel formation region).

[0619] The conductive layer 241 is provided on the insulating layer 261 and embedded in the insulating layer 254. The conductive layer 241 is connected to one of the source and drain of the transistor 310 by a conductive layer 271 embedded in the insulating layer 261. The conductive layer 271 functions as a plug. The insulating layer 243 is provided covering the conductive layer 241. The conductive layer 245 is provided in the region that overlaps with the conductive layer 241 via the insulating layer 243.

[0620] Furthermore, it is preferable to provide a conductive layer surrounding the outside of the display unit 281 (or pixel unit 284) in at least one of the conductive layer layers of layer 101. This conductive layer can also be called a guard ring. By providing this conductive layer, it is possible to suppress the application of high voltage to elements such as transistors and light-emitting devices due to charging by ESD (electrostatic discharge) or plasma-based processes, which could cause these elements to be destroyed.

[0621] An insulating layer 253 is provided covering the capacitance 240, and an insulating layer 191, a conductive layer 250R, a conductive layer 250G, and a conductive layer 250B are provided on the insulating layer 253. The conductive layers 250R, 250G, and 250B each function as, for example, wiring. The conductive layer 250R is connected to the conductive layer 241 by a conductive layer 256 embedded in the insulating layer 253. The conductive layer 256 functions as a plug. The same applies to the conductive layers 250G and 250B.

[0622] The insulating layer 253 can preferably be an inorganic insulating film such as an oxide insulating film, a nitride insulating film, an oxidative nitride insulating film, and an oxidative nitride insulating film. For example, one or more silicon oxide films, silicon oxidative nitride films, aluminum oxide films, silicon nitride films, and silicon nitride oxide films can preferably be used as the insulating layer 253.

[0623] Furthermore, the insulating layer 253 may be made of a material with a low dielectric constant. For example, it can be formed using silicon oxide (SiOF) with several percent of fluorine introduced, silicon oxide (SiOC) with several percent of carbon introduced, fluorinated silicate glass (FSG), organic silicate glass (OSG), hydrogenated silsesquioxane (HSQ), methylsilsesquioxane (MSQ), organic polymer, fluororesin (polytetrafluoroethylene), polyimide, fluorine-added amorphous carbon, etc.

[0624] An insulating layer 191 and a conductive layer 250 are provided on the insulating layer 253, and a conductive layer 250 is provided on the conductive layer 256.

[0625] An insulating layer 188 is provided covering the insulating layer 191 and the conductive layer 250, and an insulating layer 192 is provided on the insulating layer 188. A conductive layer 111 and an insulating layer 109 are provided on the insulating layer 192, and a light-emitting device 130 is provided on the conductive layer 111.

[0626] The conductive layer 111R is connected to the conductive layer 250R by plugs 170R embedded in the insulating layers 188 and 192. The plugs 170R function as plugs. The same applies to the conductive layers 111G and 111B.

[0627] Figure 36 shows an example in which light-emitting devices 130R, 130G, and 130B have the same structure as the laminated structure shown in Figure 1B. An insulator is provided in the region between adjacent light-emitting devices 130. In Figure 36, etc., an insulating layer 109, an insulating layer 125, and an insulating layer 127 on the insulating layer 125 are provided in this region. A mask layer 118R is located on layer 113R of light-emitting device 130R, a mask layer 118G is located on layer 113G of light-emitting device 130G, and a mask layer 118B is located on layer 113B of light-emitting device 130B.

[0628] Pixel electrodes 199 are provided on the upper and side surfaces of the conductive layer 111. The conductive layer 111 has the same surface as the trenches formed in the insulating layer 192, and the pixel electrodes 199 are provided on the same side surfaces of the conductive layer 111 and the insulating layer 192. The ends or lower surfaces of the pixel electrodes 199 are located below the lower surface of the conductive layer 111. The pixel electrodes 199 function as one of the electrodes of the light-emitting device. In Figure 36, etc., in the laminated structure of the conductive layer 111 and the pixel electrodes 199, the pixel electrodes 199 may mainly function as the anode, and the conductive layer 111 may mainly function as a conductive layer to enhance conductivity.

[0629] A protective layer 128 is provided on the light-emitting device 130, and a flat insulating layer 122 is provided on the protective layer 128. A substrate 120 is bonded to the insulating layer 122 by an adhesive layer 129. Details of the components from the light-emitting device to the substrate 120 can be found in Embodiment 1. The substrate 120 corresponds to the substrate 292 in Figure 35A.

[0630] [Display Device 100B] The display device 100B shown in Figure 37 has a configuration in which transistors 310A and 310B, each with a channel formed on a semiconductor substrate...

Claims

Having a first insulating layer on a first conductive layer, A second conductive layer is located in contact with the upper surface of the first insulating layer. The upper and side surfaces of the second conductive layer are covered, and the first electrodes of the first light-emitting device are provided. The second conductive layer is electrically connected to the first conductive layer. The first insulating layer and the second conductive layer have a first side surface having the same surface, The first electrode covers the first side surface, Display device. 　 A first insulating layer is provided on the first conductive layer and the third conductive layer. The first insulating layer is in contact with a second conductive layer and a fourth conductive layer, The upper and side surfaces of the second conductive layer are covered, and the first electrodes of the first light-emitting device are provided. The second conductive layer is electrically connected to the first conductive layer via the first insulating layer. The upper and side surfaces of the fourth conductive layer are covered by the first electrode of the second light-emitting device, The fourth conductive layer is electrically connected to the third conductive layer via the first insulating layer. The first insulating layer and the second conductive layer have a first side surface having the same surface, The first insulating layer and the fourth conductive layer have a second side surface having the same surface, The first electrode of the first light-emitting device covers the first side surface, The first electrode of the second light-emitting device covers the second side surface, The first insulating layer has a trench between the first light-emitting device and the second light-emitting device. Display device. 　 In claim 2, The width of the trench in the first insulating layer has a region wider than the distance between the side surface of the second conductive layer and the side surface of the fourth conductive layer. Display device. 　 In claim 2, The first insulating layer has a trench between the first light-emitting device and the second light-emitting device that is deeper than the thickness of the first electrode. Display device. 　 In claim 2, The bottom surface of the trench is located between the upper surfaces of the first conductive layer and the third conductive layer and the lower ends of the first electrodes of the first light-emitting device and the second light-emitting device. Display device. 　 In claim 2 or claim 5, The trench has a second insulating layer, The second insulating layer is in contact with the side surface of the first electrode of the first light-emitting device, the side surface of the first electrode of the second light-emitting device, the side surface of the first insulating layer, and the bottom surface of the first insulating layer. Display device. 　 In claim 6, A third insulating layer is provided on a part of the first electrode of the first light-emitting device, a part of the first electrode of the second light-emitting device, and the second insulating layer. Display device. 　 In claim 6, The region having an overlapping area of ​​the second insulating layer, the second conductive layer, and the first electrode of the first light-emitting device, Display device. In claim 2, The first electrode of the first light-emitting device comprises one or more selected from silver, a silver-magnesium alloy, and an Ag-Pd-Cu alloy. Display device. 　 In claim 2, The first electrode of the first light-emitting device includes one or more selected from silver, palladium, and copper, and one or more selected from indium, zinc, tin, tungsten, titanium, silicon, gallium, and oxygen. Display device. 　 In claim 10, The first electrode of the first light-emitting device described above has a structure in which a first layer, a second layer, and a third layer are stacked in order. The first and third layers comprise one or more oxides selected from indium, zinc, tin, tungsten, titanium, silicon, and gallium. The aforementioned second layer comprises one or more selected from silver, palladium, and copper. Display device. 　 In claim 2, The second conductive layer comprises one or more selected from aluminum, chromium, tantalum, titanium, molybdenum, and tungsten. Display device. 　 A first insulating layer is provided on the first conductive layer and the third conductive layer. The first insulating layer is in contact with a second conductive layer and a fourth conductive layer, The upper and side surfaces of the second conductive layer are covered, and the first electrodes of the first light-emitting device are provided. The second conductive layer is electrically connected to the first conductive layer via the first insulating layer. The upper and side surfaces of the fourth conductive layer are covered by the first electrode of the second light-emitting device, The fourth conductive layer is electrically connected to the third conductive layer via the first insulating layer. The second conductive layer has a first bottom surface, The fourth conductive layer has a second bottom surface, The first insulating layer has a trench between the first light-emitting device and the second light-emitting device. The trench has a second insulating layer, The second insulating layer is in contact with the first insulating layer, the first electrode of the first light-emitting device, the first electrode of the second light-emitting device, the first bottom surface, and the second bottom surface. Display device.

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