Display device

Abstract

To provide a high-resolution display device.SOLUTION: A display device includes a plurality of light-emitting units emitting light of different colors. The light-emitting unit has a microcavity structure (minute resonator structure) and intensifies light with a specific wavelength. In the light-emitting units emitting light of different colors, reflective layers with different thicknesses are formed, an insulating layer is formed to cover the reflective layers, and then an insulating layer with different thicknesses is formed by subjecting a top surface of the insulating layer to planarization treatment. After that, by forming, over the planarized top surface of the insulating layer, light-emitting elements overlapping with the respective reflective layers and emitting white light, the light-emitting units that intensify different colors due to different optical path lengths are separately formed.SELECTED DRAWING: Figure 6

Description

[Technical Field]

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

[0002] Note that one embodiment of the present invention is not limited to the above technical fields. The technical field of one embodiment of the present invention is a semiconductor device, a display device, a light-emitting device, a power storage device, a memory device, and the like. , electronic device, lighting device, input device, input / output device, driving method thereof, or manufacturing method thereof Semiconductor devices function by utilizing the semiconductor properties. This refers to all devices that can do this. [Background technology]

[0003] In recent years, there has been a demand for higher resolution display panels. For example, virtual reality (VR) In recent years, devices for AR (Augmented Reality) have become popular. It is being developed.

[0004] Representative display devices applicable to display panels include liquid crystal display devices, Organic EL (Electro Luminescence) elements and light-emitting diodes (LEDs) a light-emitting device equipped with a light-emitting element such as a light-emitting diode (LED), an electrophoresis Examples include electronic paper that displays information using a dynamic method.

[0005] The basic structure of an organic EL element is a layer containing a light-emitting organic compound sandwiched between a pair of electrodes. By applying a voltage to this element, light is emitted from the luminescent organic compound. A display device using such an organic EL element is a necessary component of a liquid crystal display device, etc. Since it does not require a backlight, which was previously necessary, it is thin, lightweight, has high contrast, and consumes less power. For example, an example of a display device using an organic EL element is disclosed in Patent Document 1. It is written. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-324673 Summary of the Invention [Problem to be solved by the invention]

[0007] In the wearable devices for VR or AR mentioned above, there is a focal point between the eyes and the display panel. A lens for adjusting the point is required. This lens magnifies part of the screen, If the resolution of the display panel is low, there is a problem that the sense of realism and immersion is diminished. do.

[0008] Furthermore, display panels are required to have high color reproducibility, especially the above-mentioned VR or A R devices use display panels with high color reproducibility, allowing the colors of real objects to be reproduced. By bringing the display closer, the sense of realism and immersion is enhanced.

[0009] An object of one embodiment of the present invention is to provide a display device with extremely high resolution. An object of one embodiment of the present invention is to provide a display device that achieves high color reproducibility. One aspect of the present invention aims to provide a display device that has both high definition and high color reproducibility. Another embodiment of the present invention is to provide a method for manufacturing the above-described display device. This is one of the challenges.

[0010] The description of these problems does not preclude the existence of other problems. It is not necessary for one embodiment to solve all of these problems. The subject matter can be extracted from the description, drawings, claims, etc. [Means for solving the problem]

[0011] One aspect of the present invention is a light-emitting device including a first light-emitting element, a second light-emitting element, a first insulating layer, a first optical adjusting layer, a first insulating layer, a first optical adjusting layer, a second optical adjusting layer, a first insulating layer, a first optical adjusting ... The display device has a first light-emitting element, a second light-emitting element, and a second optical adjustment layer. The light-transmitting layers are composed of a lower electrode, a light-emitting layer, and a semi-transmitting and semi-reflective upper electrode. The electrodes are laminated in this order. The first optical adjustment layer and the second optical adjustment layer are has a function of reflecting visible light. The first optical adjustment layer is thinner than the second optical adjustment layer. The first insulating layer is provided to cover the first optical adjustment layer and the second optical adjustment layer, and has an upper surface The first light emitting element overlaps the first optical adjustment layer via the first insulating layer. Thus, the second light emitting element overlaps the second optical adjustment layer via the first insulating layer.

[0012] Another embodiment of the present invention is a light-emitting element including a first light-emitting element, a second light-emitting element, a first insulating layer ... The display device has a first light-emitting element and a second optical adjustment layer. The light-emitting element includes a light-transmitting lower electrode, a light-emitting layer, and a semi-transmitting and semi-reflective layer. The first optical adjustment layer and the second optical adjustment layer are laminated in this order. The first insulating layer is provided on the surface. The first insulating layer is provided to cover the first optical adjustment layer and the second optical adjustment layer. A first portion overlapping the first optical adjustment layer and a second portion overlapping the second optical adjustment layer are intercepted. The first light-emitting element is provided on the first portion of the first insulating layer, and the second The light-emitting element is provided on the second portion of the first insulating layer. The optical adjustment layer has a function of reflecting visible light at least on its upper surface. The first insulating layer is thicker than the first optical adjustment layer. The upper surface of the first insulating layer is planarized. One part is thicker than the second part.

[0013] In the above, it is preferable to have a third light emitting element and a third optical adjustment layer. In this case, at least the upper surface of the third optical adjustment layer has a function of reflecting visible light, and It is preferable that the third optical adjustment layer is thicker than the first optical adjustment layer and the second optical adjustment layer. The upper surface of the adjustment layer is approximately flush with the upper surface of the first insulating layer, and the lower electrode of the third light-emitting element is It is preferable that the second optical adjustment layer is provided in contact with the upper surface of the third optical adjustment layer.

[0014] Another embodiment of the present invention is a light-emitting element including a first light-emitting element, a second light-emitting element, a first insulating layer ... The display device has the first optical adjustment layer and the second optical adjustment layer. a first lower electrode having a light-emitting property, a light-emitting layer, and a semi-transparent and semi-reflective upper electrode. The second light-emitting element includes a second lower electrode having light-transmitting properties, the light-emitting layer, and the upper and an electrode. The first optical adjustment layer and the second optical adjustment layer are provided on the same surface. The first insulating layer is provided to cover a part of the first optical adjustment layer and a part of the second optical adjustment layer. a first opening overlapping the first optical adjustment layer and a second opening overlapping the second optical adjustment layer; The first bottom electrode is embedded in the first opening, and the second bottom electrode is The first optical adjustment layer and the second optical adjustment layer are embedded in the second opening. The upper surface of each of the second optical adjustment layers has a function of reflecting visible light. The first insulating layer, the first lower electrode, and the second lower electrode have upper surfaces each having a height The first lower electrode is flattened so that the two electrodes are roughly aligned. It's also thick.

[0015] In the above, it is preferable to have a third light emitting element and a third optical adjustment layer. At this time, the third light emitting element includes a third lower electrode having light transmitting properties, the light emitting layer, and the upper It is preferable that the third optical adjustment layer has at least an upper surface that is irradiated with visible light. and is thicker than the first optical adjustment layer and the second optical adjustment layer. Furthermore, it is preferable that the upper surface of the third optical adjustment layer is approximately flush with the upper surface of the first insulating layer. Preferably, the third lower electrode is provided in contact with the upper surface of the third optical adjustment layer.

[0016] Another embodiment of the present invention is a light-emitting element including a first light-emitting element, a second light-emitting element, a first insulating layer, a second ... first insulating layer, a second insulating layer, a second insulating layer, the insulating layer, the third insulating layer, the first optical adjustment layer, the second optical adjustment layer, the first conductive layer, and The first light-emitting element has a first lower electrode having a light-transmitting property. The second light-emitting element has a light-emitting layer and a semi-transmissive and semi-reflective upper electrode. The first electrode has a second lower electrode having light-transmitting properties, the light-emitting layer, and the upper electrode. The optical adjustment layer and the second optical adjustment layer are provided on the same surface. a first optical adjustment layer and a second optical adjustment layer, the first optical adjustment layer being provided to cover the first optical adjustment layer and the second optical adjustment layer; The first conductive layer has a first opening overlapping the first optical adjustment layer and a second opening overlapping the second optical adjustment layer. The conductive layer is disposed inside the first opening and is in contact with the side surface of the first insulating layer and the top surface of the first optical adjustment layer. The second conductive layer is provided along the side surface of the first insulating layer inside the second opening. The second insulating layer is provided along the upper surface of the first conductive layer and the upper surface of the second optical adjustment layer. The third insulating layer is embedded in the first opening through the second conductive layer. The first lower electrode is provided on the first opening and is embedded in the first opening. The second lower electrode is provided on the second opening and is in contact with the first conductive layer at the outer edge of the second opening. The first conductive layer and the second conductive layer are in contact with each other at the outer edge of the second opening. The second optical adjustment layer has a function of reflecting visible light. The second optical adjustment layer is thicker than the first optical adjustment layer. The first insulating layer, the second insulating layer, and the third insulating layer have their upper surfaces at approximately the same height. The second insulating layer is thicker than the third insulating layer.

[0017] In the above, the first optical adjustment layer has a first film, and the second optical adjustment layer has a second film. It is preferable that the second film and the third film are laminated in this order. The third film has a function of reflecting visible light and is formed by processing the same film. It is preferable that:

[0018] In the above, the first optical adjustment layer has electrical conductivity, and the first optical adjustment layer and the lower It is preferable that the electrode is electrically connected to the electrode.

[0019] In the above, a circuit layer including a transistor and a fourth insulating layer on the circuit layer are provided. In this case, it is preferable that the first optical adjustment layer is provided on the fourth insulating layer, and It is preferable that the transistor and the first light emitting element are electrically connected. The crystalline metal oxide or single crystal silicon is used in the semiconductor layer where the channel is formed. It is preferred that the nucleic acid sequence contains a recombinant nucleic acid.

[0020] Alternatively, in the above, a first circuit layer including a first transistor and a second transistor a second circuit layer including a fourth insulating layer on the first circuit layer; In this case, the first optical adjustment layer preferably has a fifth insulating layer between the first optical adjustment layer and the second optical adjustment layer. a fourth insulating layer provided on the fourth insulating layer, the first transistor and the first light-emitting element being electrically connected to each other; In this case, the first transistor preferably has a first gate electrode in which a channel is formed. The semiconductor layer includes a crystalline metal oxide, and the second transistor has a channel formed therein. The second semiconductor layer to be formed contains a crystalline metal oxide or single-crystal silicon. is preferred.

[0021] In the above, it is preferable that a plurality of first light-emitting elements are provided. The light emitting elements are preferably arranged in a matrix with a resolution of 5000 ppi or more.

[0022] Another embodiment of the present invention is a method for manufacturing a display device, in which: forming a first optical adjustment layer and a second optical adjustment layer having different thicknesses; forming a first insulating layer over the adjustment layer and the second optical adjustment layer; a step of performing a planarization process on the first insulating layer to planarize the upper surface; forming a first lower electrode overlapping the optical adjustment layer and a second lower electrode overlapping the second optical adjustment layer; a light-emitting layer on the first lower electrode and the second lower electrode; and an upper electrode on the light-emitting layer. and forming a first optical adjustment layer and a second optical adjustment layer. The upper surfaces of both electrodes are formed to reflect visible light, and the first and second lower electrodes are The upper electrode is formed to be semi-transparent and semi-reflective. Form. [Effects of the Invention]

[0023] According to one embodiment of the present invention, a display device with extremely high resolution can be provided. Alternatively, a display device that combines high definition and high color reproducibility can be provided. A display device can be provided.

[0024] The description of these effects does not preclude the existence of other effects. An embodiment does not necessarily have to have all of these effects. can be extracted from descriptions in the specification, drawings, claims, etc. [Brief explanation of the drawings]

[0025] [Figure 1] 1 shows an example of the configuration of a display device. [Figure 2] 1 shows an example of the configuration of a display device. [Figure 3] 1A to 1C illustrate an example of a method for manufacturing a display device. [Figure 4] 1A to 1C illustrate an example of a method for manufacturing a display device. [Figure 5] 1 shows an example of the configuration of a display device. [Figure 6] 1 shows an example of the configuration of a display device. [Figure 7]1 shows an example of the configuration of a display device. [Figure 8] 1 shows an example of the configuration of a display device. [Figure 9] 1 shows an example of the configuration of a display device. [Figure 10] 1 shows an example of the configuration of a display device. [Figure 11] 1 shows an example of the configuration of a display device. [Figure 12] An example of the display module configuration. [Figure 13] 1A and 1B are a block diagram and a circuit diagram of a display device. [Figure 14] 1A and 1B are a circuit diagram and a timing chart of a display device. [Figure 15] An example of the configuration of electronic devices. [Figure 16] An example of the configuration of electronic devices. DETAILED DESCRIPTION OF THE INVENTION

[0026] Hereinafter, embodiments will be described with reference to the drawings. It is understood that the present invention may be embodied in various different forms without departing from its spirit and scope. It will be readily apparent to those skilled in the art that various modifications may be made to the embodiments and details of the present invention. However, the present invention should not be construed as being limited to the description of the following embodiments.

[0027] In each drawing described in this specification, the size of each component, the thickness of a layer, or the area The figures may be exaggerated for clarity and are not necessarily limited to that scale. I can't.

[0028] In this specification, ordinal numbers such as "first" and "second" are used to avoid confusion of components. The number is not a numerical limitation.

[0029] In the following, expressions indicating directions such as "up" and "down" basically correspond to the direction of the drawing. However, for the purpose of facilitating explanation, etc., The orientation of "up" or "down" may not be consistent with the drawings. When explaining the stacking order (or formation order) of a laminate, etc., The surface to be bonded (the surface to be formed, the supporting surface, the adhesive surface, the flat surface, etc.) is positioned above the laminate. Even if the object is placed in a certain position, the direction may be described as down and the opposite direction as up.

[0030] In addition, in this specification and the like, the terms "film" and "layer" are interchangeable. For example, the terms "conductive layer" and "insulating layer" can be interchanged with "conductive film" and "insulating layer." The term "insulating film" may be used interchangeably in some cases.

[0031] In this specification, the EL layer is provided between a pair of electrodes of a light-emitting element and includes at least It refers to a layer containing a light-emitting substance (also called a light-emitting layer) or a laminate containing a light-emitting layer. .

[0032] In this specification, a display panel, which is one aspect of a display device, displays (outputs) an image or the like on a display surface. Therefore, a display panel is one aspect of an output device.

[0033] In this specification, the substrate of the display panel is provided with, for example, an FPC (Flexible Printed Circuit). Integrated Circuit) or TCP (Tape Carrier Packa ge) or a connector such as COG (Chip On Ground) is attached to the board. The IC mounted by the (glass) method is called a display panel module or display module. It may also be called a display panel or simply a display panel.

[0034] In this specification and the like, a touch panel, which is one aspect of a display device, is a device for displaying images and the like on a display surface. The function of displaying the information and detecting when a detectable object such as a finger or stylus touches, presses, or approaches the display surface. It also functions as a touch sensor to detect when something is touching the screen. A controller is one type of input / output device.

[0035] The touch panel is, for example, a display panel (or display device) with a touch sensor, A touch panel can also be called a display panel (or display device) with a touch function. Alternatively, the display panel may have a touch sensor panel. It may also be configured to have a touch sensor function inside or on the surface.

[0036] In addition, in this specification, a touch panel substrate on which a connector or IC is mounted is referred to as a touch panel. , touch panel module, display module, or simply touch panel. be.

[0037] (Embodiment 1) In this embodiment, a display device according to one embodiment of the present invention and a manufacturing method thereof will be described. do.

[0038] A display device according to one embodiment of the present invention includes light-emitting units that emit light of different colors. The light-emitting element includes a lower electrode, an upper electrode, and A layer containing a light-emitting compound (also called a light-emitting layer or EL layer) is provided between these layers. As the optical element, it is preferable to use an electroluminescent element such as an organic EL element or an inorganic EL element. Alternatively, a light-emitting diode (LED) may be used.

[0039] The light-emitting unit also includes an insulating layer that overlaps the light-emitting element and a light-emitting element that reflects visible light through the insulating layer. Furthermore, the light-emitting element has a lower electrode on the side of the reflective layer. The upper electrode is made of a semi-transparent and semi-reflective conductive film. It is preferable to use a light-emitting unit having a so-called microcavity structure (a microresonator). structure) is realized, which intensifies light of specific wavelengths.

[0040] The two light-emitting elements provided in the two light-emitting units that emit light of different colors have the same configuration. In this case, the light emitting element is preferably a light emitting element that emits white light. The optical layer and the upper electrode are common, and the lower electrode is electrically isolated for each element. Furthermore, the distance between the light-emitting element and the reflective layer of the two light-emitting units is different. This allows different wavelengths of light to be emitted intensified.

[0041] In one aspect of the present invention, reflective layers having different thicknesses are formed, and then an insulating layer is formed to cover the reflective layers. Then, the upper surface of the insulating layer is planarized to separate the insulating layers with different thicknesses on each reflective layer. Then, on top of the planarized insulating layer, a light-emitting layer overlapping with the respective reflective layer is formed. By forming an element, different colors are enhanced by different optical paths. The optical units can be individually tailored.

[0042] That is, in the display device of one embodiment of the present invention, reflective layers having different thicknesses are provided on a surface on which the reflective layer is formed. The reflecting layer is covered with an insulating layer whose upper surface is planarized. and a light-emitting element is provided on the insulating layer in an area overlapping the reflective layer. By planarizing the upper surface of the insulating layer, the surface on which the reflective layer is to be formed (or the reflective layer The distance between the upper surface of the insulating layer and the lower surface of the reflective layer is constant regardless of the thickness of the reflective layer. The thicker the reflective layer, the thinner the insulating layer on the reflective layer; Therefore, the thickness of the insulating layer located between the light emitting element and the reflective layer is This can be controlled by varying the thickness of the reflective layer. The reflecting layer has the function of adjusting the optical distance (optical path length) depending on its thickness, so it is also called an optical adjustment layer. can also be called.

[0043] The distance between the light-emitting layer and the reflective layer is different between the two light-emitting units. The light emitted by each unit is a combination of different wavelengths. The difference in the optical distance (also called the optical path length) between the two points is determined by the difference in the thickness of the reflective layer. This allows for highly accurate control of the optical distance between the two light-emitting units, resulting in excellent color reproduction. Not only is it highly reliable, but it also reduces color unevenness between light-emitting units, allowing for a display device with high display quality. It can be produced with good retention.

[0044] In addition, the light-emitting elements of the light-emitting units exhibiting different colors are flattened. Therefore, even if the light-emitting units exhibit different colors, the light-emitting units can be uniformly illuminated. Since light emitting elements having the same structure are formed on the same plane, the surface from which light is emitted (light emitting surface, Specifically, the height of the upper electrode can be made to match. Since there is no degradation of display quality due to differences in brightness, color reproduction is high and Therefore, a high-quality display device can be provided.

[0045] In addition, one of the two light-emitting units may have a configuration in which no insulating layer is provided on the reflective layer. For example, a reflective layer may be formed on the upper surface of the insulating layer so that the upper surface of the insulating layer and the upper surface of the reflective layer are substantially aligned. The insulating layer may be planarized by such a method. This allows the flattening process to be completed when the top surface of the reflective layer is exposed. At this time, before the planarization process, an insulating film is formed on the reflective layer. a layer that contains a material different from the layer and transmits visible light, and after planarization treatment, The upper surface of the reflective layer may be configured so that the upper surface of the insulating layer is approximately flush with the upper surface of the insulating layer. Since the reflective layer is not exposed to chemical treatment, deterioration of optical properties such as reflectance of the reflective layer can be prevented.

[0046] An opening is provided in the insulating layer at a position where the insulating layer overlaps the reflective layer, and a lower electrode of the light emitting element is provided inside the opening. In this case, the upper surface of the insulating layer and the upper surface of the lower electrode may be approximately flush with each other. It is preferable to perform a planarization process so that the edges of the lower electrode are aligned. Therefore, the light-emitting layer and the upper electrode can be formed on a flat surface. The angular characteristics and aperture ratio can be improved.

[0047] The display device according to one embodiment of the present invention can produce light-emitting units of different colors with extremely high precision. In addition, the surfaces on which adjacent light emitting elements are formed are flat, and no steps are formed, so that the light emitting elements can be easily formed. It is possible to arrange optical elements at an extremely high density. For example, a display device with high definition can be realized by using one or more light emitting elements (or light emitting units). The pixels having a resolution of 2000 ppi or more, preferably 3000 ppi or more, more preferably Preferably, it is 5000 ppi or more, more preferably 6000 ppi or more, and 2000 Extremely high-resolution displays arranged at resolutions of 0ppi or less, or 30,000ppi or less It is preferable to use a device.

[0048] For ease of explanation, the explanation has been given mainly using two light-emitting units. It is preferable to provide light-emitting units that exhibit three primary colors or four or more colors. Specifically, they have light-emitting units that emit red (R), green (G), and blue (B) light, respectively. Alternatively, in addition to or in place of these, yellow (Y ), cyan (C), magenta (M), white (W), or other light-emitting units are provided. This may also be configured as follows.

[0049] More specific configuration examples and manufacturing method examples will be described below with reference to the drawings.

[0050] [Configuration example 1] FIG. 1 is a cross-sectional schematic diagram illustrating a display device according to one embodiment of the present invention. The light-emitting units 120R, 120G, and 120R respectively exhibit different colors. Has B.

[0051] The light-emitting unit 120R, the light-emitting unit 120G, and the light-emitting unit 120B are The light-emitting element 110 is provided over a light-transmitting insulating layer 121. a conductive layer 111 that functions as a lower electrode, a conductive layer 113 that functions as an upper electrode, The conductive layer 111 is sandwiched between the EL layer 112 and the conductive layer 111. The conductive layer 113 has a function of transmitting visible light, and the conductive layer 113 has semi-transmittance and semi-reflectance to visible light. do.

[0052] The light emitting element 110 is formed by applying a potential difference between the conductive layer 111 and the conductive layer 113. An electroluminescent element having a function of emitting light when a current flows through 12 can be used. It is preferable to use an organic EL element using a light-emitting organic compound in the EL layer. The optical element 110 emits white light whose emission spectrum has two or more peaks in the visible light region. It is preferable that the element is a

[0053] Here, the EL layer 112 and the conductive layer 113 are formed by the light emitting element 110 provided in each light emitting unit. The conductive layer 113 is provided in common over the entire area. The conductive layer 111 provided in each light emitting element 110 functions as a light emitting element. The conductive layer 111 is, for example, a pixel electrode. It works like this.

[0054] 1, an insulating layer 115 is provided to cover the end of the conductive layer 111. The layer 115 is formed by the step at the end of the conductive layer 111, which causes the EL layer 112 to become thinner. The conductive layer 111 and the conductive layer 113 have a function of preventing an electrical short circuit. In order to improve the coverage of the insulating layer 112, as shown in FIG. The end of 15 preferably has a tapered shape.

[0055] The light-emitting unit 120R includes a light-emitting element 110 and a reflective layer 121 provided on the substrate 101. 114R (also called an optical adjustment layer), and a layer disposed between the light emitting element 110 and the reflective layer 114R. and a part of the insulating layer 121. Similarly, the light-emitting unit 120G has the light-emitting element 110 and , a reflective layer 114G, and a part of an insulating layer 121. It includes the element 110, the reflective layer 114B, and a part of the insulating layer 121.

[0056] The surface of the substrate 101 is made of a reflective layer 114R, a reflective layer 114G, a reflective layer 114B, etc. The substrate 101 is required to have at least an insulating flat surface. As described above, a circuit board having transistors, wiring, etc. is used as the substrate 101. It is also possible to use a display device that employs a passive matrix method or a segment method. In this case, an insulating substrate such as a glass substrate can be used as the substrate 101 .

[0057] The insulating layer 121 is provided to cover the reflective layer 114R, the reflective layer 114G, and the reflective layer 114B. The insulating layer 121 preferably has an upper surface that is planarized to form a flat surface. In other words, the insulating layer 121 is processed so that the height of the upper surface thereof is approximately constant regardless of the location. Alternatively, the insulating layer 121 and the surface on which the reflective layer 114R and the like are to be formed (the upper surface of the substrate 101) The distance between the two points is processed to be roughly constant regardless of location.

[0058] Here, among the three reflective layers, the reflective layer 114R is the thinnest and the reflective layer 114B is the thickest. Therefore, the insulating layer 121 located on these three reflective layers overlaps with the reflective layer 114R. The portion where the reflective layer 114B overlaps is the thickest, and the portion where the reflective layer 114B overlaps is the thinnest. The upper surface of the reflective layer and the lower surface of the conductive layer 113 in the light-emitting unit (i.e., the conductive layer 113 and the EL The distance between the interface and the layer 112 is the distance D R , distance D G , distance D B When away DR is the largest, and the distance D B is the smallest. Distance D R , distance D G , distance D B The difference is This corresponds to the difference in optical distance (optical path length) between the light-emitting units.

[0059] Of the three light-emitting units, the light-emitting unit 120R has the longest optical path length, so it emits the longest wavelength. On the other hand, the light emitting unit 120B emits the intensified light R having the shortest optical path length. Therefore, the light emitting unit 120G emits light B, which is the light with the shortest wavelength. For example, light R is light in which red light is intensified, Light G can be light with enhanced green light, and light B can be light with enhanced blue light. do.

[0060] By adopting such a configuration, the light emitting element 110 can be produced separately for each light emitting unit of a different color. This eliminates the need for separate devices, and allows for color display with high color reproducibility using elements with the same configuration. In addition, since it is not necessary to separately prepare the EL layer 112 of the light emitting element 110, For example, if the resolution exceeds 5000 ppi, It is possible to realize a display device that can

[0061] [Configuration example 2] An example of the configuration of a display device including a substrate having circuit elements will be described below.

[0062] [Configuration Example 2-1] FIG. 2A is a schematic cross-sectional view of the display device 100. The display device 100 includes a semiconductor circuit. On the substrate 101 provided, the light-emitting unit 120R and the light-emitting unit 120R illustrated in the above-mentioned configuration example 1 are 20G, and equipped with a light-emitting unit 120B.

[0063] The substrate 101 includes a circuit for driving each light-emitting unit (also called a pixel circuit) and a It is a substrate on which a semiconductor circuit is provided that functions as a drive circuit for driving the element circuit. A more specific example of the configuration of the plate 101 will be described later.

[0064] An insulating layer 122 is provided between the substrate 101 and the insulating layer 121. The upper surface of the insulating layer 122 is The insulating layer 12 forms a surface on which the reflective layers 114R, 114G, and 114B are formed. The upper surface of 2 is preferably flat.

[0065] The substrate 101 and the conductive layer 111 of the light emitting element 110 are connected by a plug 131a and a conductive layer 111. 32 and the plug 131b. The plug 131a is electrically connected to the insulating layer The conductive layer 132 is formed so as to be embedded in the opening formed in the insulating layer 122. The plug 131b is provided on the insulating layer 121. The conductive layer 111 is formed so as to be embedded in the opening that reaches the conductive layer 132. , and is provided in contact with the upper surface of the plug 131b.

[0066] In FIG. 2A, the conductive layer 132 is formed by processing the same film as the reflective layer 114B. However, the present invention is not limited to this example, and the conductive layer 132 may be formed on the reflective layer 114R or The reflective layer 114R may be formed by processing the same film as the reflective layer 114G. The same film as any two or more of the reflecting layer 114G and the reflecting layer 114B is laminated. Good too.

[0067] In addition, in FIG. 2(A), the reflective layer 114R, the reflective layer 114G, and the reflective layer 114B are formed on the substrate. 101 and the conductive layer 111 are not electrically connected. The reflective layer 114R, the reflective layer 114G, and the reflective layer 114B are in an electrically floating state. The reflective layer 114R, the reflective layer 114G, and the reflective layer 114B are electrically connected to the conductive layer 132. Alternatively, the reflective layer 1 may be electrically connected to the conductive layer 111 so that the reflective layer 1 has the same potential as the conductive layer 111. 14R, reflective layer 114G, and reflective layer 114B are electrically connected to the substrate 101. A constant potential may be applied by providing a resistor in the insulating layer 122 .

[0068] [Configuration Example 2-2] 2B is a schematic cross-sectional view of the display device 100A. The display device 100A mainly includes a reflective The display device 100 differs from the display device 100 described above in that the configurations of the layer 114G and the reflective layer 114B are different.

[0069] The reflective layer 114B is formed by, from the light emitting element 110 side, the conductive layer 141, the conductive layer 142, and the conductive layer 143. The reflective layer 114G has a laminated structure in which the conductive layer 43 is laminated in order from the light emitting element 110 side. The reflective layer 114R has a laminated structure in which a conductive layer 141 and a conductive layer 142 are laminated. It consists of 41.

[0070] Of the conductive layers 141, 142, and 143, the conductive layer 141 has a resistance to visible light. It is preferable to use a material with high reflectivity for the conductive layer 142 and the conductive layer 143. A material having a lower reflectivity than the conductive layer 141 may be used, but if the same material is used, the processing equipment may be This is preferable because it can be made common.

[0071] FIG. 2B shows an example in which the conductive layer 132 has the same laminated structure as the reflective layer 114B. It shows.

[0072] The conductive layer 142 and the conductive layer 143 do not necessarily have to be conductive. Instead, a layer formed of an insulating film or a semiconductor film may be used. In that case, the conductive layer 13 2 can be made of only a layer having conductivity (for example, conductive layer 141). The plug 131a and the plug 131b are in contact with each other without using the conductive layer 132. Alternatively, the electrical layer 111 and the substrate 101 may be connected by one plug.

[0073] [About the components] {Light-emitting element / light-emitting unit} The light emitting element 110 can be a self-luminous element. The category includes elements whose brightness is controlled by current or voltage. For example, LEDs, organic EL elements, inorganic EL elements, etc. can be used. In particular, organic EL elements It is preferable to use a child.

[0074] Light-emitting elements are available in top-emission, bottom-emission, and dual-emission types. The electrode on the light extraction side uses a conductive film that transmits visible light. For the electrode on the side where light is not extracted, it is preferable to use a conductive film that reflects visible light.

[0075] In one embodiment of the present invention, a top emission type light emitting device is used, which emits light in a direction opposite to the surface on which the light is formed. A light emitting element of a single- or dual-emission type can be suitably used.

[0076] The EL layer 112 has at least a light-emitting layer. The EL layer 112 includes the following layers other than the light-emitting layer: Materials with high hole injection properties, materials with high hole transport properties, hole blocking materials, materials with high electron transport properties Highly electron-injecting or bipolar materials (both electron-transporting and hole-transporting) The substrate may further include a layer containing a high-molecular-weight material.

[0077] The EL layer 112 can be made of either a low molecular weight compound or a high molecular weight compound. The layers constituting the EL layer 112 may contain an inorganic compound. It can be formed by methods such as deposition, transfer, printing, inkjet, and coating. can.

[0078] When a voltage higher than the threshold voltage of the light emitting element 110 is applied between the cathode and the anode, the EL layer 11 Holes are injected into 2 from the anode side, and electrons are injected from the cathode side. The injected electrons and holes are They recombine in the EL layer 112, and the luminescent material contained in the EL layer 112 emits light.

[0079] When a white light emitting element is used as the light emitting element 110, two types of It is preferable that the light emitting element contains two or more luminescent materials. White light can be obtained by selecting luminescent materials so that the light is complementary in color. For example, they emit light of R (red), G (green), B (blue), Y (yellow), O (orange), etc. or luminescent materials that emit light containing spectral components of two or more of the colors R, G, and B. It is preferable that the light-emitting element contains two or more of the above substances. It has two or more peaks within the wavelength range of the visible light region (e.g., 350 nm to 750 nm). It is preferable to use a light-emitting element made of a material having a peak in the yellow wavelength region. The optical spectrum is a material that also has spectral components in the green and red wavelength regions. is preferred.

[0080] The EL layer 112 is a layer including a light-emitting material that emits light of one color and a layer including a light-emitting material that emits light of another color. For example, the EL layer 112 may have a structure in which a light-emitting layer containing a material is laminated. The light-emitting layers may be laminated in contact with each other, or may not contain any light-emitting material. For example, the fluorescent-emitting layer and the phosphorescent-emitting layer may be laminated with the fluorescent layer and the phosphorescent layer interposed therebetween. It contains the same material (e.g., host material, assist material) as the light-emitting layer or the phosphorescent-emitting layer, and Alternatively, a region containing no light-emitting material may be provided. This facilitates fabrication and reduces the driving voltage.

[0081] The light emitting element 110 may be a single element having one EL layer, or may be a light emitting element having multiple EL layers. The device may be a tandem device in which an EL layer is stacked via a charge generating layer.

[0082] A conductive film that transmits visible light and can be used for the conductive layer 111 or the like is, for example, an indium oxide film. Acids doped with indium, indium tin oxide, indium zinc oxide, zinc oxide, and gallium It can be formed using zinc oxide, etc. Also, gold, silver, platinum, magnesium, nickel, etc. aluminum, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, or titanium Metallic materials such as tantalum, alloys containing these metallic materials, or nitrides of these metallic materials (e.g., Titanium nitride, etc. can also be used by forming it thin enough to have light-transmitting properties. A laminated film of the above materials can be used as the conductive layer. For example, a silver-magnesium alloy A laminated film of gold and indium tin oxide is preferably used because it can increase the conductivity. Graphene or the like may also be used.

[0083] Examples of conductive films that reflect visible light and can be used for each reflective layer include aluminum, Gold, platinum, silver, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, For example, a metal material such as palladium or an alloy containing such a metal material can be used. In addition, lanthanum, neodymium, germanium, etc. are added to the above metal materials and alloys. Also, alloys containing titanium, nickel, or neodymium and aluminum (aluminum) Also, alloys containing copper, palladium, magnesium, and silver may be used. An alloy containing silver and copper is preferable because it has high heat resistance. By laminating a metal film or a metal oxide film in contact with an aluminum film or an aluminum alloy film, The materials for such metal films and metal oxide films include titanium and Titanium oxide, etc. Also, the conductive film that transmits visible light and the film made of a metal material For example, a laminated film of silver and indium tin oxide, an alloy of silver and magnesium, etc. A laminated film of gold and indium tin oxide can be used.

[0084] Examples of semi-transparent and semi-reflective conductive films that can be used for the conductive layer 113 include: The conductive film that reflects visible light may be formed to be thin enough to transmit visible light. Furthermore, by forming a laminated structure of the conductive film and the conductive film that transmits visible light, It is possible to improve electrical conductivity and mechanical strength. By laminating metal oxide films, oxidation and corrosion of the conductive film that reflects visible light can be suppressed. preferable.

[0085] The semi-transparent and semi-reflective conductive film has a reflectivity for visible light (for example, 400 nm and above). The reflectance for light of a predetermined wavelength within the range of 1000 to 7000 nm is 20% or more and 80% or less, preferably It is preferable that the reflectivity is 40% or more and 70% or less. The reflectance to visible light is 40% or more and 100% or less, preferably 70% or more and 100% or less. In addition, it is preferable that the reflectance of the light-transmitting conductive film with respect to visible light is 0% or more. It is preferable to set the ratio to 40% or less, and more preferably to 0% or more and 30% or less.

[0086] The electrodes constituting the light-emitting element and the light-emitting unit are formed by evaporation or sputtering. In addition, a discharge method such as an ink jet method, a screen printing method, etc. It can be formed by any printing method or plating method.

[0087] The above-mentioned light-emitting layer, the substance having a high hole injection property, the substance having a high hole transport property, and the electrode The layer containing a substance having a high electron transporting property, a substance having a high electron injecting property, a bipolar substance, or the like is They are inorganic compounds such as quantum dots and polymer compounds (oligomers, dendrimers, polymers, etc.). For example, by using quantum dots in the light-emitting layer, the light-emitting material It can also function as a

[0088] The quantum dot materials include colloidal quantum dot materials, alloy quantum dot materials, Core-shell type quantum dot materials, core type quantum dot materials, etc. can be used. , materials containing elements from groups 12 and 16, 13 and 15, or 14 and 16 Alternatively, cadmium, selenium, zinc, sulfur, phosphorus, indium, tellurium, Quantum dot materials containing elements such as lead, gallium, arsenic, and aluminum may also be used.

[0089] The reflective layer of each light-emitting unit is formed at least in the portion closest to the light-emitting element 110. It is preferable to use the conductive film that reflects visible light.

[0090] Each light-emitting unit has a surface of a reflective layer that reflects visible light and a surface of a semi-transparent layer that is semi-transparent to visible light. The optical distance between the conductive layer and the semi-reflective layer is , mλ / 2 (m is a natural number) or its vicinity. .

[0091] Strictly speaking, the optical path length is determined by the reflecting surface of the reflecting layer and the semi-transmissive and semi-reflective surface. The product of the physical distance between the conductive layer and the reflective surface and the refractive index of the layer provided between them is related. Therefore, it is difficult to precisely adjust the surface of the reflective layer and the semi-transparent layer. and the surface of the semi-reflective conductive layer are assumed to be reflective surfaces, and the optical path length is adjusted accordingly. It is preferable.

[0092] In each light-emitting unit, the insulating layer 121 located between the reflective layer and the conductive layer 111 is It is preferable to use a material that is highly transparent to visible light. For example, a silicon oxide film, Inorganic insulating films such as silicon oxynitride film, aluminum oxide film, and hafnium oxide film are used as single layers. Alternatively, the insulating layer 121 may be made of a material having a high refractive index (for example, By using a material with a refractive index of 1.4 or more, preferably 1.5 or more, the physical thickness can be reduced. This allows for increased productivity.

[0093] [Example of manufacturing method] An example of a manufacturing method of a display device according to one embodiment of the present invention will be described with reference to the drawings. The display device 100A illustrated in the above configuration example 2 will now be described as an example.

[0094] The thin films (insulating films, semiconductor films, conductive films, etc.) that constitute the display device are formed by sputtering. , Chemical Vapor Deposition (CVD) method, Vacuum evaporation, Pulsed Laser Deposit (PLD) ion) method, Atomic Layer Deposition (ALD) The CVD method can be a plasma-enhanced chemical vapor deposition (PECVD) method. There are methods such as VD (Plasma Enhanced CVD) and thermal CVD. One of the thermal CVD methods is metal organic chemical vapor deposition (MOCVD). c CVD) method.

[0095] In addition, thin films (insulating films, semiconductor films, conductive films, etc.) that make up the display device are formed by spin coating, Dip, spray coating, inkjet, dispensing, screen printing, offset printing Printing, doctor knife method, slit coating, roll coating, curtain coating, knife coating It can be formed by the following methods.

[0096] In addition, when processing the thin film that constitutes the display device, a photolithography method or the like is used. Other methods include nanoimprinting, sandblasting, and lift-off. It is also possible to process a thin film by a film formation method using a shielding mask such as a metal mask. Alternatively, island-shaped thin films may be formed directly.

[0097] There are two typical photolithography methods: A resist mask is formed on the thin film to be processed by etching or the like. The other method is to remove the photomask after forming a photosensitive thin film. Then, the thin film is processed into a desired shape by performing development.

[0098] In photolithography, the light used for exposure is, for example, i-line (wavelength 365 nm), It uses g-ray (wavelength 436 nm), h-ray (wavelength 405 nm), or a mixture of these. In addition, ultraviolet light, KrF laser light, ArF laser light, etc. can be used. The exposure may also be performed by immersion exposure. Using extreme ultraviolet (EUV) light and X-rays, Also, electron beams can be used instead of light for exposure. The use of light, X-rays or electron beams is preferred because it allows for extremely fine processing. When exposure is performed by scanning a beam such as an electron beam, the photomask It is unnecessary.

[0099] There are three methods for etching thin films: dry etching, wet etching, and sandblasting. Methods such as these can be used.

[0100] [Preparation of Substrate 101] The substrate 101 is a substrate having heat resistance sufficient to withstand the subsequent heat treatment. When an insulating substrate is used as the substrate 101, a glass substrate, a quartz substrate, or the like can be used. Substrates such as silicon, carbon, and sapphire substrates can be used. Single crystal semiconductor substrates, polycrystalline semiconductor substrates, silicon germanium substrates, etc. A compound semiconductor substrate such as a silicon substrate, or a semiconductor substrate such as an SOI substrate can be used.

[0101] In particular, the substrate 101 is a semiconductor substrate or an insulating substrate on which a transistor or the like is formed. It is preferable to use a substrate on which a semiconductor circuit including a semiconductor element is formed. For example, a pixel circuit, a gate line driving circuit (gate driver), a source line driving circuit (source In addition to the above, it is preferable that the circuit includes an arithmetic circuit, a memory circuit, etc. etc. may be configured.

[0102] In this embodiment, a substrate on which at least a pixel circuit is formed is used as the substrate 101. .

[0103] [Formation of insulating layer 122 and plug 131a] An insulating film that will become the insulating layer 122 is formed on the substrate 101. An opening reaching the substrate 101 is formed at a position where the groove 131a is to be formed. It is preferable that the openings reach the electrodes and wiring provided on the substrate 1. After forming the conductive film so as to expose the upper surface of the insulating layer 122, a planarization process is performed. As a result, the plug 131a buried in the insulating layer 122 can be formed ( Figure 3(A)).

[0104] A typical example of planarization is chemical mechanical polishing (CPM). Polishing methods such as chemical polishing (CMP) can be suitably used. Alternatively, dry etching or plasma treatment may be used. The etching treatment and plasma treatment may be performed multiple times, or may be performed in combination. In addition, when the processes are performed in combination, the order of the processes is not particularly limited, and the order can be adjusted to suit the unevenness of the surface to be treated. The setting can be made appropriately.

[0105] [Formation of Reflective Layer 114R, Reflective Layer 114G, Reflective Layer 114B, and Conductive Layer 132] First, a conductive film 143f that will become the conductive layer 143 is formed on the insulating layer 122. A resist mask 151 is formed on the conductive film 143f (FIG. 3(B)). The resist mask 151 is formed on the portion that will later become the reflective layer 114B. The resist mask 151 is then formed on the portion that covers the upper surface of the lug 131a. The conductive layer 143 can be formed by removing the thin conductive film 143f by etching. After that, the resist mask 151 is removed.

[0106] Next, a conductive film 14 is formed on the insulating layer 122 and the conductive layer 143, which will later become the conductive layer 142. A conductive film 142f is formed, and a resist mask 152 is formed on the conductive film 142f (FIG. 3(C)). The resist mask 152 is formed by removing the conductive layer 143 (the portion of the conductive film 142f that will become the conductive layer 132) from the conductive film 142f. The insulating layer 114B is provided to cover the portion overlapping with the insulating layer 114A (including the insulating layer 114B) and the portion that will later become the reflective layer 114G. Similarly, the conductive film 142f is etched to form the conductive layer 142. .

[0107] Next, a conductive film 14 is formed on the insulating layer 122 and the conductive layer 142, which will later become the conductive layer 141. A conductive film 141f is formed, and a resist mask 153 is formed on the conductive film 141f (FIG. 3(D)). The resist mask 153 is formed on a portion of the conductive film 141f that overlaps with the conductive layer 142 and ... that overlaps with the conductive layer 142. The conductive film 141f is then etched in the same manner as above. By this, the conductive layer 141 can be formed.

[0108] As a result of the above, the reflective layer 114R, the reflective layer 114G, the reflective layer 114B, and the conductive layer 132 are It is possible to form (Figure 3(E)).

[0109] In addition, when an insulating film is used instead of the conductive film 143f or the conductive film 142f, these The resist mask 151 or the resist mask 152 is formed so as not to be formed in the portion that becomes the conductive layer 132. The mask 152 may be configured not to be provided in the portion that will become the conductive layer 132 .

[0110] In FIG. 3C, the edge of the resist mask 152 and the edge of the conductive layer 143 are aligned. Although the resist mask 152 is shown to be formed so as to match the pattern, these do not necessarily coincide exactly. In addition, the resist mask 152 is formed to cover the edge of the conductive layer 143. In that case, the conductive layer 142 may be formed to cover the end portions of the conductive layer 143. The same applies to the positional relationship between the resist mask 153 and the conductive layer 142.

[0111] [Formation of insulating layer 121 and plug 131b] The reflective layer 114R, the reflective layer 114G, the reflective layer 114B, and the conductive layer 132 are covered with an insulating layer 1 An insulating film 121f, which will later become the insulating layer 121, is formed on the substrate 22 (FIG. 4(A)).

[0112] Next, an opening is formed in the insulating film 121f down to the conductive layer 132, and a conductive material is applied to fill the opening. As shown in FIG. 4B, a conductive film 131bf that will later become the plug 131b is formed.

[0113] Thereafter, the upper surface of the insulating film 121f is exposed, and the insulating film 121f on the reflective layer 114B is By performing the planarization process until the desired thickness is reached, the insulating layer 121 with its top surface planarized and the insulating layer 122 with its top surface planarized are formed. A plug 131b can be formed embedded in the insulating layer 121 (FIG. 4(C)).

[0114] The insulating film 121f has a thickness of at least a portion overlapping with the reflective layer 114B after the planarization process. The thickness of the insulating film 121f is set to be equal to or greater than the thickness of the insulating film 121f to be formed. Due to this influence, a part of the conductive film 131bf remains on the upper surface of the insulating film 121f after the planarization process. Therefore, the insulating film 121f is formed to a sufficient thickness in advance and then subjected to a planarization process. During the processing, an additional flattening process is performed after the upper surface of the insulating film 121f is exposed. This makes it possible to suitably remove the remaining conductive film 131bf.

[0115] The planarization process is performed so that the portion of the insulating layer 121 overlapping the reflective layer 114B has a desired thickness. For example, when using the CMP method, first, the insulating film 121 Polish at a constant processing speed until part of the top surface of f is exposed. By polishing the insulating film 121f under slow conditions until it reaches a desired thickness, high precision processing can be achieved. This makes it possible to

[0116] The end point of polishing can be detected by irradiating the surface of the object with light and measuring the change in the reflected light. This is an optical method to detect the change in the polishing resistance that the processing equipment receives from the surface to be processed. A physical method that applies magnetic field lines to the surface to be treated and uses the changes in the magnetic field lines caused by eddy currents. There are ways to do this.

[0117] After the upper surface of the insulating film 121f is exposed, the insulating film 121f is optically measured by using a laser interferometer or the like. By performing the polishing process under conditions of a slow processing speed while monitoring the thickness of the insulating film 121f, The thickness of the insulating layer 121 can be controlled with high precision. The polishing process may be repeated several times until the desired thickness is achieved.

[0118] [Formation of Conductive Layer 111] A conductive film is formed on the insulating layer 121 and the plug 131b, and unnecessary portions are removed by etching. By removing the conductive layer 111, the conductive layer 111 is formed to be electrically connected to the plug 131b.

[0119] [Formation of insulating layer 115] Next, an insulating film is formed to cover the conductive layer 111 and the insulating layer 121, and unnecessary portions are etched away. By removing the insulating layer 115 by etching, the insulating layer 115 covering the end of the conductive layer 111 is formed (FIG. 4(D)). In the area where the insulating layer 115 overlaps with the conductive layer 111, the reflective layer 114R and the reflective layer 114R are formed. The insulating layer 114 is processed to have an opening that overlaps with the reflecting layer 114G or the reflecting layer 114B.

[0120] The end of the insulating layer 115 on the conductive layer 111 is tapered. It is preferable that the taper angle of the end of the insulating layer 115 (the angle between the surface to be formed and the end face) is is greater than 0 degrees and less than 60 degrees, preferably greater than 5 degrees and less than 45 degrees, more preferably less than 5 degrees It is preferable to set the angle to 30 degrees or less.

[0121] The insulating layer 115 can be formed of an organic insulating film or an inorganic insulating film. For high-resolution (e.g., 2000 ppi or higher) display devices, inorganic insulating films should be used. is preferred.

[0122] [Formation of EL layer 112 and conductive layer 113] Next, an EL layer 112 and a conductive layer 113 are formed in this order on the conductive layer 111 and the insulating layer 115. By doing so, the light emitting element 110 is formed (FIG. 4(E)).

[0123] The EL layer 112 includes at least a layer containing a light-emitting compound. The layer may have a laminated structure of a layer, an electron transport layer, a charge generation layer, a hole transport layer, and a hole injection layer. The EL layer 112 is formed by a liquid phase method such as a vapor deposition method or an inkjet method. can be done.

[0124] The conductive layer 113 is formed to have semi-transmittance and semi-reflection properties with respect to visible light. For example, a metal film or alloy film thin enough to transmit visible light can be used. A light-transmitting conductive film (for example, a metal oxide film) may be stacked on such a film.

[0125] As a result, the light-emitting units 120R and 120G, which have different optical distances, , and light-emitting unit 120B can be formed.

[0126] According to the above example of the manufacturing method, the difference in optical distance between each light-emitting unit can be controlled by changing the thickness of each reflective layer. Since it is possible to precisely control the chromaticity of each light-emitting unit, This makes it possible to easily fabricate a display device with excellent color reproducibility and extremely high display quality. .

[0127] Furthermore, the light emitting element 110 and each reflective layer can be formed on an insulating layer whose upper surface is flattened. Furthermore, the lower electrode (conductive layer 111) of the light emitting element 110 is connected to the pixel of the substrate 101 via a plug. Since it can be electrically connected to circuits, etc., it can form extremely fine pixels. It is possible to realize a very high-definition display device. 10 can be arranged on top of the pixel circuit and the drive circuit, so the aperture ratio (effective light-emitting area ratio) ) can be realized.

[0128] [Configuration example 3] The following describes a configuration example of a display device that is partially different from the above configuration examples 1 and 2. I will explain.

[0129] [Configuration Example 3-1] FIG. 5A shows a schematic cross-sectional view of the display device 100B.

[0130] The light-emitting unit 120R of the display device 100B includes a reflective layer 114R and a light-emitting element 11 The light-emitting element 110R includes a conductive layer 111R, an EL layer 112, and a conductive layer 113. It has.

[0131] The reflective layer 114R is electrically connected to the substrate 101 via a plug 131a. In addition, an opening reaching the reflective layer 114R is provided in the insulating layer 121 on the reflective layer 114R. A conductive layer 111R is buried inside the opening. The upper surface of the conductive layer 111R is flattened so that no large step occurs at the boundary between them. The EL layer 112 is formed on the upper surface of the planarized conductive layer 111R and the insulating layer 121. A conductive layer 113 is provided on the EL layer 112 so as to be in contact with the upper surface. Since the surface on which the EL layer 112 is formed is flattened, the insulating layer 115 exemplified in the above configuration example is not required. Therefore, the aperture ratio can be increased.

[0132] In the display device 100B, the reflective layer 114R and the conductive layer 111R are electrically connected. Therefore, the conductive layer 132 and the plug 131b of the display device 100A are not provided. Furthermore, since the upper surface of the plug 131a is flattened, the plug The area overlapping with the lug 131a can also be used as the light-emitting area of ​​the light-emitting unit 120R. , the aperture ratio can be increased.

[0133] The light-emitting unit 120G includes a light-emitting element 110G and a reflective layer 114G. The light-emitting unit 110G includes a conductive layer 111G, an EL layer 112, and a conductive layer 113. The light-emitting unit 120G is the same as the light-emitting unit 120 except for the configuration of the reflective layer 114G and the thickness of the conductive layer 111G. It is the same as R. The reflective layer 114G has a conductive layer 141 and a conductive layer 142 stacked together. The upper surface of the conductive layer 111G is flattened in the same manner as the conductive layer 111R. G is formed thinner than the conductive layer 111R by the thickness of the conductive layer 142.

[0134] The light-emitting unit 120B includes a light-emitting element 110B and a reflective layer 114B. The light-emitting unit 110B includes a conductive layer 111B, an EL layer 112, and a conductive layer 113. The light-emitting unit 120B has the same structure as the light-emitting unit 12 except for the structure of the reflective layer 114B and the thickness of the conductive layer 111B. 0R, and the light-emitting unit 120G. The reflective layer 114B is made of a conductive layer 141, a conductive layer 1 42 and a conductive layer 143 are laminated on the upper surface of the conductive layer 111B. Since the conductive layer 111B is planarized in the same manner as the conductive layer 111G, the conductive layer 111B is planarized in the same manner as the conductive layer 143. It is made thinner by the thickness of

[0135] [Configuration Example 3-2] FIG. 5B shows a schematic cross-sectional view of the display device 100C.

[0136] The light-emitting unit 120R of the display device 100C includes a light-emitting element 110, a reflective layer 116R, and a The reflective layer 116R includes a conductive layer 141, a conductive layer 144, and an insulating layer 146R. It has.

[0137] The conductive layer 141 of the reflective layer 116R is provided on the insulating layer 122 and electrically connected to the plug 131a. The insulating layer 121 has an opening that reaches the conductive layer 141. The conductive layer 144 is provided in the opening of the insulating layer 121, and the upper surface of the conductive layer 144 and the opening The insulating layer 146R is provided along the side wall. The insulating layer 121 is provided so as to be embedded in the region surrounded by the conductive layer 144. The edge layer 146R and the conductive layer 144 each have a flattened upper surface.

[0138] The conductive layer 111 of the light emitting element 110 of the light emitting unit 120R is made of an insulating layer 121 and an insulating The conductive layer 144 is provided in contact with the upper surface of the conductive layer 146R. and conductive layer 111 are electrically connected at the outer edge of the opening in insulating layer 121. With this configuration, the substrate 101 and the conductive layer 111 are connected to the plug 131a and the conductive layer 111. 141 and the conductive layer 144. The unit 120R can also use the portion overlapping with the plug 131a as a light-emitting region. Therefore, the aperture ratio can be increased.

[0139] The light-emitting unit 120G includes an insulating layer 146R instead of the insulating layer 146R and the reflective layer 116R. The light-emitting unit 120R differs from the light-emitting unit 120R in that it has a reflective layer 116G and a reflective layer 116G. 6G includes a conductive layer 141, a conductive layer 142, and a conductive layer 144. The insulating layer 146G includes The thickness of the insulating layer 146R is processed to be thinner by the thickness of the conductive layer 142. .

[0140] The light-emitting unit 120B includes an insulating layer 146R instead of the insulating layer 146R and the reflective layer 116R. 6B and a reflective layer 116G. 6G includes a conductive layer 141, a conductive layer 142, a conductive layer 143, and a conductive layer 144. The layer 146B has a thickness that is greater than that of the insulating layer 146R by the thickness of the conductive layer 142 and the conductive layer 143. It is processed to be thinner.

[0141] [Configuration example 4] Below, a description will be given of an example of the configuration of a display device that is partially different from the above-mentioned examples of the configuration.

[0142] [Configuration Example 4-1] 6A is a schematic cross-sectional view of a display device 100D. The display device 100D mainly includes a light-emitting The display device 100A differs from the display device 100A in that the configuration of the unit 120B is different.

[0143] In the light-emitting unit 120B, the upper surface of the conductive layer 141 and the upper surface of the insulating layer 121 are substantially flush with each other. An insulating layer 121 is located between the conductive layer 111 and the conductive layer 141. The conductive layer 111 and the conductive layer 141 are not electrically connected to each other, but are provided in contact with each other. It continues.

[0144] The plug 131a provided in the light-emitting unit 120B is provided in contact with the conductive layer 143. The substrate 101 and the conductive layer 111 are connected by the plug 131a, the conductive layer 143, and the conductive layer 142. , and are electrically connected via the conductive layer 141. As a result, the light-emitting unit 120B There is no need to provide the conductive layer 132, and the portion overlapping with the plug 131a is used as the light-emitting region. In particular, when the light emitting unit 120B emits blue light, the aperture ratio can be increased. In the case of a light-emitting unit that emits blue light, which has low visibility, the light-emitting area is divided into two areas, one for emitting blue light and the other for emitting blue light. This not only improves the display quality, but also makes the light-emitting area larger than that of the conventional LCD. Power consumption can be reduced.

[0145] In addition, by adopting such a configuration, the conductive layer 121 can be easily flattened during the flattening process of the upper surface of the insulating layer 121. The point at which it is detected that the layer 141 is exposed can be taken as the end point of the planarization process. Therefore, the thickness of the insulating layer 121 of the light-emitting unit 120R and the light-emitting unit 120G is precisely adjusted. This allows accurate control of the chromaticity due to the deviation in the optical path. This makes it less susceptible to cracking and increases production yield.

[0146] The conductive layer 111 may have the same thickness between each light-emitting unit. In the light-emitting unit 120B, an insulating layer 121 is provided between the conductive layer 111 and the reflective layer 114B. Therefore, compared to the display device 100A illustrated in Configuration Example 2, It is preferable to form the conductive layer 111 thick. It can be set according to the optical distance of 0B.

[0147] [Configuration Example 4-2] FIG. 6B is a schematic cross-sectional view of the display device 100E.

[0148] The light-emitting unit 120R includes a light-emitting element 110R, a conductive layer 145, and a reflective layer 114R. The light-emitting element 110R has a conductive layer 111R, an EL layer 112, and a conductive layer 113. .

[0149] The conductive layer 141 constituting the reflective layer 114R is formed on the insulating layer 12 so as to be in contact with the plug 131a. The conductive layer 145 has a light-transmitting property and is provided over the conductive layer 141. The insulating layer 121 has an opening that reaches the conductive layer 145. The conductive layer 111R is 45, and is embedded in the opening of the insulating layer 121. The upper surface of the conductive layer 111R and the upper surface of the insulating layer 121 are arranged so that there is no step at the boundary between them. The substrate 101 and the conductive layer 111R are planarized as shown in FIG. 1 and the conductive layer 145. The light-emitting unit 120R is electrically connected to the plug 13. The area overlapping with 1a can also be used as a light-emitting area.

[0150] The light-emitting unit 120G includes a light-emitting element 110G, a conductive layer 145, and a reflective layer 114G. The light-emitting element 110G has a conductive layer 111G, an EL layer 112, and a conductive layer 113. The light-emitting unit 120G has a reflective layer 114G including a conductive layer 141 and a conductive layer 142. The other components are the same as those of the light-emitting unit 120R. It is formed thinner than the conductive layer 111R by the thickness.

[0151] The light-emitting unit 120B includes a light-emitting element 110B, a conductive layer 145, and a reflective layer 114B. The light emitting element 110B is different from the light emitting elements 110R and 110G in that the conductive layer 1 The difference is that it does not have a conductive layer corresponding to 11R or conductive layer 111G. The light-emitting element 110B includes a conductive layer 145 that functions as a lower electrode, an EL layer 112, and a conductive In the light-emitting unit 120B, the conductive layer 145 is The upper surface is provided so as to be positioned on approximately the same plane as the upper surface of insulating layer 121.

[0152] With this configuration, the conductive layer 14 The point at which it is detected that the 5 is exposed can be set as the end point of the flattening process. , when the insulating layer 121 is planarized, the thickness of the conductive layer 111R of the light-emitting unit 120R is and the thickness of the conductive layer 111G of the light-emitting unit 120B can be controlled with precision. can.

[0153] In each light-emitting unit, a light-transmitting conductive layer 145 is formed on the conductive layer 145, which constitutes a reflective surface. By covering the upper surface of the insulating layer 141, the insulating layer 121 can be easily formed during the formation of the openings and the planarization process. During the etching process, the upper surface of the conductive layer 141 can be prevented from being exposed to etching or planarization. As a result, the reflectance of the upper surface of the conductive layer 141 is reduced due to deterioration or corrosion, and The conductive layer 145 can be formed by using a material selected from the group consisting of: For example, a conductive metal oxide film can be used.

[0154] [Configuration example 5] A more specific example of a display device including a transistor will be described below.

[0155] [Configuration Example 5-1] FIG. 7 is a schematic cross-sectional view of the display device 200A.

[0156] The display device 200A includes a light-emitting unit 120R, a light-emitting unit 120G, and a light-emitting unit 120L. 20B, a capacitor element 240, a transistor 210, and the like.

[0157] The transistor 210 is a transistor in which a channel region is formed in the substrate 201 . The substrate 201 may be a semiconductor substrate such as a single crystal silicon substrate. The transistor 210 includes a portion of the substrate 201, a conductive layer 211, a low resistance region 212, and an insulating layer The conductive layer 211 functions as a gate electrode. 213 is located between the substrate 201 and the conductive layer 211 and functions as a gate insulating layer. The resistor region 212 is a region in the substrate 201 where impurities are doped, and serves as a source or drain. The insulating layer 214 is provided to cover the side surface of the conductive layer 211. It acts as a wall insulating layer.

[0158] Also, a device is provided between two adjacent transistors 210 so as to be embedded in the substrate 201. A daughter isolation layer 215 is provided.

[0159] In addition, an insulating layer 261 is provided to cover the transistor 210, and a capacitance element is formed on the insulating layer 261. A child 240 is provided.

[0160] The capacitance element 240 is made up of a conductive layer 241, a conductive layer 242, and an insulating layer 243 located between them. The conductive layer 241 functions as one electrode of the capacitor 240, and the conductive layer 242 The insulating layer 243 functions as the dielectric of the capacitor 240. It functions as such.

[0161] The conductive layer 241 is provided on the insulating layer 261, and the plug 271 is embedded in the insulating layer 261. is electrically connected to one of the source and drain of the transistor 210 by The insulating layer 243 is provided to cover the conductive layer 241. The conductive layer 242 is The conductive layer 241 is provided in a region overlapping the conductive layer 241 .

[0162] The insulating layer 122 is provided to cover the capacitor element 240, and the light-emitting unit 1 is provided on the insulating layer 122. 20R, a light-emitting unit 120G, a light-emitting unit 120B, a conductive layer 132, etc. Here, the light emitting units 120R, 120G, 120B, As the structure of the conductive layer 132, an example using the structure illustrated in Structural Example 2-2 and FIG. 2B will be described. However, the present invention is not limited to this, and various configurations exemplified above can be applied.

[0163] The display device 200A includes an insulating layer 161 and an insulating layer 162 that cover the conductive layer 113 of the light-emitting element 110. These three insulating layers are provided in the light emitting element 110. The insulating layer 161 and the insulating layer 162 function as a protective layer to prevent impurities such as water from diffusing. 63 is made of silicon oxide film, silicon nitride film, aluminum oxide film, etc., which have low moisture permeability. It is preferable to use an organic insulating film. By using an organic insulating film for the insulating layer 162, the area below the insulating layer 162 can be reduced. The influence of the uneven shape on the side can be alleviated, and the surface on which the insulating layer 163 is formed can be made smooth. This makes it difficult for defects such as pinholes to occur in the insulating layer 163, and the moisture permeability of the protective layer is improved. The configuration of the protective layer that covers the light emitting element 110 is not limited to this. The film may have a single layer or two layer structure, or may have a laminated structure of four or more layers.

[0164] On the insulating layer 163, a colored layer 165R overlapping the light-emitting unit 120R ... and a colored layer 165R overlapping the light-emitting unit 120R are provided. A colored layer 165G overlapping the light-emitting unit 20G and a colored layer 165B overlapping the light-emitting unit 120B are provided. For example, the colored layer 165R transmits red light, and the colored layer 165G transmits green light. The colored layer 165B transmits blue light, and the colored layer 165C transmits blue light. The color purity can be improved, and a display device with higher display quality can be realized. By forming each colored layer on 63, the colored layer can be formed on the substrate 202 side, which will be described later. In all cases, it is easy to align each light-emitting unit with each colored layer, making it possible to produce a very high-definition display device. This can be achieved.

[0165] The display device 200A has a substrate 202 on the viewing side. The substrate 202 and the substrate 201 are connected to each other. The substrate 202 is made of a glass substrate, a quartz substrate, a surface treatment layer, or the like. A substrate having light-transmitting properties, such as a fiber substrate or a plastic substrate, can be used.

[0166] By adopting such a configuration, a display device with extremely high resolution and high display quality can be realized. .

[0167] [Modification of Configuration Example 5-1] The display device 200B shown in FIG. 8 is different from the display device 200A in that the configuration of the capacitance element is different. It mainly differs from.

[0168] The display device 200B shown in FIG. 8 includes a reflective layer 114R, a reflective layer 114G, and a reflective layer 114 B also serves as one electrode of the capacitor 240A.

[0169] The reflective layer 114R, the reflective layer 114G, and the reflective layer 114B are each formed on the insulating layer 243. The reflective layer 114R, the reflective layer 114G, and the reflective layer 114B are each The source of the transistor 210 is connected via the plug 271, the conductive layer 251a, and the plug 131a. On the other hand, the conductive layer 241 is electrically connected to either the source or the drain of the plug 1. It is electrically connected to the conductive layer 251b via 31c.

[0170] By adopting such a configuration, the manufacturing process can be simplified compared to the display device 200A. This allows for a reduction in production costs.

[0171] [Configuration Example 5-2] FIG. 9 is a schematic cross-sectional view of the display device 200C. The display device 200C has a transistor The main difference from the display device 200A is the configuration.

[0172] The transistor 220 has a semiconductor layer in which a channel is formed, and a metal oxide (oxide semiconductor) This is a transistor to which a MOSFET (also called a MOSFET) is applied.

[0173] The transistor 220 includes a semiconductor layer 221, a metal oxide layer 222, an insulating layer 223, and a conductive layer 224, a conductive layer 225, an insulating layer 226, a conductive layer 227, and the like.

[0174] The substrate 201a on which the transistor 220 is provided may be the insulating substrate or semiconductor substrate described above. A conductive substrate may be used.

[0175] An insulating layer 232 is provided on the substrate 201a. Therefore, impurities such as water and hydrogen diffuse into the transistor 220 and from the semiconductor layer 221. It functions as a barrier layer that prevents oxygen from being released to the insulating layer 232 side. For example, silicon oxide films such as aluminum oxide films, hafnium oxide films, and silicon nitride films are used. A film through which hydrogen and oxygen are less likely to diffuse than a silicon film can be used.

[0176] A conductive layer 227 is provided on the insulating layer 232, and an insulating layer 226 is provided to cover the conductive layer 227. The conductive layer 227 serves as a first gate electrode of the transistor 220 and is an insulating layer. A portion of the edge layer 226 functions as the first gate insulating layer. It is preferable to use an oxide insulating film such as a silicon oxide film in the portion in contact with the conductor layer 221. The upper surface of the insulating layer 226 is preferably planarized.

[0177] The semiconductor layer 221 is provided on the insulating layer 226. The semiconductor layer 221 has semiconductor properties. It is preferable that the semiconductor layer 221 has a metal oxide (also referred to as an oxide semiconductor) film. The details of the materials that can be suitably used will be described later.

[0178] The pair of conductive layers 225 is provided on and in contact with the semiconductor layer 221 and serves as a source electrode and a drain electrode. The metal oxide layer 222 functions as an electrode. The metal oxide layer 222 is provided to cover the top surface of the semiconductor layer 221. On the metal oxide layer 222, a second gate insulating film is preferably formed. An insulating layer 223 serving as an insulating layer and a conductive layer 224 serving as a second gate electrode are stacked. It is arranged in layers.

[0179] An insulating layer 228 is provided to cover the transistor 220, and an insulating layer 228 is formed on the insulating layer 228. The insulating layer 228 is provided to prevent water from entering the transistor 220 from the insulating layer 261 and the like. The diffusion of impurities such as silicon and hydrogen and the desorption of oxygen from the semiconductor layer 221 are prevented. The insulating layer 228 functions as a barrier layer. You can be there.

[0180] The plug 271 electrically connected to the conductive layer 225 is embedded in the insulating layer 261. Here, the plug 271 is formed on the side surface of the opening of the insulating layer 261 and the conductive layer 22. A conductive layer 271a covers a part of the upper surface of the conductive layer 271b. At this time, it is preferable that the conductive layer 271a has a thickness that is small enough to prevent hydrogen and oxygen from diffusing. It is preferable to use a highly conductive material.

[0181] [Configuration Example 5-3] FIG. 10 is a schematic cross-sectional view of a display device 200D. The display device 200D has a substrate 201. A transistor 210 in which a channel is formed, and a metal oxide in the semiconductor layer in which the channel is formed. The transistor 220 includes a semiconductor layer.

[0182] An insulating layer 261 is provided to cover the transistor 210, and a conductive layer 251 is formed on the insulating layer 261. An insulating layer 262 is provided to cover the conductive layer 251. The conductive layer 251 and the conductive layer 252 are provided as wirings. In addition, the insulating layer 263 and the insulating layer 232 are provided to cover the conductive layer 252, and the insulating layer 263 and the insulating layer 232 are provided to cover the conductive layer 252. The transistor 220 is provided on the layer 232. An insulating layer 265 is provided, and a capacitor 240 is provided over the insulating layer 265. 240 and transistor 220 are electrically connected by a plug 274 .

[0183] The transistor 220 can be used as a transistor that constitutes a pixel circuit. The transistor 210 is a transistor that configures a pixel circuit and drives the pixel circuit. and transistors that configure the drive circuits (gate line drive circuit, source line drive circuit) for The transistors 210 and 220 can be used as a arithmetic circuit. The semiconductor device can be used as a transistor that constitutes various circuits such as a gate or memory circuit.

[0184] By using this configuration, not only the pixel circuits but also the drive circuits etc. can be placed directly below the light-emitting units. Therefore, the display device can be formed more simply than when a driving circuit is provided around the display area. It is possible to miniaturize the

[0185] [Configuration Example 5-4] 11 is a schematic cross-sectional view of the display device 200E. The main difference between the 200D and the 200D is that two transistors using oxide semiconductors are stacked. It's wrong.

[0186] The display device 200E has a transistor between the transistor 210 and the transistor 220. The transistor 230 has a first gate electrode. The transistor 230 has a similar structure to the transistor 220. Similar to 220, it may have a first gate electrode.

[0187] An insulating layer 263 and an insulating layer 231 are provided to cover the conductive layer 252, and a conductive layer 263 is provided on the insulating layer 231. The transistor 230 and the conductive layer 252 are connected by a plug 2 73, the conductive layer 253, and the plug 272 are electrically connected to each other. An insulating layer 264 and an insulating layer 232 are provided over the transistor 253. A heater 220 is provided.

[0188] For example, the transistor 220 is a transistor for controlling the current flowing through the light emitting element 110. The transistor 230 also functions as a transistor for controlling the selection state of the pixel. The transistor 210 also functions as a selection transistor. It functions as a transistor that constitutes a driving circuit.

[0189] In this way, by stacking three or more layers in which transistors are formed, the area occupied by the pixel can be reduced. can be further reduced, and a high-definition display device can be realized.

[0190] [About the components] Components such as transistors that can be applied to a display device will be described below.

[0191] [Transistor] The transistor has a conductive layer that functions as a gate electrode, a semiconductor layer, and a a conductive layer that functions as a drain electrode; a conductive layer that functions as a gate insulating layer; and an insulating layer.

[0192] Note that the structure of a transistor included in a display device of one embodiment of the present invention is not particularly limited. For example, a planar type transistor or a staggered type transistor may be used. Alternatively, a top gate or bottom gate transistor may be used. Alternatively, gate electrodes may be provided above and below the channel. It may also be included.

[0193] The crystallinity of the semiconductor material used in the transistor is not particularly limited. Single crystal semiconductors or semiconductors with crystallinity other than single crystal (microcrystalline semiconductors, polycrystalline semiconductors) A single-crystal semiconductor or a semiconductor having a crystalline region in part may be used. It is preferable to use a crystalline semiconductor because it can suppress deterioration of transistor characteristics.

[0194] In the following, we will focus on transistors that use a metal oxide film as a semiconductor layer in which a channel is formed. We will explain about this.

[0195] The semiconductor material used for the transistor has an energy gap of 2 eV or more, and is preferably Metal oxides having a voltage of about 2.5 eV or more, more preferably 3 eV or more, can be used. A typical example is a metal oxide containing indium, such as the CAC-OS etc. can be used.

[0196] Metal oxides with a wider band gap than silicon and a lower carrier density are used. The transistor has a low off-state current, which is The accumulated charge can be maintained for a long period of time.

[0197] The semiconductor layer may be made of, for example, indium, zinc, and M (aluminum, titanium, gallium, germanium, etc.). Rumanium, yttrium, zirconium, lanthanum, cerium, tin, neodymium or It can be a film expressed as an In-M-Zn oxide containing metals such as hafnium .

[0198] When the metal oxide constituting the semiconductor layer is an In-M-Zn oxide, The atomic ratio of the metal elements in the sputtering target used to form a film is In≧M It is preferable that Zn≧M is satisfied. The atomic ratios were In:M:Zn=1:1:1, In:M:Zn=1:1:1.2, In :M:Zn=3:1:2, In:M:Zn=4:2:3, In:M:Zn=4:2:4. 1, In:M:Zn=5:1:6, In:M:Zn=5:1:7, In:M:Zn=5: The atomic ratio of the semiconductor layers to be formed is preferably 1:8 or the like. This includes a ±40% variation in the atomic ratio of metal elements contained in the ring target.

[0199] The semiconductor layer is made of a metal oxide film having a low carrier density. Carrier density is 1×10 17 / cm 3 Less than 1 × 10 15 / cm 3 Below, further Preferably 1 x 10 13 / cm 3 Less than or equal to 1×10 11 / cm 3 Below, More preferably, 1×10 10 / cm 3 Less than 1 x 10 -9 / cm 3 More than a career High density metal oxides can be used. Such metal oxides can be high purity intrinsic or It is called a high-purity intrinsic metal oxide in terms of quality. The metal oxide has a low impurity concentration and a defect level. Because of its low density, it can be said to be a metal oxide with stable properties.

[0200] However, the semiconductor characteristics and electrical characteristics (electric field characteristics) of the required transistors are not limited to these. An oxide semiconductor having an appropriate composition may be used depending on the semiconductor properties (e.g., effective mobility, threshold voltage, etc.). In order to obtain the required semiconductor characteristics of the transistor, the carrier density and impurity of the semiconductor layer are By appropriately adjusting the concentration, defect density, atomic ratio of metal elements to oxygen, interatomic distance, density, etc. It is preferable that:

[0201] In the metal oxides that make up the semiconductor layer, silicon and carbon, which are elements of Group 14, If it is included, oxygen vacancies increase in the semiconductor layer, causing it to become n-type. The silicon and carbon concentrations in the layer (obtained by secondary ion mass spectrometry) were calculated by 2× 10 18 atoms / cm 3 Less than or equal to 2 x 10 17 atoms / cm 3 The following do.

[0202] In addition, alkali metals and alkaline earth metals generate carriers when bonded with metal oxides. This may result in an increase in the off-state current of the transistor. Alkali metals or alkaline earth metals obtained by secondary ion mass spectrometry in body layers. The concentration of 18 atoms / cm 3 Less than or equal to 2 x 10 16 atoms / cm 3 Do the following:

[0203] In addition, if the metal oxide that makes up the semiconductor layer contains nitrogen, the electrons that act as carriers This increases the carrier density and makes it easier to become n-type. Therefore, transistors using this material tend to be normally-on. The nitrogen concentration obtained by secondary ion mass spectrometry is 5×10 18 atoms / cm 3 below It is preferable to do so.

[0204] Oxide semiconductors are classified into single-crystal oxide semiconductors and non-single-crystal oxide semiconductors. As a single-crystal oxide semiconductor, CAAC-OS (c-axis-aligned crystal-doped oxide semiconductor) stalline oxide semiconductor), polycrystalline oxide semiconductor, nc-OS(nanocrystalline oxide semiconductor r), pseudo-amorphous oxide semiconductor (a-like OS) oxide semiconductor), and amorphous oxide semiconductor.

[0205] In addition, a semiconductor layer of a transistor disclosed in one embodiment of the present invention may contain CAC-OS(Cl oud-Aligned Composite oxide semiconductor r) may also be used.

[0206] Note that the semiconductor layer of the transistor disclosed in one embodiment of the present invention is A non-single-crystal oxide semiconductor or CAC-OS can be preferably used. As the OS, nc-OS or CAAC-OS can be preferably used.

[0207] In one embodiment of the present invention, a CAC-OS semiconductor layer is used for a transistor. By using CAC-OS, transistors can have excellent electrical characteristics and high reliability. can be granted.

[0208] The semiconductor layer is divided into a CAAC-OS region, a polycrystalline oxide semiconductor region, and an nc-OS region. a region of a pseudo-amorphous oxide semiconductor, and a region of an amorphous oxide semiconductor; It may be a hybrid film. The hybrid film may have, for example, a single-layer structure or a laminated structure including any two or more of the regions described above. There may be a case where it has a single-layer structure or a laminated structure including any two or more of the regions described above.

[0209] <Configuration of CAC-OS> Hereinafter, the configuration of CAC (C loud-Aligned Composite)-OS that can be used for the transistor disclosed in one aspect of the present invention will be described.

[0210] CAC-OS is, for example, a composition in which elements constituting a metal oxide are unevenly distributed in a size of 0.5 nm or more and 10 nm or less, preferably 1 nm or more and 2 nm or less, or in the vicinity thereof. In the following, in the metal oxide, one or more metal elements are unevenly distributed, and the region having the metal element is mixed in a size of 0.5 nm or more and 10 nm or less, preferably 1 nm or more and 2 nm or less, or in the vicinity thereof, and this state is also referred to as a mosaic state or a patch state. Hereinafter, in the metal oxide, one or more metal elements are unevenly distributed, and the region having the metal element is mixed in a size of 0.5 nm or more and 10 nm or less, preferably 1 nm or more and 2 nm or less, or in the vicinity thereof, and this state is also referred to as a mosaic state or a patch state. Hereinafter, in the metal oxide, one or more metal elements are unevenly distributed, and the region having the metal element is mixed in a size of 0.5 nm or more and 10 nm or less, preferably 1 nm or more and 2 nm or less, or in the vicinity thereof, and this state is also referred to as a mosaic state or a patch state. Hereinafter, in the metal oxide, one or more metal elements are unevenly distributed, and the region having the metal element is mixed in a size of 0.5 nm or more and 10 nm or less, preferably 1 nm or more and 2 nm or less, or in the vicinity thereof, and this state is also referred to as a mosaic state or a patch state. Hereinafter, in the metal oxide, one or more metal elements are unevenly distributed, and the region having the metal element is mixed in a size of 0.5 nm or more and 10 nm or less, preferably 1 nm or more and 2 nm or less, or in the vicinity thereof, and this state is also referred to as a mosaic state or a patch state. Hereinafter, in the metal oxide, one or more metal elements are unevenly distributed, and the region having the metal element is mixed in a size of 0.5 nm or more and 10 nm or less, preferably 1 nm or more and 2 nm or less, or in the vicinity thereof, and this state is also referred to as a mosaic state or a patch state.

[0211] The metal oxide preferably contains at least indium. In particular, it preferably contains indium and zinc. In addition to these, one or more selected from aluminum, gallium, yttrium, copper, vanadium, beryllium, boron, silicon, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, or magnesium may be included. The metal oxide preferably contains at least indium. In particular, it preferably contains indium and zinc. In addition to these, one or more selected from aluminum, gallium, yttrium, copper, vanadium, beryllium, boron, silicon, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, or magnesium may be included. The metal oxide preferably contains at least indium. In particular, it preferably contains indium and zinc. In addition to these, one or more selected from aluminum, gallium, yttrium, copper, vanadium, beryllium, boron, silicon, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, or magnesium may be included. The metal oxide preferably contains at least indium. In particular, it preferably contains indium and zinc. In addition to these, one or more selected from aluminum, gallium, yttrium, copper, vanadium, beryllium, boron, silicon, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, or magnesium may be included. The metal oxide preferably contains at least indium. In particular, it preferably contains indium and zinc. In addition to these, one or more selected from aluminum, gallium, yttrium, copper, vanadium, beryllium, boron, silicon, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, or magnesium may be included. The metal oxide preferably contains at least indium. In particular, it preferably contains indium and zinc. In addition to these, one or more selected from aluminum, gallium, yttrium, copper, vanadium, beryllium, boron, silicon, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, or magnesium may be included.

[0212] For example, in In-Ga-Zn oxide, CAC-OS (among CAC-OS, In-Ga-Zn oxide may be particularly referred to as CAC-IGZO.) is indium oxide For example, in In-Ga-Zn oxide, CAC-OS (among CAC-OS, In-Ga-Zn oxide may be particularly referred to as CAC-IGZO.) is indium oxide (hereinafter referred to as InO X1 (X1 is a real number greater than 0.) or Indium Zinc oxide (hereinafter referred to as In X2 Zn Y2 O Z2 (X2, Y2, and Z2 are real numbers greater than 0. ) and gallium oxide (GaO X3 (X3 is a real number greater than 0) ), or gallium zinc oxide (hereinafter referred to as Ga X4 Zn Y4 O Z4 (X4, Y4, and Z1 and Z2 are real numbers greater than 0.) The material is separated into mosaics. The mosaic-like InO X1 , or In X2 Zn Y2 O Z2 is uniformly distributed in the film This is a cloud-like configuration (hereinafter also referred to as a cloud-like configuration).

[0213] In other words, CAC-OS is X3 The region where In is the main component and X2 Zn Y2 O Z2 , or InO X1 A composite metal oxide having a structure in which a region in which In this specification, for example, the atomic ratio of In to the element M in the first region is is greater than the atomic ratio of In to the element M in the second region. Compared to region 2, the concentration of In is higher.

[0214] IGZO is a common name and refers to a compound made of In, Ga, Zn, and O. A typical example is InGaO3(ZnO) m1 (m1 is a natural number), or In (1+x0) Ga (1-x0) O3(ZnO) m0(-1≦x0≦1, m0 is an arbitrary number) Examples of the crystalline compounds include those represented by the formula:

[0215] The crystalline compound has a single crystal structure, a polycrystalline structure, or a CAAC structure. The CAAC structure is a structure in which multiple IGZO nanocrystals have a c-axis orientation and are aligned in the ab plane. The crystal structure is non-oriented and connected.

[0216] On the other hand, CAC-OS is a material structure of metal oxides. In a material composition containing Ga, Zn, and O, some nanoparticles with Ga as the main component were observed. The region where the In nanoparticles are observed is shown in part. This refers to a structure in which the crystals are randomly dispersed in a mosaic pattern. Structure is a secondary factor.

[0217] Note that CAC-OS does not include a laminated structure of two or more films with different compositions. For example, a structure consisting of two layers, one containing In as the main component and the other containing Ga as the main component, Not at all.

[0218] In addition, GaO X3 The region where In is the main component and X2 Zn Y2 O Z2 , or InO X1 In some cases, a clear boundary between the region where the main component is the chromatic aberration and the region where the chromatic aberration is the main component may not be observed.

[0219] Instead of gallium, aluminum, yttrium, copper, vanadium, and beryllium can be used. Aluminum, boron, silicon, titanium, iron, nickel, germanium, zirconium, molybdenum lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, or magnesium If one or more selected elements such as cesium are included, CAC-OS will In the region, nanoparticles containing the metal element as the main component are observed, and in the region, In is the main component. The nanoparticle-like regions are randomly dispersed in a mosaic pattern. This refers to

[0220] CAC-OS is formed by sputtering under conditions where the substrate is not intentionally heated. When the CAC-OS is formed by a sputtering method, the deposition gas The gas is selected from an inert gas (typically argon), oxygen gas, and nitrogen gas. One or more of these may be used. The lower the flow rate ratio of the gas, the more preferable. For example, the flow rate ratio of oxygen gas is preferably 0% or more and less than 30%. It is more preferable to set the content to 0% or more and 10% or less.

[0221] CAC-OS is an X-ray diffraction (XRD) measurement method. When measured using one of the out-of-plane θ / 2θ scans In other words, from the X-ray diffraction measurement, no clear peaks are observed. It can be seen that no orientation in the ab plane direction or the c axis direction is observed in the fixed region.

[0222] In addition, CAC-OS uses an electron beam with a probe diameter of 1 nm (also called a nanobeam electron beam). In the electron beam diffraction pattern obtained by irradiating the sample, a ring-shaped region with high brightness and the corresponding Several bright spots are observed within the ring-shaped region. Therefore, from the electron diffraction pattern, it is possible to determine that CAC The crystal structure of -OS is nc(na It can be seen that the crystalline structure is no-crystal.

[0223] For example, in the CAC-OS of In-Ga-Zn oxide, energy dispersive X Energy Dispersive X-ray spectroscopy (EDX) EDX mapping obtained using scopy revealed that GaO X3 The region where is the principal component And, In X2 Zn Y2 O Z2 , or InO X1 The area where the main component is unevenly distributed and mixed It can be confirmed that the compound has a structure similar to that of the compound shown in FIG.

[0224] CAC-OS has a structure different from that of IGZO compounds, in which metal elements are uniformly distributed. CAC-OS has different properties from GZO compounds. X3 The main components are and the region where In X2 Zn Y2 O Z2 , or InO X1 The area where is the main component and the area where is The phases are separated into individual elements, resulting in a mosaic structure of regions each consisting of a different element as the main component.

[0225] Here, In X2 Zn Y2 O Z2 , or InO X1 The region where is the main component is GaO X This is a region with high conductivity compared to the region where In is the main component. X2 Zn Y2 O Z2 , or InO X1 The carriers flow through the area where the main component is gold. Therefore, the conductivity of In is expressed as a metal oxide. X2 Zn Y2 O Z2 , or InO X The region where 1 is the main component is distributed in a cloud-like manner in the metal oxide, resulting in a high field-effect transfer Mobility (μ) can be achieved.

[0226] On the other hand, GaO X3 The region where the main components are In X2 Zn Y2 O Z2 , or InO X1 This region has higher insulating properties than the region where GaO is the main component. X3 etc. The distribution of the region in which the main component is is in the metal oxide suppresses leakage current and provides good switching. Switching operation can be realized.

[0227] Therefore, when CAC-OS is used in a semiconductor device, GaO X3 Insulation and , In X2 Zn Y2 O Z2 , or InO X1 The conductivity caused by the This results in a high on-state current (I on ), and high field-effect mobility (μ) can be done.

[0228] Furthermore, semiconductor devices using CAC-OS have high reliability. It is ideal for various semiconductor devices including displays.

[0229] In addition, a transistor having a CAC-OS semiconductor layer has high field-effect mobility and Because of its high dynamic range, the transistor is connected to a driving circuit, typically a scanning By using this in a line driver circuit, it is possible to provide a display device with a narrow frame width (also called a narrow frame). In addition, the transistor can be used in a signal line driver circuit (particularly, a signal line driver (Demultiplexer connected to the output terminal of the shift register of the operation circuit) Therefore, it is possible to provide a display device with a small number of wires connected to the display device.

[0230] In addition, the transistor with CAC-OS in the semiconductor layer is a transistor using low-temperature polysilicon. Unlike conventional transistors, no laser crystallization process is required. Even for display devices, it is possible to reduce manufacturing costs. ("4K resolution", "4K2K", "4K"), Super Hi-Vision ("8K resolution" In the case of high-resolution and large display devices such as "8K", "8K4K", and "8K", By using a transistor having a CAC-OS semiconductor layer in the driver circuit and display portion, This is preferable because it is possible to write in a short time and reduce display defects.

[0231] Alternatively, silicon may be used as the semiconductor in which the channel of the transistor is formed. Amorphous silicon may be used as the capacitor, but crystalline silicon is particularly preferred. For example, microcrystalline silicon, polycrystalline silicon, single crystal silicon, etc. In particular, polycrystalline silicon can be formed at a lower temperature than single-crystalline silicon. It also has higher field-effect mobility and higher reliability than amorphous silicon.

[0232] [Conductive Layer] In addition to the gate, source, and drain of the transistor, various wiring and Materials that can be used for conductive layers such as electrodes include aluminum, titanium, chromium, and titanium dioxide. Aluminum, nickel, copper, yttrium, zirconium, molybdenum, silver, tantalum, or titanium Examples of such metals include tungsten and alloys containing tungsten as the main component. Films containing the materials can be used as single layers or as laminated structures. For example, silicon a single layer structure of aluminum film containing titanium; a two-layer structure of aluminum film laminated on titanium film; Two-layer structure with aluminum film laminated on stainless steel film, copper-magnesium-aluminum alloy Two-layer structure with copper film laminated on gold film, two-layer structure with copper film laminated on titanium film, tungsten Two-layer structure with copper film laminated on top of titanium film or titanium nitride film, and aluminum film laminated on top of that. A titanium film or a titanium nitride film is formed on the aluminum or copper film. Layer structure, molybdenum film or molybdenum nitride film, and aluminum film or A three-layer structure in which a copper film is laminated and a molybdenum film or molybdenum nitride film is formed on top of that It is also possible to use oxides such as indium oxide, tin oxide, or zinc oxide. In addition, copper containing manganese is preferable because it improves the controllability of the shape by etching. .

[0233] [Insulating layer] Examples of insulating materials that can be used for each insulating layer include acrylic and epoxy. In addition to resins and resins with siloxane bonds, silicon oxide, silicon oxynitride, silicon nitride oxide, Inorganic insulating materials such as silicon, silicon nitride, and aluminum oxide can also be used.

[0234] In addition, the light emitting element is preferably provided between a pair of insulating films with low water permeability. This makes it possible to prevent impurities such as water from entering the light emitting element, and to prevent a decrease in the reliability of the device. It can be suppressed.

[0235] As insulating films with low water permeability, films containing nitrogen and silicon such as silicon nitride film and silicon nitride oxide film are used. and films containing nitrogen and aluminum, such as an aluminum nitride film. A silicon oxide film, a silicon oxynitride film, an aluminum oxide film, or the like may also be used.

[0236] For example, the water vapor permeation rate of a low-permeability insulating film is 1×10 -5 [g / (m 2 ·day) ] or less, preferably 1 × 10 -6 [g / (m 2 ·day)] or less, preferably 1 × 1 0 -7 [g / (m 2 ·day)] or less, more preferably 1 × 10 -8 [g / (m 2 ·d ay)] below.

[0237] [Display module configuration example] A structural example of a display module including a display device according to one embodiment of the present invention will be described below. do.

[0238] 12A is a perspective schematic diagram of the display module 280. The display module 280 is The display device 200 includes the display device 200 shown in FIG. The display devices exemplified in (display device 200A to display device 200E) can be applied. do.

[0239] The display module 280 has a substrate 201 and a substrate 202. The display unit 281 is an area in the display module 280 where an image is displayed. This is an area where light from each pixel provided in a pixel section 284 (described later) can be seen.

[0240] FIG. 12(B) is a perspective view showing a schematic configuration of the substrate 201 side. 1 is a circuit section 282, a pixel circuit section 283 on the circuit section 282, and a pixel circuit section 283 on the pixel circuit section 283. The pixel portion 284 on the substrate 201 is laminated. The terminal portion 285 for connecting to the FPC 290 is provided in the portion not covered by the terminal portion 285. The circuit section 282 is electrically connected by a wiring section 286 that is made up of a plurality of wirings. There are.

[0241] The pixel section 284 has a plurality of pixels 284a arranged in a matrix. An enlarged view of one pixel 284a is shown on the right side of the figure. 20R, light-emitting unit 120G, and light-emitting unit 120B.

[0242] The pixel circuit section 283 has a plurality of pixel circuits 283a arranged in a matrix. The pixel circuit 283a controls the light emission of three light-emitting units included in one pixel 284a. One pixel circuit 283a is a circuit that controls the light emission of one light-emitting unit. For example, the pixel circuit 283a may be provided in one light-emitting unit. Each transistor has one selection transistor and one current control transistor (drive transistor). and a capacitance element. The gate of the transistor is connected to the gate signal, and the source signal is connected to either the source or the drain. This realizes an active matrix display device.

[0243] The circuit section 282 has a circuit for driving each pixel circuit 283a of the pixel circuit section 283. For example, it is preferable to have a gate line driving circuit, a source line driving circuit, etc. It may also have a circuit, a memory circuit, a power supply circuit, etc.

[0244] The FPC 290 is a wiring for supplying a video signal and a power supply potential to the circuit section 282 from the outside. An IC may also be mounted on the FPC290.

[0245] The display module 280 has a pixel circuit section 283, a circuit section 282, etc. below a pixel section 284. Since it can be configured as a laminated structure, the aperture ratio (effective display area ratio) of the display unit 281 can be extremely increased. For example, the aperture ratio of the display unit 281 can be set to 40% or more and less than 100%. Preferably, it is 50% or more and 95% or less, and more preferably, it is 60% or more and 95% or less. In addition, the pixels 284a can be arranged at an extremely high density, and the resolution of the display unit 281 can be improved. For example, the display unit 281 can have a resolution of 2000 ppi or more, preferably Preferably, it is 3000 ppi or more, more preferably 5000 ppi or more, and even more preferably 6 Resolution of 20,000 ppi or more, or 30,000 ppi or less 284a is preferably arranged at 280 degrees.

[0246] Such a display module 280 has extremely high resolution, and is therefore suitable for head-mounted displays. It can be used effectively in VR devices such as displays, or in glasses-type AR devices. For example, in the case of a configuration in which the display unit of the display module 280 is viewed through a lens, However, the display module 280 has an extremely high-definition display section 281, so it is difficult to display with a lens. Even when the display is enlarged, the pixels are not visible, providing a highly immersive display. The module 280 is not limited to this, and is preferably used in electronic devices having a relatively small display unit. For example, it can be suitably used in the display unit of a wearable electronic device such as a smart watch. It is possible.

[0247] This embodiment may be combined, at least in part, with other embodiments described in this specification. It can be implemented in combination.

[0248] (Embodiment 2) In this embodiment, a display device of one embodiment of the present invention will be described with reference to FIGS.

[0249] The display device shown in FIG. 13A includes a pixel portion 502, a driver circuit portion 504, and a protection circuit 50 6 and a terminal portion 507. Note that the protection circuit 506 may not be provided. .

[0250] The pixel section 502 is a plurality of pixels arranged in X rows and Y columns (X and Y are each independently a natural number of 2 or more). The display device has a plurality of pixel circuits 501 for driving a number of display elements.

[0251] The driving circuit unit 504 is a gate driver that outputs scanning signals to the gate lines GL_1 to GL_X. a source driver 504a that supplies data signals to the data lines DL_1 to DL_Y; The gate driver 504a includes a driver circuit such as a shift register The source driver 504b may be configured to have, for example, a plurality of analog switches. Also, the source driver 504 is configured using a shift register or the like. b may be configured.

[0252] The terminal unit 507 is used to input power, control signals, image signals, etc. from an external circuit to the display device. This refers to the part where terminals for connecting the power supply to the power source are provided.

[0253] When a potential outside a certain range is applied to the wiring to which the protection circuit 506 is connected, the protection circuit 506 The protection circuit 506 shown in FIG. For example, the scanning line GL, which is the wiring between the gate driver 504a and the pixel circuit 501, Various wirings such as the data line DL which is the wiring between the source driver 504b and the pixel circuit 501 Connected.

[0254] The gate driver 504a and the source driver 504b are connected to the pixel section 502 and The gate driver circuit or the source driver circuit may be provided on the same substrate. A separately formed substrate (for example, a driving circuit formed of a single crystal semiconductor film or a polycrystalline semiconductor film) circuit board) by COG or TAB (Tape Automated Bonding) It may also be configured to be mounted on a substrate.

[0255] In particular, the gate driver 504a and the source driver 504b are disposed below the pixel section 502. It is preferable to do so.

[0256] Furthermore, the plurality of pixel circuits 501 shown in FIG. 13(A) may be, for example, a configuration shown in FIG. 13(B). It can be said that:

[0257] The pixel circuit 501 shown in FIG. 13B includes transistors 552 and 554 and a capacitor 56. The pixel circuit 501 also includes a data line DL_n, a scanning line DL_n, and a light-emitting element 572. A line GL_m, a potential supply line VL_a, a power supply line VL_b, etc. are connected to the line GL_m.

[0258] A high power supply potential VDD is applied to one of the potential supply lines VL_a and VL_b. The other terminal is supplied with a low power supply potential VSS. The current flowing through the light-emitting element 572 is controlled in accordance with the potential applied to the light-emitting element 572. The brightness of the light emitted from 72 is controlled.

[0259] This embodiment may be combined, at least in part, with other embodiments described in this specification. It can be implemented in combination.

[0260] (Embodiment 3) Hereinafter, a memory for correcting a gray scale displayed on a pixel that can be applied to one embodiment of the present invention will be described. A pixel circuit including the above and a display device having the same will be described.

[0261] [Circuit configuration] 14A shows a circuit diagram of the pixel circuit 400. The pixel circuit 400 includes a transistor M The pixel circuit 400 includes a transistor M2, a capacitor C1, and a circuit 401. The wiring S1, the wiring S2, the wiring G1, and the wiring G2 are connected.

[0262] The transistor M1 has a gate connected to a wiring G1, a source and a drain connected to a wiring S1, and The other terminal is connected to one electrode of the capacitor C1. The gate of the transistor M2 is connected to the wiring. G2, one of the source and drain is connected to the wiring S2, and the other is connected to the other electrode of the capacitor C1, and 401 and 402, respectively.

[0263] The circuit 401 is a circuit including at least one display element. Although light-emitting elements such as organic EL elements and LED elements can be used, In addition to this, liquid crystal elements or MEMS (Micro Electro Mechanical Systems) Mechanical Systems elements, etc. may also be used.

[0264] The node connecting the transistor M1 and the capacitor C1 is N1, and the node connecting the transistor M2 and the circuit 40 is N2. Let N2 be the node connecting to 1.

[0265] The pixel circuit 400 maintains the potential of the node N1 by turning off the transistor M1. Furthermore, by turning off the transistor M2, the voltage of the node N2 can be maintained. In addition, when the transistor M2 is in the off state, the transistor By writing a predetermined potential to node N1 via capacitor M1, capacitive coupling via capacitor C1 This allows the potential of the node N2 to be changed in accordance with the change in the potential of the node N1.

[0266] Here, one or both of the transistors M1 and M2 may be The transistor using an oxide semiconductor, as exemplified in 1, can be used. Therefore, the potentials of the nodes N1 and N2 can be maintained for a long period of time due to the extremely low off-state current. In addition, when the period for which the potential of each node is held is short (specifically, when the frame In cases where the system frequency is 30 Hz or more, a transistor using a semiconductor such as silicon is used. A printer may also be used.

[0267] [Drive method example] Next, an example of a method of operating the pixel circuit 400 will be described with reference to FIG. (B) is a timing chart relating to the operation of the pixel circuit 400. For ease of understanding, various resistances such as wiring resistance, parasitic capacitances of transistors and wiring, The influence of the threshold voltage of the transistor and the like is not taken into consideration.

[0268] In the operation shown in FIG. 14B, one frame period is divided into a period T1 and a period T2. T1 is a period during which a potential is written to node N2, and T2 is a period during which a potential is written to node N1. It is a period.

[0269] [Period T1] In the period T1, a potential that turns on the transistor is applied to both the wiring G1 and the wiring G2. In addition, the wiring S1 is connected to a fixed potential V ref The first data is supplied to the wiring S2. Voltage V w supply.

[0270] The node N1 is connected to the line S1 via the transistor M1. ref is given. The node N2 is supplied with a first data potential V w is given. Therefore, the potential difference V across the capacitance C1 w -V ref is maintained.

[0271] [Period T2] Subsequently, in a period T2, a potential that turns on the transistor M1 is applied to the wiring G1. A potential that turns off the transistor M2 is applied to the line G2. Data potential V data A predetermined constant potential is applied to the wiring S2, or a floating potential is applied to the wiring S3. It may also be used as a

[0272] The node N1 is supplied with a second data potential V data is given. At this time, due to the capacitive coupling of the capacitor C1, the second data potential V data Depending on node N That is, the first data potential Vw and the potential In FIG. 14(B), dV is a positive value. Although the potential V data is the potential V re f It may be lower.

[0273] Here, the potential dV is roughly determined by the capacitance value of the capacitor C1 and the capacitance value of the circuit 401. When the capacitance value of the capacitor C1 is sufficiently larger than the capacitance value of the circuit 401, the potential dV is Data potential V data The potential is close to

[0274] In this way, the pixel circuit 400 is a circuit including a display element that combines two types of data signals. Since the potential supplied to the line 401 can be generated, the gradation can be corrected in the pixel circuit 400. It will be possible to do this.

[0275] Furthermore, the pixel circuit 400 generates a potential that exceeds the maximum potential that can be supplied to the wirings S1 and S2. For example, when a light-emitting element is used, a high dynamic range ( In addition, when using liquid crystal elements, overdriving is possible. It is possible to realize drive, etc.

[0276] [Application example] The pixel circuit 400EL shown in FIG. 14C includes a circuit 401EL. includes a light-emitting element EL, a transistor M3, and a capacitor C2.

[0277] The transistor M3 has a gate connected to the node N2 and one electrode of the capacitor C2, and a source and drain connected to the node N2 and one electrode of the capacitor C2. One of the drains is a wiring to which a potential VH is applied, and the other is one electrode of the light-emitting element EL. The capacitor C2 is connected to the other electrode at a potential V comConnect with the wiring given. The other electrode of the light-emitting element EL is at a potential V L Connect with the wiring given.

[0278] The transistor M3 has a function of controlling the current supplied to the light-emitting element EL. functions as a storage capacitor. Capacitor C2 can be omitted if not required.

[0279] In this example, the anode side of the light-emitting element EL is connected to the transistor M3. However, a transistor M3 may be connected to the cathode side. H and potential V L The value of can be changed as appropriate.

[0280] The pixel circuit 400EL generates a light-emitting element by applying a high potential to the gate of the transistor M3. Since a large current can be passed through the child EL, it is possible to realize, for example, HDR display. In addition, by supplying a correction signal to the wiring S1 or wiring S2, the transistor M3 and It is also possible to correct variations in the electrical characteristics of the light-emitting element EL.

[0281] It should be noted that the circuit is not limited to the example shown in FIG. 14(C), and a circuit may be constructed by adding a separate transistor, capacitor, etc. The configuration may be as follows.

[0282] This embodiment may be combined, at least in part, with other embodiments described in this specification. It can be implemented in combination.

[0283] (Fourth embodiment) In this embodiment, structural examples of electronic devices to which the display device of one embodiment of the present invention is applied will be described. Reveal.

[0284] The display device and the display module of one embodiment of the present invention are Such electronic devices can be applied to, for example, television sets, portable personal computers, monitor devices, digital signage, pachinko machines, games In addition to electronic devices with relatively large screens such as smartphones and tablets, digital cameras and digital video cameras Cameras, digital photo frames, mobile phones, portable game consoles, personal digital assistants, sound reproduction devices, etc.

[0285] In particular, the display device and the display module according to one embodiment of the present invention can improve the resolution. Therefore, it can be suitably used in electronic devices having a relatively small display unit. Examples of child devices include wristwatch-type and bracelet-type information terminals (wearable devices), , VR devices such as head-mounted displays, or glasses-type AR devices, etc. The present invention can be suitably used in wearable devices that can be attached to the head.

[0286] 15A shows a perspective view of an eyeglass-type electronic device 700. The electronic device 700 is a pair of a display panel 701, a pair of housings 702, a pair of optical members 703, a pair of mounting portions 704, etc. It has.

[0287] The electronic device 700 displays an image displayed on the display panel 701 in the display area 706 of the optical member 703. In addition, since the optical member 703 is translucent, the user can project an image. The image displayed in the display area 706 is superimposed on the transmitted image viewed through the optical member 703. Therefore, electronic device 700 is an electronic device capable of AR display.

[0288] One of the housings 702 is provided with a camera 705 that can capture images of the front. Although not shown, one of the housings 702 may be connected to a wireless receiver or a cable. The housing 702 is provided with a connector that can supply video signals and the like from the outside. By providing an acceleration sensor such as a gyro sensor in the housing 702, the direction of the user's head can be detected. It is also possible to detect the orientation and display an image in the display area 706 according to the orientation. The housing 702 is preferably provided with a battery, and in this case, wireless or wired It can be charged by

[0289] Next, a method of projecting an image onto the display area 706 of the electronic device 700 will be described with reference to FIG. 15(B). The housing 702 contains a display panel 701, a lens 711, a reflector 7 12 is provided in the portion of the optical member 703 corresponding to the display area 706. It has a reflecting surface 713 that functions as a mirror.

[0290] Light 715 emitted from the display panel 701 passes through the lens 711 and strikes the reflector 712. Inside the optical member 703, the light 715 is reflected by the optical element 703. The light is repeatedly totally reflected at the end surface of the material 703 and reaches the reflecting surface 713. As a result, the user can see the light 715 reflected by the reflective surface 713 and the optical Both the light 716 transmitted through the material 703 (including the reflective surface 713) and the light 716 transmitted through the material 703 can be seen. .

[0291] FIG. 15 shows an example in which the reflector 712 and the reflecting surface 713 each have a curved surface. This allows for greater freedom in optical design than when these are flat surfaces. The optical member 703 can be made thinner. You may do so.

[0292] The reflector 712 can be a member having a mirror surface, and preferably has high reflectivity. Furthermore, a half mirror that utilizes the reflection of a metal film may be used as the reflecting surface 713. However, if a prism using total reflection is used, the transmittance of the transmitted light 716 can be increased. can be done.

[0293] Here, the housing 702 controls the distance between the lens 711 and the display panel 701 and the angle between them. It is preferable that the lens has a mechanism for adjusting the focus, enlarging the image, For example, the lens 711 or the display panel 701 can be used to perform operations such as zooming out. One or both of these may be configured to be movable in the direction of the optical axis.

[0294] Furthermore, the housing 702 preferably has a mechanism that allows the angle of the reflector 712 to be adjusted. By changing the angle of the reflector 712, the position of the display area 706 where the image is displayed can be changed. This allows the display area 706 to be positioned optimally according to the position of the user's eyes. It becomes possible to place

[0295] The display device or display module of one embodiment of the present invention is applied to the display panel 701. Therefore, the electronic device 700 can be made to be capable of displaying images with extremely high definition. can.

[0296] 16(A) and (B) show perspective views of a goggle-type electronic device 750. 16(A) is a perspective view showing the front, top, and left side of the electronic device 750, and FIG. 16(B) is a perspective view showing the electronic device 750. 7A and 7B are perspective views of the back, bottom, and right side of the device 750. FIG.

[0297] The electronic device 750 includes a pair of display panels 751, a housing 752, a pair of mounting portions 754, and a buffer. The pair of display panels 751 includes a member 755 and a pair of lenses 756. They are provided at positions inside the lens 756 where they can be seen through the lens 756.

[0298] The electronic device 750 is an electronic device for VR. A user wearing the electronic device 750 The image displayed on the display panel 751 can be viewed through the lens 756. By displaying different images on a pair of display panels 751, a 3D display using parallax is performed. You can also do this.

[0299] An input terminal 757 and an output terminal 758 are provided on the rear side of the housing 752. The input terminal 757 receives a video signal from a video output device or the like, and a video signal from a buffer provided in the housing 752. A cable for supplying power to charge the battery can be connected. 58 functions as an audio output terminal, for example, to connect earphones or headphones. It is possible to output audio data via wireless communication or to use an external When audio is output from the video output device, the audio output terminal does not need to be provided.

[0300] The housing 752 also has a lens 756 and a display panel 751 that can be adjusted to fit the user's eye position. It is preferable that the device has a mechanism for adjusting the left and right positions so that the device can be positioned optimally. In addition, the housing 752 can be configured to change the distance between the lens 756 and the display panel 751. It is preferable that the optical system has a mechanism for adjusting the focus.

[0301] The display device or the display module of one embodiment of the present invention is applied to the display panel 751. Therefore, the electronic device 750 can be made to be capable of displaying images with extremely high definition. This allows the user to feel a high level of immersion.

[0302] The cushioning member 755 is the part that comes into contact with the user's face (forehead, cheeks, etc.). By fitting closely to the user's face, light leakage can be prevented, enhancing the sense of immersion. The cushioning member 755 is in close contact with the user's face when the user wears the electronic device 750. It is preferable to use soft materials such as rubber, silicone rubber, and urethane. Materials such as cotton, sponge, etc. can be used. The surface of the sponge, etc. can be made of cloth or leather (natural Leather or synthetic leather), etc., the user's face and the cushioning material 755 are covered with It is difficult for gaps to form between the panels, and light leakage can be effectively prevented. In addition to being pleasant to the touch, it also prevents the user from feeling cold when worn in cold weather. The members that come into contact with the user's skin, such as the cushioning member 755 and the attachment part 754, A removable configuration is preferable because it allows for easy cleaning and replacement.

[0303] This embodiment may be combined, at least in part, with other embodiments described in this specification. It can be implemented in combination. [Explanation of symbols]

[0304] 100: display device, 100A to E: display device, 101: substrate, 110: light emitting element, 110 B: Light-emitting element, 110G: Light-emitting element, 110R: Light-emitting element, 111: Conductive layer, 111B: Conductive layer, 111G: Conductive layer, 111R: Conductive layer, 112: EL layer, 113: Conductive layer, 11 4: Reflective layer, 114B: Reflective layer, 114G: Reflective layer, 114R: Reflective layer, 115: Insulating layer , 116G: reflective layer, 116R: reflective layer, 120B: light-emitting unit, 120G: light-emitting unit 120R: light emitting unit; 121: insulating layer; 121f: insulating film; 122: insulating layer; 131a: plug, 131b: plug, 131bf: conductive film, 131c: plug, 132 : conductive layer, 141: conductive layer, 141f: conductive film, 142: conductive layer, 142f: conductive film, 1 43: conductive layer, 143f: conductive film, 144: conductive layer, 145: conductive layer, 146B: insulating layer 146G: insulating layer, 146R: insulating layer, 151: resist mask, 152: resist mask mask, 153: resist mask, 161: insulating layer, 162: insulating layer, 163: insulating layer, 1 64: Adhesive layer, 165B: Colored layer, 165G: Colored layer, 165R: Colored layer, 200: Display Device, 200A to E: display device, 201: substrate, 201a: substrate, 202: substrate, 210 : transistor, 211: conductive layer, 212: low resistance region, 213: insulating layer, 214: insulating layer, 215: element isolation layer, 220: transistor, 221: semiconductor layer, 222: metal oxide 223: insulating layer; 224: conductive layer; 225: conductive layer; 226: insulating layer; 227: conductive layer 228: insulating layer, 230: transistor, 231: insulating layer, 232: insulating layer, 24 0: Capacitor element, 240A: Capacitor element, 241: Conductive layer, 242: Conductive layer, 243: Insulating layer , 251: conductive layer, 251a: conductive layer, 251b: conductive layer, 252: conductive layer, 253: conductive layer 261: insulating layer, 262: insulating layer, 263: insulating layer, 264: insulating layer, 265: insulating layer Edge layer, 271: plug, 271a: conductive layer, 271b: conductive layer, 272: plug, 273 : plug, 274: plug, 280: display module, 281: display unit, 282: circuit unit , 283: pixel circuit section, 283a: pixel circuit, 284: pixel section, 284a: pixel, 285 : Terminal section, 286: Wiring section, 290: FPC

Claims

1. a first light-emitting element, a second light-emitting element, a first insulating layer, a first optical adjustment layer, and a second optical adjustment layer; the first light-emitting element has a first lower electrode having light-transmitting properties, a light-emitting layer, and an upper electrode having semi-transmitting properties and semi-reflective properties; the second light-emitting element includes a second lower electrode having light-transmitting properties, the light-emitting layer, and the upper electrode; the first optical adjustment layer and the second optical adjustment layer are provided on the same surface, the first insulating layer is provided to cover a portion of the first optical adjustment layer and a portion of the second optical adjustment layer, and has a first opening in a region overlapping with the first optical adjustment layer and a second opening in a region overlapping with the second optical adjustment layer; the first lower electrode is provided inside the first opening, the second lower electrode is provided inside the second opening, the first optical adjustment layer has a first film, the second optical adjustment layer is formed by laminating a second film and a third film in this order, the first film and the third film have a function of reflecting visible light, The first bottom electrode is thicker than the second bottom electrode. Display device.

2. a first light-emitting element, a second light-emitting element, a first insulating layer, a first optical adjustment layer, and a second optical adjustment layer; the first light-emitting element has a first lower electrode having light-transmitting properties, a light-emitting layer, and an upper electrode having semi-transmitting properties and semi-reflective properties; the second light-emitting element includes a second lower electrode having light-transmitting properties, the light-emitting layer, and the upper electrode; the first optical adjustment layer and the second optical adjustment layer are provided on the same surface, the first insulating layer is provided to cover a portion of the first optical adjustment layer and a portion of the second optical adjustment layer, and has a first opening in a region overlapping with the first optical adjustment layer and a second opening in a region overlapping with the second optical adjustment layer; the first lower electrode is provided inside the first opening, the second lower electrode is provided inside the second opening, the first optical adjustment layer has a first conductive layer, the second optical adjustment layer is formed by laminating a second conductive layer and a third conductive layer in this order; the first conductive layer and the third conductive layer have a function of reflecting visible light, The first bottom electrode is thicker than the second bottom electrode. Display device.

3. In claim 1 or claim 2, further comprising a third light-emitting element and a third optical adjustment layer; the third light-emitting element includes a third lower electrode having light-transmitting properties, the light-emitting layer, and the upper electrode; the third optical adjustment layer has a function of reflecting visible light at least on its upper surface, and is thicker than the first optical adjustment layer and the second optical adjustment layer; the third lower electrode is provided in contact with an upper surface of the third optical adjustment layer; Display device.

4. In any one of claims 1 to 3, a plurality of the first light-emitting elements; The first light-emitting elements are arranged in a matrix with a resolution of 5000 ppi or more. Display device.

Images