US-12628422-B2 - Display device and method for fabricating display device

US12628422B2US 12628422 B2US12628422 B2US 12628422B2US-12628422-B2

Abstract

A high-resolution display device and a fabrication method thereof are provided. The display device includes a first insulating layer; a light-emitting element and a first conductive layer over the first insulating layer; a first layer over the first conductive layer; a second conductive layer over the first layer; a second insulating layer over the light-emitting element, the second conductive layer, and the first insulating layer; and a third conductive layer over the second insulating layer. The light-emitting element includes a fourth conductive layer, a second layer over the fourth conductive layer, a third layer over the second layer, and a fifth conductive layer over the third layer. The third conductive layer includes a region in contact with the second conductive layer through a first opening formed in the second insulating layer and a region in contact with the fifth conductive layer through a second opening formed in the second insulating layer; the second layer contains a light-emitting compound; the first conductive layer and the fourth conductive layer contain the same material; the first layer and the third layer contain the same material; and the second conductive layer and the fifth conductive layer contain the same material.

Inventors

Shunpei Yamazaki
Takayuki Ikeda
Kenichi Okazaki
Yasumasa Yamane
Hajime Kimura
Tatsuya Onuki

Assignees

SEMICONDUCTOR ENERGY LABORATORY CO., LTD.

Dates

Publication Date: 20260512
Application Date: 20220105
Priority Date: 20210114

Claims (16)

1 . A display device comprising: a first insulating layer; and a light-emitting element and a structure body over the first insulating layer, wherein the structure body is configured to be a wiring or a plug, wherein the structure body comprises: a first conductive layer over and in contact with the first insulating layer; a first layer over the first conductive layer; and a second conductive layer over the first layer, wherein a third conductive layer is over the light-emitting element and the second conductive layer, wherein the light-emitting element comprises: a fourth conductive layer over and in contact with the first insulating layer; a second layer over the fourth conductive layer; a third layer over the second layer; and a fifth conductive layer over the third layer, wherein the third conductive layer is over and in contact with the second conductive layer and the fifth conductive layer, wherein the second layer comprises a light-emitting compound, wherein the first conductive layer comprises a material identical to a material of the fourth conductive layer, wherein the first layer comprises a material identical to a material of the third layer, and wherein the second conductive layer comprises a material identical to a material of the fifth conductive layer.
2 . The display device according to claim 1 , wherein the third layer comprises a substance with a high electron-injection property.
3 . The display device according to claim 1 , wherein the third layer comprises lithium fluoride.
4 . A display device comprising: a first insulating layer; a light-emitting element and a structure body over the first insulating layer; and a second insulating layer over the light-emitting element and the structure body, wherein the structure body is configured to be a wiring or a plug, wherein the structure body comprises: a first conductive layer over and in contact with the first insulating layer; a first layer over the first conductive layer; and a second conductive layer over the first layer, wherein a third conductive layer is over the second insulating layer, wherein the light-emitting element comprises: a fourth conductive layer over and in contact with the first insulating layer; a second layer over the fourth conductive layer; a third layer over the second layer; and a fifth conductive layer over the third layer, wherein the second insulating layer is in contact with each of a side surface of the fourth conductive layer, a side surface of the second layer, a side surface of the third layer, a side surface of the fifth conductive layer, and a top surface of the fifth conductive layer, wherein the second insulating layer comprises a first opening overlapping with the second conductive layer, and a second opening overlapping with the fifth conductive layer, wherein the third conductive layer is in contact with the second conductive layer through the first opening, and in contact with the fifth conductive layer through the second opening, wherein the second layer comprises a light-emitting compound, wherein the first conductive layer comprises a material identical to a material of the fourth conductive layer, wherein the first layer comprises a material identical to a material of the third layer, and wherein the second conductive layer comprises a material identical to a material of the fifth conductive layer.
5 . The display device according to claim 4 , wherein the second insulating layer has a stacked-layer structure of a third insulating layer and a fourth insulating layer over the third insulating layer, wherein the third insulating layer is in contact with each of the side surface of the fourth conductive layer, the side surface of the second layer, the side surface of the third layer, the side surface of the fifth conductive layer, and the top surface of the fifth conductive layer, wherein the third insulating layer comprises aluminum and oxygen, and wherein the fourth insulating layer comprises silicon and nitrogen.
6 . The display device according to claim 5 , further comprising a gap in a region that is positioned between the third insulating layer and the fourth insulating layer and does not overlap with the fifth conductive layer.
7 . The display device according to claim 4 , wherein the third layer comprises a substance with a high electron-injection property.
8 . The display device according to claim 4 , wherein the third layer comprises lithium fluoride.
9 . A method for fabricating a display device, the method comprising the steps of: forming a first conductive film over a first insulating layer; forming a first film comprising a light-emitting compound over the first conductive film; forming a first sacrificial layer over the first film; forming a first resist mask over the first sacrificial layer; forming a second sacrificial layer from the first sacrificial layer and a second film from the first film by removing the first sacrificial layer and the first film that are not covered with the first resist mask; removing the second sacrificial layer; forming a third film over the second film; forming a second conductive film over the third film; forming a second resist mask over the second conductive film; and forming a fifth conductive layer and a second conductive layer from the second conductive film, a third layer and a first layer from the third film, a second layer from the second film, and a fourth conductive layer and a first conductive layer from the first conductive film by removing the second conductive film, the third film, the second film, and the first conductive film that are not covered with the second resist mask.
10 . The method for fabricating a display device, according to claim 9 , wherein a second insulating layer is formed over the second conductive layer, the fifth conductive layer, and the first insulating layer after the fifth conductive layer, the second conductive layer, the third layer, the first layer, the second layer, the fourth conductive layer, and the first conductive layer are formed, wherein a first opening positioned in a region overlapping with the second conductive layer and a second opening positioned in a region overlapping with the fifth conductive layer are formed in the second insulating layer, and wherein a third conductive layer is formed in contact with the second conductive layer through the first opening and in contact with the fifth conductive layer through the second opening.
11 . The method for fabricating a display device, according to claim 10 , wherein the second insulating layer has a stacked-layer structure of a third insulating layer and a fourth insulating layer over the third insulating layer, wherein the third insulating layer is formed by an ALD method, and wherein the fourth insulating layer is formed by a sputtering method.
12 . The method for fabricating a display device, according to claim 10 , wherein the second insulating layer has a stacked-layer structure of a third insulating layer, a fourth insulating layer over the third insulating layer, and a fifth insulating layer over the fourth insulating layer, wherein the third insulating layer and the fifth insulating layer are formed by an ALD method, and wherein the fourth insulating layer is formed by a sputtering method.
13 . A method for fabricating a display device, the method comprising the steps of: forming a first conductive film over a first insulating layer; forming a first film comprising a light-emitting compound over the first conductive film; forming a first sacrificial layer over the first film; forming a first resist mask over the first sacrificial layer; forming a second sacrificial layer from the first sacrificial layer and a second film from the first film by removing the first sacrificial layer and the first film that are not covered with the first resist mask; removing the second sacrificial layer; forming a third film using a metal mask over the second film; forming a second conductive film over the third film and the first conductive film; forming a second resist mask over the second conductive film; and forming a fifth conductive layer and a second conductive layer from the second conductive film, a third layer from the third film, a second layer from the second film, and a fourth conductive layer and a first conductive layer that is in contact with the second conductive layer from the first conductive film by removing the second conductive film, the third film, the second film, and the first conductive film that are not covered with the second resist mask.
14 . The method for fabricating a display device, according to claim 13 , wherein a second insulating layer is formed over the second conductive layer, the fifth conductive layer, and the first insulating layer after the fifth conductive layer, the second conductive layer, the third layer, the second layer, the fourth conductive layer, and the first conductive layer are formed, wherein a first opening positioned in a region overlapping with the second conductive layer and a second opening positioned in a region overlapping with the fifth conductive layer are formed in the second insulating layer, and wherein a third conductive layer is formed in contact with the second conductive layer through the first opening and in contact with the fifth conductive layer through the second opening.
15 . The method for fabricating a display device, according to claim 14 , wherein the second insulating layer has a stacked-layer structure of a third insulating layer and a fourth insulating layer over the third insulating layer, wherein the third insulating layer is formed by an ALD method, and wherein the fourth insulating layer is formed by a sputtering method.
16 . The method for fabricating a display device, according to claim 14 , wherein the second insulating layer has a stacked-layer structure of a third insulating layer, a fourth insulating layer over the third insulating layer, and a fifth insulating layer over the fourth insulating layer, wherein the third insulating layer and the fifth insulating layer are formed by an ALD method, and wherein the fourth insulating layer is formed by a sputtering method.

Description

TECHNICAL FIELD One embodiment of the present invention relates to a display device. One embodiment of the present invention relates to a method for fabricating a display device. Note that one embodiment of the present invention is not limited to the above technical field. Examples of the technical field of one embodiment of the present invention disclosed in this specification and the like include a semiconductor device, a display device, a light-emitting device, a power storage device, a memory device, an electronic device, a lighting device, an input device, an input/output device, a driving method thereof, and a manufacturing method thereof. Note that in this specification and the like, a semiconductor device generally means a device that can function by utilizing semiconductor characteristics. BACKGROUND ART In recent years, higher-resolution display panels have been required. As a device that requires a high-resolution display panel, for example, devices for virtual reality (VR), augmented reality (AR), substitutional reality (SR), or mixed reality (MR) are given and have been actively developed in recent years. Examples of a display device that can be used for a display panel include, typically, a liquid crystal display device, a light-emitting device including a light-emitting element such as an organic EL (Electro Luminescence) element or a light-emitting diode (LED), and electronic paper performing display by an electrophoretic method or the like. For example, the basic structure of an organic EL element is a structure in which a layer containing a light-emitting organic compound is provided between a pair of electrodes. By voltage application to this element, light emission can be obtained from the light-emitting organic compound. A display device using such an organic EL element does not need a backlight that is necessary for a liquid crystal display device and the like; thus, a thin, lightweight, high-contrast, and low-power display device can be achieved. Patent Document 1, for example, discloses an example of a display device using an organic EL element. REFERENCE Patent Document [Patent Document 1] Japanese Published Patent Application No. 2002-324673 SUMMARY OF THE INVENTION Problems to be Solved by the Invention For example, in the above-described device for VR, AR, SR, or MR that is wearable, a lens for focus adjustment needs to be provided between eyes and the display panel. Since part of the screen is enlarged by the lens, low resolution of the display panel might cause a problem of weak sense of reality and immersion. The display panel is also required to have high color reproducibility. In particular, when using the display panel with high color reproducibility, the above-described device for VR, AR, SR, or MR can perform display with colors that are close to those of the actual objects, leading to higher sense of reality and immersion. 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 in which high color reproducibility is achieved. An object of one embodiment of the present invention is to provide a high-luminance display device. An object of one embodiment of the present invention is to provide a highly reliable display device. An object of one embodiment of the present invention is to provide a method for manufacturing the above-described display device. Note that the description of these objects does not preclude the existence of other objects. One embodiment of the present invention does not have to achieve all the objects. Note that objects other than these can be derived from the description of the specification, the drawings, the claims, and the like. Means for Solving the Problems One embodiment of the present invention is a display device including a first insulating layer, a light-emitting element and a first conductive layer over the first insulating layer, a first layer over the first conductive layer, a second conductive layer over the first layer, and a third conductive layer over the light-emitting element and the second conductive layer. The light-emitting element includes a fourth conductive layer, a second layer over the fourth conductive layer, a third layer over the second layer, and a fifth conductive layer over the third layer; the third conductive layer includes a region in contact with the second conductive layer and a region in contact with the fifth conductive layer; the second layer contains a light-emitting compound; the first conductive layer contains a material identical to a material of the fourth conductive layer; the first layer contains a material identical to a material of the third layer; and the second conductive layer contains a material identical to a material of the fifth conductive layer. Another embodiment of the present invention is a display device including a first insulating layer, a light-