US-12622117-B2 - Image display device manufacturing method and image display device

US12622117B2US 12622117 B2US12622117 B2US 12622117B2US-12622117-B2

Abstract

An image display device manufacturing method according to an embodiment includes preparing a semiconductor layer, joining the semiconductor layer to a first substrate with a first metal layer interposed therebetween, bonding the semiconductor layer to a light-transmitting substrate, removing the first substrate, etching the semiconductor layer to form a light-emitting element including a light-emitting surface and an upper surface, etching the first metal layer to form a light-blocking electrode covering the upper surface, forming a first insulating film covering the light-emitting element and the light-blocking electrode, forming a circuit element on the first insulating film, forming a second insulating film covering the first insulating film and the circuit element, forming a first via passing through the first insulating film and the second insulating film, and forming a first wiring layer on the second insulating film.

Inventors

Hajime Akimoto

Assignees

NICHIA CORPORATION

Dates

Publication Date: 20260505
Application Date: 20230224
Priority Date: 20200917

Claims (12)

1 . An image display device manufacturing method comprising: preparing a semiconductor layer comprising a light-emitting layer; joining the semiconductor layer to a first substrate with a first metal layer interposed therebetween; bonding the semiconductor layer to a first surface of a light-transmitting substrate; removing the first substrate; etching the semiconductor layer to form, on the first surface of the light-transmitting substrate, a light-emitting element comprising a light-emitting surface and an upper surface located on a side opposite to the light-emitting surface; etching the first metal layer to form a light-blocking electrode covering and electrically connected to the upper surface of the light-emitting element; forming a first insulating film covering the first surface of the light-transmitting substrate, the light-emitting element, and the light-blocking electrode; forming a circuit element on the first insulating film; forming a second insulating film covering the first insulating film and the circuit element; forming a first via passing through the first insulating film and the second insulating film; and forming a first wiring layer on the second insulating film, wherein: the first via is located between the first wiring layer and the light-blocking electrode, and electrically connects the first wiring layer and the light-blocking electrode.
2 . The image display device manufacturing method according to claim 1 , wherein: the step of preparing the semiconductor layer comprises forming the first metal layer on the semiconductor layer.
3 . The image display device manufacturing method according to claim 1 , further comprising: before the step of joining the semiconductor layer to the first substrate, forming the first metal layer on a joining surface of the first substrate.
4 . The image display device manufacturing method according to claim 1 , further comprising: before the step of bonding the semiconductor layer, roughening an exposed surface of the semiconductor layer to form a roughened surface, and forming a film having light transmittance across the roughened surface.
5 . The image display device manufacturing method according to claim 1 , further comprising: forming a second via passing through the first insulating film and the second insulating film, wherein the light-emitting element comprises a connecting portion, and the second via is located between and electrically connects the first wiring layer and the connecting portion.
6 . The image display device manufacturing method according to claim 1 , further comprising: before the step of bonding the semiconductor layer, forming a conductive layer having light transmittance on the semiconductor layer; and after the step of removing the first substrate, etching the conductive layer to form a second wiring layer.
7 . The image display device manufacturing method according to claim 6 , further comprising: forming a second via passing through the first insulating film and the second insulating film, wherein: the second via is located between and electrically connects the first wiring layer and the second wiring layer.
8 . The image display device manufacturing method according to claim 1 , further comprising: before the step of forming the circuit element, forming a light-blocking layer on the first insulating film.
9 . The image display device manufacturing method according to claim 1 , wherein: the semiconductor layer comprises a gallium nitride compound semiconductor.
10 . The image display device manufacturing method according to claim 1 , further comprising: forming a wavelength conversion member on a second surface of the light-transmitting substrate opposite to the first surface.
11 . The image display device manufacturing method according to claim 1 , further comprising: removing the light-transmitting substrate and forming a wavelength conversion member in place of the light-transmitting substrate.
12 . An image display device manufacturing method comprising: preparing a semiconductor layer comprising a light-emitting layer; bonding the semiconductor layer to a first surface of a light-transmitting substrate; forming a second metal layer on the semiconductor layer; etching the semiconductor layer to form, on the first surface of the light-transmitting substrate, a light-emitting element comprising a light-emitting surface and an upper surface located on a side opposite to the light-emitting surface; etching the second metal layer to form a light-blocking electrode covering and electrically connected to the upper surface of the light-emitting element; forming a first insulating film covering the first surface of the light-transmitting substrate, the light-emitting element, and the light-blocking electrode; forming a circuit element on the first insulating film; forming a second insulating film covering the circuit element and the first insulating film; forming a first via passing through the first insulating film and the second insulating film; and forming a first wiring layer on the second insulating film, wherein: the first via is located between the first wiring layer and the light-blocking electrode, and electrically connects the first wiring layer and the light-blocking electrode.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS The present application is a bypass continuation of PCT Application No. PCT/JP2021/032527, filed Sep. 3, 2021, which claims priority to Japanese Application No. 2020-156716, filed Sep. 17, 2020. The contents of these applications are hereby incorporated by reference in their entireties. BACKGROUND The present disclosure relates to an image display device manufacturing method and an image display device. Realization of a thin image display device having high brightness, a wide viewing angle, high contrast, and low power consumption has been desired. To accommodate such market demands, advancements have been made in the development of a display device that utilizes a self-light-emitting element. The emergence of a display device that uses, as a self-light-emitting element, a micro light-emitting diode (LED), which is a fine light-emitting element, is expected. As a manufacturing method of a display device that uses a micro LED, a method of sequentially transferring individually formed micro LEDs to a drive circuit has been introduced. Nevertheless, as the number of micro LED elements increases as image quality advances, such as for full high definition, 4K, and 8K, in the individual formation and the sequential transfer of a large number of micro LEDs to a substrate on which a drive circuit and the like are formed, a significant amount of time is required for the transfer process. Furthermore, connection failure or the like between a micro LED and the drive circuit or the like may occur, resulting in a decrease in yield. There is known a technique of growing a semiconductor layer including a light-emitting layer on a Si substrate, forming an electrode on the semiconductor layer, and then bonding the semiconductor layer to a circuit substrate on which a drive circuit is formed (refer to Patent Document 1: JP 2002-141492 A, for example). SUMMARY Certain embodiments of the present disclosure are directed to an image display device manufacturing method and an image display device that reduce a transfer process of a light-emitting element and improve yield. An image display device manufacturing method according to an embodiment of the present disclosure includes preparing a semiconductor layer including a light-emitting layer, joining the semiconductor layer to a first substrate with a first metal layer interposed therebetween, bonding the semiconductor layer to a first surface of a light-transmitting substrate, removing the first substrate, etching the semiconductor layer to form, on the first surface, a light-emitting element including a light-emitting surface and an upper surface provided on a side opposite to the light-emitting surface, etching the first metal layer to form a light-blocking electrode covering the upper surface and electrically connected to the upper surface, forming a first insulating film covering the first surface, the light-emitting element, and the light-blocking electrode, forming a circuit element on the first insulating film, forming a second insulating film covering the first insulating film and the circuit element, forming a first via passing through the first insulating film and the second insulating film, and forming a first wiring layer on the second insulating film. The first via is provided between the first wiring layer and the light-blocking electrode, and allows electrical connection between the first wiring layer and the light-blocking electrode. An image display device manufacturing method according to an embodiment of the present disclosure includes preparing a semiconductor layer including a light-emitting layer, bonding the semiconductor layer to a first surface of a light-transmitting substrate, removing the first substrate and subsequently forming a second metal layer on the semiconductor layer, etching the semiconductor layer to form, on the first surface, a light-emitting element including a light-emitting surface and an upper surface provided on a side opposite to the light-emitting surface, etching the second metal layer to form a light-blocking electrode covering the upper surface and electrically connected to the upper surface, forming a first insulating film covering the first surface, the light-emitting element, and the light-blocking electrode, forming a circuit element on the first insulating film, forming a second insulating film covering the circuit element and the first insulating film, forming a first via passing through the first insulating film and the second insulating film, and forming a first wiring layer on the second insulating film. The first via is provided between the first wiring layer and the light-blocking electrode, and allows electrical connection between the first wiring layer and the light-blocking electrode. An image display device according to another embodiment of the present disclosure includes a light-transmitting member including a first surface, a light-emitting element, on the first surface,