US-12628465-B2 - Method for manufacturing inorganic light emitter

US12628465B2US 12628465 B2US12628465 B2US 12628465B2US-12628465-B2

Abstract

A method for manufacturing an inorganic light emitter, include arranging an inorganic light emitting element on one surface of a substrate; separating the inorganic light emitting element from the substrate while forming an oxide layer on a first surface of the inorganic light emitting element by emitting laser light to the first surface under an atmosphere having an oxygen concentration higher than an oxygen concentration of air, the first surface contacting the one surface of the substrate; and stacking the inorganic light emitting element separated at the separating on an array substrate to manufacture the inorganic light emitter.

Inventors

Masanobu Ikeda
Yasuhiro Kanaya

Assignees

MAGNOLIA WHITE CORPORATION

Dates

Publication Date: 20260512
Application Date: 20210924
Priority Date: 20190329

Claims (13)

1 . A method for manufacturing an inorganic light emitter, the method comprising: arranging an inorganic light emitting element comprising an n-type clad layer on one surface of a substrate; separating the inorganic light emitting element from the substrate while forming an oxide layer on a first surface of the inorganic light emitting element by emitting laser light to the first surface under an atmosphere having an oxygen concentration higher than an oxygen concentration of air, the first surface contacting the one surface of the substrate; stacking the inorganic light emitting element separated at the separating on an array substrate to manufacture the inorganic light emitter; forming a conductive coupling layer; and forming a cathode electrode that is coupled to the n-type clad layer that is under the oxide layer, the cathode electrode extends through a plurality of through-holes penetrating the oxide layer, wherein the conductive coupling layer is a different material than the cathode electrode, the cathode electrode directly contacts the n-type clad layer and the conductive coupling layer, the oxide layer, the conductive coupling layer, and the cathode electrode are layered in this order on the first surface of the inorganic light emitting element, and the conductive coupling layer is a different material than the oxide layer.
2 . The method for manufacturing the inorganic light emitter according to claim 1 , wherein the oxygen concentration is set to be in a range of 22% to 30% at the separating.
3 . The method for manufacturing the inorganic light emitter according to claim 1 , wherein the arranging includes forming the inorganic light emitting element above a formation substrate, and the separating includes separating the inorganic light emitting element from the formation substrate by emitting the laser light to the inorganic light emitting element above the formation substrate.
4 . The method for manufacturing the inorganic light emitter according to claim 3 , wherein the separating includes transferring the inorganic light emitting element onto the array substrate from the formation substrate such that a second surface of the inorganic light emitting element on an opposite side to the first surface makes contact with a surface of the array substrate, by emitting the laser light to the inorganic light emitting element in a state where the one surface of the formation substrate is made to face the surface of the array substrate.
5 . The method for manufacturing the inorganic light emitter according to claim 3 , wherein the separating includes first separating of transferring the inorganic light emitting element onto a transfer substrate from the formation substrate such that a second surface of the inorganic light emitting element on an opposite side to the first surface makes contact with a surface of the transfer substrate, by emitting the laser light to the inorganic light emitting element in a state where the one surface of the formation substrate is made to face the surface of the transfer substrate; and second separating of separating the inorganic light emitting element transferred onto the surface of the transfer substrate from the surface of the transfer substrate and transferring the inorganic light emitting element onto the array substrate.
6 . The method for manufacturing the inorganic light emitter according to claim 5 , wherein the second separating includes transferring the inorganic light emitting element onto the array substrate from the transfer substrate such that the first surface of the inorganic light emitting element makes contact with a surface of the array substrate, while forming a second oxide layer on the second surface of the inorganic light emitting element, by emitting the laser light to the inorganic light emitting element in a state where the surface of the transfer substrate is made to face the surface of the array substrate.
7 . The method for manufacturing the inorganic light emitter according to claim 5 , wherein the second separating includes transferring the inorganic light emitting element onto the array substrate from the transfer substrate by pressurizing the first surface of the inorganic light emitting element above the transfer substrate while making the first surface contact with a surface of the array substrate.
8 . The method for manufacturing the inorganic light emitter according to claim 3 , wherein the inorganic light emitting element is configured by stacking, above the formation substrate, the n-type clad layer, a light emitting layer, and a p-type clad layer in this order from a side of a surface of the formation substrate.
9 . The method for manufacturing the inorganic light emitter according to claim 1 , wherein the conductive coupling layer includes at least one of titanium and tin between the oxide layer of the light emitting element and an electrode provided above the array substrate.
10 . The method for manufacturing the inorganic light emitter according to claim 1 , wherein the conductive coupling layer is provided between the oxide layer and a lower surface of the cathode electrode.
11 . The method for manufacturing the inorganic light emitter according to claim 1 , wherein the cathode electrode is coupled to the n-type clad layer through the plurality of through-holes.
12 . The method for manufacturing the inorganic light emitter according to claim 1 , wherein the conductive coupling layer is provided under a lower surface of the cathode electrode without overlapping the through-holes of the oxide layer.
13 . The method for manufacturing the inorganic light emitter according to claim 1 , wherein the conductive coupling layer includes a first member that is a tin layer and a second members that are made of titanium, and the second members are dotted in the first member.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application claims the benefit of priority from Japanese Patent Application No. 2019-068912 filed on Mar. 29, 2019 and International Patent Application No. PCT/JP2020/013919 filed on Mar. 27, 2020, the entire contents of which are incorporated herein by reference. BACKGROUND 1. Technical Field What is disclosed herein relates to a method for manufacturing an inorganic light emitter. 2. Description of the Related Art In recent years, inorganic EL displays using, as display elements, inorganic light emitting diodes (micro LEDs), that is, inorganic light emitting elements have attracted attentions. The inorganic EL displays have the configuration in which the light emitting elements outputting light in different colors are arrayed on an array substrate. The inorganic EL displays use self-light emitting elements, thereby eliminating the necessity of a light source, and output light through no color filter, thereby achieving high light usage efficiency. The inorganic EL displays are excellent in environment resistance in comparison with organic EL displays using organic light emitting diodes (OLEDs) as the display elements. Each inorganic light emitting element is formed on a formation substrate and is separated from the formation substrate by emitting laser light to the inorganic light emitting element on the formation substrate in some cases (for example, see Japanese Patent No. 4285776). The inorganic light emitting element separated from the formation substrate is stacked on the array substrate to manufacture an inorganic light emitter. When the inorganic light emitting element is excessively irradiated with laser light, there is a risk that the inorganic light emitting element is deteriorated and performance such as light emitting efficiency is lowered. Accordingly, prevention of deterioration in the performance is desired when the inorganic light emitting element is separated from the substrate to manufacture the inorganic light emitter. The present disclose has been made in view of the above-mentioned problem, and an object thereof is to provide a method for manufacturing an inorganic light emitter preventing deterioration in performance. SUMMARY According to an aspect, a method for manufacturing an inorganic light emitter includes arranging an inorganic light emitting element on one surface of a substrate; separating the inorganic light emitting element from the substrate while forming an oxide layer on a first surface of the inorganic light emitting element by emitting laser light to the first surface under an atmosphere having an oxygen concentration higher than an oxygen concentration of air, the first surface contacting the one surface of the substrate; and stacking the inorganic light emitting element separated at the separating on an array substrate to manufacture the inorganic light emitter. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view illustrating an example of the configuration of a display device according to a first embodiment; FIG. 2 is a plan view illustrating a plurality of pixels; FIG. 3 is a circuit diagram illustrating an example of the configuration of a pixel circuit of the display device; FIG. 4 is a cross-sectional view cut along line IV-IV′ in FIG. 1; FIG. 5 is a cross-sectional view illustrating an example of the configuration of a light emitter according to the first embodiment; FIG. 6 is a schematic view illustrating an example of a coupling layer; FIG. 7 is a view for explaining a lamination method of the light emitter according to the first embodiment; FIG. 8 is a view illustrating a light emitter in another example of the first embodiment; FIG. 9 is a view for explaining a lamination method of the light emitter in another example of the first embodiment; FIG. 10 is a cross-sectional view illustrating an example of the configuration of a light emitter according to a second embodiment; FIG. 11 is a view for explaining a lamination method of the light emitter according to the second embodiment; FIG. 12 is a view illustrating a light emitter in another example of the second embodiment; FIG. 13 is a view for explaining a lamination method of the light emitter in another example of the second embodiment; FIG. 14 is a view for explaining a lamination method of a light emitter according to a third embodiment; FIG. 15 is a cross-sectional view illustrating an example of the configuration of the light emitter according to the third embodiment; FIG. 16 is a view for explaining a lamination method of the light emitter in another example of the third embodiment; and FIG. 17 is a cross-sectional view illustrating an example of the configuration of the light emitter in another example of the third embodiment. DETAILED DESCRIPTION Hereinafter, embodiments of the present disclose will be described with reference to the drawings. What is disclosed herein is merely an example, and it is needless to say that appropriate modifications within t