# US 2019/0378953 A1 · Light emitting element, method of manufacturing the same, and display device including the same

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- Number: US 2019/0378953 A1
- Document ID: US20190378953A1
- Status: Published application
- Kind: A1
- Application number: 16/274,109
- Filed: 2019-02-12
- Published: 2019-12-12
- Earliest claimed: 2018-06-11
- Assignees: Samsung Display Co., Ltd.
- Applicants: Samsung Display Co., Ltd.
- Inventors: Jung Hong MIN; Dae Hyun KIM; Seung A LEE; Hyun Min CHO; Jong Hyuk KANG; Dong Uk KIM; Hyun Deok IM; Hyung Rae CHA
- Web page: https://patentgrep.com/patent/US20190378953A1

## CPC

- H10H 20/01335: {the light-emitting regions comprising nitride materials}
- H10H 20/821: of the light-emitting regions, e.g. non-planar junctions
- H10H 20/01: Manufacture or treatment
- H10H 20/825: containing nitrogen, e.g. GaN
- H10H 20/831: characterised by their shape
- H10H 29/142: {Two-dimensional arrangements, e.g. asymmetric LED layout}
- H10P 50/00: Etching of wafers, substrates or parts of devices
- H10H 20/032: {of electrodes}
- H10H 20/034: {of coatings}
- H10H 20/84: Coatings, e.g. passivation layers or antireflective coatings
- H10H 20/857: Interconnections, e.g. lead-frames, bond wires or solder balls
- H10H: INORGANIC LIGHT-EMITTING SEMICONDUCTOR DEVICES HAVING POTENTIAL BARRIERS
- H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10

## Abstract

A light emitting element, a method of manufacturing a light emitting element, and a display device including a light emitting element are provided. A method of manufacturing a light emitting element includes: preparing a lower panel including a substrate and a first sub conductive semiconductor layer on the substrate; forming a first mask layer including at least one mask pattern on at least a part of the lower panel to be spaced apart from each other and an opening region in which the mask patterns are spaced apart from each other; laminating a first conductive semiconductor layer, an active material layer, and a second conductive semiconductor layer on the first mask layer to form an element laminate; etching the element laminate in a vertical direction to form an element rod; and removing the mask pattern to separate the element rod from the lower panel.

## Claims

### Claim 1

A method of manufacturing a light emitting element, the method comprising:
preparing a lower panel comprising a substrate and a first sub conductive semiconductor layer on the substrate;
forming a first mask layer comprising at least one mask pattern on at least a part of the lower panel to be spaced apart from each other, and an opening region in which the mask patterns are spaced apart from each other;
laminating a first conductive semiconductor layer, an active material layer, and a second conductive semiconductor layer on the first mask layer to form an element laminate;
etching the element laminate in a vertical direction to form an element rod; and
removing the mask pattern to separate the element rod from the lower panel.

### Claim 2 (depends on 1)

The method of claim 1,
wherein the forming of the element laminate comprises:
growing semiconductor crystals of the first sub conductive semiconductor layer in a vertical direction in the opening region in which the mask patterns are spaced apart from each other;
growing the semiconductor crystals on the mask pattern of the first mask layer in a horizontal direction; and
merging crystal grains of the semiconductor crystals on the mask pattern.

### Claim 3 (depends on 1)

The method of claim 1,
wherein the forming of the element rod comprises:
forming a second mask layer on the element laminate, the second mask layer including a hard mask layer and a nanopattern layer in which at least one nanopattern is spaced apart from each other on the hard mask layer;
vertically etching a region in which the nanopatterns are spaced apart from each other to form a hole; and
removing the second mask layer.

### Claim 4 (depends on 3)

The method of claim 3, further comprising forming an electrode material layer between the element laminate and the hard mask layer.

### Claim 5 (depends on 1)

The method of claim 1,
wherein the forming of the light emitting element comprises:
forming an insulating film on a side surface of the element rod; and
dissolving the mask pattern to separate the element rod provided with the insulating film from the lower panel.

### Claim 6 (depends on 5)

The method of claim 5, wherein the light emitting element comprises a separation surface, at which the element rod is separated from the lower panel, and which is substantially flat and parallel to an upper surface of the second conductive semiconductor layer.

### Claim 7 (depends on 6)

The method of claim 6, wherein the separation surface of the light emitting element has a surface roughness from 8 nm Ra to 12 nm Ra.

### Claim 8 (depends on 1)

The method of claim 1, wherein the mask pattern comprises at least one selected from silicon oxide, silicon nitride, silicon oxynitride, ITO, ZnO, IGO, graphene, and graphene oxide.

### Claim 9 (depends on 8)

The method of claim 8, wherein the mask pattern has a structure in which at least one layer is laminated, an insulating material layer comprising an insulating material is on a surface contacting the lower panel, and a conductive material layer comprising a conductive material is on the insulating material.

### Claim 10 (depends on 9)

The method of claim 9, wherein the conductive material layer is attached to the light emitting element in the forming of the mask pattern to form an electrode layer.

### Claim 11 (depends on 1)

The method of claim 1, wherein, in the first mask layer, the opening has a circular cross-sectional structure.

### Claim 12 (depends on 1)

The method of claim 1, wherein, in the first mask layer, the at least one mask pattern is between a side of the lower substrate and another side thereof facing the side, and arranged to be spaced apart from each other in a second direction perpendicular to the first direction in which the mask pattern is connected to form the opening.

### Claim 13 (depends on 12)

The method of claim 12, wherein, in the first mask layer, a ratio of a length of the mask pattern measured in the second direction to a length of the opening measured in the second direction is from 2.5:1 to 3.5:1.

### Claim 14

A light emitting element, comprising:
a first semiconductor layer doped with a first polarity;
an active layer on the first semiconductor layer;
a second semiconductor layer doped with a second polarity opposite to the first polarity; and
an insulating layer surrounding side surfaces of the first semiconductor layer, the second semiconductor layer, and the active layer,
wherein a surface roughness of a lower surface of the first semiconductor layer is different from a surface roughness of an upper surface of the second semiconductor layer.

### Claim 15 (depends on 14)

The light emitting element of claim 14, further comprising at least one electrode layer on the lower surface of the first semiconductor layer and the upper surface of the second semiconductor layer.

### Claim 16 (depends on 14)

The light emitting element of claim 14, wherein the lower surface of the first semiconductor layer and the upper surface of the second semiconductor layer have a surface roughness from 8 nm Ra to 12 nm Ra.

### Claim 17

A display device, comprising:
a base substrate;
first and second electrodes spaced apart from each other;
a first contact electrode on an upper surface of the first electrode;
a second contact electrode on an upper surface of the second electrode; and
at least one light emitting element in a region in which the first electrode and the second electrode are spaced apart from each other,
wherein both side surfaces of the light emitting element contacting the first contact electrode and the second contact electrode have a flat shape to be parallel to a surface perpendicular to the base substrate.

### Claim 18 (depends on 17)

The display device of claim 17,
wherein the light emitting element comprises:
an n-type semiconductor layer;
an active layer on the n-type semiconductor layer to emit light of a specific wavelength band;
a p-type semiconductor layer on the active layer; and
an insulating film surrounding side surfaces of the n-type semiconductor layer, the p-type semiconductor layer, and the active layer,
wherein a length measured in a direction in which the n-type semiconductor layer and the p-type semiconductor layer are laminated is longer than a vertical length between the first electrode and the second electrode.

### Claim 19 (depends on 18)

The display device of claim 18, wherein the first contact electrode and the second contact electrode are in vertical contact with the base substrate in a region contacting the light emitting element.

### Claim 20 (depends on 17)

The display device of claim 17, further comprising at least one passivation layer on an outer surface of the insulating layer of the light emitting element.