Single crystal growth method which includes covering a part of a surface of a raw material for sublimation with a metal carbide powder

Patent metadata

Field	Value
Publication number	US-11111599-B2
Application number	US-201916559875-A
Country	US
Kind code	B2
Filing date	Sep 4, 2019
Priority date	Sep 6, 2018
Publication date	Sep 7, 2021
Grant date	Sep 7, 2021

Abstract

The present invention provides a single crystal growth method capable of suppressing the recrystallization of the raw material gas subjected to sublimation on the surface of the raw material, and suppressing the generation of different polytypes in the crystal growing single crystal. The single crystal growth method is carried out in a crucible comprising an inner bottom for providing a raw material and a crystal mounting part facing the inner bottom. The method comprises in the following order: providing the raw material in the inner bottom; covering at least a part of a surface of the raw material with a metal carbide powder in a plan view from the crystal mounting part; and growing a single crystal disposed in the crystal mounting part by sublimating the raw material by heating.

First claim

What is claimed is:

1. A single crystal growth method, which is carried out in a crucible comprising an inner bottom for providing a raw material and a crystal mounting part facing the inner bottom,
the method comprising in the following order:
providing the raw material in the inner bottom;
covering a part but not the entire surface of the raw material with a metal carbide powder in a plan view from the crystal mounting part; and
growing a single crystal disposed in the crystal mounting part by sublimating the raw material by heating,
wherein in the covering step, an area covered with the metal carbide powder includes a central area of the surface of the raw material, and
the central area is an area of 20 area % of the total surface area in plan view at a top surface of the raw material from a center of the surface of the raw material.

2. The single crystal growth method of claim 1 ,
wherein a particle diameter of the metal carbide powder is 0.1 mm or more and 2.0 mm or less.

3. The single crystal growth method of claim 1 ,
wherein the metal carbide powder is a tantalum carbide powder.

4. The single crystal growth method according to claim 1 ,
wherein an average thickness of a covered area made of the metal carbide powder in the covering step is 1.0 mm or more and 30 mm or less.

5. The single crystal growth method of claim 1 ,
wherein the temperature of the central area is lower than that of a peripheral area.

6. The single crystal growth method of claim 1 ,
wherein a temperature of the central area is at least 15° C. lower than a maximum temperature in the surface of the raw material.

7. The single crystal growth method of claim 1 ,
wherein a partition plate is used to divide the area to be covered.

8. The single crystal growth method of claim 1 ,
wherein a surface of the metal carbide powder is in a range within 20 mm from the raw material surface.

Assignees

• Showa Denko Kk

Inventors

• Fujikawa Yohei

Classifications

• C30B29/36 Primary

  Carbides · CPC title

• C30B29/60

  characterised by shape · CPC title

• C30B25/12

  Substrate holders or susceptors · CPC title

• C30B23/005

  Controlling or regulating flux or flow of depositing species or vapour · CPC title

• C30B23/002

  Controlling or regulating · CPC title