Method for growing silicon carbide crystal

Patent metadata

Field	Value
Publication number	US-9945047-B2
Application number	US-201414559299-A
Country	US
Kind code	B2
Filing date	Dec 3, 2014
Priority date	Dec 6, 2013
Publication date	Apr 17, 2018
Grant date	Apr 17, 2018

Abstract

In the present invention, a crucible formed of SiC as a main component is used as a container for a Si—C solution. The SiC crucible is heated such that, for example, an isothermal line representing a temperature distribution within the crucible draws an inverted convex shape; and Si and C, which are derived from a main component SiC of the crucible, are eluted from a high-temperature surface region of the crucible in contact with the Si—C solution, into the Si—C solution, thereby suppressing precipitation of a SiC polycrystal on a surface of the crucible in contact with the Si—C solution. To the Si—C solution of this state, a SiC seed crystal is moved down from the upper portion of the crucible closer to the Si—C solution and brought into contact with the Si—C solution to grow a SiC single crystal on the SiC seed crystal.

First claim

What is claimed is:

1. A method for growing a silicon carbide crystal by a solution method using a crucible formed of SiC as a main component, as a container for a Si—C solution, comprising
heating the crucible to elute Si and C, which are derived from a main component SiC of the crucible, from a high-temperature surface region of the crucible in contact with the Si—C solution, into the Si—C solution so that precipitation of a SiC polycrystal on a surface of the crucible in contact with the Si—C solution is suppressed by elution of the Si and C into the Si—C solution; and
moving down a SiC seed crystal closer to the Si—C solution from an upper portion of the crucible and bringing the seed crystal into contact with the Si—C solution to grow a SiC single crystal on the SiC seed crystal, and wherein
the heating is carried out to form a temperature distribution where the temperature of the Si—C solution in the crucible increases from the top to the bottom, and at the bottom portion of the crucible has the highest temperature.

2. The method for growing a silicon carbide crystal according to claim 1 , wherein metal M having an effect of improving solubility of C in the Si—C solution is added in advance to the Si—C solution.

3. The method for growing a silicon carbide crystal according to claim 1 , wherein the temperature of the Si—C solution is controlled by the heating within the range of 1300° C. to 2300° C.

4. The method for growing a silicon carbide crystal according to claim 1 , wherein the heating is carried out in a state where the crucible formed of SiC as a main component is contained in a second crucible formed of a heat-resistant carbon material.

5. The method for growing a silicon carbide crystal according to claim 1 , wherein the heating is carried out such that an isothermal line representing a temperature distribution within the crucible draws an inverted convex shape.

6. The method for growing a silicon carbide crystal according to claim 5 , wherein metal M having an effect of improving solubility of C in the Si—C solution is added in advance to the Si—C solution.

7. The method for growing a silicon carbide crystal according to claim 5 , wherein the temperature of the Si—C solution is controlled by the heating within the range of 1300° C. to 2300° C.

8. The method for growing a silicon carbide crystal according to claim 5 , wherein the heating is carried out in a state where the crucible formed of SiC as a main component is contained in a second crucible formed of a heat-resistant carbon material.

Assignees

• Shinetsu Chemical Co

Inventors

• Shinya Naofumi
• Hamaguchi Yu
• Yamagata Norio
• Minowa Takehisa

Classifications

• C30B13/02 Primary

  Zone-melting with a solvent, e.g. travelling solvent process · CPC title

• C30B15/02

  adding crystallising materials or reactants forming it in situ to the melt · CPC title

• C30B29/36

  Carbides · CPC title

• C30B15/206

  the thermal history of growing the ingot · CPC title

• C30B11/08

  every component of the crystal composition being added during the crystallisation · CPC title