SiC single crystal production method and production apparatus

Patent metadata

Field	Value
Publication number	US-10968535-B2
Application number	US-201815946334-A
Country	US
Kind code	B2
Filing date	Apr 5, 2018
Priority date	Apr 26, 2017
Publication date	Apr 6, 2021
Grant date	Apr 6, 2021

Abstract

A method for a SiC single crystal that allow prolonged growth to be achieved are provided. A method for producing a SiC single crystal in which a seed crystal substrate held on a seed crystal holding shaft is contacted with a Si—C solution having a temperature gradient such that a temperature of the Si—C solution decreases from an interior of the Si—C solution toward a liquid level of the Si—C solution, in a graphite crucible, to grow a SiC single crystal, wherein the method comprises the steps of: electromagnetic stirring of the Si—C solution with an induction coil to produce a flow, and heating of a lower part of the graphite crucible with a resistance heater.

First claim

What is claimed is:

1. A method for producing a SiC single crystal in which a seed crystal substrate held on a seed crystal holding shaft is contacted with a Si—C solution having a temperature gradient such that a temperature of the Si—C solution decreases from an interior of the Si—C solution toward a liquid level of the Si—C solution, in a graphite crucible, to grow a SiC single crystal, wherein the method comprises the steps of:
electromagnetic stirring of the Si—C solution with an induction coil to produce a flow, and
heating of a lower part of the graphite crucible with a resistance heater,
wherein the resistance heater is situated, at least in part, approximately horizontally, in a manner facing the lower face of the bottom section of the graphite crucible.

2. The method for producing a SiC single crystal according to claim 1 , wherein the heating of the lower part of the graphite crucible comprises at least one of heating of a bottom section of the graphite crucible and heating of a crucible-holding shaft that holds the bottom section of the graphite crucible.

3. The method for producing a SiC single crystal according to claim 1 , wherein the method further comprises heating of side sections of the graphite crucible with the resistance heater.

4. The method for producing a SiC single crystal according to claim 2 , wherein the method further comprises heating of side sections of the graphite crucible with the resistance heater.

5. An apparatus for production of a SiC single crystal comprising:
a graphite crucible that houses a Si—C solution,
an induction coil,
a resistance heater, and
a seed crystal holding shaft disposed in a movable manner in the vertical direction,
the apparatus being employed in a solution process in which a seed crystal substrate held on the seed crystal holding shaft is contacted with the Si—C solution that has been heated so as to have a temperature gradient in which a temperature of the Si—C solution decreases from an interior of the Si—C solution toward a liquid level of the Si—C solution, to grow a SiC single crystal from the seed crystal substrate,
wherein the graphite crucible is held on the crucible-holding shaft by a bottom section of the graphite crucible,
the induction coil is situated surrounding side sections of the graphite crucible,
the resistance heater is disposed at a location such that the resistance heater heats a lower part of the graphite crucible, and
the resistance heater is situated, at least in part, approximately horizontally, in a manner facing the lower face of the bottom section of the graphite crucible.

6. The apparatus for production of a SiC single crystal according to claim 5 , wherein the resistance heater is disposed in at least one of a location facing a lower face of the bottom section of the graphite crucible and a location surrounding the crucible-holding shaft.

7. The apparatus for production of a SiC single crystal according to claim 5 , wherein the resistance heater is further disposed surrounding the side sections of the graphite crucible and inside the induction coil.

8. The apparatus for production of a SiC single crystal according to claim 6 , wherein the resistance heater is further disposed surrounding the side sections of the graphite crucible and inside the induction coil.

Assignees

• Toyota Motor Co Ltd

Inventors

• Doi Masayoshi
• Daikoku Hironori
• Kado Motohisa
• Sato Tomohiro
• Seki Kazuaki
• Kusunoki Kazuhiko
• Kishida Yutaka

Classifications

• C30B30/02

  using electric fields, e.g. electrolysis · CPC title

• C30B29/36 Primary

  Carbides · CPC title

• C30B11/003 Primary

  Heating or cooling of the melt or the crystallised material · CPC title

• C30B11/002

  Crucibles or containers for supporting the melt · CPC title

• C30B9/06

  using as solvent a component of the crystal composition · CPC title