Method and apparatus for producing single crystal, substrate for growing single crystal and method for heating single crystal

• US 6,786,969 B2
• Filed: 12/21/2001
• Issued: 09/07/2004
• Est. Priority Date: 12/28/2000
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Nakamura, Daisuke, Hirose, Fusao, Sugiyama, Naohiro, Okamoto, Atsuto, Oguri, Emi, Kondo, Hiroyuki
• Primary Examiner(s): Norton, Nadine G.
• Assistant Examiner(s): ANDERSON, MATTHEW A
• Application Number:
  US10/024,471
• Publication Number:
  US 20020083892A1
• Time in Patent Office: 991 Days
• Field of Search: 117/200, 117/900, 118/715, 118/720, 118/724, 118/726, 118/728
• US Class Current: 117/200
• CPC Class Codes: C30B 23/00 Single-crystal growth by condensing evaporated or sublimed materials
• CPC Class Codes: C30B 23/002 Controlling or regulating
• CPC Class Codes: C30B 29/36 Carbides
• CPC Class Codes: Y10T 117/10 Apparatus

Abstract

It is the purpose of the present invention to prevent a macroscopic defect in the production of an SiC single crystal. SiC source material powder and an SiC seed crystal are disposed inside a graphite crucible, and the SiC source material powder is thermally sublimated and recrystallized on a front surface of the SiC seed crystal to grow an SiC single crystal. In this sublimation-recrystallization method, a protection layer is provided on a back surface of the SiC seed crystal. The SiC seed crystal is mechanically supported by a supporting part disposed on the graphite crucible without bonding. Thereby, it is possible to improve the thermal maldistribution on the back surface of the SiC seed crystal and possible to suppress damage of the protection layer due to the thermal maldistribution. Thus, macroscopic defects in the grown SiC single crystal are preferably suppressed.

Claims

1. An apparatus for producing a silicon carbide single crystal where a silicon carbide single crystal substrate that is a seed crystal is disposed inside a container and a source material for the silicon carbide single crystal is supplied to grow the silicon carbide single crystal on the silicon carbide single crystal substrate, the apparatus characterized in that:

a protection layer is formed on a back surface the silicon carbide single crystal substrate;

a supporting part is provided on an inner wall of the container for disposing the silicon carbide single crystal substrate to a predetermined position in the container,

wherein the supporting part supports the silicon carbide single crystal substrate at a periphery of a back surface of the silicon carbide single crystal substrate such that an entire front surface of the silicon carbide single crystal substrate faces the source material to grow the silicon carbide single crystal on a front surface.

2. The apparatus for producing a silicon carbide single crystal as in claim 1, further characterized in that:

an opening is formed in a wall of the container at a position facing the protection layer of the silicon carbide single crystal substrate; and

a lid-shaped member is provided so as to close the opening.

3. The apparatus for producing a silicon carbide single crystal as in claim 1, further characterized in that:

the protection layer is one of a carbon layer, a layer of carbide with metal having a high melting point, a silicon carbide epitaxial layer, a silicon carbide polycrystalline layer, a silicon carbide amorphous layer and a multilayer film constituted of the above layers.

4. The apparatus for producing a silicon carbide single crystal as in claim 1, further characterized in that a gap with predetermined width is provided between the protection layer of the silicon carbide single crystal substrate and an inner wall of the container.

5. The apparatus for producing a silicon carbide single crystal as in claim 1, further characterized in that:

the supporting part supports the substrate by being adhered to the substrate with an adhesive.

6. An apparatus for producing a silicon carbide single crystal where a silicon carbide single crystal substrate that is a seed crystal is disposed inside a container and a source material for the silicon carbide single crystal is supplied to grow the silicon carbide single crystal on the silicon carbide single crystal substrate, the apparatus characterized in that:

the silicon carbide single crystal substrate having a protection layer on a back surface is disposed so as to close an opening formed in a wall of the container;

the silicon carbide single crystal substrate is supported by a supporting part disposed on a side wall defining the opening such that an entire front surface of the silicon carbide single crystal substrate faces the source material to grow the silicon carbide single crystal; and

the protection layer is exposed to an outside space.

7. The apparatus for producing a silicon carbide single crystal as in claim 6, further characterized in that:

the protection layer is a carbon layer that enables a temperature of the silicon carbide single crystal substrate to be monitored from the outside space.

8. An apparatus for producing a silicon carbide single crystal where a silicon carbide single crystal substrate that is a seed crystal is disposed inside a container and a source material for the silicon carbide single crystal is supplied to grow the silicon carbide single crystal on the silicon carbide single crystal substrate, the apparatus characterized in that:

a protection layer is formed on a back surface the silicon carbide single crystal substrate;

a supporting part is provided on an inner wall of the container for disposing the silicon carbide single crystal substrate to a predetermined position in the container,

wherein the supporting part mechanically supports the silicon carbide single crystal substrate at a periphery of the substrate such that a gap with a predetermined width is provided between the protection layer of the silicon carbide single crystal substrate and an inner wall of the container;

an opening is formed in a wall of the container at a position facing the protection layer of the silicon carbide single crystal substrate; and

a lid-shaped member is provided so as to close the opening and to adjust the predetermined width of the gap.

9. A substrate for growing a silicon carbide single crystal, comprising:

a silicon carbide single crystal substrate, which is a seed crystal; and

a protection layer formed on a back surface of the silicon carbide single crystal substrate, wherein

a front surface of the silicon carbide single crystal substrate has a supported face supported by a supporting part and disposed at a periphery of the front surface; and

a growth face disposed on a center of the front surface and projecting toward a source material, the growth face for growing the silicon carbide single crystal,

wherein the growth face has a conically shaped inner surface that protrudes from the supported face.