APPARATUS AND METHOD FOR PRODUCTION OF SiC SINGLE CRYSTAL

• US 20120160153A1
• Filed: 12/15/2011
• Published: 06/28/2012
• Est. Priority Date: 12/28/2010
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Sakamoto, Hidemitsu, Kusunoki, Kazuhiko, Kamei, Kazuhito, ISHII, Tomokazu
• Granted Patent: US 9,322,112 B2
• Time in Patent Office: Days
• US Class Current: 117/11
• CPC Class Codes: C30B 17/00 Single-crystal growth onto a seed which remains in the melt during growth, e.g. Nacken-Kyropoulos method C30B15/00 takes precedence
• CPC Class Codes: C30B 29/36 Carbides
• CPC Class Codes: Y10T 117/1068 including heating or cooling details [e.g., shield configuration]
• CPC Class Codes: Y10T 117/1088 including heating or cooling details

Abstract

To suppress 3D or convex growth and ensure a high flatness, an apparatus for producing an SiC single crystal includes: a container which holds an SiC solution, a portion for maintaining the solution in the container at a suitable temperature, a shaft having a lower end part acting as a portion for holding an SiC seed crystal in planar contact with an overall back surface of a crystal growth face and acting as a portion for cooling the SiC seed crystal, and a portion of the holding shaft for enabling an SiC single crystal to continuously grow at the crystal growth face by maintaining the crystal growth face brought into contact with the solution, a lower end part of the shaft having a portion for obtaining a uniform in-plane temperature distribution of the crystal growth face brought into planar contact, and a method for the same.

Claims

1. An apparatus for production of an SiC single crystal comprising:

a container which holds an SiC solution,

a temperature controlling means for maintaining said SiC solution in said container at a suitable temperature,

a holding shaft which has a lower end part which acts as a holding means for holding an SiC seed crystal in a state in planar contact with an overall back surface of a crystal growth face and which acts as a cooling means for cooling said SiC seed crystal, and

a position controlling means of said holding shaft for enabling an SiC single crystal to continuously grow at said crystal growth face by maintaining said crystal growth face in a state brought into contact with said SiC solution,

said apparatus characterized in that said lower end part of said holding shaft has a temperature leveling means for obtaining a uniform in-plane temperature distribution of said crystal growth face brought into said planar contact.

2. An apparatus for production of an SiC single crystal as set forth in claim 1, wherein

said holding shaft is provided with a supply channel and return channel of a cooling fluid which extend to said lower end part through the body of said holding shaft along its length direction,

said lower end part forms a hollow body surrounded by a bottom part which holds said SiC single crystal in planar contact with its outside and side walls which rise from the peripheral edges of said bottom part and connect to said body of said holding shaft, so that said cooling fluid which is sprayed from said supply channel into said hollow body strikes said bottom part and cools said SiC single crystal through said bottom part and passes through said return channel to be discharged from said hollow body, and

said bottom part of said hollow body is reduced in thickness from the center part where said cooling fluid from said supply channel strikes toward the peripheral edges toward said return channel and thereby acts as said temperature leveling means.

3. An apparatus for production of an SiC single crystal as set forth in claim 1, wherein

a temperature leveling plate with a higher heat conductivity in a direction perpendicular to a growth direction of the SiC single crystal compared to that growth direction is interposed between said lower end part and said SiC seed crystal.

4. An apparatus for production of an SiC single crystal as set forth in claim 2, wherein

a temperature leveling plate with a higher heat conductivity in a direction perpendicular to a growth direction of the SiC single crystal compared to that growth direction is interposed between said lower end part and said SiC seed crystal.

5. An apparatus for production of an SiC single crystal as set forth in claim 1, which

covers an outer circumference of said holding shaft by a heat insulating material.

6. A method of production of an SiC single crystal comprising the steps of

preparing a container which holds an SiC solution,

controlling the temperature so as to maintain said SiC solution in said container at a suitable temperature,

holding an SiC seed crystal at a lower end part of a holding shaft in a state in planar contact with an overall back surface of a crystal growth face using said lower end part as a cooling means to cool said SiC seed crystal, and

controlling the position of said holding shaft for enabling an SiC single crystal to continuously grow at said crystal growth face by maintaining said crystal growth face in a state brought into contact with said SiC solution,

said method characterized by further having a step of obtaining a uniform in-plane temperature distribution of said crystal growth face brought into said planar contact, by using a temperature leveling means provided at said lower end part of said holding shaft.