SiC epitaxial wafer and method for manufacturing the same

Patent metadata

Field	Value
Publication number	US-9679767-B2
Application number	US-201314407397-A
Country	US
Kind code	B2
Filing date	Jun 19, 2013
Priority date	Jun 19, 2012
Publication date	Jun 13, 2017
Grant date	Jun 13, 2017

Abstract

Provided is a method of manufacturing a SiC epitaxial wafer including a SiC epitaxial layer on a SiC substrate using a SiC-CVD furnace which is installed in a glove box. The method includes a SiC substrate placement step of placing the SiC substrate in the SiC-CVD furnace while circulating gas in the glove box.

First claim

The invention claimed is:

1. A method of manufacturing a SiC epitaxial wafer including a SiC epitaxial layer on a SiC substrate using a SiC-CVD furnace which is installed in a glove box, comprising:
a SiC substrate placement step of placing the SiC substrate in the SiC-CVD furnace while circulating gas in the glove box,
wherein the SiC-CVD furnace includes a susceptor that has a wafer mounting portion on which a wafer is placed, a ceiling that faces an upper surface of the susceptor such that a reaction space is formed between the ceiling and the susceptor, and a shielding plate that is provided so close to a lower surface of the ceiling that a deposit is prevented from being attached to the lower surface of the ceiling,
a surface of the shielding plate which faces the susceptor is coated with one of a silicon carbide film and a pyrolytic carbon film, or the shielding plate is made of silicon carbide, and
the method further includes a step of measuring the surface density of triangular defects including a piece of a member which is placed in the SiC-CVD furnace as a starting point in a SiC epitaxial film of a previously manufactured SiC epitaxial wafer and manufacturing the next SiC epitaxial wafer.

2. The method of manufacturing a SiC epitaxial wafer according to claim 1 ,
wherein the gas is circulated before and after the SiC substrate is placed in the SiC-CVD furnace.

3. The method of manufacturing a SiC epitaxial wafer according to claim 2 ,
wherein the gas is circulated at least 3 minutes before the SiC substrate is placed in the SiC-CVD furnace.

4. The method of manufacturing a SiC epitaxial wafer according to claim 1 ,
wherein the SiC substrate placement step is performed after it is checked that particle number density in the glove box is equal to or less than a predetermined value.

5. The method of manufacturing a SiC epitaxial wafer according to claim 1 ,
wherein, when the measurement result shows that the surface density of the triangular defects including a piece of a member which is placed in the SiC-CVD furnace as the starting point is greater than a predetermined value, the shielding plate is replaced and the next SiC epitaxial wafer is manufactured.

6. A method of manufacturing a SiC epitaxial wafer including a SiC epitaxial layer on a SiC substrate using a SiC-CVD furnace which is installed in a glove box, comprising:
a SiC substrate placement step of placing the SiC substrate in the SiC-CVD furnace while circulating gas in the glove box,
wherein the SiC-CVD furnace includes a susceptor that has a wafer mounting portion on which a wafer is placed and a ceiling that faces an upper surface of the susceptor such that a reaction space is formed between the ceiling and the susceptor,
a surface of the ceiling which faces the susceptor is coated with one of a silicon carbide film and a pyrolytic carbon film, or the ceiling is made of silicon carbide, and
the method further includes a step of measuring the surface density of triangular defects including a piece of a member which is placed in the SiC-CVD furnace as a starting point in a SiC epitaxial film of a previously manufactured SiC epitaxial wafer and manufacturing the next SiC epitaxial wafer.

7. The method of manufacturing a SiC epitaxial wafer according to claim 6 ,
wherein, when the measurement result shows that the surface density of the triangular defects including a piece of a member which is placed in the SiC-CVD furnace as the starting point is greater than a predetermined value, the ceiling is replaced and the next SiC epitaxial wafer is manufactured.

Assignees

• Showa Denko Kk

Inventors

• Miyasaka Akira
• Tajima Yutaka
• KAGESHIMA Yoshiaki
• Muto Daisuke
• Momose Kenji

Classifications

• H10P74/203

  Structural properties, e.g. testing or measuring thicknesses, line widths, warpage, bond strengths or physical defects · CPC title

• H10P14/3442

  N-type · CPC title

• H10P14/2926

  Crystal orientations · CPC title

• H10P14/2904

  Silicon carbide · CPC title

• H10P14/3408

  Silicon carbide · CPC title