Method for cleaning base, heat process method for semiconductor wafer, and method for manufacturing solid-state image capturing apparatus

Patent metadata

Field	Value
Publication number	US-9508571-B2
Application number	US-201514701122-A
Country	US
Kind code	B2
Filing date	Apr 30, 2015
Priority date	May 12, 2014
Publication date	Nov 29, 2016
Grant date	Nov 29, 2016

Abstract

A method for cleaning a base for supporting an object to process in an apparatus configured to perform a heat process, the method comprising a first step of forming an oxide film on the base including silicon carbide, by subjecting the base to a heat process in a gas atmosphere including oxygen, and a second step of, after the first step, subjecting the base to a heat process in a gas atmosphere including steam, wherein the first step is performed for 10 hours at a temperature of 1000° C. or more.

First claim

What is claimed is:

1. A method for cleaning a base for supporting a semiconductor wafer in a chamber of a processing apparatus, the processing apparatus configured to perform a heat process on the semiconductor wafer, the method comprising:
preparing the base constituted by material including silicon carbide;
cleaning the base using a cleaning liquid;
performing a first heat process on the base in a gas atmosphere including oxygen so as to form an oxide film on a surface of the base; and
performing a second heat process, after the performing of the first heat process, on the base in a gas atmosphere including steam so as to thicken the oxide film,
wherein the first heat process is performed for 10 hours or more at a temperature of 1000° C. or more,
whereby an Fe impurity density of the semiconductor wafer in a case of performing a heat process using the base obtained after the performing of the second heat process is lower than an Fe impurity density of the semiconductor wafer in a case of performing a heat process using the base obtained after the performing of the first heat process and before the performing of the second heat process.

2. The method according to claim 1 , wherein the second heat process is performed at a temperature of 1000° C. or more.

3. The method according to claim 1 , wherein the second heat process is performed under a condition such that a flow amount of the steam is 5 slm or more and a heat process time is 10 hours or more.

4. The method according to claim 1 , wherein the first heat process is performed under a condition such that a flow amount of the oxygen is 10 slm or more.

5. The method according to claim 1 , further comprising installing the base in a chamber of an apparatus for performing the first and second processes, before the performing of the first process and the performing of the second process.

6. The method according to claim 1 , wherein hydrofluoric acid is used as the cleaning liquid in the cleaning the base.

7. The method according to claim 1 , wherein:
after the cleaning of the base and before the performing of the first heat process, an impurity is attached on the surface of the base;
after the performing of the first heat process and before the performing of the second heat process, part of the impurity is buried in the oxide film; and
after the performing of the second heat process, the impurity is buried in the oxide film deeper than after the performing of the first heat process and before the performing of the second heat process.

8. The method according to claim 1 , further comprising installing the base in the chamber of the processing apparatus, after the performing of the second heat process.

9. The method according to claim 8 , wherein the semiconductor wafer is in contact with the base installed in the chamber of the processing apparatus, in performing the heat process on the semiconductor wafer by the processing apparatus.

10. A heat process method for a semiconductor wafer, the method comprising:
cleaning the base using the method according to claim 1 ;
placing the semiconductor wafer on the base; and
performing the heat process on the semiconductor wafer.

11. A method for manufacturing a solid-state image capturing apparatus, the method comprising:
performing the heat process for the semiconductor wafer using the method according to claim 9 ; and
forming a photoelectric conversion element on the semiconductor wafer.

Assignees

• Canon Kk

Inventors

• Ogawa Toshiyuki
• Ukigaya Nobutaka

Classifications

• H10P72/7616

  characterised by a coating, a hardness or a material · CPC title

• H10P72/0414

  using mainly spraying means, e.g. nozzles · CPC title

• H10P70/18

  by combined dry cleaning and wet cleaning (H10P70/52 takes precedence) · CPC title

• H10P72/0434 Primary

  mainly by convection · CPC title

• B08B7/0071

  by heating (B08B7/0035 takes precedence) · CPC title