The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 10, 1995
Filed:
Apr. 30, 1993
Reiji Niino, Kofu, JP;
Yoshiyuki Fujita, Kofu, JP;
Hideki Lee, Nirasaki, JP;
Yasuo Imamura, Yokohama, JP;
Toshiharu Nishimura, Kofu, JP;
Yuuichi Mikata, Kawasaki, JP;
Shinji Miyazaki, Yokkaichi, JP;
Takahiko Moriya, Yokohama, JP;
Katsuya Okumura, Poughkeepsie, NY (US);
Tokyo Electron Limited, Tokyo, JP;
Abstract
Prior to formation of a polysilicon film on a wafer, a pre-coat film having a thickness of 1 .mu.m and consisting of polysilicon is formed on the inner wall surface of a reaction tube or the surface of a member incorporated in the reaction tube. A polysilicon film is formed on the wafer at a temperature of 450.degree. C. to 650.degree. C. A cleaning gas containing ClF.sub.3 having a concentration of 10 to 50 vol. % is supplied into the reaction tube at a flow rate to an area of an object be cleaned of 750 to 3,500 SCCM/m.sup.2 to remove a polysilicon film deposited on the inner wall surface of the reaction tube or the surface of the member incorporated in the reaction tube by etching using the ClF.sub.3. In this case, the cleaning gas is supplied while a temperature in the reaction tube is kept at a temperature of 450.degree. C. to 650.degree. C. and in a pressure condition set at the kept temperature such that an etching rate of a polysilicon film by the cleaning gas is higher than an etching rate of quartz constituting the reaction tube or the member incorporated in the reaction tube.