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:
Jul. 08, 2008
Filed:
Apr. 16, 2003
Nobumitsu Takase, Tokyo, JP;
Hideshi Nishikawa, Tokyo, JP;
Makoto Ito, Tokyo, JP;
Koji Sueoka, Tokyo, JP;
Shinsuke Sadamitsu, Tokyo, JP;
Nobumitsu Takase, Tokyo, JP;
Hideshi Nishikawa, Tokyo, JP;
Makoto Ito, Tokyo, JP;
Koji Sueoka, Tokyo, JP;
Shinsuke Sadamitsu, Tokyo, JP;
Sumitomo Mitsubishi Silicon Corporation, Tokyo, JP;
Abstract
A high-resistance silicon wafer is manufactured in which a gettering ability, mechanical strength, and economical efficiency are excellent and an oxygen thermal donor is effectively prevented from being generated in a heat treatment for forming a circuit, which is implemented on the side of a device maker. A heat treatment for forming an oxygen precipitate nucleus is performed at 500 to 900° C. for 5 hours or more in a non-oxidizing atmosphere and a heat treatment for growing an oxygen precipitate is performed at 950 to 1050° C. for 10 hours or more on a high-oxygen and carbon-doped high-resistance silicon wafer in which resistivity is 100 Ωcm or more, an oxygen concentration is 14×10atoms/cm(ASTM F-121, 1979) or more and a carbon concentration is 0.5×10atoms/cmor more. By these heat treatments, a remaining oxygen concentration in the wafer is controlled to be 12×10atoms/cm(ASTM F-121, 1979) or less. Thus, there is provided a high-resistance, low-oxygen and high-strength silicon wafer in which resistivity is 100 Ωcm or more and an oxygen precipitate (BMD) having a size of 0.2 μm is formed so as to have high density of 1×10/cmor more.