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. 25, 2011
Filed:
Aug. 11, 2005
Kouzo Nakamura, Kanagawa, JP;
Susumu Maeda, Kanagawa, JP;
Kouichirou Hayashida, Kanagawa, JP;
Takahisa Sugiman, Kanagawa, JP;
Katsuhiko Sugisawa, Kanagawa, JP;
Kouzo Nakamura, Kanagawa, JP;
Susumu Maeda, Kanagawa, JP;
Kouichirou Hayashida, Kanagawa, JP;
Takahisa Sugiman, Kanagawa, JP;
Katsuhiko Sugisawa, Kanagawa, JP;
Sumco Techxiv Corporation, Kanagawa, JP;
Abstract
An epitaxial wafer and a high-temperature heat treatment wafer having an excellent gettering capability are obtained by performing epitaxial growth or a high-temperature heat treatment. A relational equation relating the density to the radius of an oxygen precipitate introduced in a silicon crystal doped with nitrogen at the time of crystal growth can be derived from the nitrogen concentration and the cooling rate around 1100° C. during crystal growth, and the oxygen precipitate density to be obtained after a heat treatment can be predicted from the derived relational equation relating the oxygen precipitate density to the radius, the oxygen concentration, and the wafer heat treatment process. Also, an epitaxially grown wafer and a high-temperature annealed wafer whose oxygen precipitate density has been controlled to an appropriate density are obtained, using conditions predicted by the method.