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:
Aug. 28, 2012
Filed:
Nov. 12, 2004
Shinsuke Sadamitsu, Tokyo, JP;
Masataka Hourai, Tokyo, JP;
Shinsuke Sadamitsu, Tokyo, JP;
Masataka Hourai, Tokyo, JP;
Sumitomo Mitsubishi Silicon Corporation, Tokyo, JP;
Abstract
Disclosed are high resistivity silicon wafers, wherein the interstitial oxygen concentration thereof is 8×10atoms/cm(ASTM F121-1979) or less, BMD (Bulk Micro Defect) density—oxygen precipitate within wafer—is 5×10pieces/cmor less, and an electric resistivity thereof is 100 Ω·cm or more. And further disclosed are high resistivity silicon wafers having an electric resistivity of 100 Ω·cm or more, which are cut from crystal region where no COP (Crystal Originated Particle) exist, and in which neither COP (Crystal Originated Particle) nor oxygen precipitate exist at the area from wafer surface to the depth of 5 μm or more owing to high temperature treatment. It is preferable that, in said high resistivity wafers, carbon concentration in wafers is 1×10atoms/cmor more (ASTM F123-1981), and/or nitrogen concentration is 1×10atoms/cmor more. Accordingly, high resistivity silicon wafers are provided, wherein the mechanical strength thereof is highly secured, and an excellent characteristic to slip generation is provided, so as to be optimal for base wafers of silicon wafers having a SOI structure or an epitaxial structure.