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:
Mar. 27, 2012
Filed:
Nov. 29, 2007
Katsuhiko Nakai, Yamaguchi, JP;
Sei Fukushima, Kanagawa, JP;
Katsuhiko Nakai, Yamaguchi, JP;
Sei Fukushima, Kanagawa, JP;
Siltronic AG, Munich, DE;
Abstract
Silicon wafers and a process for their manufacture wherein both slip dislocation and occurrence of warpage are suppressed include heat treatment to provide wafers having plate-shaped BMDs, a density of BMDs whose diagonal lengths are in a range of 10 nm to 120 nm, of BMDs present in the bulk of the wafer at a distance of 50 μm or more is 1×10/cmor more, and the density of BMDs whose diagonal lengths are 750 nm or more in the wafer bulk is 1×10/cmor less, and the interstitial oxygen concentration is 5×10atoms/cmor less. The process involves low and high temperature heat treating at under defined temperature ramping rates.