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. 19, 2013
Filed:
Aug. 27, 2009
Timo Mueller, Burghausen, DE;
Gudrun Kissinger, Lebus, DE;
Walter Heuwieser, Neuoetting, DE;
Martin Weber, Kastl, DE;
Timo Mueller, Burghausen, DE;
Gudrun Kissinger, Lebus, DE;
Walter Heuwieser, Neuoetting, DE;
Martin Weber, Kastl, DE;
Siltronic AG, Munich, DE;
Abstract
Semiconductor wafers composed of monocrystalline silicon and doped with nitrogen contain an OSF region and a Pregion, wherein the OSF region extends from the center radially toward the edge of the wafer as far as the Pregion; the wafer has an OSF density of less than 10 cm, a BMD density in the bulk of at least 3.5×10cm, and a radial distribution of the BMD density with a fluctuation range BMD/BMDof not more than 3. The wafers are produced by controlling initial nitrogen content and maintaining oxygen within a narrow window, followed by a heat treatment.