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:
May. 08, 2012
Filed:
Dec. 19, 2007
Martin Weber, Kastl, DE;
Herbert Schmidt, Halsbach, DE;
Wilfried Von Ammon, Hochburg/Ach, AT;
Siltronic AG, Munich, DE;
Abstract
Semiconductor wafers of silicon are produced by pulling a single crystal from a melt contained in a crucible and slicing semiconductor wafers from the pulled single crystal, heat being delivered to a center of the growing single crystal at the boundary with the melt during the pulling of the single crystal, a CUSP magnetic field applied such that a neutral surface of the CUSP magnetic field intersects a pulling axis of the single crystal at a distance of at least 50 mm from a surface of the melt. An apparatus suitable therefore contains a CUSP field positioned such that a neutral field intersects the axis of the crystal in the crucible 50 mm or more from the melt surface.