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:
Oct. 25, 2011
Filed:
Jan. 29, 2008
Andreas Sattler, Trostberg, DE;
Wilfried Von Ammon, Hochburg/Ach, AT;
Martin Weber, Kastl, DE;
Walter Haeckl, Zeilarn, DE;
Herbert Schmidt, Halsbach, DE;
Andreas Sattler, Trostberg, DE;
Wilfried von Ammon, Hochburg/Ach, AT;
Martin Weber, Kastl, DE;
Walter Haeckl, Zeilarn, DE;
Herbert Schmidt, Halsbach, DE;
Siltronic AG, Munich, DE;
Abstract
Semiconductor wafers of silicon are produced by pulling a single crystal growing on a phase boundary from a melt contained in a crucible and cutting of semiconductor wafers therefrom, wherein during pulling of the single crystal, heat is delivered to a center of the phase boundary and a radial profile of a ratio V/G from the center to an edge of the phase boundary is controlled, G being the temperature gradient perpendicular to the phase boundary and V being the pull rate. The radial profile of the ratio V/G is controlled so that the effect of thermomechanical stress in the single crystal adjoining the phase boundary, is compensated with respect to creation of intrinsic point defects. The invention also relates to defect-free semiconductor wafers of silicon, which can be produced economically by this method.