Semiconductor wafers of silicon and method for their production

US8231725B2 · kind B2 · utility

Assignee

• Siltronic AG · DE

Inventors

• Andreas Sattler · Trostberg, DE
• Wilfried von Ammon · Burghausen, DE
• Martin Weber · Borgo San Lazzaro, DE
• Walter Haeckl · Zeilarn, DE
• Herbert Schmidt · Friedberg, DE

Key dates

• Filing date: Sep 6, 2011
• Grant date: Jul 31, 2012
• Expiry date: Sep 6, 2031

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C30B15/203
• WIPO field: Surface technology, coating
• WIPO sector: Chemistry

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.