Patent ID: 7922813
Filing Date: 2011-04-12
Classification: C30B

Abstract:
1. A method for producing epitaxially coated silicon wafers, in which a multiplicity of silicon wafers which are polished at least on their front sides are provided and successively and individually coated in an epitaxy reactor, comprising: placing one of the silicon wafers on a susceptor in the epitaxy reactor, pretreating the wafer under a hydrogen atmosphere in a first step, adding an etching medium to the hydrogen atmosphere in a second step, subsequently epitaxially coating the wafer on its polished front side, and removing the wafer from the epitaxy reactor, and afterwards heating the susceptor to a temperature of at least 1000° C. under a hydrogen atmosphere, and after a specific number of epitaxial coatings etching the susceptor followed by a momentary coating of the susceptor with silicon wherein the silicon wafer is characterized by a parameter R30 -1 mm of −10 nm to +10 nm, corresponding to a deviation, at a distance of 1 mm from the edge of the silicon wafer, of an average thickness cross section with respect to a reference line determined by regression.