Process and apparatus for epitaxially coating a semiconductor wafer and epitaxially coated semiconductor wafer

Abstract

A process for epitaxially coating the front surface of a semiconductor wafer in a CVD reactor, the front surface of the semiconductor wafer being exposed to a process gas which contains a source gas and a carrier gas, and the back surface of the semiconductor wafer being exposed to a displacement gas, wherein the displacement gas contains no more than 5% by volume of hydrogen, with the result that diffusion of dopants out of the back surface of the semiconductor wafer, which is intensified by hydrogen, is substantially avoided. With this process, it is possible to produce a semiconductor wafer with a substrate resistivity of ≦100 mΩcm and a resistivity of the epitaxial layer of >1 Ωcm without back-surface coating, the epitaxial layer of which semiconductor wafer has a resistance inhomogeneity of <10%.

Dependencies are inferred from the claim text.