Epitaxial silicon wafer with intrinsic gettering and a method for the preparation thereof

摘要

A wafer is characterized in that the wafer has a non-uniform distribution of crystal lattice vacancies, wherein the concentration of crystal lattice vacancies in the bulk layer are greater than the concentration of crystal lattice vacancies in the front surface layer. In addition, the front surface of the wafer has an epitaxial layer, having a thickness of less than about 2.0 mum, deposited thereon. A process comprises heating a surface of a wafer starting material to remove a silicon oxide layer from the surface and depositing an epitaxial layer onto the surface to form an epitaxial wafer. The epitaxial wafer is then heated to a soak temperature of at least about 1175° C. while exposing the epitaxial layer to an oxidizing atmosphere comprising an oxidant, and the wafer is cooled at a rate of at least about 10° C./sec.