EPITAXIAL SILICON WAFER AND METHOD FOR PRODUCING THE EPITAXIAL SILICON WAFER

摘要

A method for producing an epitaxial silicon wafer, including a preliminary thermal treatment step of subjecting a silicon wafer to thermal treatment for increasing a density of oxygen precipitates, the silicon wafer being one that has an oxygen concentration in a range of 9×1017 atoms/cm3 to 16×1017 atoms/cm3, contains no dislocation cluster and no COP, and contains an oxygen precipitation suppression region, and an epitaxial layer forming step of forming an epitaxial layer on a surface of the silicon wafer after the preliminary thermal treatment step. The production method further includes a thermal treatment condition determining step of determining a thermal treatment condition in the preliminary thermal treatment step, based on a ratio of the oxygen precipitation suppression region of the silicon wafer before the preliminary thermal treatment step is carried out.

主权项

1. An epitaxial silicon wafer having an epitaxial layer on a surface of a silicon wafer that contains no dislocation cluster and no COP,
wherein when an oxygen precipitate density is evaluated by subjecting the epitaxial silicon water to oxygen precipitate evaluation thermal treatment in which the epitaxial silicon wafer is thermally treated at 1000° C. for 16 hours, a density of oxygen precipitates in a central portion in a thickness direction of the silicon wafer is 5×104/cm2 or more throughout an entire region in a radial direction of the silicon wafer.