SI SUBSTRATE FOR EPITAXIAL WAFER AND ITS MANUFACTURING METHOD

摘要

PROBLEM TO BE SOLVED: To produce an epitaxial wafer having a superior crystallinity without involving any dislocation in surface Si single crystal and no defect in view of the fine structure. SOLUTION: A Si substrate is heavily doped with Sb to provide a specified Sb concn. (Sbo ). Its surface Sb concn. (Sbs ) at its outermost face to grow an epitaxial film is 1×10<17> atoms/cm<3> or less and the Sb concn. increases at a gradient up to an Sb concn. (Sbx ) over (Sbo )×0.5 in the depth of at least 2 microns from the outermost face. The substrate can be produced by heat-treating its surface to grow the epitaxial film in a H -or/and Ar-containing gas atmosphere with (Sbs ) of at least 1×10<17> atoms/cm<3> or less.