Patent ID: 7985660

Claim:
A method for manufacturing an SOI wafer, comprising at least: a step of preparing a base wafer consisting of a p + silicon single crystal wafer containing a p-type dopant in the entire wafer at a high concentration and a bond wafer consisting of a silicon single crystal wafer containing a dopant at a lower concentration than that of the p-type dopant in the base wafer; a step of forming a silicon oxide film on the entire surface of the base wafer based on thermal oxidation; a step of bonding the bond wafer to the base wafer through the silicon oxide film on the base wafer; and a step of reducing a thickness of the bond wafer to form an SOI layer, wherein a step of forming a CVD insulator film on a back surface of the base wafer on an opposite side of a bonding surface of the base wafer is provided before the thermal oxidation step for the base wafer.