SOI WAFER AND METHOD FOR MANUFACTURING SOI WAFER

摘要

A method for manufacturing an SOI wafer comprises steps of forming an ion implanted layer (24) in a bond wafer (21) by conducting implantation of ions such as hydrogen ions through the surface of the bond wafer, of bonding the ion implanted surface of the bond wafer and a surface of a base wafer (22) directly or via an oxide film (23), and of separating a part of the bond wafer at the ion implanted layer by a heat treatment. In this method, a silicon wafer which is a silicon single crystal grown by the Czochralski method in an N region lying outside the ring-shaped OSF and free from a defect region sensed by a Cu deposition method is used as the bond wafer. By using this method, an SOI wafer free from very small pits caused by hydrofluoric acid cleaning or the like and having excellent electrical properties can be manufactured without increasing the processing steps even when an extremely thin SOI layer (27) having a thickness, for example, of 200 nm or less is formed.