Method for manufacturing SOI wafer

A method for manufacturing an SOI wafer, said method comprising:

• forming insulating films in a front surface and a mirror-polished rear surface of an active layer wafer;
• removing said insulating film in said front surface of said active layer wafer;
• after the removing, subjecting said active layer wafer to a rapid thermal annealing process in a nitridation gas atmosphere to form a vacancy layer including vacancies in a surface portion of said front surface;
• bonding said active layer wafer and a support wafer with said insulating film formed in said rear surface therebetween so as to form a bonded wafer, after the rapid thermal annealing process;
• subjecting said bonded wafer to a heat treatment for bonding enhancement in an oxidizing atmosphere which enhances a bonding strength between said active layer wafer and said support wafer and forms a denuded zone layer in said surface portion of said front surface and a BMD layer under said denuded zone layer in said active layer wafer;
• and
• thinning said active layer wafer in said bonded wafer and removing said denuded zone layer and said BMD layer so as to form an SOI layer in a surface portion of said rear surface of said active layer wafer.