A method for producing a bonded wafer by the ion implantation delamination method
includes at least a step of bonding a bond wafer having a micro bubble layer formed
by gaseous ion implantation and a base wafer serving as a support substrate and
a step of delaminating the bond wafer at the micro bubble layer as a border to
form a thin film on the base wafer. After the delamination of the bond wafer, the
bonded wafer is subjected to a heat treatment in an atmosphere of an inert gas,
hydrogen or a mixed gas thereof, then the bonded wafer is subjected to thermal
oxidation to form a thermal oxide film on the surface of the thin film, and then
the thermal oxide film is removed to reduce thickness of the thin film.
