Patent ID: 8021958

Claim:
A method for manufacturing an SOI substrate, comprising the steps of: forming a first oxide film on a surface of a single crystal semiconductor substrate by performing first thermal oxidation treatment on the single crystal semiconductor substrate; forming an embrittlement region in the single crystal semiconductor substrate by irradiating the single crystal semiconductor substrate with ions through the first oxide film; bonding a surface of the first oxide film over the single crystal semiconductor substrate and a first surface of a semiconductor substrate; forming a single crystal semiconductor layer over the semiconductor substrate with the first oxide film interposed therebetween by separating the single crystal semiconductor substrate by heat treatment at the embrittlement region; irradiating the single crystal semiconductor layer with a laser beam in an inert atmosphere; forming a second oxide film over the single crystal semiconductor layer and a second surface of the semiconductor substrate by performing second thermal oxidation treatment; and removing the second oxide film.