Patent ID: 8187926

Claim:
A method of manufacturing a semiconductor device, said method comprising the steps of: forming a silicon oxide film on a first single crystal silicon substrate; adding hydrogen to the first single crystal silicon substrate through the silicon oxide film to form a hydrogen added layer in the first single crystal silicon substrate; bonding the first single crystal silicon substrate to a second substrate through the silicon oxide film with a bonded interface therebetween, said second substrate being as a support; separating the first single crystal silicon substrate by a first heat treatment; carrying out a second heat treatment to a single crystal silicon film which remains on the second substrate in the separating step so that the bonded interface becomes stable; flattening a surface of the single crystal silicon film; forming a silicon island by patterning the single crystal silicon film after carrying out the second heat treatment; thermally oxidizing an upper and side surfaces of the silicon island in an oxidizing atmosphere containing a halogen element to form an insulating film; and forming a gate electrode over the silicon island with the insulating film interposed therebetween.