Patent ID: 7449395

Claim:
A method of fabricating a composite substrate which comprises: providing a source substrate comprising a semiconductor material and a support substrate; providing an insulating layer on the source substrate; applying a recovery heat treatment for heat treatment of the insulating layer under conditions sufficient to enhance the electrical characteristics of the insulating layer and its interface with the semiconductor material of the source substrate; providing plasma activation after applying the recovery heat treatment either on a front face of the recovery heat treated insulating layer, on a front face of the support substrate, or on both faces, to enhance bonding strength compared to faces(s) that do not receive plasma activation after the recovery heat treatment; bonding the front face of the insulating layer with the front face of the support substrate after plasma activation to form a bonded substrate; and removing a back portion of the source substrate from the bonded substrate while retaining an active layer that comprises a remaining portion of the source substrate bonded to the support substrate with the insulating layer interposed between the support substrate and the active layer.