Patent ID: 7598153

Claim:
A method for fabricating bonded substrate structures, the method comprising, providing a thickness of single crystal silicon material transferred from a first silicon substrate coupled to a second silicon substrate, the second silicon substrate having a second surface region that is joined to a first surface region from the thickness of single crystal silicon material to form of an interface region having a first characteristic including a silicon oxide material between the thickness of single crystal silicon material and the second silicon substrate; subjecting the interface region to a thermal process to cause a change to the interface region from the first characteristic to a second characteristic, the second characteristic being free from the silicon oxide material and being an epitaxially formed silicon material provided between the thickness of single crystal silicon material and the second silicon substrate; and maintaining the interface region free of multiple voids during the thermal process to form the epitaxially formed silicon material to electrically couple the thickness of single crystal silicon material to the second silicon substrate, the method further comprising performing a non-contact smoothing process on a cleaved surface of the thickness of single crystal silicon.