Patent ID: 8039401

Claim:
A method for forming a hybrid substrate, comprising: providing first and second substrates having different crystalline orientations; bonding the first and second substrates together to thereby form a unitary hybrid substrate; removing predefined portions of the first substrate to form openings in the first substrate through which surface regions of the second substrate are exposed; and carrying out a selective epitaxial growth process that is selective with respect to the crystalline orientations of the first and second substrates to thereby form epitaxial silicon from the exposed surfaces of the second substrate but not from exposed surfaces of the first substrate, wherein the epitaxial silicon formed from the exposed surfaces of the second substrate has the same crystalline orientation as the second substrate; wherein the selective epitaxial growth process comprises a chlorine-containing etchant that provides a faster etch rate of the epi along the exposed surfaces of the first substrate than the epi along the exposed surfaces of the second substrate.