Patent ID: 8350295

Claim:
A method comprising: providing an apparatus including: a first substrate; an etch stop layer including aluminum gallium arsenide or indium gallium phosphide formed over the first substrate; an inverted epitaxial structure formed over etch stop layer in a manner such that the etch stop layer is between the first substrate and the inverted epitaxial structure and such that a frontside of the inverted epitaxial structure faces the etch stop layer and a backside of the inverted epitaxial structure faces away from the etch stop layer; and an oxide layer formed over the backside of the inverted epitaxial structure; after providing the apparatus, forming a second substrate over the oxide layer such that the oxide layer is between the backside of the active layer and the second substrate; and after said forming the second substrate, removing the first substrate and the etch stop layer to expose the frontside of the inverted epitaxial structure.