Patent ID: 8679942
Filing Date: 2014-03-25
Classification: H01L

Abstract:
1. A method of fabricating a semiconductor substrate, comprising: forming a strained donor structure by forming a III-nitride material on a first substrate with a desired lattice strain and a Ga-face on a first surface of the III-nitride material and an N-face on a second surface of the III-nitride material; selecting an attachment surface, wherein the attachment surface is the first surface to form an N-polar composite substrate or the second surface to form a Ga-polar composite substrate; forming a weakened zone in the strained donor structure at a predetermined depth to define a strained seed layer between the attachment surface and the weakened zone and a residual strained donor structure between the weakened zone and a surface opposite the attachment surface; bonding a support substrate to the attachment surface of the III-nitride material; separating the residual strained donor structure from the strained seed layer at the weakened zone to form a strained composite substrate comprising the support substrate and the strained seed layer; epitaxially growing at least one additional layer of semiconductor material on the strained seed layer of the strained composite substrate to deposit a device structure; and selecting the desired lattice strain and a resulting strained lattice parameter of the III-nitride material and a composition of the at least one additional layer of semiconductor material and causing a reduction in a difference between the strained lattice parameter of the III-nitride material of the strained seed layer and an equilibrium lattice parameter of the at least one additional layer of semiconductor material.