Reduced defect densities in graded buffer layers by tensile strained interlayers

摘要

A semiconductor stack includes a substrate; a first semiconductor layer disposed on the substrate; a tensile strained interlayer layer disposed on the first semiconductor layer; and a second semiconductor layer disposed on the strained interlayer; wherein the difference in strain between the first semiconductor layer and the tensile strained interlayer is about 1 to about 2%.