Method of making a semiconductor device having a semiconductor material on a relaxed semiconductor including replacing a strained, selective etchable material, with a low density dielectric in a cavity

摘要

A semiconductor device comprising a substrate having a region protruding from the substrate surface; a relaxed semiconductor disposed on the region; an additional semiconductor disposed on the relaxed semiconductor; and low density dielectric disposed next to and at least partially underneath the relaxed semiconductor and adjacent to the protruding region of the substrate.