Patent ID: 7018910

Claim:
A method of preparing a semiconductor wafer, comprising: growing a first layer of a first material in a strained state on a matching substrate comprising a matching layer; growing a second layer of a semiconductor second material, different from the first material, in a relaxed state on the first layer to form a boundary between the first and second layers and to form a composite structure which comprises the matching, first, and second layers, wherein the first and second layers each have substantially the same first lattice parameter; creating a region of weakness in the matching substrate to facilitate splitting; splitting the composite structure at the region of weakness into: an unfinished wafer that includes the second layer, the first layer, and at least a remaining portion of the matching layer, and a handle wafer: removing the remaining portion of the matching layer from the first layer; and removing the first layer from the second layer to produce a surface on the second layer that is substantially smooth and of substantially uniform thickness.