Patent ID: 7465646

Claim:
A method for fabricating a wafer structure having a strained silicon utility layer, comprising: providing a prototype wafer as a silicon on insulator structure which comprises at least a support substrate, a strained silicon model layer upon the support substrate, and at least one insulator layer between the support substrate and the strained silicon model layer; providing a relaxed silicon-germanium layer on the strained silicon model layer; providing a strained silicon utility layer on the relaxed silicon-germanium layer to form an intermediate structure, wherein the strained silicon utility layer has the same strain characteristics as the strained silicon model layer; detaching the strained silicon utility layer from the intermediate structure at a predetermined zone of weakness in the relaxed silicon-germanium layer to form a wafer structure having a strained silicon utility layer; and removing any residual portions of the relaxed silicon-germanium layer from the strained silicon model layer after the detachment step so that the prototype wafer can be recycled.