METHOD OF MEASURING CRYSTAL DEFECTS IN THIN SI/SIGE BILAYERS

摘要

A method of measuring crystalline defects in thin Si/SiGe bilayers is provided to delineate crystalline defects from a Si layer located on an SiGe alloy layer by using an improved defect etchant. A first etching process is performed to etch a structure including an Si layer(16) located on an SiGe alloy layer(14) with a defect etchant that is defect selective in Si to form at least one pit defect in the Si layer that is in contact with the SiGe alloy layer. A second etching process is performed to etch the structure containing the at least one pit defect with the same or different etchant as the first etching such that the second etching undercuts the SiGe layer beneath the at least one pit defect.