Patent ID: 7507988

Claim:
A heterostructure comprising: a Si-containing substrate; an insulating region comprising a crystalline or non-crystalline oxide or nitride that is resistant to Ge diffusion present atop the Si-containing substrate, said insulating region is patterned and includes an upper region that is comprised of a thermal oxide; a substantially relaxed SiGe layer present atop the insulating region, wherein the substantially relaxed SiGe layer has a thickness of from about 2000 nm or less, a measured lattice relaxation of from about 50 to about 80% and a defect density of less than about 10 8 defects/cm 2 ; a strained epitaxial Si layer located atop the substantially relaxed SiGe layer; and at least one alternating stack comprising a bottom relaxed SiGe layer and an top strained Si layer located on said strained epitaxial Si layer.