Patent ID: 6949761

Claim:
A semiconductor layer structure comprising: a relaxed Si 1-x Ge x layer; wherein said relaxed Si 1-x Ge x layer is doped either partially or wholly p-type, a bottom Si 1-z Ge z buffer layer on top of said relaxed Si 1-x Ge x layer; a tensile tensile-strained Si quantum well layer on top of said bottom Si 1-z Ge z buffer layer; a top Si 1-m Ge m buffer layer on top of said tensile tensile-strained Si quantum well layer; and, a Si cap layer on top of said top Si 1-m Ge m buffer layer, wherein said relaxed bottom Si 1-z Ge z buffer layer, tensile-strained Si quantum well layer, and top Si 1-m Ge m buffer layer and Si cap layer are substantially undoped.