Patent ID: 8373154

Claim:
An apparatus comprising: a selectively grown first layer of a silicon material suitable as a first channel for a first circuit device on a first area of a Si 1-X Ge X material defining a first interface surface of a substrate of graded relaxed silicon germanium material; wherein the layer of silicon material is under a tensile strain caused by a lattice spacing of the silicon material being smaller than a lattice spacing of the Si 1-X Ge X material at the first interface, wherein X is between 0.1 and 0.3; a selectively grown second layer of a Si 1-Y Ge Y material suitable as a second channel for a second circuit device on a second area of a Si 1-X Ge X material defining a second interface surface of the substrate of graded relaxed silicon germanium material; wherein the layer of Si 1-Y Ge Y material is under a compressive strain caused by a lattice spacing of the Si 1-Y Ge Y material being larger than a lattice spacing of the Si 1-x Ge x material at the second interface, wherein X<Y, and Y is between 0.2 and 0.6; a gate dielectric layer in contact with the selectively grown silicon material and the selectively grown Si 1-Y Ge Y material; and a gate electrode on the gate dielectric layer.