Patent ID: 8853792

Claim:
A semiconductor device comprising: a semiconductor device structure having a first region of a first semiconductor material and a second region of a second semiconductor material; a first transistor comprising: a first layer of a mobility-enhancing material in the first region; and a first gate stack overlying the first layer, the first gate stack comprising: a deposited oxide layer overlying the first layer, the deposited oxide layer having a first thickness, an oxygen-diffusion barrier layer overlying the deposited oxide layer, a first portion of a layer of high-k dielectric material overlying the oxygen-diffusion barrier layer, and a first portion of a layer of conductive material overlying the first portion of the layer of high-k dielectric material, wherein sidewalls of the first portion of the layer of conductive material, sidewalls of the first portion of the layer of high-k dielectric material, and sidewalls of the oxygen-diffusion barrier layer of the first gate stack are vertically aligned; and a second transistor comprising: a second layer of the mobility-enhancing material in the second region; and a second gate stack overlying the second layer, the second gate stack comprising: an oxide layer overlying the second layer, the oxide layer having a second thickness, the second thickness being less than the first thickness, a second portion of the layer of high-k dielectric material overlying the oxide layer of the second region, and a second portion of the layer of conductive material overlying the second portion of the layer of high-k dielectric material.