Patent ID: 7666730
Filing Date: 2010-02-23
Classification: H01L

Abstract:
1. A method for forming a semiconductor structure, the method comprising: forming a channel region layer over a semiconductor layer, the semiconductor layer comprising a first well region and a second well region, and the channel region layer being formed over the second well region; forming a protection layer over the channel region layer; forming a first gate dielectric layer over the first well region; forming a first metal gate electrode layer over the first gate dielectric; removing the protection layer after the forming the first metal gate electrode layer; forming a second gate dielectric layer over the channel region layer; forming a second metal gate electrode layer over the second gate dielectric layer, wherein the second metal gate electrode layer is a different metal than the first metal gate electrode layer; and forming a first gate stack comprising a portion of each of the first gate dielectric layer and the first metal gate electrode layer over the first well region and forming a second gate stack comprising a portion of each of the second gate dielectric layer and the second metal gate electrode layer over the channel region layer and over the second well region.