| 摘要 |
A p-type field effect transistor (PFET) and an n-type field effect transistor (NFET) are formed by patterning of a gate dielectric layer, a thin silicon layer, and a silicon-germanium alloy layer. After formation of the source/drain regions and gate spacers, silicon germanium alloy portions are removed from gate stacks. A dielectric layer is formed and patterned to cover an NFET gate electrode, while exposing a thin silicon portion for a PFET. Germanium is selectively deposited on semiconductor surfaces including the exposed silicon portion. The dielectric layer is removed and a metal layer is deposited and reacted with underlying semiconductor material to form a metal silicide for a gate electrode of the NFET, while forming a metal silicide-germanide alloy for a gate electrode of the PFET.
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