Semiconductor device and manufacturing method
AssigneeSeiko Epson Corporation
InventorsTeruo Takizawa, Hiroyuki Shimada
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Abstract
A semiconductor device comprising a metal-oxide-semiconductor field-effect transistor well controllably brings the work function of a gate electrode close to the intrinsic mid gap energy of silicon, thereby lowering the concentration of impurities in a channel. By this, the deterioration of carrier mobility is prevented and a metal-oxide-semiconductor field-effect transistor is obtained. A gate electrode has a multi-layer structure of a p-type polycrystalline or a single-crystalline germanium film 3 and a low resistance conductive film 4.
Claims5
A semiconductor device, comprising:
- a silicon substrate,
- a gate insulation film on the silicon substrate,
- a germanium film on the gate insulation film,
- a polysilicon film on the germanium film, and
- a transition metal nitride in direct contact with the polysilicon film,
- wherein p-type impurities are doped into the germanium film, and a range of concentration of the p-type impurities is about 1017 to 1020 cm−3.
A semiconductor device, comprising:
- a substrate;
- an insulation film on the substrate;
- a silicon film on the insulation fil;
- a gate insulation film on the silicon film;
- a germanium film on the gate insulation film;
- a polysilicon film on the germanium film;
- and
- a transition metal nitride in direct contact with the polysilicon film,
- wherein p-type impurities are doped into the germanium film, and a range of concentration of the p-type impurities is about 1017 to 1020 cm−3.
Dependencies are inferred from the claim text.