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US 6,713,779 B2Granted
Semiconductor device and method of manufacturing the same
AssigneeKabushiki Kaisha Toshiba
InventorsTsutomu Tezuka, Shinichi Takagi
Life of this patent
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Abstract
An object of the invention is to provide a complete depletion-mode SOI field-effect transistor in which transistors having different threshold voltages are integrated. A SiGe film having a high Ge composition and a SiGe film having a low Ge composition are formed on an insulating film, and strain-Si films are respectively formed thereon. Transistors including channel regions in the strain-Si films obtained as a result of this are formed, so that the transistors having different threshold voltages can be integrated.
Claims16
A semiconductor device comprising:
- a first lattice-relaxed Si1−xGex film formed on a first region on an insulating film, wherein a Ge composition x is in a range of 0 to 1;
- a second lattice-relaxed SiGe film having a Ge composition greater than the first lattice-relaxed Si1−xGex film, wherein the second lattice-relaxed SiGe film is formed on a second region on the insulating film;
- a first strain-Si film formed on the first lattice-relaxed Si1−xGex film;
- a second strain-Si film formed on the second lattice-relaxed SiGe film;
- a complete depletion-mode first field-effect transistor including the first strain-Si film as a channel;
- and
- a complete depletion-mode second field-effect transistor including the second strain-Si film as a channel, threshold value of the second field-effect transistor is different from threshold value of the first field-effect transistor.
4 more elements
A semiconductor device comprising:
- a substrate;
- an insulating film;
- a first field-effect transistor including a first lattice-relaxed Si1−xGex film having a Ge composition x in a range of 0 to 1 and formed in a first region on the insulating film, a first strain-Si film formed on the first lattice-relaxed Si1−xGex film, a first gate insulating film formed on the first strain-Si film, a first gate electrode formed on the first gate insulating film, and a first source region and a first drain region separately formed in the first strain-Si film;
- and
- a second field-effect transistor including a second lattice-relaxed SiGe film formed in a second region on the insulating film, a second strain-Si film formed on the second lattice-relaxed SiGe film, a second gate insulating film formed on the second strain-Si film, a second gate electrode formed on the second gate insulating film, and a second source region and a second drain region separately formed in the second strain-Si film, wherein a threshold voltage of the second field-effect transistor is different from a threshold voltage of the first field-effect transistor.
2 more elements
Dependencies are inferred from the claim text.