Semiconductor device and method of manufacturing the same
AssigneeKabushiki Kaisha Toshiba
InventorKazuya Ohuchi
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Abstract
An aspect of the present invention includes a first conductive type semiconductor region formed in a semiconductor substrate, a gate electrode formed on the first conductive type semiconductor region, a channel region formed immediately below the gate electrode in the first conductive type semiconductor region, and a second conductive type first diffusion layers constituting source/drain regions formed at opposite sides of the channel region in the first conductive type semiconductor region, the gate electrode being formed of polycrystalline silicon-germanium, in which the germanium concentration of at least one of the source side and the drain side is higher than that of the central portion.
Claims18
A semiconductor device comprising:
- a first conductive type semiconductor region formed in a semiconductor substrate;
- a gate electrode formed on said first conductive type semiconductor region;
- a channel region formed immediately below said gate electrode in said first conductive type semiconductor region;
- and
- a second conductive type first diffusion layer constituting source/drain regions formed at opposite sides of said channel region in said first conductive type semiconductor region,
- said gate electrode being formed of polycrystalline silicon-germanium, in which germanium concentration of at least one of a source side and a drain side is higher than that of a central portion.
A semiconductor device comprising:
- a first conductive type semiconductor region formed in a semiconductor substrate;
- a gate electrode of polycrystalline silicon-germanium formed on said first conductive type semiconductor region;
- a channel region formed immediately below said gate electrode in said first conductive type semiconductor region;
- a second conductive type first diffusion layer constituting source/drain regions formed at opposite sides of said channel region in said first conductive type semiconductor region;
- and
- an oxide layer formed on at least one of said source region side and a drain region side of said gate electrode,
- a germanium concentration in a region with a thickness substantially identical to the thickness of said oxide layer, ranging from the side of said gate electrode where said oxide layer is formed, is 1.5 to 2 times the germanium concentration of a central portion of said gate electrode.
A semiconductor device comprising:
- a first MISFET including:
- a first conductive type first semiconductor region formed in a semiconductor substrate;
- a first gate electrode formed on said first semiconductor region;
- a first channel region formed immediately below said first gate electrode in said first semiconductor region;
- and
- a second conductive type first diffusion layer constituting source/drain regions formed at opposite sides of said first channel region in said first conductive type semiconductor region;
- and
- a second MISFET including:
- a second conductive type second semiconductor region formed in the semiconductor substrate and isolated from said first semiconductor region;
- a second gate electrode formed on said second semiconductor region;
- a second channel region formed immediately below said second gate electrode in said second semiconductor region;
- and
- a first conductive type second diffusion layer constituting source/drain regions formed at opposite sides of said second channel region in said second conductive type semiconductor region,
- said first and second gate electrodes being formed of polycrystalline silicon-germanium, in which germanium concentration of at least one of a source side and a drain side is higher than a central portion.
A method of manufacturing a semiconductor device comprising:
- forming a gate electrode containing polycrystalline silicon-germanium on a first conductive type semiconductor region in a semiconductor substrate;
- selectively forming a first insulating layer on said gate electrode such that a portion near one side of said gate electrode is exposed;
- and
- forming an oxide layer by selectively oxidizing silicon near the exposed side of said gate electrode.
A method of manufacturing a semiconductor device comprising:
- forming a gate electrode containing polycrystalline silicon-germanium on a first conductive type semiconductor region in a semiconductor substrate;
- and
- forming an oxide layer all over the gate electrode by selectively oxidizing silicon in the gate electrode.
Dependencies are inferred from the claim text.