Method of fabricating a semiconductor device with a non-uniform gate insulating film
AssigneeKabushiki Kaisha Toshiba
InventorsYoshio Ozawa, Isao Kamioka
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Abstract
A semiconductor device includes a semiconductor substrate, a gate insulating film formed on the semiconductor substrate, a gate electrode formed on the gate insulating film, a source/drain diffusion layer formed in the semiconductor substrate at both sides of the gate electrode, and a channel region formed in the semiconductor substrate between a source and a drain of the source/drain diffusion layer and arranged below the gate insulating film, wherein an upper surface of the source/drain diffusion layer is positioned below a bottom surface of the gate electrode, and an upper surface of the channel region is positioned below the upper surface of the source/drain diffusion layer.
Claims10
A semiconductor device manufacturing method comprising:
- forming a gate insulating film on a semiconductor substrate;
- selectively forming a gate electrode on the gate insulating film;
- forming a nitrogen-containing insulating film by nitriding an exposed portion of the gate insulating film;
- performing thermal oxidation that an oxide amount at an upper surface of the semiconductor substrate and at a bottom surface of the gate electrode reduces from an end portion to a central portion of a channel region beneath the gate electrode, forming a sidewall layer on a side surface of the gate electrode, and thickening the gate insulating film in a lower end portion of the gate electrode;
- and
- forming a source/drain diffusion layer in the semiconductor substrate.
Dependencies are inferred from the claim text.