Method for manufacturing semiconductor device
AssigneeAsahi Kasei Microdevices Corporation
InventorsShogo Katsuki, Toshiro Sakamoto
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Abstract
A method for manufacturing a semiconductor device, includes forming a first gate oxide film in each of a first region and a second region by thermally oxidizing a silicon substrate, forming a CVD oxide film on the first gate oxide film, implanting fluorine into each of the first region and the second region through the CVD oxide film and the first gate oxide film, removing the CVD oxide film from the first gate oxide film in the second region, removing the first gate oxide film from the second region, and forming a second gate oxide film in the second region by thermally oxidizing the silicon substrate.
Claims4
A method for manufacturing a semiconductor device, the semiconductor device including a first MOS transistor in a first region of a semiconductor substrate and a second MOS transistor in a second region of the semiconductor substrate, the method comprising:
- forming a first gate oxide film in each of the first region and the second region by thermally oxidizing the semiconductor substrate;
- forming a protective film on the first gate oxide film;
- implanting fluorine into each of the first region and the second region through the protective film and the first gate oxide film;
- removing, after the implantation of the fluoride, the protective film from the first gate oxide film in the second region;
- removing the first gate oxide film from the second region;
- and
- forming a second gate oxide film in the second region by thermally oxidizing the semiconductor substrate in a state where the first gate oxide film is left in the first region and the first gate oxide film is removed from the second region, the second gate oxide film being different in thickness or type from the first gate oxide film.
Dependencies are inferred from the claim text.