Semiconductor device and method of manufacturing the same
AssigneeNEC Corporation
InventorEiji Hasegawa
Life of this patent
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Abstract
To prevent a thick gate oxide film from being damaged by a cleaning and hydrofluoric-acid treatment preprocess performed prior to formation of a thin gate oxide film. A thick first gate oxide film is formed, and an insulating film, having etching resistance against the cleaning and hydrofluoric-acid treatment process for formation of thin second gate oxide film, is formed in an upper region of the first gate oxide film. A resist is then formed in a region where a thick gate insulating film is to be formed, and etching is performed on the first gate oxide film with the resist as a mask. The resist is stripped, then cleaning and hydrofluoric-acid treatment are performed on the silicon surface in a region where a thin gate insulating film is to be formed, and the thin second gate oxide film is formed.
Claims19
A method of manufacturing a semiconductor device, comprising:
- (a) forming a first film on a first region of a substrate;
- (b) forming a second film on a second region of said substrate, wherein said first film is substantially resistant to etching during removal of a natural oxide film from said second region before forming said second film;
- and
- (c) forming a third film, which is thinner than said second film, on a third region of said substrate, wherein said third film is substantially resistant to etching during removal of a second natural oxide film on said third region of said substrate before forming said third film.
A method of manufacturing a semiconductor device, comprising:
- forming a first film on a first region of a substrate, said first film comprising a first gate silicon oxide layer on said substrate and a cover layer on said first gate silicon oxide film;
- and
- forming a second film on a second region of said substrate after removing a natural oxide film on said second region by using a hydrofluoric-acid, wherein said cover layer is an oxinitride film performing as a mask for said first film during removing said natural oxide film.
A method of manufacturing a semiconductor device, comprising:
- forming a first film on a first region of a substrate, said first film comprising a first gate silicon oxide layer on said substrate and a cover layer on said first gate silicon oxide film:
- and
- forming a second film on a second region of said substrate after removing a natural oxide film on said second region by using a hydrofluoric-acid, wherein said cover layer is a silicon nitride layer which is disposed on said first gate silicon oxide layer and performs as a mask for said first film during removing said natural oxide film.
A method of manufacturing a semiconductor device, comprising:
- forming a first film on a first region of a substrate, said first film comprising a first gate silicon oxide layer on said substrate and a cover layer on said first gate silicon oxide film;
- and
- forming a second film on a second region of said substrate after removing a natural oxide film on said second region by using a hydrofluoric-acid, wherein said cover layer is one material selected from the group consisting of Al2O3, Ta2O5, TiO2, ZrO2, and HfO2 which is disposed on said first gate silicon oxide layer and performs as a mask for said first film during removing said natural oxide film.
Dependencies are inferred from the claim text.