Non-volatile semiconductor memory device and manufacturing method therefor
AssigneeMitsubishi Denki Kabushiki Kaisha
InventorsJun Ohtani, Tsukasa Ooishi
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Abstract
A non-volatile semiconductor memory device of the present invention is provided with a semiconductor substrate having a main surface, an ONO film (a laminated film of an oxide film, a nitride film and an oxide film) formed on the main surface and having a charge storage part, a pair of buried diffusion bit lines formed in the semiconductor substrate located on both sides of the ONO film, oxide films deposited on the main surface so as to cover the buried diffusion bit lines, and a transfer gate electrode formed on the ONO film.
Claims10
A non-volatile semiconductor memory device comprising:
- a semiconductor substrate having a main surface;
- a first insulating film formed on said main surface and having a charge storage part;
- first and second impurity diffusion regions formed in said semiconductor substrate located on both sides of said first insulating film;
- second and third insulating films deposited on said main surface so as to cover said first and second impurity diffusion regions;
- and
- a gate electrode formed on said first insulating film.
A manufacturing method for a non-volatile semiconductor memory device, comprising the steps of:
- forming a first insulating film having a charge storage part on a main surface of a semiconductor substrate;
- selectively forming a mask film on said first insulating film, and patterning said first insulating film by using the mask film;
- implanting impurities into said semiconductor substrate by using said mask film and said patterned first insulating film as a mask, and forming first and second impurity diffusion regions;
- depositing a second insulating film over said main surface so as to cover said mask film and first and second impurity diffusion regions;
- reducing the thickness of said second insulating film from the upper surface of said second insulating film, and exposing said mask film and filling in said second insulating film between said patterned first insulating films;
- and
- forming a gate electrode on said first insulating film after removing said mask film.
A manufacturing method for a non-volatile semiconductor memory device, comprising the steps of:
- forming a first insulating film having a lamination structure formed of a first oxide film, a nitride film served as a charge storage part, and a second oxide film, on a main surface of a semiconductor substrate;
- selectively forming a mask film on said first insulating film, and patterning said first insulating film by using the mask film;
- implanting impurities into said semiconductor substrate by using said mask film and said patterned first insulating films as a mask, and thereby forming first and second impurity diffusion regions;
- removing said mask film;
- depositing a second insulating film over said main surface so as to cover said first and second impurity diffusion regions;
- reducing the thickness of said second insulating film from the upper surface of said second insulating film, and thereby exposing said nitride film and filling in said second insulating film between said patterned first insulating films;
- and
- forming a gate electrode on said first insulating film.
Dependencies are inferred from the claim text.