Semiconductor device having STI without divot and its manufacture
AssigneeFujitsu Limited
InventorHiroyuki Ohta
Life of this patent
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Abstract
The method of manufacturing a semiconductor device has the steps of: etching a semiconductor substrate to form an isolation trench by using as a mask a pattern including a first silicon nitride film and having a window; depositing a second silicon nitride film covering an inner surface of the isolation trench; forming a first silicon oxide film burying the isolation trench; etching and removing the first silicon oxide film in an upper region of the isolation trench; etching and removing the exposed second silicon nitride film; chemical-mechanical-polishing the second silicon oxide film; and etching and removing the exposed first silicon nitride film.
Claims14
A method of manufacturing a semiconductor device, comprising the steps of:
- (a) forming a pattern on a surface of a semiconductor substrate, said pattern including a first silicon nitride film and having a window used for forming an isolation trench;
- (b) etching said semiconductor substrate by using said pattern as a mask, to form the isolation trench;
- (c) depositing a second silicon nitride film covering an inner surface of said isolation trench;
- (d) forming a first silicon oxide film covering said second silicon nitride film and burying said isolation trench;
- (f) etching said first silicon oxide film to remove said first silicon oxide film in an upper region of said isolation trench;
- (g) etching and removing exposed part of said second silicon nitride film;
- (h) forming a second silicon oxide film burying said isolation trench;
- (i) chemical-mechanical-polishing said second silicon oxide film by using said first silicon nitride film as a stopper;
- and
- (j) etching and removing said first silicon nitride film exposed.
Dependencies are inferred from the claim text.