Claims
- 1. A method of manufacturing a semiconductor device having an isolation structure using a field oxide film and an isolation structure using a shield gate electrode, comprising the steps of:forming field oxide films at a main surface of a semiconductor substrate by selective thermal oxidation; forming a first gate insulating film at the main surface of said substrate at portion where said field oxide films are not formed; patterning and forming a first conductor film to serve as a first gate electrode and a shield gate electrode on said first gate insulating film; removing said first gate insulating film in a region where said first conductor film is not formed to expose said substrate; forming a second gate insulating film on said substrate so exposed; and patterning and forming a second conductor film to serve as a second gate electrode on said second gate insulating film.
- 2. A method of manufacturing a semiconductor device according to claim 1, wherein said second gate insulating film is thinner than said first gate insulating film.
Priority Claims (2)
Number |
Date |
Country |
Kind |
07-188253 |
Jun 1995 |
JP |
|
07-262162 |
Sep 1995 |
JP |
|
Parent Case Info
This application is a divisional of application Ser. No. 09/725,714, filed Nov. 30, 2000 U.S. Pat. No. 6,482,692, which is a divisional of application Ser. No. 08/667,587, filed on Jun. 24, 1996, U.S. Pat. No. 6,201,275.
US Referenced Citations (12)
Foreign Referenced Citations (3)
Number |
Date |
Country |
56-70644 |
Jan 1981 |
JP |
63-305548 |
Dec 1988 |
JP |
61-75555 |
Jun 1994 |
JP |