| US 7,517,760 B2 | ||
| Semiconductor device manufacturing method including three gate insulating films | ||
| Hideyuki Arai, Toyama (Japan); Takashi Nakabayashi, Toyama (Japan); and Yasutoshi Okuno, Kyoto (Japan) | ||
| Assigned to Panasonic Corporation, Osaka (Japan) | ||
| Filed on Feb. 06, 2007, as Appl. No. 11/702,593. | ||
| Claims priority of application No. 2006-098247 (JP), filed on Mar. 31, 2006. | ||
| Prior Publication US 2007/0275529 A1, Nov. 29, 2007 | ||
| Int. Cl. H01L 21/8234 (2006.01); H01L 21/8236 (2006.01); H01L 21/336 (2006.01) | ||
| U.S. Cl. 438—275 [438/276; 438/289; 438/296; 257/E21.409] | 12 Claims |
| 1. A method for manufacturing a semiconductor device which includes: a first active region, a second active region, and a
third active region which are formed in a semiconductor substrate and are separated from one another by element isolation
regions; a first gate electrode formed on the first active region with a first gate insulating film interposed; a second gate
electrode formed on the second active region with a second gate insulating film thinner than the first gate insulating film
interposed; and a third gate electrode formed on the third active region with a third gate insulating film thinner than the
second gate insulating film interposed, the method comprising:
a step (a) of forming protective insulating films on the first active region, the second active region, and the third active
region;
a step (b) of removing the protective insulating films formed on the first active region and the third active region;
a step (c) of forming, after the step (b), an insulating film to be the first gate insulating film on each of the first active
region and the third active region;
a step (d) of removing, after the step (c), the protective insulating film formed on the second active region;
a step (e) of forming, after the step (d), an insulating film to be the second gate insulating film on the second active region;
a step (f) of removing, after the step (e), the insulating film to be the first gate insulating film formed on the third active
region; and
a step (g) of forming, after the step (f), an insulating film to be the third gate insulating film on the third active region.
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