Semiconductor device and method for manufacturing the same
AssigneeMitsubishi Denki Kabushiki Kaisha
InventorsKiyoshi Mori, Akinobu Teramoto
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Abstract
Isolation regions 12 are formed on a silicon substrate 10 to isolate NMOS and PMOS regions in which to form NMOS and PMOS transistors respectively. A silicon oxide film 14 and an amorphous silicon film 16 are formed as a gate insulating film on the silicon substrate 10. N-type impurities are injected into the NMOS regions (FIG. 1A). A WSi film 22 is formed on the amorphous silicon film 16, and N-type impurities are injected only into the PMOS regions of the film 16 (FIG. 1C). A silicon oxide film 28 and a silicon nitride film 30 are formed on the WSi film 22 and then etched into gate electrodes (FIG. 1E).
Claims9
A method for manufacturing a semiconductor device including MOS transistors, said method comprising the steps of:
- forming an isolation region on a silicon substrate so as to isolate a plurality of MOS regions including an NMOS region and a PMOS region in which to form MOS transistors;
- forming a first insulating film as a gate insulating film on said silicon substrate;
- forming a silicon film on said first insulating film;
- injecting N-type impurities into said silicon film within said NMOS region;
- forming a tungsten silicide film on said silicon film;
- injecting P-type impurities into said tungsten silicide film within said PMOS region;
- forming a second insulating film on said tungsten silicide film;
- and
- patterning said first insulating film, said silicon film, said tungsten silicide film and said second insulating film into gate electrodes;
- wherein
- no P-type impurities are injected into said silicon film in said PMOS region, and no N-type impurities are injected into said tungsten silicide film in said NMOS region.
Dependencies are inferred from the claim text.