Semiconductor device and manufacturing method thereof
View Patent ↗A technique capable of reducing threshold voltage and reducing high-temperature heat treatment after forming a gate electrode is provided. An n-type MIS transistor or a p-type MIS transistor is formed on an active region isolated by an element isolation region of a semiconductor substrate. In the n-type MIS transistor, a gate electrode is formed through a gate insulating film, and the gate electrode is composed of a hafnium silicide film. On the other hand, in the p-type MIS transistor, a gate electrode is formed through a gate insulating film, and the gate electrode is composed of a platinum silicide film. Also, the gate electrodes are formed after the activation annealing (heat treatment) for activating impurities implanted into a source region and a drain region.
1. A semiconductor device, comprising a CMIS transistor which includes:
a p-type MIS transistor including
(a1) a first gate insulating film formed over a semiconductor substrate,
(a2) a first gate electrode formed over said first gate insulating film, and
(a3) a first source region and a first drain region formed in said semiconductor substrate; and
an n-type MIS transistor including
(b1) a second gate insulating film formed over said semiconductor substrate,
(b2) a second gate electrode formed over said second gate insulating film, and
(b3) a second source region and a second drain region formed in said semiconductor substrate,
wherein said first gate electrode includes a first metal silicide film, and said first metal silicide film is also formed over said first source region, said first drain region, said second source region, and said second drain region,
wherein said second gate electrode includes a second metal silicide film which is different from said first metal silicide film,
wherein said first metal silicide film has a work function approximate to the valence band of silicon,
wherein said second metal silicide film has a work function approximate to the conduction band of silicon, and
wherein said first metal silicide film has a sheet resistance smaller than a sheet resistance of said second metal silicide film.
2. A semiconductor device according to claim 1 ,
wherein said first metal silicide film is a platinum silicide film.
3. A semiconductor device according to claim 2 ,
wherein said second metal silicide film is a hafnium silicide film.
4. A semiconductor device according to claim 3 ,
wherein said first and second gate insulating films have a dielectric constant higher than that of silicon oxide film.
5. A semiconductor device according to claim 4 ,
wherein said first and second gate insulating films are formed of hafnium oxide, aluminum oxide, hafnium aluminate, zirconium oxide or La 2 O 3 .
6. A semiconductor device according to claim 1 ,
wherein said first source region and said first drain region have a first p-type impurity region and a second p-type impurity region, respectively, said second p-type impurity region having a higher impurity concentration than said first p-type impurity region,
wherein said second source region and said second drain region have a first n-type impurity region and a second n-type impurity region, respectively, said second n-type impurity region having a higher impurity concentration than said first n-type impurity region, and
wherein said first metal silicide films are formed over said second p-type impurity region and said second n-type impurity region, respectively.
7. A semiconductor device according to claim 6 ,
wherein said first metal silicide film is a platinum silicide film.
8. A semiconductor device according to claim 7 ,
wherein said second metal silicide film is a hafnium silicide film.
9. A semiconductor device according to claim 8 ,
wherein said first and second gate insulating films have a dielectric constant higher than that of silicon oxide film.
10. A semiconductor device according to claim 6 ,
wherein said second metal silicide film is a hafnium silicide film.
11. A semiconductor device according to claim 6 ,
wherein said first and second gate insulating films have a dielectric constant higher than that of silicon oxide film.
12. A semiconductor device according to claim 1 ,
wherein said second metal silicide film is a hafnium silicide film.
13. A semiconductor device according to claim 1 ,
wherein said first and second gate insulating films have a dielectric constant higher than that of silicon oxide film.
14. A semiconductor device according to claim 1 ,
wherein said first and second gate insulating films are formed of hafnium oxide, aluminum oxide, hafnium aluminate, zirconium oxide or La 2 O 3 .