Semiconductor device and manufacturing method for the same
In a semiconductor substrate on which are formed an N-type MOS transistor and a P-type MOS transistor, the gate electrode of the N-type MOS transistor comprises a tungsten film, which makes contact with a gate insulation film, and the gate electrode of the P-type MOS transistor comprises a tungsten film, which makes contact with a gate insulation film, and the concentration of carbon contained in the former tungsten film is less than the concentration of carbon contained in the latter tungsten film.
1. A semiconductor device, comprising:
an N-type MOS transistor having a first gate electrode comprising a first conductor film, which comes in contact with a gate insulation film, at least a part of the first gate electrode is covered by an insulation film containing 1E21cm −3 or more of hydrogen; and
a P-type MOS transistor having a second gate electrode comprising a second conductor film, which comes in contact with the gate insulation film, and which contains carbon in a higher concentration than a concentration of carbon contained in the first conductor film, the P-type MOS transistor not being covered by the insulation film.
2. The semiconductor device according to claim 1 , wherein the work function of the second conductor film is not less than 4.8eV but less than 5.1eV.
3. The semiconductor device according to claim 2 , wherein the first conductor film and the second conductor film are made from the same metal material or the same alloy material.
4. The semiconductor device according to claim 1 , wherein the insulation film is a silicon nitride film.
5. The semiconductor device according to claim 1 , wherein the first gate electrode and the second gate electrode, respectively, comprise a polysilicon film having a metal silicide layer on the surface thereof, on the first conductor film and the second conductor film.
6. The semiconductor device according to claim 1 , wherein the insulation film is disposed on an interlayer insulation film formed to the same height as the first gate electrode and the second gate electrode, which are formed on a substrate.