Semiconductor device and method of manufacturing the same

A semiconductor device comprising:

• a semiconductor substrate having isolation regions;
• a p-type MIS transistor comprising a pair of source/drain regions formed in the semiconductor substrate, a gate insulating film formed on the semiconductor substrate, and a gate electrode formed on the gate insulating film and having a carbide layer of a first metal at least at the gate electrode/gate insulating film interface;
• and
• an n-type MIS transistor comprising a pair of source/drain regions formed in the semiconductor substrate, a gate insulating film formed on the semiconductor substrate, and a gate electrode formed on the gate insulating film and having a boride layer of the first metal at least at the gate electrode/gate insulating film.

A method of manufacturing a semiconductor device, comprising:

• forming an insulating film on a semiconductor substrate having a p-type impurity region and an n-type impurity region which are isolated from each other;
• forming a metal layer on the insulating film;
• forming a boron source film selectively on the metal layer located in the p-type impurity region;
• heat-treating the semiconductor substrate having the boron source film to change all the metal layer to metal boride film thereof to selectively form a metal boride film in the p-type impurity region;
• forming a gate electrode of an n-type MIS transistor in the p-type impurity region by selectively removing the metal boride film;
• forming a gate electrode of a p-type MIS transistor in the n-type impurity region by selectively removing the metal film;
• and
• forming sidewall insulating films on a sidewall of gate electrode of the n-type MIS transistor and a sidewall of gate electrode of the p-type MIS transistor.

A method of manufacturing a semiconductor device, comprising:

• forming an insulating film on a semiconductor substrate having a p-type impurity region and an n-type impurity region which are isolated from each other;
• forming a metal boride layer on the insulating film;
• forming a boron absorption film selectively on the metal boride film located in the n-type impurity region;
• heat-treating the semiconductor substrate having the boron absorption film formed thereon to diffuse boron from the metal boride film in the n-type impurity region to selectively form a metal layer contacted with the insulating film;
• forming a gate electrode of an n-type MIS transistor in the p-type impurity region by selectively removing the metal boride film;
• forming a gate electrode of a p-type MIS transistor in the n-type impurity region by selectively removing the metal film;
• and
• forming sidewall insulating films on a sidewall of gate electrode of the n-type MIS transistor and a sidewall of gate electrode of the p-type MIS transistor.

A method of manufacturing a semiconductor device, comprising:

• forming an insulating film on a semiconductor substrate having a p-type impurity region and an n-type impurity region which are isolated from each other;
• forming a metal layer on the insulating film;
• ion-implanting boron selectively into the metal layer located in the p-type impurity region to form a metal boride film;
• forming a gate electrode of an n-type MIS transistor in the p-type impurity region by selectively removing the metal boride film;
• forming a gate electrode of a p-type MIS transistor in the n-type impurity region by selectively removing the metal film;
• and
• forming sidewall insulating films on a sidewall of gate electrode of the n-type MIS transistor and a sidewall of gate electrode of the p-type MIS transistor.

A method of manufacturing a semiconductor device, comprising:

• forming an insulating film on a semiconductor substrate having a p-type impurity region and an n-type impurity region which are isolated from each other;
• selectively forming a boron layer through adsorption of boron on the insulating film which is located in the p-type impurity region;
• forming a metal layer on the boron film and on the insulating film;
• heat-treating the semiconductor substrate having the metal layer formed thereon to diffuse boron from the boron film into the metal layer to selectively form a metal boride film in the p-type impurity region, the metal boride film being contacted with the insulating film;
• forming a gate electrode of an n-type MIS transistor in the p-type impurity region by selectively removing the metal boride film;
• forming a gate electrode of a p-type MIS transistor in the n-type impurity region by selectively removing the metal film;
• and
• forming sidewall insulating films on a sidewall of gate electrode of the n-type MIS transistor and a sidewall of gate electrode of the p-type MIS transistor.