Patent ID: 7646067
Filing Date: 2010-01-12
Classification: H01L,Y10S

Abstract:
1. A complementary metal-oxide-semiconductor transistor, comprising: a semiconductor substrate including a first region and a second region; an n-typed metal-oxide-semiconductor transistor formed at the first region of the semiconductor substrate, the n-typed metal-oxide-semiconductor transistor including a first source/drain pair, a first channel region and a first gate pattern, the first source/drain pair being formed at a surface of the semiconductor substrate and doped with n-typed impurities, the first channel region being formed at a surface portion of the semiconductor substrate located between a source and a drain of the first source/drain pair, the first gate pattern being formed on the first channel region and including a first gate insulating layer, a first gate conductive layer and a second gate conductive layer, the first gate conductive layer including a metal having a nitrogen concentration increasing in a direction from a lower portion toward an upper portion, the metal having a work function of about 4.0 eV to about 4.3 eV, and the second gate conductive layer including a material having an electrical resistance lower than that of the first gate conductive layer; and a p-typed metal-oxide-semiconductor transistor formed at the second region of the semiconductor substrate, the p-typed metal-oxide-semiconductor transistor including a second source/drain pair, a second channel region and a second gate pattern, the second source/drain pair being formed at a surface of the semiconductor substrate and doped with n-typed impurities, the second channel region being formed at a surface portion of the semiconductor substrate located between a source and a drain of the second source/drain pair, the second gate pattern being formed on the second channel region and including a second gate insulating layer, a third gate conductive layer and a fourth gate conductive layer, the third gate conductive layer including a metal having a nitrogen concentration increasing in a direction from a lower portion toward an upper portion, the metal having a work function of about 4.7 eV to about 5.0 eV, and the fourth gate conductive layer including a material having an electrical resistance lower than that of the third gate conductive layer, wherein: the first gate conductive layer has a double-layered structure including a lower first gate conductive layer formed on the first gate insulating layer and an upper first gate conductive layer formed on the lower first gate conductive layer, the lower first gate conductive layer being formed using a metal that does not include nitrogen, the upper first gate conductive layer being formed using a metal that includes nitrogen, and the third gate conductive layer has a double-layered structure including a lower third gate conductive layer formed on the second gate insulating layer and an upper third gate conductive layer formed on the lower second gate conductive layer, the lower third gate conductive layer being formed using a metal that does not include nitrogen, the upper third gate conductive layer being formed using a metal that includes nitrogen.