Semiconductor device and method for manufacturing the same

A semiconductor device comprising an N-type transistor and a P-type transistor,

• wherein the N-type transistor comprises:
• a first gate insulating film comprising a high dielectric film on a semiconductor substrate;
• and
• a first gate electrode comprising a TaxNy comprising Ta3N5 film on the first gate insulating film;
• wherein the first gate insulating film comprises a first material decreasing an effective work function of the first gate electrode,
• the P-type transistor comprises:
• a SiGe film on the semiconductor substrate;
• a second gate insulating film comprising the high dielectric film on the SiGe film;
• and
• a second gate electrode on the second gate insulating film;
• wherein the second gate electrode comprises:
• a first conducting film made of TaxNy on the second gate insulating film;
• a second insulating film on the first conducting film, the second insulating film being made of a second material increasing an effective work function of the second gate electrode;
• a third conducting film on the second insulating film, the third conducting film being made of a material identical to a material of the first conducting film;
• a fourth insulating film on the third conducting film, the fourth insulating film being made of the first material;
• and
• a fifth conducting film on the fourth insulating film, the fifth conducting film being made of a material identical to the material of the first conducting film.

A method for manufacturing a semiconductor device comprising:

• forming a P-type diffusion layer on a place for forming an N-type transistor and forming an N-type diffusion layer on a place for forming a P-type transistor in a semiconductor substrate;
• forming a SiGe film on the N-type diffusion layer;
• forming a first insulating film on the P-type diffusion layer and on the SiGe film;
• forming a second insulating film on the first insulating film on the P-type diffusion layer and forming a third insulating film on the first insulating film above the N-type diffusion layer;
• forming a fourth insulating film on the second and the third insulating films, or between the first and the second insulting films and between the first and the third insulating films, the fourth insulating film being a high dielectric film;
• forming a fifth conducting film on the fourth insulating film, or on the second and the third insulating films, the fifth insulating film being made of TaxNy comprising Ta3N5;
• and
• forming gate insulating films of the N-type and P-type transistors by removing a part of the first to fourth insulating films, and forming gate electrodes of the N-type and P-type transistors by removing a part of the fifth conducting film;
• wherein the second insulating film in the gate insulating film of the N-type transistor comprises a first material decreasing an effective work function of the gate electrode of the N-type transistor, and
• the third insulating film in the gate insulating film of the P-type transistor comprises a second material increasing an effective work function of the gate electrode of the P-type transistor.