Semiconductor device and manufacturing method therefor

A semiconductor device, comprising:

• a semiconductor substrate;
• a first gate electrode formed on a first active region of the semiconductor substrate with a first gate oxide film placed therebetween;
• a first diffusion layer formed generally at a position of the first gate electrode;
• a first gate electrode sidewall insulating film covering a sidewall of the first gate oxide film;
• a first silicon nitride film covering the first active region;
• a second gate electrode formed on a second active region of the semiconductor substrate through a second gate oxide film;
• a second diffusion layer formed generally at a position of the second gate electrode;
• and
• a second silicon nitride film covering the second region and having a stress different from a stress of the first silicon nitride film;
• wherein the first gate electrode and the second gate electrode are formed of metal gate electrodes at the same time.

A manufacturing method for a semiconductor device, comprising the steps of:

• forming a first active region in a semiconductor substrate;
• forming a first metal gate electrode on the first active region with a first gate insulating film placed therebetween;
• forming a first diffusion layer generally at a position of the first metal gate electrode;
• forming a first gate electrode sidewall insulating film on a sidewall of the first metal gate electrode;
• etching the first gate electrode sidewall insulating film;
• and
• forming a first silicon nitride film covering the first active region.