Semiconductor device and method for manufacturing the same

A method for manufacturing a semiconductor device, comprising:

• forming a first semiconductor layer having strain above a substrate;
• forming a second semiconductor layer on the first semiconductor layer, the second semiconductor layer controlling the strain of the first semiconductor layer;
• patterning the second semiconductor layer and the first semiconductor layer into mesa shapes, and dividing the second semiconductor layer having the mesa shape into first and second semiconductor regions isolated from each other through patterning;
• forming a gate insulating film on a portion of the first semiconductor layer, the portion being located between the first semiconductor region and the second semiconductor region;
• forming a gate electrode on the gate insulating film;
• and
• forming a source region and a drain region by introducing impurities into at least the first and second semiconductor regions.

A method for manufacturing a semiconductor device, comprising:

• forming a first semiconductor layer having strain above a substrate;
• forming a protection film selectively on a region of the first semiconductor layer, a gate being to be formed on the region;
• forming a second semiconductor layer on first portions of the first semiconductor layer, the first portions being other than the region on which the protection film is formed, the second semiconductor layer controlling the strain of the first semiconductor layer;
• patterning the protection film, the second semiconductor layer, and the first semiconductor layer into mesa shapes, and removing the protection film;
• forming a gate insulating film on a second portion of the first semiconductor layer, the protection film having been removed from the second portion of the first semiconductor layer;
• forming a gate electrode on the gate insulating film;
• and
• forming a source region and a drain region by introducing impurities into at least the second semiconductor layer.