Patent ID: 8916431

Claim:
A method of manufacturing a semiconductor device comprising: forming a first impurity layer of a first conductivity type in a first region of a semiconductor substrate; forming a second impurity layer of a second conductivity type in a second region of the semiconductor substrate; epitaxially growing a semiconductor layer above the semiconductor substrate with the first impurity layer and the second impurity layer formed in; forming above the semiconductor layer a mask covering the first region and exposing the second region; removing a part of the semiconductor layer by using the mask to thin a thickness of the semiconductor layer in the second region; removing the mask; forming a first gate insulating film above the semiconductor layer in the first region and a second gate insulating film of a film thickness equal to a film thickness of the first gate insulating film above the semiconductor layer in the second region; and forming a first gate electrode and a second gate electrode respectively above the first gate insulating film and above the second gate insulating film.