Patent ID: 7247914
Filing Date: 2007-07-24
Classification: H01L

Abstract:
1. A semiconductor device, comprising: a first gate insulating film formed on a first nMOS transistor region in a semiconductor substrate and containing nitrogen; a second gate insulating film formed on a first pMOS transistor region in the semiconductor substrate and containing nitrogen; a third gate insulating film formed on a second nMOS transistor region in the semiconductor substrate and containing nitrogen; and a fourth gate insulating film formed on a second pMOS transistor region in the semiconductor substrate and containing nitrogen, wherein each of the third gate insulating film and the fourth gate insulating film has a thickness smaller than that of each of the first gate insulating film and the second gate insulating film, the first gate insulating film has a nitrogen concentration peak at the interface between the first gate insulating film and the semiconductor substrate, and each of the second, third and fourth gate insulating films has a nitrogen concentration peak only near an associated one of gate electrodes formed on the second, third and fourth gate insulating films, respectively.