Patent ID: 7768039
Filing Date: 2010-08-03
Classification: H01L

Abstract:
1. A semiconductor device comprising: a first field effect transistor having a first gate insulating film and a first gate electrode composed of polysilicon into which impurities have been introduced; and a second field effect transistor having a second gate insulating film and a second gate electrode composed of polysilicon into which impurities have been introduced, a gate width of said second field effect transistor being narrower than that of said first field effect transistor, a conduction type of the second field effect transistor coinciding with that of said first field effect transistor, and an impurity concentration in said second gate electrode is lower than the impurity concentration in said first gate electrode, wherein said first and second gate insulating films have same thickness each other, wherein the thickness of said first and second gate insulating films is between 0.8 nm and 1.5 nm, wherein a gate width of said first field effect transistor is equal to or greater than 0.5 μm, wherein a gate width of said second field effect transistor is equal to or less than 0.5 μm, and wherein said impurity concentration in said second gate electrode is 60% to 70% of said impurity concentration in said first gate electrode.