Abstract: A MOSFET includes a semiconductor substrate of a first conductivity type including a field region and an active region; a gate insulating film on a portion of the active region, the gate insulating film having two edge parts and a mid-part, the two edge parts being thicker than the mid-part; a gate electrode on the gate insulating film; sidewall spacers on the sides of the gate electrode and the gate insulating film; heavily doped regions of a second conductivity type in the semiconductor substrate under the two edge parts of the gate insulating film; normally doped regions of the second conductivity type in the semiconductor substrate on both sides of the gate insulating film; lightly doped regions of the second conductivity type in the semiconductor substrate on the sides of the sidewall spacers; and doped regions of the first conductivity type below the normally doped region of the second conductivity type under the sidewall spacers.

Abstract: A MOSFET includes a semiconductor substrate of a first conductivity type including a field region and an active region; a gate insulating film on a portion of the active region, the gate insulating film having two edge parts and a mid-part, the two edge parts being thicker than the mid-part; a gate electrode on the gate insulating film; sidewall spacers on the sides of the gate electrode and the gate insulating film; heavily doped regions of a second conductivity type in the semiconductor substrate under the two edge parts of the gate insulating film; normally doped regions of the second conductivity type in the semiconductor substrate on both sides of the gate insulating film; lightly doped regions of the second conductivity type in the semiconductor substrate on the sides of the sidewall spacers; and doped regions of the first conductivity type below the normally doped region of the second conductivity type under the sidewall spacers.