Patent ID: 6506646
Filing Date: 2003-01-14
Classification: H01L

Abstract:
A method of manufacturing a semiconductor device, comprising:forming a gate insulator film on a surface of a semiconductor substrate; forming a drain region near a top surface of the semiconductor substrate; forming a mask structure on the gate insulating film including an area covering the drain region, the mask structure including a stop film and further including a through hole exposing an area of the gate insulating film; forming side walls in the through hole, the side walls extending from the gate insulating film up to the stop film, but not extending to a top of the through hole; using the mask structure and the side walls as a mask, doping an impurity into a portion of the substrate beneath the through hole to form a source region; removing at least a portion of the exposed area of the gate insulating film; forming a tunnel insulator film where the portion of the exposed area of the gate insulating film was removed; and forming a gate structure above the gate insulating film.