Patent ID: 6399468
Filing Date: 2002-06-04
Classification: H01L

Abstract:
A method of manufacturing a semiconductor device, comprising the steps of:forming a second conductive type of well region by introducing impurities of a second conductive type in a first conductive type of semiconductor substrate; forming a low density first conductive type of impurities layer and a low density second conductive type of impurities layer at an interval by respectively implanting and diffusing impurities of a first conductive type and impurities of a second conductive type into/in the second conductive type of well region; forming an ion implanted layer by implanting impurities of a second conductive type from the low density second conductive type of impurities layer to a part of the low density first conductive type of impurities layer; selectively oxidizing a region on the substrate to form a local oxide film and forming a middle density second conductive type of impurities layer by diffusing the ion implanted layer; forming a gate insulating film in a region except the local oxide film and forming a gate electrode from the gate insulating film to the local oxide film; and forming a high density source region and a high density drain region by implanting impurities of a second conductive type using resist films respectively having an opening on a source formation region formed in the low density first conductive type of impurities layer and on a drain formation region formed in the low density second conductive type of impurities layer as a mask.