SEMICONDUCTOR MEMORY DEVICE AND FABRICATING METHOD THEREOF TO PREVENT REDUCTION OF LENGTH OF EFFECTIVE GATE DUE TO DIFFUSION OF IMPURITIES

摘要

PURPOSE: A semiconductor memory device and a fabricating method thereof are provided to prevent reduction of a length of an effective gate due to diffusion of impurities by insulating an impurity region and a gate electrode without forming a LOCOS region. CONSTITUTION: A semiconductor substrate(1) has a main surface. First and second impurity regions are respectively formed on the main surface of the semiconductor substrate. First and second insulating layers are formed on the first and second impurity regions, respectively, and deposited on the main surface so as to protrude above the main surface. An ONO(Oxide-Nitride-Oxide) layer(2,3,4) is formed between the first and second insulating layers. A gate electrode extends over the ONO layer and the first and second insulating layers.