Semiconductor device and method of manufacturing the same

A semiconductor device comprising:

• a semiconductor substrate having an upper surface;
• an element isolation insulating film isolating an element formation region of the semiconductor substrate, the element isolation insulating film having an upper surface;
• a plurality of memory cell transistors formed in the element formation region and provided with respective gate electrodes;
• and
• a stopper film for forming a contact, formed both on a sidewall of the gate electrode of each memory cell transistor and on the element isolation insulating film between the gate electrodes, wherein a level difference between the upper surface of the element isolation insulating film and the upper surface of the semiconductor substrate in the element isolation region is set so that a level difference between the gate electrodes is smaller than a level difference in the gate electrode, and wherein the surface of the semiconductor substrate in the drain contact formation region is located lower than the surface of the semiconductor substrate corresponding to the gate electrode.