SEMICONDUCTOR STORAGE DEVICE AND ITS MANUFACTURING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a semiconductor storage device which can contrive capacity enlargement and voltage lowering. SOLUTION: A tunnel insulating film is made on the region of one part of the surface of a semiconductor substrate. A floating gate electrode is made on the tunnel insulating film. The flank of the floating gate electrode and the surface of the semiconductor substrate on both sides of the floating gate electrode are covered with a gate insulating film. A first control gate electrode is arranged through a gate insulating film on the flank of the floating gate electrode and the surface of the semiconductor substrate on both sides of the floating gate electrode. A pair of impurity added regions are made on the surface layer of the semiconductor substrate on both sides of the gate structure including the floating gate electrode and the first control gate electrode.