Patent ID: 8912062

Claim:
A method of manufacturing a semiconductor storage device comprising: forming a select gate electrode on a channel region of a substrate via a gate insulating film; forming a gate-isolation insulating film on a surface of a substrate inclusive of the select gate electrode; after a silicon layer is formed on the surface of the gate-isolation insulating film, forming sidewall-shaped first and second control gate electrodes by etching back the silicon layer; forming first and second impurity regions on both sides of a channel region of the substrate in self-aligning fashion; and exposing surfaces of the select gate electrode and first and second impurity regions by removing the gate-isolation insulating film on the select gate electrode and first and second impurity regions; wherein at said forming the first and second impurity regions, the second impurity regions are formed in such a manner that second impurity regions adjacent along the column direction are joined together; and at said forming the select gate electrode, the select gate electrode is formed into a ring shape so as to surround an area in which the second impurity regions are formed.