Semiconductor device and method of manufacturing the same

A method of manufacturing a semiconductor device, the method comprising the steps of:

• forming a first insulating film on a semiconductor substrate;
• forming a charge storage layer on the first insulating film;
• forming an element isolation groove by processing the charge storage layer, the first insulating film, and the semiconductor substrate;
• embedding an element isolation insulating film into the element isolation groove and planarizing the element isolation insulating film;
• exposing a sidewall of the semiconductor substrate by etching back the semiconductor substrate in a formation region of a select gate transistor while the element isolation insulating film and the charge storage layer in a formation region of a memory cell transistor are masked;
• doping impurities into an upper surface portion of the semiconductor substrate in the formation region of the select gate transistor;
• forming an insulating film on the sidewall of the semiconductor substrate;
• forming a control gate electrode film on the insulating film;
• and
• processing a gate electrode of the select gate transistor and a gate electrode of the memory cell transistor.