Nonvolatile memory device and method of fabricating the same

A nonvolatile memory device includes a semiconductor substrate; a source region that is formed in the semiconductor substrate; a gate insulating film that is formed so as to partially overlap the source region on the semiconductor substrate; a floating gate that is formed on the gate insulating film so as to have a structure forming a uniform electric field in the portion that overlaps the source region; a control gate that is formed so as to be electrically isolated along one sidewall of the floating gate from an upper part of the floating gate, an inter-gate insulating film that is interposed between the floating gate and the control gate, and a drain region that is formed so as to be adjacent the other side of the control gate.