Nonvolatile semiconductor memory device

摘要

Disclosed is a nonvolatile semiconductor memory device in which a disturbance phenomenon can be prevented. A nonvolatile semiconductor memory device has a semiconductor substrate, and a floating gate electrode formed on the semiconductor substrate via a gate insulating film. The floating gate electrode includes a lower conductive layer formed on the gate insulating film and having a first width W1 in a channel width direction, and an upper conductive layer formed on the lower conductive layer and having a second width W2 wider than the first width W1 in the channel width direction.