NON-VOLATILE SEMICONDUCTOR STORAGE DEVICE AND MANUFACTURING METHOD THEREOF

摘要

PROBLEM TO BE SOLVED: To provide a non-volatile semiconductor storage device with little variation in electric characteristics among memory cells. SOLUTION: A floating gate electrode 7 provided on a substrate 1 comprises two or more kinds of materials with different carrier capturing efficiencies. The carrier is accumulated at the floating gate electrode 7 for storing data to constitute a region with little variation of a threshold voltage. The part with little variation is used as a margin for circuit operation, for less variation among cells and faster operation.