NONVOLATILE SEMICONDUCTOR MEMORY DEVICE AND ITS OPERATING METHOD

摘要

PROBLEM TO BE SOLVED: To realize the action by which the threshold voltage of a memory device can be raised to the maximum with a voltage corresponding to a power-supply voltage. SOLUTION: A memory transistor 1 formed between a semiconductor substrate 2 and a gate electrode 6 and having a laminate film 5 with charge accumulating ability has different channel lengths Lmin which is estimated as the boundary for deciding whether a short-channel effect occurs or not in both writing-in and reading-out, and has the channel length L of a real device between the different channel lengths Lmin (R) and Lmin (W). COPYRIGHT: (C)2006,JPO&NCIPI