MULTI-LEVEL NON-VOLATILE SEMICONDUCTOR MEMORY DEVICE

摘要

PROBLEM TO BE SOLVED: To improve writing, erasure and read characteristics in a non-volatile semiconductor memory device, employing an MOSFET in which floating gate electrodes are formed on the both sidewalls of the control gate electrode as a memory element. SOLUTION: A control gate electrode (122) is formed, so that one part thereof is extended upward from floating gate electrodes (124a and 124b) formed on the both sidewalls thereof, to cover the floating gate electrodes. Also source and drain regions (126a and 126b) are formed along the external boundaries of the floating gate electrodes (124a and 124b) so as to implant electric charges into two floating gate electrodes independently.