OPERATION SCHEME WITH CHARGE BALANCING FOR CHARGE TRAPPING NON-VOLATILE MEMORY

摘要

PROBLEM TO BE SOLVED: To provide a memory cell in which programming and erasing can be performed over many times and improved charge retention and reliability are specified. SOLUTION: A memory cell with a charge trapping structure has multiple bias mechanisms. Multiple cycles of applying the bias mechanisms while lowering and raising a threshold voltage of the memory cell leave a distribution of charges in the charge trapping layer. The charge interferes with the threshold voltage achievable in the memory cell. This distribution of charge is balanced by applying a charge balancing bias mechanism at intervals during which a plurality of programs and erase cycles occurs. Also, the charge balancing bias mechanism is applied prior to the beginning of program and erase cycles of the memory cell. COPYRIGHT: (C)2006,JPO&NCIPI