ERASE METHOD OF NON-VOLATILE SEMICONDUCTOR MEMORY

摘要

PURPOSE: An erase method of a non-volatile semiconductor memory is provided to improve a tolerance characteristic by controlling deterioration of a tunnel oxide layer in each memory cell, and to shorten overall erase time by obviating the necessity of an erase program regarding a word line not having a memory cell to erase. CONSTITUTION: A scanning process is performed regarding each word line to determine whether a memory cell to erase is in the word line. If the memory cell to erase is not in the word line, an erase process is not performed regarding the memory cells in the word line. If the memory cell to erase is in the word line, memory cells in an erase state out of every memory cell in the word line are programmed. Every memory cell in the word line including the memory cell to erase is erased.