SEMICONDUCTOR MEMORY DEVICE AND ITS MANUFACTURING METHOD

摘要

PROBLEM TO BE SOLVED: To enable a fine memory cell to be designed by eliminating mask shift (alignment shift) to a field oxide film. SOLUTION: The semiconductor memory device has a tapered field oxide film 31 formed on a semiconductor substrate, and a reversely tapered floating gate 32 which is formed between the tapered field oxide films 31 on a semiconductor substrate.