NONVOLATILE SEMICONDUCTOR MEMORY DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a multiple value mask ROM which is difficult to receive the influence of short channel effect without using a special refinement technol ogy. SOLUTION: A source Shottky electrode 14 is formed on the region 4 of MOS FET which is the memory cell of a mask ROM and a drain Shottky electrode 15 is formed on the drain region 5. The multiple value condition is stored because the distances between the source region 4 and the gate electrode 3 is different.