PROGRAMMING METHOD OF FLASH MEMORY CELL

摘要

PROBLEM TO BE SOLVED: To provide a programming method which is capable of not only improving a split-gate flash memory cell in programming efficiency and characteristics, but also easily making it low in power consumption without changing it in structure. SOLUTION: A depletion region 30 formed in a source region is expanded downwards from the surface of a silicon substrate to generate minority carrier at a trapping center located in the expanded depletion region, and the generated minority carriers become hot electrons as receiving energy from a high-electric field region formed between a select gate 19 and a floating gate 15 on the silicon substrate by a voltage applied to a drain region 13. Furthermore, hot electrons are injected into a floating gate by a vertical electric field formed by a high voltage applied to the control gate 17.