SEMICONDUCTOR MEMORY AND ITS FABRICATING METHOD

摘要

PROBLEM TO BE SOLVED: To enhance the reliability of a memory by preventing a tunnel film from becoming thin due to a level difference step. SOLUTION: A control gate electrode 14 is formed selectively on a semiconductor substrate 11 through a first insulation film 13 and a floating gate electrode 16 is formed on one side face of the control gate electrode 14 through a second insulation film 15. The semiconductor substrate 11 has a level difference region 11c connecting a first major surface 11a and a second major surface while being covered with the floating gate electrode 16 wherein the level difference region 11c comprises a first level difference step 111 for connection with the first major surface 11a and a second level difference step 112 for connecting the first level difference step 111 with the second major surface 11b.