SEMICONDUCTOR MEMORY DEVICE AND ITS MANUFACTURING METHOD

摘要

PROBLEM TO BE SOLVED: To reduce a memory element area by forming an erasing gate electrode to pull out charges onto an element separating insulation film. SOLUTION: A control gate electrode 3 is formed on a semiconductor substrate 1 through a first gate insulation film 6, and a first protection insulation film 7 is formed on the control gate electrode 3. A floating gate electrode 4 opposed to the control gate electrode 3 through a capacity insulation film 11 and opposed to a semiconductor substrate 1 through a second gate insulation film 10 is formed on one wall surface of a groove part 1a formed in the semiconductor substrate 1. An erasing gate electrode 5 insulated from the control gate electrode 3 by a first protection insulation film 7 and a second gate insulating film 10 and tunnel-coupled to the floating gate electrode 4 through a tunnel insulation film 12 is formed on the element separating insulation film 2.