NONVOLATILE MEMORY DEVICE HAVING IMPROVED FLOATING GATE COUPLING RATIO AND ITS FABRICATING METHOD

摘要

PURPOSE: The device improves the coupling ratio of a floating gate and has an active region with flat surface to maintain the capacitance constantly between the floating gate and a channel. CONSTITUTION: The device is formed on a semiconductor substrate(100) in an active region and is formed continuously in one region, and comprises a gate insulation film(130a, 130b) having a different thickness in a center region and in an edge region of the active region. The gate insulation film in the edge region of the active region adjacent to a field oxide(120) is formed thickly to prevent tunneling and is formed so thick that tunneling can be occurred.