FLASH MEMORY CELL AND MANUFACTURE THEREOF

PROBLEM TO BE SOLVED: To provide a flash memory cell and its manufacturing method. SOLUTION: The first conductive film 103, with which the prescribed region of a semiconductor substrate 100 is exposed separately from a gate insulating film 102 and an element isolation film, is formed on the upper part of the semiconductor substrate 100, and a tunnel oxide film and the first interlayer insulating film are formed on the surface of the semiconductor substrate 100 exposed by the first conductive film 103 and on the surface of the first conductive film 103. A floating gate is formed by the second conductive film, which is extended to the upper part of the first conductive film 103 on the circumference of the tunnel oxide film, covering the tunnel oxide film, and the second interlayer insulating film 107 is formed on the surface of the floating gate. The third conductive film 109, which is electrically connected to the first conductive film 103, is formed on the second interlayer insulating film 107, and a gate electrode constituted by the first conductive film 103 and the third conductive film 109 is formed. Accordingly, as the area where the floating gate and the control gate are superposed can be maximized, the capacitive coupling coefficient of a flash memory cell can be increased.