| 摘要 |
PURPOSE:To enable to realize an easily and securely writable and erasable EEPROM even under a state of low voltage in an intensified field concentration by a method wherein an ion beam etching is performed on the surfaces of electrodes consisting of polycrystalline silicon, etc., and small protrusions, each having a small radius of curvature, are formed in large numbers. CONSTITUTION:A first polycrystalline silicon pattern 3 is formed on an insulating layer 2 formed on a semiconductor substrate 1. Ion beams 10 are irradiated on this first polycrystalline layer 3 and when a sputter etching is performed on the surface thereof, conic protrusions, whose vertical angles are respectively about 20 deg., are countlessly formed on the surface of the polycrystalline silicon layer 3. Then, an interlayer insulating layer 4 and a second polycrystalline silicon layer 5 are formed, and similarly, the ion beams 10 are irradiated and acute protrusions are formed on the second polycrystalline silicon layer 5 as well. After this, an interlayer insulating film 6 and a third polycrystalline silicon layer 7 are formed, and moreover, a phosphorus glass layer 8 and an Al electrode 9 are formed. As a result, the purposive EEPROM is completed. |
