| 摘要 |
PURPOSE: To increase the surface area of an electric charge storage electrode by forming a trench at the specific region of a field oxide film, forming the electric charge electrode that is long in vertical direction from the deep position of the trench to a high position, and forming the electric charge storage electrode that is extended to the part of the trench also in horizontal direction. CONSTITUTION: After a photosensitive film 27 is applied to the entire structure of a transistor, a trench 27* is formed at the specific region of a field oxide film 22. Then, after the photosensitive film 27 is eliminated, a nitride film 28 is formed after it is diffused to the inside of the trench 27* and to the specific region at the upper part of a gate electrode 24, an electric charge storage electrode 29 is formed. Then, a polysilicon film 31 located at the upper part of the oxide film is etched and a plurality of electric charge storage electrodes 31* with a rod-shaped end face vertical to the side wall of the trench part 27* are formed, thus increasing the surface area of the electric charge storage electrodes 29 and 31* and hence increasing a capacitor capacity. |
