| 摘要 |
PURPOSE:To improve the yield and reliability of a 1-transistor type memory cell while the capacitance of its capacitance part is increased. CONSTITUTION:A trench 1a is formed in the capacitance part of a 1-transistor type memory cell. A charge storing electrode 4 which has fine semi-spherical protrusions and recesses is formed on the side surfaces and the bottom of the trench 1a. The trench 1a is filled with a capacitance electrode 6 with a capacitance insulating film 5 provided on the surface of the electrode 4 therebetween. For instance, the charge storing electrode 4 is composed of a polycrystalline silicon film which has semi-spherical grains made to grow on its surface. Thus, by providing fine unevenness on the charge storing electrode 4, its surface area is increased, the capacitance of the memory cell is increased, the capacitance part composed of the trench, the electrodes, etc., can be formed easily and the yield and reliability can be improved. |
