| 摘要 |
PURPOSE: To increase the surface area of an electrode without increasing the occupation area of a capacitor part by increasing a surface area after formation of a first polysilicon film of a large grain size and by making the surface of a second polysilicon film rough thereon. CONSTITUTION: A first polysilicon film 4 with a fixed grain size is formed on a semiconductor substrate 1, it is immersed in phosphoric acid solution and is separated to a plurality for forming a plurality of island-like first polysilicon films 5. A second polysilicon film 6 is formed on a plurality of island-like first polysilicon films 5, it is immersed in phosphoric acid solution for making a surface of the second polysilicon film 6 rough and a second polysilicon film 7 having an increased surface area is thereby formed. Thereby, it is possible to form a lower electrode of further increased surface area and to increase a surface area of an electrode, namely a capacitance value without increasing an occupation area of a capacitor of a semiconductor device. |
