| 摘要 |
PROBLEM TO BE SOLVED: To increase the capacitor capacitance by depositing an impurity on a rough-surface polysilicon and heat treating it to accelerate diffusion of the impurity in the polysilicon to thereby increase the surface area of a conductive film growing thereon. SOLUTION: In a conductive part 12 forming step, this part 12 can be formed by a lower layer polysilicon contg. an impurity. On a substrate 11 having a thin oxide film, the lower layer polysilicon for the part 12 is formed e.g. by the low pressure CVD method. To make this polysilicon conductive, an impurity e.g. As is implanted by the ion implanting method and it is heat treated. After forming the part 12, at a pre-treating step, this part is cleaned. In a capacitor forming step, a lower electrode 13, dielectric 14 and upper electrode 15 of a capacitor are formed like a laminate on the conductive part 12. |
