| 摘要 |
PURPOSE:To obtain a sufficiently large capacity in spite of small occupied area by forming a rectangular unevenness part on the surface of an electrode constituting a capacitor, and increasing the surface area. CONSTITUTION:A semiconductor substrate 9 is oxidized, and a first gate oxide film 1 is formed; first polysilicon is grown, and a word line 2 is formed; by using the word line 2 as a mask, impurity ion is implanted, and a diffusion layer 8 is formed; after an interlayer film 3 is formed, second polysilicon 5 is grown; a rectangular patterning is performed, and dry etching is performed; thus a recessed part is formed and unevenness is imparted to the second polysilicon 5. After that, by oxidizing the polysilicon, a capacitor oxide film 4 is formed, and third polysilicon 6 is arranged thereon: thereby forming a memory capacitor. By the effect of the above unevenness, the surface area of the capacitor is increased, and a large capacity is obtained in spite of small occupied area. |
