| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for manufacturing a semiconductor device, wherein concentration of an electric field on the bottom end of a trench and thinning of an insulating film are hardly generated. SOLUTION: Residual polysilicon 9 is left on the bottom end 6 of the trench 2, a second sacrificial oxide film 10 is formed and eliminated, the bottom end 6 of the trench 2 is rounded, and then an oxide film 11 for a capacitor is formed, thereby preventing concentration of an electric field on the bottom end 6 of the trench and the thinning of the oxide film 11. |
