| 摘要 |
PURPOSE:To increase the surface area of stack-polysilicon and increase the cell capacity by etching back time specific part of the stacked polysilicon. CONSTITUTION:Phosphorus diffusion, etc., to stacked polysilicon 1 is performed after growing the stacked polysilicon 1 at the time of forming a capacity part. Then, polysilicon is etched in order to remove the contact of the polysilicon with the diffusion layer 9 using photoresist 11 as a mask and a part 12 shown by the dotted lines is removed. At that time, the bottom limit condition of the remaining silicon film is the condition that the polysilicon is not completely removed. Etch back is performed partially on the contact with the diffusion layer 9. The polysilicon 1 is etched in the prescribed shape using the photoresist 13 as a mask so as to remove an unnecessary part 14 and the electrode of the capacity part is formed. The stack polysilicon 1 is permitted to be thin on the contact with the diffused layer 9. At the contact, the surface area of the stacked polysilicon side wall is increased. |
