Method for making a DRAM capacitor using a double layer of insitu doped polysilicon and undoped amorphous polysilicon with HSG polysilicon

摘要

A method of making a capacitor over a contact. The method comprises the steps of: (a) depositing an oxide layer over said contact; (b) forming a dual damascene opening in said oxide layer over said contact; (c) depositing a layer of insitu doped polysilicon over said dual damascene opening and said oxide layer; (d) depositing a layer of undoped amorphous polysilicon over said layer of insitu doped polysilicon; (e) removing said layer of undoped amorphous polysilicon and said layer of insitu doped polysilicon that is outside of said dual damascene opening; (f) removing said oxide layer to leave a dual damascene structure comprising insitu doped polysilicon and undoped amorphous polysilicon; (g) forming hemispherical grain (HSG) polysilicon on the surface of said dual damascene structure; (h) forming a dielectric layer over said dual damascene structure; and (i) forming a top electrode over said dielectric layer.