Method of forming a robust, modular MIS (metal-insulator-semiconductor) capacitor with improved capacitance density

摘要

A method of forming a capacitor structure comprises: forming a doped polysilicon layer on an underlying dielectric layer; forming a dielectric stack on the doped polysilicon layer; forming a contact hole in the dielectric stack to expose a surface region of the doped polysilicon layer; forming a conductive contact plug that fills the contact hole and is in contact with the exposed surface of the doped polysilicon layer; forming a plurality of trenches in the dielectric stack such that each trench exposes a corresponding surface region of the doped polysilicon layer; forming a conductive bottom capacitor plate on exposed surfaces of the of the dielectric stack and on exposed surfaces of the doped polysilicon layer; forming a capacitor dielectric layer on the bottom capacitor plate; and forming a conductive top capacitor plate on the capacitor dielectric layer.