Method of forming inside rough and outside smooth hsg electrodes and capacitor structure

Abstract

A container capacitor and method of forming the container capacitor are provided. The container capacitor comprises a lower electrode fabricated by forming a layer of doped polysilicon within a container in an insulative layer disposed on a substrate; forming a barrier layer over the polysilicon layer within the container; removing the insulative layer to expose the polysilicon layer outside the container; nitridizing the exposed polysilicon layer at a low temperature, preferably by remote plasma nitridation; removing the barrier layer to expose the inner surface of the polysilicon layer within the container; and forming HSG polysilicon over the inner surface of the polysilicon layer. The capacitor can be completed by forming a dielectric layer over the lower electrode, and an upper electrode over the dielectric layer. The cup-shaped bottom electrode formed within the container defines an interior surface comprising HSG polysilicon, and an exterior surface comprising smooth polysilicon.