Method to fabricate high reliable metal capacitor within copper back-end process

Abstract

A new method is provided for the creation of a high-reliability metal capacitor as part of back-end processing. A first layer of metal interconnect is created, ac contact point is provided in the surface of the first layer of interconnect aligned with which a capacitor is to be created. A copper interconnect is formed overlying the contact point using TaN for the bottom plate, a high dielectric-constant dielectric material capacitor and using TaN for the top plate. The deposited layers are patterned and etched, a spacer layer is formed over sidewalls of the capacitor to prevent capacitor sidewall leakage. Top interconnect metal is then formed by first depositing a layer of etch stop material for further interconnection of the capacitor and the semiconductor devices provided in the underlying substrate.