Asymmetric MIM capacitor for DRAM devices

摘要

A bilayer second electrode for a MIM DRAM capacitor is formed wherein the layer of the electrode that is in contact with the dielectric layer (i.e. bottom layer) has a composition that is resistant to oxidation during subsequent anneal steps and have rutile templating capability. Examples include SnO2 and RuO2. The capacitor stack including the bottom layer is subjected to a PMA treatment to reduce the oxygen vacancies in the dielectric layer and reduce the interface states at the dielectric/second electrode interface. The other component of the bilayer (i.e. top layer) is a high work function, high conductivity metal or conductive metal compound.