Al-interconnect/Cu-plug structure for FeRAM multilevel interconnect

An Al-interconnect/Cu-plug structure, whereby a plug is filled by electrochemical deposition (ECD) for FeRAM interconnection, has been developed. Conventionally sputtered Al for current FeRAM devices cannot fill high aspect ratio plugs. A high aspect ratio plug can successfully be filled by ECD Cu and PZT degradation with this structure is much less than that with an Al-interconnect/W-plug structure, which has been widely adopted for DRAM and logic devices.