New metallized side wall inactivation technology for ultra-fine micrometer ic applications

摘要

A method is provided for forming metal interconnect structures which resists the formation of pile-ups caused by electromigration. Each metal interconnect structure includes an aluminum interconnect sandwiched between two refractory metal layers. The method of the present invention involves forming a layer of aluminum intermetallic alloy on the sidewalls of the aluminum interconnects. The layer of aluminum intermetallic alloy provides reinforcement for the sidewalls. The layer of aluminum intermetallic alloy comprises aluminum-refractory metal alloy. The aluminum-refractory metal alloy is formed by reacting the exposed aluminum on the sidewalls with refractory metal-containing precursor material. After the formation of the layer of aluminum intermetallic alloy the sidewalls of the aluminum interconnects, the formation of pile-ups will be suppressed. Thus, the lifetime of the aluminum interconnects is extended. Accordingly, the method of the present invention improves the reliability and wear resistance of integrated circuits employing aluminum interconnects.