Copper is a promising candidate to replace aluminum in ULSI metallization and providing better conductivity and reliability. ULSI metallization is conducted by electrodepositing copper from ethylenediamine complex baths using the additives glycine, ammonium sulfate, and a small quantity of 2, 2′-bipyridyl. This bath exhibited good throwing power, and filled trenches and contact holes on silicon wafers by copper deposits with good mechanical properties. As mentioned, application to ULSI metallization formed by electrodeposition of copper using ethylenediamine complex baths appears possible.
