Aluminum–samarium alloy for interconnections in integrated circuits

Abstract

Thin films of aluminum alloyed with copper, silicon, or titanium have been conventionally used as interconnection materials in integrated circuits to reduce hillock growth, electromigration, and junction spiking. The interconnection resistivity of these homogeneous alloys is, however, too high for maximum performance integrated circuits. In this work, hillock growth, resistivity, and stress were investigated for aluminum alloyed with samarium (Al-1 wt. % Sm) as an alternative interconnection material. The results indicated that Al–Sm metallization exhibits very favorable properties, namely, low resistivity and good thermal stability including hillock growth resistance, for potential integrated circuit applications. Other property measurements and process and material compatibility studies are, however, desired prior to its application.