A novel Al-Sc (scandium) alloy for future LSI interconnection

Abstract

A new aluminum alloy, Al-Sc (scandium), has been studied in comparison with a conventional Al-Si-Cu alloy for future LSI interconnection. It has been found that Sc addition into Al completely suppressed a failure caused by a stress-induced migration phenomenon (SM) in submicron lines and hillock generation, while showing superior electromigration (EM) performance to conventional Cu addition. The new impurity, Sc, precipitates and presumably acts as a sink site for vacancies, which are the origin of the degradation in reliability by SM and EM.<>