ELECTROMIGRATION STUDIES OF Al-INTERMETALLIC STRUCTURES.

Abstract

The use of an intermetallic layer in Al conductor lines has been reported to improve the electromigration lifetime. This paper summarizes the results of a metallurgical study of the electromigration behavior of the intermetallic structure. The investigation focused on three fundamental characteristics: the mass transport under a direct current, the microstructure and the distribution of the current density. The improvement in the electromigration lifetime is attributed primarily to improved microstructure of the conductor line and the redundant barrier function of the intermetallic layer.