Current-induced morphological evolution and reliability of Ag interconnects fabricated by a printing method based on nanoparticles

Abstract

Ag interconnects fabricated by a printing method were tested under accelerated temperature and current stressing to investigate their electrical reliability and morphological evolution. Under an accelerated current stressing condition, Ag metal atoms migrated in the direction of the electron wind force, resulting in simultaneous particle growth and increased resistance. The origin of the morphological change and resistance increase was considered to be the Joule heating at the necks between particles due to the current crowding effect. Joule heating at the necks of the connected particles accelerated the electromigration (EM) phenomenon, which generated abnormal particle growth in the Ag interconnects, which eventually resulted in failure during the reliability tests. The experimental results for Ag interconnects annealed under different conditions provide further evidence of the relation between electrical reliability and morphological change.