Electromigration damage in aluminum film conductors

Abstract

Electromigration studies of large- and fine-grain aluminum films showed that fine-grain films were characterized by a mixed orientation and a grain size of ≈2 μ, and that large-grain films had a highly preferred 98% 〈111〉 orientation and a grain size of ≈8 μ. Stripes fabricated from the large-grained films had a consistently longer life, higher activation energy, and lower standard deviation of the life distribution than stripes fabricated from fine-grained films. These results are interpreted in terms of the nature of flux divergences in the two films. Calculations give the magnitude of vacancy supersaturations at various structural divergences present in the films studied. © 1970 The American Institute of Physics.