Effect of surface treatment on electromigration in aluminum films

Abstract

Surface treatment methods for educing aluminum electromigration are studied. Simple methods for reducing aluminum electromigration have been found. Oxygen-plasma treatment and a H/sub 2/O/sub 2/ dip after aluminum patterning are shown to improve conductor life with respect to electromigration. By the oxygen-plasma treatment, the mean times to failure is improved more than two time over that for the current method. This improvement of life is a function of the oxygen-plasma treatment time and is affected by aluminum annealing and the material used for passivation. By H/sub 2/O/sub 2/ dip treatment, the mean time to failure is improved more than three times over that obtained using the current method. This improvement of life depends on the aluminum area exposed to the H/sub 2/O/sub 2/ dip. The improvement of conductor life due to surface treatments can be explained by suppression of the aluminum surface and/or grain diffusivity due to oxidation of the aluminum surface.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>