Electromigration Failure in Thin Film Silicides and Polysilicon/Silicide (Polycide) Structures

Thin film conductor stripes (150 nm thick), of silicides of tantalum and tungsten deposited on to thermal oxide as well as silicides deposited on to 150 nm of n-type polycrystalline silicon were stressed at high DC current densities (<106 A/cm2) untill open-circuit failure. All of the stripes failed by electromigration. The sign of the charge carrier in silicides of Ta and W, determined by failure location, was opposite to the published data determined from the Hall effect.