TEMPERATURE-DEPENDENCE OF ELECTROMIGRATION THRESHOLD IN CU

Electromigration threshold, the product of current density, j, and the threshold length, l(th), was measured for unencapsulated thin-film Cu conductors using edge-displacement techniques. jl(th) was measured be tween 175 and 275 degrees C, and was found to be temperature dependent above 200 degrees C where jl(th) decreased with increasing temperatur e. It is suggested that the temperature dependence of the electromigra tion threshold may be obtained by considering the effects of the chang ing deformation mechanisms with changing temperature. (C) 1997 America n Institute of Physics.