Effect of Film Thickness on the Thermo-Mechanical Behavior of Unpassivated Cu(Ag) Thin Films during Thermal Cycling

Abstract

The stress‐temperature and stress‐time behavior in electrochemically deposited Cu(1.5 at% Ag) was investigated by substrate curvature measurements. Film stress is separated into the average stress in the grain boundary and the average stress in the grain volume by assuming that grain boundary diffusion is the dominant stress relaxation mechanism. The athermal flow stress, the activation energy for grain boundary diffusion, and the elastic properties are discussed in dependence on film thickness.