Combined resistance and temperature change measurement for the study of electromigration

Abstract

A resistometric method has been developed to measure electromigration kinetic parameters under high current stress conditions in a short time. In this technique, the resistance R and the temperature increase ΔT of thin film stripes are measured simultaneously. A thin film thermocouple, which is formed adjacent to the thin film stripe, is used for temperature measurement. The resistance change due to electromigration, R EM, is calculated by using the following equation R EW = R − R 0 (1 + αΔT). ( R 0: initial resistance, α: temperature coefficient). In this manner one distinguishes between electromigration and the effect of joule heating. The activation energies derived from d R EM/d t vs T plots are 0.55 eV for pure Al and 0.82 eV for Al-2 wt% Cu. This. experiment can be done in a short period of time with no external heater needed, and thus allows for an easy evaluation of electromigration kinetic parameters.