Electromigration reliability and activation energy of Bi₂Te₃ thermoelectric film

Reliability problems caused by metal electromigration failure have attracted much attention, but it is barely investigated for thermoelectric semiconductors with increased current density in micro thermoelectric devices. Herein, we investigate electromigration reliability of a Bi₂Te₃ thermoelectric film with the current densities of ∼10⁴ A/cm². The failure mechanism and thermoelectric performance change of the Bi₂Te₃ film at different current densities by controlling the temperature are discussed, indicating the reliability issue is a comprehensive problem involving multiphysics effects. In addition, the activation energy of Bi₂Te₃ materials, as an essential electromigration parameter, is measured and calculated to be about 0.8 eV by the resistance change method. This work provides much guidance to the reliable service of thin-film TE devices operating under high current density.