Electromigration and coagulation in thin films of pure indium and pure tin

The time to failure due to de‐current passage in pure indium and pure tin films is studied. Two regions of failure behaviour can clearly be distinguished. In one region failure starts with melting followed by coagulation. In the other the time to failure is mainly determined by electromigration. The corresponding activation energies for electromigration in In and Sn appear to be quite different. This is discussed in terms of different behaviours of the effective charge.