Electromigration in gold and copper thin film conductors

The electromigration behavior of gold thin film conductors with molybdenum, niobium, hafnium and zirconium adhesion layers and of copper thin film conductors with chromium and niobium adhesion layers was investigated under various fabrication and testing conditions. Niobium increases the electromigration lifetime of gold conductors by more than an order of magnitude, while hafnium and zirconium also improve it but by lesser amounts. Sputter-deposited gold conductors appear to be superior to vapor-deposited gold conductors. Pulse powering also increases the electromigration lifetime. In copper conductors chromium adhesion layers do not affect the electromigration lifetime, while niobium adhesion layers appear to reduce it. © 1980, All rights reserved.