Electromigration in electroplated gold micro contacts

Current densities in micro contacts are increasing. Therefore electromigration as failure mechanism becomes more important. In this paper, we discuss newly developed gold micro contact structures for electromigration tests. The structure is a free standing electroplated contact without bonding interface. The process flow as well as the experimental setup are described in detail. These novel structures are compared to so called dogbone structures. A simple model is derived to describe the void growth in the bump and the resistance curve. The model and the experimental results are compared.