Incubation, time-dependent drift and saturation during Al-Si-Cu electromigration: modelling and implications for design

Resistance data from Al-Si-Cu contact electromigration test structures clearly show three different stages: incubation, time-dependent drift and ultimately saturation. A detailed model describing all three stages was developed. By using this model, a length dependent lifetime can be calculated and data obtained from different test structures can be compared directly with each other. Moreover, it can be predicted that due to the length dependent saturation, lines below a certain length never reach the failure criterion. Taking this information into account during the design phase leads to very robust interconnects