Modeling and microstructural characterization of incubation, time-dependent drift and saturation during electromigration in Al-Si-Cu stripes

Resistance data of passivated Al-Si-Cu contact electromigration test struct ures clearly show three different stages: incubation, time-dependent drift and ultimately saturation. A detailed model describing all three stages was developed and evidenced by a thorough analysis of the tested material. By using this model, a length dependent lifetime can be calculated and data ob tained from different test structures can be compared directly with each ot her. Moreover, it can be predicted that due to the length dependent saturat ion, lines below a certain length will never reach the failure criterion! T aking this information into account during the design phase leads to very r obust interconnects. (C) 1999 Elsevier Science Ltd. All rights reserved.