Structure-dependent behavior of stress-induced voiding in Cu interconnects
Document Type
Article
Publication Date
5-3-2010
Abstract
Stress modeling and cross-section failure analysis by focused-ion-beam have been used to investigate stress-induced voiding phenomena in Cu interconnects. The voiding mechanism and the effect of the interconnect structure on the stress migration have been studied. The results show that the most concentrated tensile stress appears and voids form at corners of vias on top surfaces of Cu M1 lines. A simple model of stress induced voiding in which vacancies arise due to the increase of the chemical potential under tensile stress and diffuse under the force of stress gradient along the main diffusing path indicates that stress gradient rather than stress itself determines the voiding rate. Cu interconnects with larger vias show less resistance to stress-induced voiding due to larger stress gradient at corners of vias. © 2009 Elsevier B.V. All rights reserved.
Publication Source (Journal or Book title)
Thin Solid Films
First Page
3778
Last Page
3781
Recommended Citation
Wu, Z., Yang, Y., Chai, C., Li, Y., Wang, J., Li, B., & Liu, J. (2010). Structure-dependent behavior of stress-induced voiding in Cu interconnects. Thin Solid Films, 518 (14), 3778-3781. https://doi.org/10.1016/j.tsf.2009.12.093