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Defect and Microstructural Evolution in Thermally Cycled Cu Through-Silicon Vias



Chukwudi A. Okoro, James Marro, Yaw S. Obeng, Kathleen Richardson


In this study, the effect of thermal cycling on defect generation, microstructure, and the RF signal integrity of blind Cu through-silicon via (TSV) were investigated. Three different thermal cycling profiles were used; each differentiated by their peak cycling temperature (100°C, 150°C, 200 °C) and the time needed to complete one cycle (cycle time). The study was performed on two Cu-TSV wafer sample types; one containing large processing-induced voids (voided sample), the other without (non-voided sample). It was found that the RF signal return loss |S11| of the Cu-TSVs degraded upon thermal cycling for both the voided and the non-voided sample types. This was attributed to the increase in the void area due to the formation of new voids, rather than the growth of pre-existing voids. On the other hand, the grain orientation and grain sizes of the Cu-TSVs were found to be unaffected by all studied thermal cycling conditions and sample types.
Microelectronics Reliability


Okoro, C. , Marro, J. , Obeng, Y. and Richardson, K. (2014), Defect and Microstructural Evolution in Thermally Cycled Cu Through-Silicon Vias, Microelectronics Reliability, [online], (Accessed May 29, 2024)


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Created June 14, 2014, Updated February 19, 2017