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

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Author(s): Chukwudi A. Okoro; James Marro; Yaw S. Obeng; Kathleen Richardson;
Title: Defect and Microstructural Evolution in Thermally Cycled Cu Through-Silicon Vias
Published: June 14, 2014
Abstract: 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.
Citation: Microelectronics Reliability
Pages: 8 pp.
Research Areas: Semiconductors, Microelectronics, Materials Science
PDF version: PDF Document Click here to retrieve PDF version of paper (2MB)