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Publication Citation: X-Ray Micro-Beam Diffraction Determination of Full Stress Tensors in Cu TSVs

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Author(s): Chukwudi A. Okoro; Lyle E. Levine; Oleg A. Kirillov; Yaw S. Obeng; Ruqing Xu; Jonathan Z. Tischler; Wenjun Liu; Klaus Hummler;
Title: X-Ray Micro-Beam Diffraction Determination of Full Stress Tensors in Cu TSVs
Published: May 28, 2013
Abstract: We report the first non-destructive, depth resolved determination of the full stress tensor in Cu through-silicon vias (TSVs), using synchrotron based micro-beam X-ray diffraction. Two adjacent Cu TSVs were studied; one deliberately capped with SiO2, the other without (uncapped). Both Cu TSVs were found to be in a state of tensile hydrostatic stress that fluctuated considerably with depth. The average hydrostatic stress across the capped and the uncapped Cu TSVs was found to be (99 MPa ± 13 MPa) and (118 MPa ± 18 MPa), respectively. This apparent disparity between the mean hydrostatic stresses is attributed to local differences in their microstructure, and not to the differences in capping.
Proceedings: Proceeding of IEEE Electronic Components and Technology Conference (ECTC)
Pages: pp. 648 - 652
Location: Las Vegas, NV
Dates: May 28-31, 2013
Research Areas: Synchrotron, Metals, Semiconductor Materials