Woodruff School of Mechanical Engineering

Guest Speaker


Addressing the Thermo-Mechanical Challenges of Cu Through-Silicon Via (TSV) Interconnect for Reliable 3D Integrated Circuits


Dr. Chukwudi Okoro


National Institute of Standards and Technology, Gaithersburg, MD


Monday, March 23, 2015 at 11:00:00 AM


MRDC Building, Room 4211


Dr. Suresh Sitaraman


For 50 years, Moore’s law has had unparalleled success due to the continuous shrinking of transistor feature size. Unfortunately, the size of a transistor is quickly approaching that of an atom, signaling that the end of Moore’s law is in view. While there are many potential alternatives for continued improvement in the performance of electronic devices, system integration-based technology, the three-dimensional integrated circuit (3D-IC) is prominently regarded as the way forward. 3D-IC is achieved by the use of a unique interconnect called through-silicon via (TSV), which are fabricated vertically through the silicon dies. This results in the mismatch in the material properties of TSV (Cu) and its surrounding matrix, leading to the buildup of stresses under thermo-mechanical loads, thus, undermining the reliability performance of 3D-IC packages. In this seminar, a multi-disciplinary approach is presented for the understanding, measurement and analysis of the thermo-mechanical reliability challenges presented by the use TSV interconnect in 3D-IC packages. This includes the use of the wafer curvature method, synchrotron-based X-ray micro-diffraction technique, finite element modeling and the microwave-based techniques.


Dr. Chukwudi Okoro obtained his PhD degree in Mechanical Engineering from Katholieke Universiteit (Catholic University), Leuven, Belgium (2010). His PhD Thesis study, entitled “Thermo-Mechanical Characterization of Copper Through-Silicon Via Interconnect for 3D Chip Stacking,” was performed at Imec, a world renowned micro- and nanoelectronics research center, in Leuven, Belgium. Since 2011, Dr. Okoro has been working at the National Institute of Standards and Technology (NIST), Gaithersburg, Maryland, initially as a Post-Doctoral Scientist and currently as a Research Scientist. Prior to joining Imec in 2006, Dr. Okoro worked as an intern at the National Physical Laboratory (NPL), Teddington, England on a research topic entitled “Isothermal Mechanical Fatigue Measurement of Lead-free Solder Joints”. He has authored/co-authored more than 34 technical publications in referred journals and conference proceedings. His research interest are in the areas of material characterization and thermo-mechanical analysis of interconnects and advanced electronic packages.


Refreshments will be served.