Session Speaker Semiconductor Hardware and Materials

Topological Semimetals for Scaled Back-End-Of-Line Interconnect Beyond Copper

Dr. Ching-Tzu Chen (陳敬慈)

Research Staff Member

IBM Thomas J Watson Research Center

Yorktown Heights, NY 10598



Dr. Ching-Tzu Chen is a Research Staff Member at IBM where she joined in 2007 after receiving her PhD in Physics from Caltech. Her main research interests include emergent memory technologies for AI hardware, topological materials for interconnect, memory and compute, spintronics, and nanotechnology. She received the IBM Outstanding Technical Achievement Awards in 2018 and 2010 for her work on nano-spintronics and novel superconductivity. Since 2016, she has served on the Science Advisory Board of the SRC Joint University Microelectronics Program, and she was on the Physical Sciences Council in 2019-2020 to curate and define IBM’s physical sciences research portfolio. She is a regular referee for APS, AIP and Nature Publishing Group journals and IEEE conferences. She also helps reviewing proposals for NSF and DoE’s Basic Energy Sciences.


In today’s integrated circuits, as the scaling of front-end devices becomes increasingly difficult, improvements at the back-end-of-line (BEOL) and packaging level have also become crucial for the overall system power-performance scaling. However, the RC delay of the BEOL interconnect has hit a major bottleneck. When the metal linewidth drops below the electron mean-free path (~39 nm for Cu), its resistivity increases in a power-law manner due to increased electron scattering, which calls for new interconnect materials.

This talk introduces topological semimetals as a potential solution. After reviewing the desirable properties of topological semimetals for interconnect applications, we will use CoSi as an example to demonstrate the decreasing resistance-area product with scaling, in sharp contrast to conventional interconnect metals. We will end the presentation with a few guidelines for future materials search in this space.

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