Electrical and Thermal Performance Tuning of Spoof Plasmonic Interconnect

Abstract

This work introduces an electromagnetic metastructure based interconnect design that could address the critical need for electrical bandwidth and heat dissipation in high-speed, chiplet integration. We leverage silicon as the substrate for its superior thermal properties, and to counteract its high dielectric constant that typically causes high mutual capacitance among interconnects, we've engineered a periodically corrugated, compact metallic structure enabling signal propagation via strongly confined spoof surface plasmon polaritons (SSPPs). By placing this engineered metal on a $50$ $\mu$m oxide layer atop Si substrate, we achieved a low insertion loss of $0.015$ dB/cm and a $10$ dB reduction in crosstalk noise within $5$ GHz, resulting in a bandwidth $2.5\times$ as high as that of a standard microstriplines of the same footprint. Furthermore, a $5$ ns input pulse showed minimal distortion and a $0.13$ ns/cm propagation delay in our proposed interconnect. Critically, the thin oxide layer minimally impacted the heat dissipation of Si substrate, demonstrating a fourfold reduction in temperature compared to an FR4 substrate. These full-wave simulation-supported findings present a viable pathway for high-density, thermally efficient interconnects in advanced packaging.