Low-temperature bonding of Si and polycrystalline diamond with ultra-low thermal boundary resistance by reactive nanolayers

Abstract

Thermal management is a critical challenge in modern electronics and recent key innovations have focused on integrating diamond directly onto semiconductors for efficient cooling. However, the connection of diamond/semiconductor that can simultaneously achieve low thermal boundary resistance (TBR), minimal thermal budget, and sufficient mechanical robustness remains a formidable challenge. Here, we propose a collective wafer-level bonding technique to connect polycrystalline diamonds and semiconductors at 200 °C by reactive metallic nanolayers. The resulting silicon/diamond connections exhibited an ultra-low TBR of 9.74 m2 K GW–1, drastically outperforming conventional die-attach technologies. These connections also demonstrate superior reliability, withstanding at least 1000 thermal cycles and 1000 h of high temperature/humidity torture. These properties were affiliated with the recrystallized microstructure of the designed metallic interlayers. This demonstration represents an advancement for low-temperature and high-throughput integration of diamonds on semiconductors, potentially enabling currently thermally limited applications in electronics.