Thermal boundary conductance enhancement of the Si/diamond interface via atomic transition strategy

Abstract

Developing multi-chip systems introduces significant thermal management challenges, due to dense vertical stacking and interconnections. Specifically, the increased number of interfaces within the heat conduction path of the chips significantly impedes the effective heat transfer. This study utilizes a series of molecular dynamics simulations to explore how the structure and atomic composition at interfaces affect their thermal conduction abilities. This study initially reveals substantial differences in thermal conduction capabilities between Si/Diamond, SiC/Diamond, and Diamond/Diamond interfaces. Further investigations focus on interfaces between different structures of SiC and diamond, clearly identifying the atomic composition and structure at the interface as key factors influencing thermal boundary conductance (TBC). Based on these findings, the study proposes a strategy for atomic transition that involves inserting SiC into the Si/Diamond interface. Under optimal thickness conditions for the SiC transition layer, a significant increase in theoretical TBC is achieved, from 477.1 MW/m²K to 701.1 MW/m²K, which is twice the value predicted by the existing diffusive mismatch model (DMM) for Si/Diamond interfaces. Lastly, through the developed 3D IC model, the study examines the impact of TBC variations on the peak temperature of the entire device, thereby further emphasizing the importance of enhancing interface thermal conduction capabilities. This series provides strategic guidance for thermal management in 3D ICs and offers a theoretical basis for chip design and material selection.