Ion Implantation Enhanced Nucleation Facilitates Heat Transport across Atomically-Sharp Semiconductor Interfaces

TL;DR

This paper demonstrates an ultrahigh thermal boundary conductance at the atomically-sharp AlN-SiC interface, achieved through ion implantation, significantly improving heat transport in semiconductor interfaces for electronic device performance.

Contribution

It introduces an ion implantation-enhanced nucleation epitaxy method that achieves one of the highest TBC values for semiconductor interfaces, with detailed atomistic and spectroscopic analysis.

Findings

Achieved TBC of approximately 800 MW/m2-K at AlN-SiC interface.

Nearly half of the acoustic phonon modes exhibit near-unity transmission.

Identified interfacial phonon modes linking mismatched phonon spectra.

Abstract

Overheating is a critical bottleneck limiting the performance and reliability of next-generation high-power and high-frequency electronics. Interfacial thermal resistance constitutes a significant portion of the total thermal resistance. In this study, we report an ultrahigh thermal boundary conductance (TBC) of approximately 800 MW/m2-K at the atomically-sharp AlN-SiC interface, achieved through an ion implantation-enhanced nucleation epitaxy technique. This value is among the highest TBC values reported for semiconductor interfaces, confirmed by structural characterizations which show an ultrahigh-quality interface. Atomistic Green Function calculations reveal that elastic phonon transmission dominates the interface, with nearly half of the acoustic modes (0-15 THz) exhibiting near-unity transmission due to the atomically sharp structure. Furthermore, using high-energy-resolution electron energy loss spectroscopy, we probe vibrational properties with nanometer spatial resolution and identify unique interfacial phonon modes connecting the mismatched phonon spectra, confirmed by molecular dynamics simulations. The ultrahigh TBC is attributed to both the high elastic phonon transmission due to the high quality interfaces and the inelastic phonon scattering channel due to interfacial phonon modes. These findings not only advance the fundamental understanding of interfacial thermal transport but also provide a pathway for effective thermal management in emerging electronic devices.