MD-modified DMM analysis of thermal boundary resistance in diamond/GaN heterostructures

Abstract

The development of gallium nitride (GaN) devices toward higher power density and frequency has been seriously limited by self-heating effects, which significantly impact device performance. Although the integration with diamond provides a promising solution for GaN thermal management, the thermal boundary resistance (TBR) at the diamond/GaN interface remains the main factor limiting high-power-density operation. In this work, a molecular dynamics-modified diffuse mismatch model is established to analyze the thermal transport across the diamond/GaN interfaces with the impact of inner carbon diffusion. The deviation between the simulation results and the experiments is within 10%. This model effectively overcomes the challenges associated with mismatched mixed interatomic potentials in multi-material heterostructures. It enables the quantitative decomposition of complex interlayer structures to isolate specific thermal contributions. Crucially, the study reveals a compensation mechanism of TBR, where diffusion-enhanced transport mitigates thickness-induced penalties. This finding defines a high-stability process window, providing vital guidance for optimizing heat dissipation in diamond/GaN hetero-integration.