First-principles calculations of interfacial thermal transport properties between SiC/Si substrates and compounds of boron with selected group V elements.

Abstract

In this paper, the interfacial thermal transport properties at the interfaces between the cubic compounds of boron with selected group V elements (BP, BN, BAs and BSb) and various substrates (Si, 6H-SiC and 3C-SiC) were studied by first-principles calculations. Systematic analysis of the effect of crystal information on interfacial thermal transport is performed based on the study of phonon density of states, atomic mass, crystal structure and spectral heat flux, respectively. The results show that the overlap of the phonon density of states of the two interface materials is related to the interfacial thermal conductance. Other crystal information, the atomic mass and lattice constant, which cannot directly reflect the trend of interfacial thermal conductance, can only play a predictive role. Further deep insight suggests that the interfacial thermal conductance also depends strongly on the phonon thermal transport characteristics of different materials and the frequency-dependent spectral heat flux. The results from this work unveil the fact that Si and SiC as the substrate materials do not have absolute superiority or inferiority, depending on the matching rate of many factors of the two materials at the interfaces. This study explores the phonon-level mechanisms for interfacial thermal transport between compounds of boron with group V elements and Si/SiC substrates and provides effective ways to improve the interfacial thermal transport in silicon based modern micro/nano-electronic devices.