SiC is a robust semiconductor material considered ideal for high-power application due to its material stability and large bulk thermal conductivity defined by the very fast phonons. In this paper, however, we show that both material-interface scattering and total-internal reflection significantly limit the SiC-nanostructure phonon transport and hence the heat dissipation in a typical device. For simplicity we focus on planar SiC nanostructures and calculate the thermal transport both parallel to the layers in a substrate/SiC/oxide heterostructure and across a SiC/metal gate or contact. We find that the phonon-interface scattering produces a heterostructure thermal conductivity significantly smaller than what is predicted in a traditional heat-transport calculation. We also document that the high-temperature heat flow across the metal/SiC interface is limited by total-internal reflection effects and maximizes with a small difference in the metal/SiC sound velocities.
@article{arxiv.cond-mat/0407122,
title = {Thermal transport in SiC nanostructures},
author = {Eleni Ziambaras and Per Hyldgaard},
journal= {arXiv preprint arXiv:cond-mat/0407122},
year = {2007}
}