Thermal transport at 6H-SiC/graphene buffer layer/GaN heterogeneous interface

摘要

We investigate the epitaxial growth of graphene on SiC and thermal transport at 6H-SiC/graphene buffer layer/ GaN heterogeneous interface. Under Tersoff-Erhart-Albe potential (TEA) and environment-dependent interatomic potential (EDIP), graphene buffer layer (GBL) is epitaxially grown by simulated annealing method, and simulations show that TEA potential is superior to EDIP potential by evaluation of nucleation temperature, radial distribution function, average atomic binding energy, atomic structure and bond length. Further, by thermal relaxation method, single-vacancy defects in graphene can reduce interface thermal resistance (ITR) at 6H-SiC/ GBL/GaN heterogeneous interface with maximum reduction of 9.6%, meaning that ITR can be reduced by defect engineering. In addition, with the increase of nucleation areas, especially the bonding of different nucleation zones, ITR also has a highest decline of 17.9%, and energy is easier to pass through the interface, illustrating the importance of graphene integrity for interfacial heat transfer. At last, the increase in temperature (300 K to 1100 K) results in a maximum 19.6% decrease in ITR, indicating that ITR is sensitive to temperature. The selection of potential and the analysis of the heat transfer of the three-materials heterogeneous interface contribute to thermal design of graphene-based semiconductor devices.