Monte Carlo simulation of phonon transport across Si-Si and SiO2 interfaces

We present a Monte Carlo simulation tool to address phonon transport in silicon and silica by solving the Boltzmann Transport Equation. This tool aims to provide useful data for thermal microscopy at nanoscale where samples and tips may be of various size and shape. It enables also to predict the effect of an oxide layer or interface between similar materials. Especially, we compute the thermal conductance of Si/Si and Si/SiO₂ nanofilms in the temperature range from 100 K to 500 K. The results are in good agreement with previous molecular dynamics simulations. The thermal conductance between a tip and a sample is computed under simple assumptions. It is shown that the conductance depends greatly on the geometry and that it is possible to detect interfaces in samples by measuring the contact conductance.