A DSMC Study of the Si/Ge Interface Thermal Resistance

In this paper, we present some preliminary simulation results of the thermal resistance associated with a Si/Ge interface. The interface thermal resistance is obtained via a Monte-Carlo (DSMC) simulation tool based on the phonon Boltzmann equation and the single relaxation time approximation. The simulation is made one-dimensional in order to save the computational time by taking advantage of the statistical symmetry in problem. The interface is partially specular and partially diffuse. An inelastic acoustic mismatch model is employed to determine the transmissivity. The interface thermal resistance is consequently computed as a function of the specular reflection fraction. Two different phonon dispersion relations, a sine model and a cubic one, are employed for comparison. Phonon properties are temperature-dependent. Attention will be paid to the difference in the so obtained temperature distributions, particularly near the interface, and the calculated interface thermal resistances. These simulation results are also compared with their finite-difference counterparts with constant phonon properties for the sake of ensuring the validity of the DSMC solver and for the sake of exploring the influence of temperature dependence. Future work will be concentrated on the influence of the layer thicknesses between finitely many interfaces on the interface thermal resistance.