Estimating Kapitza Resistance Between ${\rm Si}\hbox{-}{\rm SiO}_{2}$ Interface Using Molecular Dynamics Simulations

Abstract

The interface between nano-scale films is of relevance in many critical applications. Specifically, recent technological advances in semiconductor industry that utilize silicon-on-insulator devices have given importance to the understanding of thermal transport across ${\rm Si}{\hbox{-}}{\rm SiO}_{2}$ interface. Estimates of interfacial (Kapitza) resistance to the thermal transport across ${\rm Si}{\hbox{-}}{\rm SiO}_{2}$ films do not appear to exist at the present time. In this paper, we develop and carryout reverse non-equilibrium molecular dynamics simulations by imposing known heat flux to determine the Kapitza resistance between ${\rm Si}{\hbox{-}}{\rm SiO}_{2}$ thin films. For the ${\rm Si}{\hbox{-}}{\rm SiO}_{2}$ interface, the average Kapitza resistance for a ${\sim}{8}~{\rm\AA}$ thick oxide layer system was 0.503 ${\times}10^{-9}~{\rm m}^{2}{\rm K}/{\rm W}$ and for a ${\sim}{\rm 11.5}~{\rm\AA}$ thick oxide layer system was 0.518 $\,\times 10^{-9}~{\rm m}^{2}{\rm K}/{\rm W}$ . These values were of the same order of magnitude as the Kapitza resistance values determined from the acoustic mismatch model and the diffuse mismatch model for the ${\rm Si}\hbox{-}{\rm SiO}_{2}$ interface.