Effect of the thickness of amorphous silicon intermediate layer on the thermal transport of silicon/diamond interface

Abstract

The effect of the thickness of the amorphous silicon (a-Si) intermediate layer on the thermal transport of the Si/diamond heterointerface is investigated by using molecular dynamics simulations. It is found that the TBC of the Si/diamond heterostructure with a 0.5-nm-thick a-Si intermediate layer increases by more than 38 % in comparison with that of the Si/diamond without the a-Si intermediate layer. Meanwhile, the thermal boundary conductance (TBC) of Si/diamond decreases with the increasing thickness of an introduced a-Si intermediate layer. Furthermore, by examining the phonon vibrational spectrum, we found that introducing the a-Si intermediate layer at the interface between Si and diamond alleviates the phonon mismatch between Si and diamond, which increases the available heat transport channels and therefore leads to an increase in TBC. Finally, we observed that the TBC increases with the temperature of the Si/diamond heterostructure due to the enhancement of the inelastic scattering of phonons. These results indicate that the thermal transport of the Si/diamond heterointerface can be effectively regulated by controlling the thickness of the a-Si intermediate layer, which also provides further insight into thermal management design in Si/diamond-based electronic devices.