Ballistic phonon transport in strained Si/SiGe nanostructures with an application to strained-silicon transistors

In this manuscript, different aspects of nanoscale thermal transport in strained silicon transistors will be addressed. The two-dimensional Boltzmann transport equations for phonons have been solved in order to capture effect of ballistic phonon transport in the thin strained silicon layer on heat conduction through the device. A model based on acoustic mismatch has been incorporated to the BTE solver in order to predict the effect of Si/SiGe interface roughness on the lateral and normal energy transport in the strained-Si layer. It is shown that the lateral thermal conductivity of a 15 nm strained-Si layer deposited on the SiGe substrate, depending on the interface quality, can vary from 12 to 17 W/m-K which is nearly an order of magnitude smaller than that of the bulk value. The self-heating problem and also the importance of thermal resistance of the Si/SiGe interface on self-heating in the strained-Si transistors at high speed operation are explained.