Ballistic phonon transport and self-heating effects in strained-silicon transistors

Abstract

In this manuscript, different aspects of nanoscale thermal transport in strained silicon transistors will be addressed. The two-dimensional Boltzmann transport equations for phonons in Si and SiGe alloy layers, along with the acoustic mismatch model for the interface, are used to capture the sub-continuum heat conduction effects in the device. It is shown that the lateral thermal conductivity of a 10-nm strained-Si layer grown on the SiGe underlayer can vary from 14 to 20W/m-K, depending on the interface specularity parameter. The resulting temperature distribution in the device is used to predict the impact of self-heating on performance of future generations of strained-Si devices. The analysis shows that the merits of strained-Si technology can be suppressed by excessive self-heating; therefore, additional considerations in the design of these devices need to be taken into account.