Thermal Simulation for Nanoscale FinFET Using First-Principles Nongray Phonon Boltzmann Transport Equation

Abstract In recent years, nanoscale devices, represented by the fin field-effect transistor (FinFET), have significantly enhanced computational performance while simultaneously presenting heightened thermal challenges. Consequently, thermal simulation has become an indispensable component in advanced nanoscale device design and thermal management. Classical thermal simulation, based on the heat diffusion equation, proves inadequate in describing non-Fourier effects at nanoscale, given that the characteristic length is smaller than the phonon mean free path. Therefore, the phonon Boltzmann transport equation (BTE) has emerged as the solely promising method to achieve the non-Fourier thermal simulation. However, to date, accurate and efficient phonon-BTE-based thermal simulation for realistic three-dimensional devices have not been achieved. In this study, we implement non-Fourier thermal simulation for a realistic three-dimensional silicon-based FinFET by utilizing the first-principles-based nongray phonon BTE and achieve quantitative alignment with previous experimental measurements. The accurate phonon properties are obtained through first-principles calculations without fitting parameters. Utilizing our efficient phonon BTE software, GiftBTE, we acquire a high-resolution temperature distribution of the device. Moreover, this paper provides a quantitative analysis of the impact of temperature effects on the FinFET’s electrical performance, consistent with previous experiment result.