Electro-Thermal Analysis and Monte Carlo Simulation for Thermal Issue in Si Devices

Abstract

Nowadays, precise prediction of the heat generation in semiconductor devices is significant. Electro-thermal analysis is one of the attractive methods to predict the heat generation in devices. However, in electro-thermal analysis, the relaxation time approximation is applied to calculate the scattering term in momentum and energy conservation equation. And the assumption of the constant relaxation time for the scattering term of energy conservation equation and the momentum relaxation time derived from the empirical carrier mobility are conventionally applied. For precise prediction of the relaxation times, Monte Carlo (MC) simulation can be applied. In this research, we consider the importance of these relaxation times for heat generation in semiconductor devices. We compare the results with conventional relaxation times and those with the relaxation time from MC simulation in electro-thermal analysis. The calculation results show the electro-thermal analysis with the conventional relaxation time model will overestimate the heat generation density in lower electric field of devices and in higher clock frequency devices.