Electro-Thermal Analysis and Monte Carlo Simulation for Thermal Design of Si Devices

Nowadays, precise prediction of heat generation in semiconductor devices is important. An electro-thermal analysis is an attractive method to predict heat generation in devices. In this analysis, momentum and energy relaxation times are taken as the important parameters. Calculated heat generation density is dependent on the energy relaxation time. Conventionally, these relaxation times have been determined by simple models. For a more precise prediction of the relaxation times, Monte Carlo (MC) simulation should be employed. In this research, the impact of these relaxation times on the heat generation in a semiconductor device is evaluated. The results of an electro-thermal analysis using conventional relaxation times (conventional model) and of one using the relaxation times from a MC simulation (MC model) are compared. The calculation results show that the conventional model overestimates the heat generation density especially under a high electric field. The estimated heat generation density of the conventional model is 10% and 25% larger in the case of 100 and 500 kV/cm electric fields, respectively. It can be concluded that, for the thermal design of high-power semiconductor devices in power electronics, appropriate values of the relaxation times, which are obtained from the MC simulation, are required.