Abstract

With the constant increase of transistor power density, electro thermal modeling is becoming a necessity for accurate prediction of device electrical performances. For this reason, this paper deals with a methodology to obtain a precise nonlinear thermal model based on Model Order Reduction of a three dimensional thermal Finite Element (FE) description. This reduced thermal model is based on the Ritz vector approach which ensure the steady state solution in every case. An equivalent SPICE subcircuit implementation for circuit simulation is proposed and discussed. The nonlinear approach of the reduced model is based on the Kirchoff transformation. The model has been successfully implemented in a circuit simulator for a PHEMT device.