Modelling of self-heating effect in thin SOI and Partial SOI LDMOS power devices

Abstract

This paper presents a comprehensive 2-D and 1-D study of the self-heating effect in thin Silicon-on-Insulator (SOI) and Partial SOI LDMOS power devices. A simple 1-D self-heating model based on a PSPICE RC thermal circuit which accounts for the temperature rise in on-state, transient and short-circuit conditions is developed. Unlike previous 1-D modelling attempts for SOI devices, our model takes into account the feedback effect of the local device temperature on the thermal conductivity and specific heat through an equivalent electrical RC network consisting of voltage controlled resistors and capacitors. The 1-D model is thoroughly assessed against extensive 2-D thermal simulations performed using the SILVACO-ATLAS device simulator and the results indicate an excellent agreement in all operating conditions. Furthermore, an accurate comparison between the thin SOI and Partial SOI devices is carried out.