An effective thermal circuit model for electro-thermal simulation of SOI analog circuits

摘要

A physics-based thermal circuit model is developed for electro-thermal simulation of SOI analog circuits. The circuit model integrates a non-isothermal device thermal circuit with interconnect thermal networks and is validated with high accuracy against finite element simulations in different layout structures. The non-isothermal circuit model is implemented in BSIMSOI to account for self-heating effect (SHE) in a Spice simulator, and applied to electro-thermal simulation of an SOI cascode current mirror constructed using different layouts. Effects of layout design on electric and thermal behaviors are investigated in detail. Influences of BOX thickness are also examined. It has been shown that the proposed non-isothermal approach is able to effectively account for influences of layout design, self-heating, high temperature gradients along the islands, interconnect temperature distributions, thermal coupling, and heat losses via BOX and interconnects, etc., in SOI current mirror structures. The model provides basic concepts and thermal circuits that can be extended to develop an effective model for electro-thermal simulation of SOI analog ICs.