Extracting the temperature dependence of thermal resistance from temperature-controlled DC measurements of sige HBTs

In this paper we study and analyze the existing techniques in literature to extract the self-heating thermal resistance from the measured DC electrical behaviour of silicon-germanium heterojunction bipolar transistors (SiGe HBTs) focusing their dependence on device junction temperature and propose a simple extraction technique that shows superior accuracy than the existing extraction methodologies. Our approach is scalable and validated with model card simulations across different emitter geometries for a wide temperature range. We also present the applicability of our approach on measured data of a SiGe HBT fabricated in STMicroelectronics B55 process.