| MS Seminar

Name of the Speaker: Mr. Sovan Barman (EE21S011)
Guide: Prof. Anjan Chakravorty
Co-Guide: Prof.Suresh Balanethiram (NIT Puducherry)
Venue: ESB-244 (Seminar Hall)
Online meeting link: meet.google.com/kif-ucre-xxz
Date/Time: 1st July 2024 (Monday), 11.00 AM
Title: A Study of Self-Heating Effect and Related Parameter Extraction in SiGe HBTs

Abstract :

Silicon-germanium heterojunction bipolar transistors (SiGe HBTs) have been a serious contender for RF and sub-mm-applications because of their excellent capability to operate at high current and high frequency regime. For power amplifier applications, multi-finger SiGe HBTs realized in modern BiCMOS processes are regularly used. Since such devices operate at high current densities, resulting self-heating effects (SHE) seriously influence the device operation other than posing long-term reliability issues. The elevated temperature caused by the SHE alters the operating point by modifying the temperature sensitive state variables within the devices. From the perspective of equivalent circuit models, parameter values are altered due to the SHE, posing a serious challenge to accurately extract the electrical and thermal network related parameters at nominal temperature.

In this seminar, first of all we present a systematic procedure to extract thermal resistances and capacitances in a multi-node thermal network model to accurately capture the SHE in SiGe HBTs. Secondly, we put forward a simplified extraction methodology to obtain temperature dependent emitter and collector resistances along with an improvement in thermal resistance estimation. FInally we venture into obtaining isothermal electrical characteristics from the usual DC and minimal or zero pulsed measurements in order to aid the temperature independent electrical model parameter extraction.