Characterization of intra device mutual thermal coupling in multi finger SiGe:C HBTs

TL;DR

This paper investigates the mutual thermal coupling in multi-finger SiGe:C HBTs using 3D thermal simulations and implements the parameters in a model that accurately predicts device behavior, validated by measurements.

Contribution

It introduces a detailed thermal coupling characterization method and integrates it into a transistor model for improved accuracy in circuit simulations.

Findings

Thermal coupling parameters were successfully extracted from 3D TCAD simulations.

The model with thermal coupling shows excellent agreement with experimental measurements.

Enhanced understanding of intra-device thermal effects in multi-finger HBTs.

Abstract

This paper studies the mutual coupling in trench isolated multi emitter bipolar transistors fabricated in a Si/SiGe:C HBT technology STMicroelectronics featuring fT and fmax of ~300GHz and ~400GHz, respectively. Thermal coupling parameters are extracted using three dimensional (3D) thermal TCAD simulations. The obtained parameters are implemented in a distributed transistor model that considers self-heating as well as thermal coupling between emitter fingers. Very good agreement is achieved between circuit simulations and DC measurements carried out on an in house designed test structure.