A rigorous assessment of electro-thermal device instabilities via Harmonic Balance modeling

This paper presents a rigorous numerical approach to the assessment of electro-thermal instabilities arising in high-power semiconductor devices operating under time-periodic conditions. The methodology is entirely developed in the frequency domain with reference to the harmonic balance technique, i.e. no time-domain calculations are required for the determination of the Floquet multipliers exploited for the stability analysis. As an example of application, the current gain collapse occurring in multifinger AlGaAs/GaAs HBTs is studied and compared to the customary stability criterion based on a purely static analysis.