| PhD Viva

Name of the Speaker: Mr. Shanbhag Ajay Govindray (EE18D415)
Guide: Prof. Amitava Das Gupta
Online meeting link: https://meet.google.com/odp-semv-jgs
Date/Time: 21st March 2025 (Friday), 3:30 PM
Title: Advancements in Modeling, Characterization and Buffer Design of GaN HEMTs considering Effects of Traps

Abstract :

Gallium Nitride (GaN) High Electron Mobility Transistors (HEMTs) are key for high-frequency and high-power applications due to their superior performance, though traps within the material pose challenges to device behavior and reliability. This thesis tackles these challenges by incorporating effects of traps in the current ICM compact model, advanced buffer designs in presence of traps, and precise characterization techniques to mitigate trap effects. It first presents ICM GaN HEMT compact model that incorporate trap-related phenomena in DC, small-signal, and transient conditions. This model is validated against industrial and TCAD data. The thesis also proposes a method to accurately extract thermal resistance in the presence of traps by decoupling the effects of trapping and self-heating. The extracted thermal resistance is validated using the developed compact model. Lastly, it explores the benefits of a thin AlGaN back barrier combined with C-GaN for mm-wave high-voltage GaN HEMTs, with simulations identifying the optimal buffer design that minimizes trapping effects and enhances breakdown voltage, making it suitable for high-power, high-frequency applications.