Physics-Based TCAD Simulation and Calibration of 600 V GaN/AlGaN/GaN Device Characteristics and Analysis of Interface Traps

This study proposes an analysis of the physics-based TCAD (Technology Computer-Aided Design) simulation procedure for GaN/AlGaN/GaN HEMT (High Electron Mobility Transistor) device structures grown on Si (111) substrate which is calibrated against measurement data. The presence of traps and activation energies in the device structure will impact the performance of a device, the source of traps and position of traps in the device remains as a complex exercise until today. The key parameters for the precise tuning of threshold voltage (V-th) in GaN transistors are the control of the positive fixed charges -5 x 10(12) cm(-2), donor-like traps -3 x 10(13) cm(-2) at the nitride/GaN interfaces, the energy of the donor-like traps 1.42 eV below the conduction band and the acceptor traps activation energy in the AlGaN layer and buffer regions with 0.59 eV below the conduction band. Hence in this paper, the sensitivity of the trap mechanisms in GaN/AlGaN/GaN HEMT transistors, understanding the absolute vertical electric field distribution, electron density and the physical characteristics of the device has been investigated and the results are in good agreement with GaN experimental data.

Automated summary

This study presents an analysis of the physics-based TCAD simulation procedure for GaN/AlGaN/GaN HEMT device structures grown on Si (111) substrate, calibrated against measurement data. The study investigates the impact of traps on device performance and the complexity of identifying their source and position in the device. The research focuses on key parameters for tuning threshold voltage in GaN transistors and demonstrates good agreement with experimental data.