Pulsed Gallium Nitride Transistor Characterization

This thesis focuses on the characterization of the Gallium Nitride (GaN) High-Electron-Mobility Transistors (HEMTs) through pulsed measurement techniques aimed at investigating their dynamic behavior. GaN devices, while offering high efficiency and power capability, suffer from dispersive effects such as self-heating and charge trapping phenomena, which strongly influence their transient and large-signal performance. To study these phenomena, a dedicated pulsed setup was developed, combining an Arbitrary Waveform Generator (AWG) and a digital oscilloscope, both controlled via custom MATLAB routines. The setup enables generation and acquisition of pulsed I-V and double-pulse waveforms, providing flexibility across a wide range of bias conditions and time scales. By capturing the transient current response under different quiescent and dynamic conditions, the setup allows the extraction of trap-related capture and emission dynamics, manifested as current collapse, knee walkout, and dynamic R(on). The proposed approach targets the characterization of dispersive processes that are critical for both power switching and RF operation. The developed system represents a versatile platform for dynamic GaN device characterization and forms a basis for future compact modeling, bridging measurement data with predictive behavioral models applicable to high-frequency and high-power applications.