Compact Modeling of High-Voltage Gallium Nitride Power Semiconductor Devices for Advanced Power Electronics Design

This work presents a physics-based compact GaN device model that can predict the performance characteristics of a wide range of GaN devices for power electronics applications. The model has been validated against the measured characteristics of a 650 V commercially available GaN device. The higher voltage range devices exhibit quasi-saturation on-state behavior due to drift resistance, which is evident from their on-state behavior. Also, higher voltage GaN devices have significant nonlinear capacitance characteristics due to the presence of field plates connected to the source and gate terminals. The field plates are fabricated to improve the electric-field distribution in the channel. The field plates result in significant nonlinearity in the channel capacitance that can be quantified as successive depletion in the device capacitances. The model accurately captures these phenomena in the dc and C-V device characteristics. The model also captures the third-quadrant behavior of all GaN devices with model parameters that are decoupled from the first quadrant while maintaining continuity between the first and third quadrants. Dynamic validation of the model is performed from the double-pulse test. The proposed model can be used to characterize commercially available high-voltage GaN devices that can be used in power electronic applications and design. © 2020 IEEE.