Physics-based Compact Model of GaN/AlGaN Schottky Barrier Diode and SiC MOSFET

Abstract

Silicon Carbide (SiC) and Gallium Nitride (GaN) are actively employed in Power Electronics (PE) circuits due to their superior material properties. They both have wide bandgap, high carrier saturation velocity and high thermal conductivity, enabling High Voltage (HV), High Frequency (HF) and High Power (HP) applications. Besides using materials with superior properties, device structure innovations further improve power device performance, such as multi-dimensional structures including super-junction, multi-channel and FinFETs. Compared with one-dimensional structure, it could enhance trade-off between Breakdown Voltage (BV) and On-state Resistance (RON). In order to facilitate circuit design using SiC/GaN transistors with innovative device architectures, there is a growing demand of accurate, scalable, robust and standardized compact models. Using an innovative modular approach, this thesis first proposes a compact model for multi-channel AlGaN/GaN Schottky Barrier Diode (SBD) for kilo-volt applications. The modelling approach, detailed model formation as well as model evaluation against an experimental SBD with five stacked 2DEG channels are explained in detail. Using a similar modular formulation method, the thesis also proposes Waterloo Virtual-source SiC Compact Model (WAVSiC), a comprehensive and user-friendly physics-based compact model for SiC MOSFETs. Accuracy, flexibility and scalability are demonstrated for WAVSiC via benchmarking against measurements of commercial devices. The WAVSiC model is also validated for computational efficiency and robustness, circuit simulator compatibility and ready for Process Design Kit (PDK) integration. In summary, by using a modular approach, the thesis introduces two innovative physics-based compact models for wide-bandgap power electronic devices with accuracy, scalability, and computational efficiency, enabling efficient circuit simulation and PDK development based on these device technologies.