Modeling of Future GaN MOSFETs for Electric Ship Applications

This paper presents the design and simulation of a 1.2 kV, 100A vertical GaN based MOSFET for electric ship applications. First, a physics-based TCAD model of the proposed vertical GaN MOSFET structure is briefly discussed. The proposed MOSFET structure employs hybrid edge termination to achieve high-breakdown characteristics with low on-resistance. The feasibility of the proposed device is demonstrated through static characterization, and a circuit-simulation model of the GaN MOSFET is extracted from the TCAD design. A similarly rated commercially available SiC MOSFET is also modeled in the circuit simulation software using data extracted from the datasheet. Circuit simulation of a two-switch buck-boost DC-DC converter is then implemented and the MOSFETs are tested to compare converter efficiency with respect to switching frequency. The results show that the low technology readiness level vertical GaN planar MOSFET shows results comparable to those of the commercially available SiC device. Thus, this paper can be used to further guide and improve the implementation methodologies of future vertical GaN MOSFETs.