Electrical Performances of GaN-based Vertical Trench MOSFETs with Cylindrical and Hexagonal Structure

—In this paper, we designed and analyzed the electrical performances of gallium-nitride (GaN)-based vertical trench metal-oxide-semiconductor field-effect-transistors (MOSFETs) using three-dimensional technical computer-aided design (3-D TCAD) simulation. The cylindrical device is generally considered as superior device than the polygonal devices because it has better gate controllability. In the case of GaN-based vertical devices, however, the cylindrical device performs inferiorly to the hexagonal device in terms of crystal directions for the GaN sidewall plane such as m-plane (1-100), a-plane (11-20), and c-plane (0001). The simulation results provide an understanding and design guidelines for which electrical properties of trench FETs are affected by cross-section shape.