Design Strategy of Vertical GaN Power Schottky Barrier Diodes with p-GaN Junction Termination Extension and Experimental Demonstration of Selective p-Doping by Implantation

Herein, the impact of the key structural parameters on the breakdown characteristics of the vertical gallium nitride (GaN) power Schottky barrier diodes (SBDs) with p-GaN junction termination extension (JTE) structures by numerical simulation is systematically investigated. With a p-type GaN structure incorporated at the edge of the Schottky junction, the electric field crowding at the edge of Schottky anode can be alleviated, effectively avoiding the premature breakdown of the devices. It is found that the acceptor concentration, thickness, width, and surface charge density of the incorporated JTE are closely associated with the electric field distribution and the reverse breakdown characteristics. The vertical SBDs with optimum p-GaN JTE parameters feature a dramatic improvement in Baliga's figure of merit, without obvious degradation in the forward and dynamic performance. Selective p-doping and acceptor activation is also demonstrated, which verifies the fabrication feasibility of the proposed JTE structures. Through the results, the way can be paved for the design and fabrication of high-performance GaN vertical power devices toward high-voltage, high-power, and high-speed applications. Herein, the design strategy of vertical GaN Schottky barrier diodes (SBDs) with p-GaN junction termination extension (JTE) structures is investigated by numerical simulation. Selective p-doping is also achieved by magnesium implantation and annealing, confirming the fabrication feasibility of p-GaN JTE. These findings can provide a theoretical guideline for the design of GaN SBDs with JTE structures towards high-voltage applications. image (c) 2024 WILEY-VCH GmbH