On the super-junction formed by using field plate for lateral AlGaN/GaN-based Schottky barrier diodes

Abstract

In this work, by using numerical TCAD simulations, we have systematically studied the impact of different field plates (FPs) on the electrical characteristics for lateral AlGaN/GaN-based Schottky barrier diodes (SBDs) with recessed anode. The FP enables the formation of a super-junction. When compared with the reference device without a FP, the proposed SBDs can generate charge-coupling effect between the FP and the recessed anode region, which can effectively reduce the electric field magnitude at the metal/sidewall interface. We also find that the electric field profiles can be affected by the FP length, insulation layer thickness and different insulation materials with various dielectric constants. By doing so, we can enhance the breakdown voltage by homogenizing the electric field distribution in the GaN drift layer. Then, the electric field at the recessed anode region can be decreased and the GaN drift layer can be extensively depleted.