Original Article

High capability of AlGaN/GaN HEMT transistors through innovative vertical field plates

¹ Engineering Department, Iran University of Science and Technology, Tehran, Iran
² Mahsa Mehrad, School of Electrical and Mechanical Engineering, University of Portsmouth, Portsmouth, UK

^* e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

Received: 12 June 2025
Accepted: 20 November 2025
Published online: 13 January 2026

Abstract

In this paper, a novel Gate and Drain side Field plate AlGaN/GaN HEMT (GDFP-HEMT) is proposed, featuring multiple vertical field plates on the gate side and both vertical and horizontal field plates on the drain side. This new configuration of the HEMTs improves the electric field distribution and device performance in comparison to the conventional AlGaN/GaN HEMT (C-HEMT). The device structure includes a carbon-doped GaN buffer layer to enhance electrical isolation and reduce leakage currents, along with Al₂O₃ as a dielectric under the gate. Simulations using TCAD-Silvaco and VICTORY DEVICE software were performed to optimize field plate design and analyze its impact on key device parameters such as electron concentration, current density, and breakdown voltage. Results show that the proposed GDFP-HEMT achieves improved current handling, reduced electric field peaks, and a significant increase in breakdown voltage, reaching up to 900 V. The analysis confirms that careful design of the field plates, including their placement and configuration, plays a crucial role in enhancing the performance of AlGaN/GaN HEMTs.