Field Plated AlGaN/GaN-on-Si HEMTs for High Voltage Switching Applications

Abstract

In this study, we fabricated AlGaN/GaN-on-Si high electron mobility transistors (HEMTs) for high voltage switching applications where both the field plate length and the gate-to-drain distance were varied for structural optimization. A tapered gate was fabricated in conjunction with the field plate in order to eectively suppress the high electric field at the gate edge. Regardless of the gate-to-drain distance, which was varied from 7 to 20 µm, the highest breakdown voltage was obtained with a short field plate length (i.e., 2 ‐ 3 µm), and the breakdown voltage monotonically decreased with increasing field plate length. A breakdown voltage of 1200 V with an on-resistance of 3.7 m ·cm 2 was achieved using a gate-to-drain distance of 20 µm and a field plate length of 3 µm.