Current status of high-power GaN HEMTs and future prospects on AlN-based devices

Abstract

In this paper, current status of development of high-power GaN high electron mobility transistors (HEMT) and future prospects on AlN-based devices are summarized. High-power X-band operation of AlGaN/GaN HEMT fabricated on free-standing AlN substrates was successfully achieved by employing polarization-controlled structures. The HEMT developed on an AlN substrate consists of a 200 nm thick GaN channel and an AlGaN buffer with an Al composition of 30%. Thanks to the high breakdown voltage of the HEMT on the AlN substrate, an output power density of 15.2 W/mm at an operating voltage of 70 V was successfully demonstrated without device technologies such as source-field plate and optimization of device dimensions. Our results will pave the way for future high-power and high-frequency devices on AlN substrates.