High breakdown voltage C-doped GaN-on-sapphire HFETs with a low specific on-resistance

High-quality C-doped GaN buffers grown on sapphire substrates were employed for the fabrication of high-power AlGaN/GaN heterojunction field effect transistors (HFETs). The fabricated device exhibited a very high breakdown voltage (BV) over 1350 V and low specific on-resistance ( AR DS(ON) ) of 3.4 mΩ cm 2 . This result is very close to the 4H-SiC limit and a record achievement for GaN-based HFETs realized on sapphire substrates, to the best of our knowledge.