GaN-based MIS-HEMTs with Al<sub>2</sub>O<sub>3</sub> dielectric deposited by low-cost and environmental-friendly mist-CVD technique
R. S. Low, Joel T. Asubar, Ali Baratov, Shunsuke Kamiya, Itsuki Nagase, S. Urano, Shinsaku Kawabata, Hirokuni Tokuda, Masaaki Kuzuhara, Yusui Nakamura, Kenta Naito, Tomohiro Motoyama, Zenji Yatabe
Abstract
Abstract We report on the fabrication and characterization of AlGaN/GaN metal-insulator-semiconductor (MIS) capacitors and high-electron-mobility transistors (MIS-HEMTs) using a 5 nm thick Al 2 O 3 dielectric deposited by cost-effective and environmental-friendly mist chemical vapor deposition (mist-CVD) technique. Practically hysteresis-free capacitance–voltage profiles were obtained from the fabricated two-terminal MIS-capacitors indicating high quality of the mist-Al 2 O 3 /AlGaN interface. Compared with reference Schottky-gate HEMTs, mist MIS-HEMTs exhibited much improved performance including higher drain current on-to-off ratio, much lower gate leakage current in both forward and reverse directions and lower subthreshold swing. These results demonstrate the potential and viability of non-vacuum mist-CVD Al 2 O 3 in the development of high-performance GaN-based MIS-HEMTs.