ISPSD 2017 CHARITAT AWARD
High Performance Fully-recessed Enhancement-Mode GaN MIS-FETs with Crystalline Oxide Interlayer
Department of Electronic and Computer Engineering, the Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
Abstract – In this work, we developed an effective technique to form a sharp and stable crystalline oxidation interlayer (COIL) between the reliable LPCVD (low pressure chemical vapor deposition)-SiNx
gate dielectric and recess-etched GaN channel. The COIL was formed using oxygen-plasma treatment, followed by in-situ annealing prior to the LPCVD-SiNx
deposition. The COIL plays the critical role of protecting the etched GaN surface from degradation during high-temperature (i.e. at ~ 780 ℃) process, which is essential for fabricating enhancement-mode GaN MIS-FETs with highly reliable LPCVD-SiNx
gate dielectric and fully recessed gate structure. The LPCVD-SiNx
/GaN MIS-FETs with COIL deliver normally-off operation with a VTH
of 1.15 V, small on resistance, thermally stable VTH
and low positive-bias temperature instability (PBTI).
Mengyuan Hua received the B.S. degree in Physics from Tsinghua University, Beijing, China, in 2013. She then joined the Hong Kong University of Science and Technology (HKUST), Hong Kong, China, where she received the Ph.D. degree in Electronic and Computer Engineering in 2017 under the supervision of Prof. Kevin J. Chen. Currently, she is a research associate at HKUST. Her research interests include GaN-based power device technology and device reliability.