*TAKAMA UNNO1, CAN ZHU2, SHUNTA HARADA1,2, HARUHIKO KOIZUMI2,4, MIHO TAGAWA1,2, TORU UJIHARA1,2,3
(1. Department of Materials Process and Eng., Nagoya Univ.(Japan), 2. Center for Integrated Res. of Future Electronics (CIRFE), Inst. of Materials and System for Sustainability (IMaSS), Nagoya Univ.(Japan), 3. GaN Advanced Device Open Innovation Lab. (GaN-OIL), National Inst. of Advanced Indus. Sci. and Tech. (AIST)(Japan), 4. Department of Electorical and Electronic Eng., Mie Univ.(Japan))