9:00 AM - 9:15 AM △ [11a-Z23-1] Effects of High-Temperature Annealing and Thermal Oxidation on Fermi level of High-Purity Semi-Insulating 4H-SiC Substrates 〇Chansoon Koo1, Mitsuaki Kaneko1, Tsunenobu Kimoto1 (1.Kyoto Univ.)