4H-SiC MISFETs With 4H-AlN Gate Insulator Isopolytypically Grown on 4H-SiC $(11\bar{2}0)$

4H silicon carbide (4H-SiC) metal-insulator- semiconductor field-effect transistors (MISFETs) with 4H aluminum nitride (4H-AlN) gate insulators have been demonstrated. The 4H-AlN layers are isopolytypically grown on 4H-SiC (112̅0) by molecular-beam epitaxy. Gate controlled transistor operation was realized using the AlN/SiC MISFETs. The MISFETs exhibit a low gate leakage current (<;10^-10 A) and normally ON characteristics with a threshold voltage of approximately -10 V and a field-effect mobility of 0.5 cm²V^-1s^-1. Capacitance-voltage measurements of AlN/SiC MIS capacitors reveal a large negative flat band shift of -10.9 V, which is consistent with the normally ON characteristics.