Effect of surface treatments on ALD Al2O3/4H-SiC metal–oxide–semiconductor field-effect transistors

Silicon carbide (4H) based metal–oxide–semiconductor field-effect transistors provide capabilities in high power and temperature inaccessible to silicon. However, the performance of thermally grown oxide-based devices remains limited by oxide/semiconductor interface defects. This research employs deposited dielectrics, Al2O3, rather than thermal oxidation. Investigation various pre-deposition processes reveals different degrees improvements electronic properties. An optimum structure preparation a nitrided surface via NO annealing, process known passivate defects, hydrogen exposure, followed Al2O3 deposition. Inversion layer mobilities as 52 cm2/V s are reported structures. Capacitance–voltage measurements mobility characteristics indicate trapping conductivity Al2O3/4H-SiC inversion channels similar SiO2/4H-SiC. Leakage currents breakdown also for MOS