High Channel Mobility of 4H-SiC MOSFET Fabricated on Macro-Stepped Surface

Improvement of the channel mobility is needed in 4H-SiC MOSFETs for the maximum utilization of the material potential for novel power devices. We have attempted to obtain smoother MOS interfaces as one of the ways to reduce the interface states which lead to decrease of the channel mobility. We formed a terrace on the macro-stepped surface by annealing in Si melt and found that it was atomically flat. We fabricated a lateral MOSFET on the macro-stepped surface and obtained a high MOS channel mobility of 102 cm2/Vs.