Excellent effects of hydrogen postoxidation annealing on inversion channel mobility of 4H-SiC MOSFET fabricated on (11 2 0) face

Abstract

Effects of hydrogen postoxidation annealing (H/sub 2/ POA) on 4H-silicon carbide (SiC) MOSFETs with wet gate oxide on the (112~0) face have been investigated. As a result, an inversion channel mobility of 110 cm/sup 2//Vs was successfully achieved using H/sub 2/ POA at 800/spl deg/C for 30 min. H/sub 2/ POA reduces the interface trap density by about one order of magnitude compared with that without H/sub 2/ POA, resulting in considerable improvement of the inversion channel mobility to 3.5 times higher than that without H/sub 2/ POA. In addition, 4H-SiC MOSFET with H/sub 2/ POA has a lower threshold voltage of 3.1 V and a wide gate voltage operation range in which the inversion channel mobility is more than 100 cm/sup 2//Vs.