Effects of high-temperature diluted-H2 annealing on effective mobility of SiC MOSFETs estimated by split capacitance-voltage technique

The effects of post-oxidation annealing (POA) in diluted-H-2 ambient on 4H-and 6H-SiC/SiO2 interfaces were investigated. Effective mobility (mu(eff)) was extracted from lateral metal-oxide-semiconductor field-effect transistors (MOSFETs) by the split capacitance-voltage (C-V) technique to determine the surface charge density and a calibration technique using two MOSFETs with different gate lengths to minimize the contribution of parasitic components. POA at 1150 degrees C in diluted-H2 ambient resulted in an enhancement of mu(eff), compared with that in N-2 ambient. It was indicated that the effects of POA in diluted-H2 ambient should be attributed to the reduction in the density of near-interface traps in oxide, which disturb the electron transportation in the inversion channel, from the measurement temperature dependence of mu(eff) for 6H-SiC MOSFETs as well as from the C-V curves of MOS capacitors fabricated on n-type 4H-SiC. (C) 2017 The Japan Society of Applied Physics