The effect of the fabrication process of n-channel 6H-SiC MOSFETs on their radiation resistance is investigated. MOSFETs that post implantation annealing for source and drain was carried out with carbon coating on the sample surface are compared to MOSFETs that post implantation annealing was carried out without carbon coating. The radiation resistance (gamma-rays) of the carbon-coated MOSFETs is higher than that of non-coated ones. The channel mobility for MOSFETs whose gate oxide was formed using pyrogenic or dry oxidation process dose not change by gamma-ray irradiation below 1x105 Gy. The value of channel mobility slightly increases with increasing dose above 1x105 Gy. No significant increase in irradiation induced interface traps is observed.