We report a comprehensive investigation on the effects of process variations on the inversion layer electron mobility of n-channel MOSFETs in 4H SiC. Experimental results show that: (1) a post-oxidation anneal in nitric oxide (NO) significantly increases mobility, (2) implant anneals at temperatures less than or equal to 1400 degreesC, polysilicon depositions at 900 degreesC, and contact anneals at 850 degreesC have no significant negative effect on channel mobility, and (3) gate material and deposition method (LPCVD polysilicon vs. sputtered Mo) has no significant effect on channel mobility.