Low temperature wet-O2 annealing process for enhancement of inversion channel mobility and suppression of Vfb instability on 4H-SiC (0001) Si-face

Abstract

For improvement of 4H-SiC metal-oxide-semiconductor field-effect-transistor performance, a post-oxidation annealing (POA) process in a wet environment after dry oxidation was systematically investigated. By tuning the wet-POA conditions, we clarified that wet-POA at low temperatures is more advantageous for both the enhancement of channel mobility and the suppression of flatband voltage instability. One of the mechanisms of channel mobility enhancement is attributed to the decrease in the density of traps in oxide near the MOS interface, rather than conventional interface traps. The effects of the wet environment on interfacial properties were also discussed based on oxide growth kinetics on 4H-SiC.