The effects of post deposition annealing in forming gas (5 % H2 in 95 % N2) ambient at different temperatures (850, 950, and 1050 oC) on metal-oxide-semiconductor characteristics of sol-gel derived HfO2 gate on n-type 4H-SiC have been investigated. After 30 min of the annealing, an accumulation of positive effective oxide charge (Qeff) has been observed in all samples. The total interface trap density and Qeff of the oxides annealed at 850 and 950 oC are comparable but an increment and reduction of the respective densities have been recorded when the oxide was annealed at 1050 oC. A reduction of near interface trap density has been revealed as the annealing temperature has been increased. These observation was closely related to the increment of leakage current density as the annealing temperature increased.