HfO 2 as a gate dielectric enables high electric field operation of SiC MIS structure and as gas sensor HfO 2 /SiC capacitors offer higher sensitivity than SiO 2 /SiC capacitors. The issue of higher density of oxygen vacancies and associated higher leakage current necessitates better passivation of HfO 2 /SiC interface. Effect of post deposition annealing in N 2 O plasma and post metallization annealing in forming gas on the structural and electrical characteristics of Pd/HfO 2 /SiC MIS capacitors are reported in this work. N 2 O plasma annealing suppresses crystallization during high temperature annealing thereby improving the thermal stability and plasma annealing followed by rapid thermal annealing in N 2 result in formation of Hf silicate at the HfO 2 /SiC interface resulting in order of magnitude lower density of interface states and gate leakage current. Post metallization annealing in forming gas for 40 min reduces interface state density by two orders while gate leakage current density is reduced by thrice. Post deposition annealing in N 2 O plasma and post metallization annealing in forming gas are observed to be effective passivation techniques improving the electrical characteristics of HfO 2 /SiC capacitors. © 2017 Elsevier B.V.