Improved interface characteristics of Mo/SiO2/4H-SiC metal-oxide-semiconductor with post-metallization annealing

The effects of post-metallization annealing (PMA) have been investigated for thermally-grown SiO2 on 4H-SiC metal-oxide-semiconductor (MOS) with a molybdenum (Mo) gate electrode. Mo is a great metal gate material for Silicon carbide (SiC) due to its high thermal budget and low thermal expansion coefficient, which allows high-temperature processing after the gate electrode formation. In this study, PMA process was carried out after Mo gate formation on thermally-grown SiO2/4H-SiC in the temperature range from 600 to 1000 °C in N2 or a forming gas ambient. The fabricated Mo/SiO2/4H-SiC MOS device annealed at 800 °C exhibited excellent interface characteristics with negligible hysteresis in comparison with as-grown or post-oxidation annealed samples.