Enhanced TiC/SiC Ohmic contacts by ECR hydrogen plasma pretreatment and low-temperature post-annealing

We proposed an electronic cyclotron resonance (ECR) microwave hydrogen plasma pretreatment (HPT) for moderately doped (1 × 1018 cm−3) SiC surfaces and formed ideal TiC/SiC Ohmic contacts with significantly low contact resistivity (1.5 × 10−5 Ω cm2) after low-temperature annealing (600 °C). This is achieved by reducing barrier height at TiC/SiC interface because of the release of pinned Fermi level by surface flattening and SiC surface states reduction after HPT, as well as the generation of donor-type carbon vacancies, which reduced the depletion-layer width for electron tunneling after annealing. Interface band structures were analyzed to elucidate the mechanism of Ohmic contact formations.