Ohmic contacts to polycrystalline 3C–SiC films for extreme environment microdevices

Ohmic contact characteristics were studied under the surface treatments of poly 3C–SiC films heteroepitaxially grown on SiO2/Si wafers by APCVD. The poly 3C–SiC surface was polished to remove submicron-sized roughness and to get flat and smooth surface using chemical–mechanical polishing (CMP) process. However, some scratching marks on the poly 3C–SiC have remained surface due to the mechanical defect of CMP process. To remove a part of subsurface damage and scratching marks, the polished surface was oxidized by wet-oxidation furnace and it has been etched by diluted HF solution. Titanium tungsten (TiW) thin film was deposited on the surface treated poly 3C–SiC using circular transmission line model as a metallization process and it was annealed through the rapid temperature annealing (RTA) process to improve interfacial adhesion. The contact resistivity of the treated 3C–SiC surface was measured as the lowest 1.2 × 10−5 Ω cm3 at 900 °C for 45 s.