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 SiO 2 /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 x 10 -5 Ω cm 3 at 900 °C for 45 s.