Ohmic Contacts of Polycystalline 3C-SiC Thin-Films Grown on Si (100) Wafers for Microsensors of Vehicle Engines

This paper describes the ohmic contact formation of polycrystalline 3C-SiC thin-films deposited on thermally grown Si (100) wafers. In this work, the TiW (titanium tungsten) film as a contact material has been deposited by RF magnetron sputter and annealed with vacuum furnace process. The specific contact resistance of the TiW contact was measured by using the C-TLM (circular transmission line method). Contact phase and interfacial reaction between TiW and poly 3C-SiC at high temperature were also analyzed by XRD (X-ray diffraction) and SEM (scanning electron microscope). TiW/poly 3C-SiC thin-films did not show cracks on the TiW film and any interfacial reaction after annealing. Especially, when the TiW/poly 3C-SiC thin-film was annealed at 800deg for 30 min., the lowest contact resistivity of 2.90times10^-5 Omega-cm² was obtained owing to the improved interfacial adhesion. Therefore, the good ohmic contact of poly 3C-SiC thin-films using the TiW thin-film are very suitable for microsensor applications in vehicle engine fields.