Indium-Tin-Oxide (ITO) Interlayer-Assisted Ohmic Contacts on n-Type 4H-SiC with Low Specific Contact Resistance

This study investigates the role of ultra-thin conductive Indium-Tin-Oxide (ITO) as an interlayer at the Metal-SiC (MS) junction to lower the overall specific contact resistance (SCR) for source drain metallization applications on n-type 4H-SiC substrates. In this work, we demonstrate an improvement in SCR by 1 order of magnitude from ~10 - 6 Ω∙cm 2 to 10 - 7 Ω∙cm 2 through the integration of an ultra-thin ITO interlayer. Barrier height ( Φ B ) lowering by ~ 0.1 eV was observed at the MS interface as deposited which could have assisted in the reduction of the SCR. Titanium-based Ohmic contacts were subsequently formed at 950 °C. Various thicknesses of ITO were examined to assess their influence on the formation of ohmic contacts to n-type SiC. An SCR ( ρ c ) of 6.9×10 - 7 Ω∙cm 2 was achieved through integration of an ultra-thin conductive ITO interlayer at the MS interface.