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

Abstract:

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∙cm² to 10^-7 Ω∙cm² 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∙cm² was achieved through integration of an ultra-thin conductive ITO interlayer at the MS interface.

• Periodical: Materials Science Forum (Volume 1159)
• Pages: 15-20
• DOI: https://doi.org/10.4028/p-omYG0i
• Online since: September 2025
• Authors: Abdul Hannan Yeo*, Qin Gui Roth Voo, Lakshmi Kanta Bera, Umesh Chand, Navab Singh, Xuan Sang Nguyen, Shiv Kumar, Surasit Chung, Jia Wei Xie, Yee Chia Yeo, Xiao Gong
• Keywords: Barrier Height, ITO Interlayer, Metal-SiC Interface, n-Type SiC, Ohmic Contact

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