Engineering low-resistance Ni/In2O3 contacts for BEOL compatible integration

Reliable engineering of low-resistance metal semiconductor (M/S) contacts is critical for advancing indium oxide (In2O3) based semiconductor technologies. As device dimensions shrink to the micrometer regime, minimizing contact resistance becomes essential to ensure channel limited operation rather than contact dominated. In this study, we systematically optimized Ni/In2O3 contacts using mild rapid thermal annealing (RTA) at 250 °C in nitrogen ambient conditions compatible with back-end-of-line (BEOL) processing and evaluated their performance using the transfer line method (TLM). Ni/In2O3 TLM structures were fabricated via photolithography and liftoff, followed by RTA at varying durations. Quantitative TLM analysis demonstrated a substantial reduction in contact resistance (RC) to 6.24 Ω, normalized contact resistance (N · RC) to 1.25×10−1 Ω cm, specific contact resistivity (ρC) to 1.53×10−6 Ω cm2, and a short transfer length (LT) of 123 nm, all achieved without intentional doping or complex metallization. This process driven, BEOL compatible approach provides a robust route to low-resistance contacts in In2O3 thin films, enabling a reliable foundation for next generation low power, high performance oxide electronics.