Low specific contact resistance between InAs/Ni–InAs evaluated by multi-sidewall TLM

The specific contact resistance ρint of the InAs/Ni–InAs interface was evaluated by the multi-sidewall transmission line method (MSTLM), where Ni–InAs was formed by alloying Ni and InAs-on-insulator substrates. The revised test structure for MSTLM has been proposed, which can be easily fabricated. By evaluating each component of the parasitic resistance separately, the specific contact resistance of the InAs/Ni–InAs was accurately extracted. As a result, the record low ρint of (4.3 ± 2.5) × 10−9 Ω cm2 among metal/III-V contacts was obtained for the 30-nm-thick InAs/Ni–InAs interface with the average electron concentration of 9.1 × 1018 cm−3 for InAs, which is close to the Landauer limit. The comparison of the experimental and theoretical ρint indicates that there is no potential barrier at the InAs/Ni–InAs interface, which is attributable to the negative Schottky barrier height for electrons of InAs.