Accurate evaluation of specific contact resistivity between InAs/Ni–InAs alloy using a multi-sidewall transmission line method

Abstract

A Ni-InAs source/drain nMOSFET is a promising future logic device. However, the specific contact resistivity, ρ int , between InAs and Ni-InAs is difficult to evaluate accurately because of the complex junction structure. In this study, we develop a multi-sidewall transmission line method (MSTLM) for the measurement of low contact resistivity with high accuracy. The MSTLM enables us to simplify the junction interface structure in terms of the resistance analysis, to eliminate the effects of the contact metal and to perform statistical analyses to mitigate sample variations. The high accuracy of measurement of ρ int is demonstrated by combining InAs-on-insulator (InAs-OI) substrates with the MSTLM. The evaluated ρ int of (3.0 ± 0.9) × 10 −8 Ω cm 2 for InAs with an electron concentration of 2 × 10 18 cm −3 is found to be in good agreement with the theoretically calculated value under a Schottky barrier height of 0 eV.

Scaling of GaSb/InAs Vertical Nanowire Esaki Diodes Down to Sub-10-nm Diameter

“…Using (3) and the materials and device parameters of Table I, we can predict Rs versus DGaSb. The specific contact resistance (𝜌 𝑐 ) for the Ni/n ++ -InAs ohmic contact is adopted from [26] at ND = 10 19 cm -3 , 𝜌 GaSb is calculated using the formula given in [27] at a doping level NA = 10 19 cm -3 , and 𝜌 InAs is adopted from [28] at a doping level ND ≈ 6×10 18 cm -3 , which is similar to the nominal doping level of the n + -InAs(Sb) portion of our devices. We adopt Lc = 25 nm since Al2O3 is removed only from the top 25 nm of the VNW, as observed in an SEM measurement right before contact metal sputtering.…”