Study on Nonlinear Electrical Characteristics of GaAs-Based Three-Branch Nanowire Junctions Controlled by Schottky Wrap Gates

Abstract

The nonlinear electrical characteristics of GaAs-based three-branch nanowire junction (TBJ) devices having Schottky wrap gates (WPGs) are investigated experimentally and theoretically, focusing on the nonlinear mechanism at room temperature in devices with large dimensions and the improvement of voltage transfer efficiency. Input–output voltage transfer curve, Vout–Vin, is characterized by changing nanowire width, W, temperature, T, and WPG gate voltage, VG, systematically. At room temperature, a bell-shaped Vout–Vin curve is observed even in the device having a nanowire width of 1,500 nm, which is ten times larger than the electron mean free path. With decreasing wire width or temperature, the output curves are sharpened and curvature in the low-input-voltage region increases. The curvature rapidly increases and voltage transfer efficiency, ΔVout/ΔVin, approaches unity when VG is decreased into the subthreshold region. A simple and compact model for the nonlinear characteristics in the nonballistic regime is introduced. The rapid change of the curvature and complex curve in the subthreshold region under VG control is due to the switching of the branch condition from resistive to capacitive by depletion underneath the WPG.