Fringe field control of one-dimensional room temperature sub-band resolved quantum transport in site controlled AlGaN/GaN lateral nanowires (Phys. Status Solidi A 2∕2017)

Abstract

GaN quantum nanowire based devices are predicted to provide a host of benefits owing to two-dimensional confinement. However, the regular patterned formation of nanowires which actually show quantum confined effects has remained a daunting challenge for GaN. Here, Kumar et al. (article No. 1600620) demonstrate that an array of regular patterned lateral nanowires of aspect ratio > 103 or higher with width <5 nm can be formed by a combination of dry and crystallographic anisotropic wet-etching processes. The large inter-subband separation leads to room-temperature sub-band resolved quantum transport in these devices as an evidence of the strong two-dimensional confinement. The drain to source current of the nanowire is controlled by the fringe field arising out of a non-contacting gate. This scheme shows an alternative method to control gate field without the problem of sidewall leakage. The main figure of the cover image shows an SEM of the fringe field lateral nanowire transistor. A typical cross-section of the nanowire is shown in the lower panel. The upper panel shows the quantum capacitance for a hypothetical 2-D and 1-D nanowire systems highlighting the importance of quantum confinement in these systems.