Fringe field control of one-dimensional room temperature sub-band resolved quantum transport in site controlled AlGaN/GaN lateral nanowires

Abstract

We have demonstrated effective fringe field control of one-dimensional electron gas (1-DEG) in AlGaN/GaN lateral nanowires. The nanowires are site controlled and formed by a combination of dry and anisotropic wet etching. The nanowire dimensions are well controlled and can have a very high length/width aspect ratio of 10 μm/5 nm or larger. The transport is controlled by a fringe gate and shows room temperature quantum transport where gradual filling of 1-D subbands gets manifested as oscillations in the transconductance. The fringe gate threshold voltage for depletion of one-dimensional electron gas is found to increase with increasing drain voltage indicating efficient control of 1-DEG. The transport characteristics and fringe field operation are explained by taking into account quantum capacitance in addition to the conventional geometric capacitance. The effect of nanowire width and fringe gate position is also discussed.