Observation of N-shaped negative differential resistance in ridge-type InGaAs/InAlAs quantum wire field-effect transistor

N-shaped negative differential resistance (NDR) with high peak-to-valley ratio (PVR) and low onset voltage (V-NDR) are clearly observed in a 50-nm gate ridge-type InGaAs/InAlAs quantum wire held-effect transistor (QWR-FET). The NDR of low onset voltage (V-NDR) and its dependence on the gate voltage are attributed to the real space transfer of channel carriers into a barrier layer underneath the gate by held-assisted tunneling. The NDR characteristic of the QWR-FET is enhanced compared with that of InGaAs/InAlAs quantum well field-effect transistor (QW-FET). The narrower channel width and shorter gate length effectively improve the PVR and V-NDR. (C) 1999 Elsevier Science B.V. All rights reserved.