Field-effect controlled resonant interband tunnelling in electron surface layers on InAs and In0.53Ga0.47As

Abstract

The authors report on an experimental study of a novel three-terminal negative differential conductance device. Interband tunnelling from an electron inversion layer through the depletion barrier into resonant states of the bulk valence band is controlled by the gate voltage Vg at an InAs or InGaAs metal-insulator-semiconductor field-effect structure. Upon increasing Vg from the threshold voltage by up to 2 V the peak current can be varied by a factor of 5000 (500) with a peak-to-valley current ratio in excess of 2(16) for InAs (InGaAs). The effective tunnelling electric field and an areal electron density, as determined by measurements under high magnetic fields, are found to be only weakly dependent on Vg and on the tunnelling voltage. The mechanism of current control is discussed in terms of a variation of effective tunnelling area.