Characterization of InAs/AlSb tunneling double barrier heterostructure by ballistic electron emission microscope with InAs as base electrode

Abstract

We characterize our InAs/AlSb double tunnel barrier heterostructure as the base electrode with the well thickness of 12 nm and symmetric barrier thickness of 2 nm by ballistic electron emission microscopy/spectroscopy using the top InAs layer of heterostructures. We present the influence of the InAs base layer thickness (3 nm, 10 nm) and the influence of the surface passivation on results of spectroscopic measurement. The mean measured barrier height was 1.11 (±0.03) eV independent of the thickness of the InAs base electrode. The mean measured height of barriers in the case of the passivated InAs base layer was found to be lower and equal to 1.059 (±0.03) eV. We also detect thresholds in spectroscopic characteristics which are in accordance with the energy of the second resonant level in the well, and with energies that are combinations of thresholds for electron–hole pair creation processes in InAs and the energy of the second resonant level in the well. A ballistic electron emission microscopy picture at a constant voltage of 1.25 V is presented.