Temperature-dependent studies of InAs base layers for ballistic electron emission microscopy

InAs is a promising base material for ballistic electron emission microscop y (BEEM), since in this material the attenuation length of ballistic electr ons is more than one order of magnitude larger than for metal base layers a nd the corresponding transmission factor for ballistic electrons is strongl y enhanced. In this work, temperature-dependent BEEM studies on InAs base l ayers grown on GaAs substrates are performed. Unlike on samples with metal base layers, it is found that the transmission coefficient of the InAs base decreases with decreasing temperature. In addition, a strongly increasing conduction band offset at the InAs-GaAs interface with decreasing temperatu re is also observed.