Electrical Properties of Thin Layers of III/V Semiconductors Obtained by Terahertz Reflectometry and Transmissometry

We investigate indium gallium arsenide samples with various doping levels using terahertz (THz) time-domain reflectometry and transmissometry in the near- and far-field. The samples have been grown on indium phosphide substrates by molecular beam epitaxy under different growth conditions yielding a wide range of electrical properties including resistances from 10(1) to 10(6) Ohm/sq. We compare THz measurements on these samples to a model based on the Tinkham Equation and standard 4-point measurements. The presented method allows non-contact and spatially resolved characterization of a broad spectrum of thin semiconductors, paving the way towards a new fast and contactless measurement technique for full-wafer characterization.