SAMOP 2023 – scientific programme

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Q: Fachverband Quantenoptik und Photonik

Q 25: Solid State Quantum Optics

Q 25.7: Talk

Wednesday, March 8, 2023, 12:30–12:45, E001

Contactless sheet resistance measurements of thin III-V semiconductors by far-field terahertz reflectometry — •Konstantin Wenzel, Steffen Breuer, Robert B. Kohlhaas, and Lars Liebermeister — Fraunhofer Institute for Telecommunications, Heinrich Hertz Institute, Einsteinufer 37, 10587 Berlin, Germany

Measuring the electrical properties of thin semiconductor layers is crucial for the development of semiconductor devices. 4-point measurements, such as van-der-Pauw and Hall, determine these properties very accurately. However, since this method requires electrical contacts, the measurement location becomes unusable for further processing. At the same time, areas of the sample used for processing are not measured. Here, we present far-field terahertz (THz) reflectometry measurements as a contactless alternative for determining the sheet resistance with spatial resolution. We investigate various doped indium gallium arsenide samples epitaxially grown on indium phosphide substrates using THz time-domain spectrometry. We compare these measurements to standard 4-point measurements and discuss the limitations of our technique. The presented THz reflectometry allows non-contact and spatially resolved characterization of a broad spectrum of thin semiconductors, paving the way towards a new measurement technique for full-wafer characterization.