Magnetotransport characterization of THz detectors based on plasma oscillations in submicron field-effect transistors

Magnetotransport characterization of field-effect transistors in view of their application as resonant detectors of THz radiation is presented. Three groups of different transistors based on GaAs/GaAlAs or GaInAs/AlGaAs heterostructures are investigated at liquid-helium temperatures and for magnetic fields of up to 14 T. The magnetic-field dependence of the transistor resistance is used for evaluation of the electron density and mobility in the transistor channel. The electron mobility and concentration determined from magnetotransport measurements are used for the interpretation of recently observed resonant detection of terahertz radiation in 0.15 µm gate length GaAs transistors and for the determination of the parameters of other field-effect transistors processed for resonant and voltage tunable detection of THz radiation.