Magnetoconductivity of GaAs Transistors as Detectors of THz Radiation

J. Łusakowski a , W. Knap b , E. Kamińska c , A. Piotrowska c and V. Gavrilenko d a Institute of Experimental Physics, University of Warsaw Hoża 69, 00-681 Warsaw, Poland b GES--CNRS --- Universite Montpellier 2, 34900 Montpellier, France c Institute of Electron Technology, al. Lotników 32/46, 02-668 Warsaw, Poland d IPM, Russian Academy of Sciences, GSP-105, Niznij Novgorod, 603950, Russia

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Magnetotransport characterisation of field effect transistors processed on GaAs/GaAlAs heterostructure was done at 4.2 K for magnetic fields (B) up to 7 T. Three field effect transistors were processed on a single dice and differed by the length (L) of the gate. Electron mobility (μ) in field effect transistors was estimated from dependence of transistor's conductivity vs. B. The results show a decrease in μ with decreasing L that suggests that scattering by edges of the gated part of a transistor limits the electron mobility. Quality factor (Q) of transistors as resonant detectors of THz radiation was calculated. A high value of Q shows that such field effect transistors with sub-micron L are promising devices that can operate at THz frequencies.

DOI: 10.12693/APhysPolA.103.545 PACS numbers: 72.30.+q, 73.61.Ey