CYCLOTRON-RESONANCE IN ASYMMETRIC MODULATION-DOPED FIELD-EFFECT TRANSISTOR HETEROSTRUCTURES USING INXGA1-XAS QUANTUM-WELL AND INAS-GAAS SUPERLATTICE CHANNELS

Cyclotron resonance and photoluminescence measurements were carried ou t on two types of modulation-doped field-effect transistor heterostruc tures whose channels were made of an InAs-GaAs short-period superlatti ce and of an InxGa1-xAs quantum well, respectively. From cyclotron res onance data a linear dependence of the channel electron effective mass on indium content was obtained for both series of samples. For a give n mean value of the indium content in the channel, the effective mass is found to be systematically higher in samples where the channel is b ased on a short-period superlattice rather than on an alloy-based chan nel. This can be attributed to larger nonparabolic effects in the form er. Calculations of nonparabolicity corrections are in agreement with these results. In our theoretical model, the energy of the electron an d heavy hole levels were determined self-consistently. (C) 1997 Americ an Vacuum Society. [S0734-211X(97)01305-X].