Characterization of GaAs and InGaAs double-quantum well heterostructure FETs

It is pointed out that among the large variety of heterostructure field effect transistors, multichannel devices present a particular originality: their transconductance profile is very flexible and depends on the structure parameters. They are therefore suited for high signal nonlinear applications. The specific case of double quantum-well structures is studied. Conventional and pseudomorphic devices are characterized under DC and RF conditions. Very high current densities (up to 1.2 A/mm) are demonstrated. The effect of different structural parameters on the transconductance and cutoff frequency is discussed. The results are analyzed in order to give a full understanding of these devices and to demonstrate their performances