AlGaAsSb buffer/barrier layer on GaAs substrate for InAs channel with high electron properties

InAs/AlGaAsSb deep quantum wells were successfully formed on GaAs substrate and examined for two electron devices: Hall elements (HEs) and field-effect transistors (FETs). With a thin buffer layer of 600 nm AlGaAsSb on a GaAs substrate, we observed high electron mobility of more than 20000 cm/sup 2//Vsec and an effective electron velocity of 2.2/spl times/10/sup 7/ cm/sec at RT for a 15 nm thick InAs channel. AlGaAsSb, lattice-matched to InAs, was discussed from the viewpoints of insulating property, carrier confinement and oxidization. Reliability data good enough for practical use were also obtained for HEs. We propose AlGaAsSb as a promising buffer/barrier layer material for InAs channel devices on GaAs substrates, and we suggest AlGaAsSb also for InGaAs channel devices.