High performance Al0.48In0.52As/Ga0.47In0.53As HFETs

MBE grown Al_0.48In_0.52As/Ga_0.47In_0.53As heterostructure field effect transistors have been fabricated on InP substrates. DC characteristics of 1.3 mu m gate devices show no kink effects and no breakdown, even for drain to gate voltages in excess of -4.5 V, thus demonstrating excellent material properties. High frequency investigations reveal a very low output conductance of about 12 mS/mm and a transconductance in excess of 420 mS/mm. Cutoff frequencies of 75 GHz are achieved for 1.3 mu m gate length. These values are the highest reported for devices of this geometry at room temperature.