0.1 µm AlSb/InAs HEMTs with InAs subchannel

AlSb/InAs HEMTs with a 0.1 µm gate length have been fabricated with a thin InAs subchannel separated from the InAs channel by 30 Å of AlSb. As a result, these HEMTs exhibit improved charge control and a higher current-gain cutoff frequency. The devices have a microwave transconductance of 850 mS/mm and an fT of 180 GHz at VDS = 0.6 V. After subtracting the gate bonding pad capacitance, an fT of 250 GHz was obtained.