0.2 µm AlSb/InAs HEMTs with 5 V gate breakdownvoltage

DC and microwave measurements on AlSb/InAs HEMTs with a gate length of 0.2 µm are reported. The reverse gate characteristics exhibit relatively low gate leakage current and gate-drain breakdown voltages as high as 5 V. Equivalent circuit modelling yields an fT of 110 GHz after removal of the gate bonding pad capacitance. The bias dependence of fmax is examined indicating a significant reduction in the unilateral gain due to impact ionisation.