RF and DC characteristics of low-leakage InAs/AlSb HFETs

InAs/AlSb HFETs with excellent RF and DC properties are reported. The drain currents are 750 mA/mm. with peak transconductance g/sub m/ of 1.1 S/mm. The gate leakage is below 1 nA//spl mu/m/sup 2/ for low gate bias. The threshold voltages of 0.25 /spl mu/m and 0.5 /spl mu/m gate-length devices are -2.5 and -1.5 V respectively, indicating short channel effects are present. Small-signal measurements on a 0.25 /spl mu/m gate-length device show f/sub /spl tau// of 120 GHz and f/sub max/ of 100 GHz at drain voltages below 0.4 V.