InAs Thin-Channel High-Electron-Mobility Transistors with Very High Current-Gain Cutoff Frequency for Emerging Submillimeter-Wave Applications

Abstract

60 nm InAs high-electron-mobility transistors (HEMTs) with a thin channel, a thin InAlAs barrier layer, and a very high gate stem structure have been fabricated and characterized. The thickness of the channel, as well as that of the InAlAs barrier layer, was reduced to 5 nm. A stem height of 250 nm with a Pt-buried gate was used in the device configuration to reduce the parasitics. A high DC transconductance of 2114 mS/mm and a current-gain cutoff frequency (fT) of 710 GHz were achieved at VDS=0.5 V.