0.1 μm gate length MODFETs with unity current gain cutoff frequency above 110 GHz

Abstract

AlGaAs/GaAs modulation-doped field-effect transistors (MODFETs) have been fabricated with ‘T’ cross-section 0.1 μm gates using electron-beam lithography. A unity current gain cutoff frequency fT of 113 GHz has been measured for a spike-doped MODFET with a GaAs buffer. This is the highest measured fT reported to date for FETs of any kind.