High performance 0.1 µm gate-length planar-doped HEMTs

AlGaAs/InGaAs/GaAs planar-doped pseudomorphic HEMTs with a gate length of 0.1µm have been successfully fabricated. A maximum extrinsic transconductance gmof 930 mS/mm, corresponding to an intrinsic gmof 1380 mS/mm, is observed in the devices at room temperature. A unity current gain cutoff frequency fTof ∼100 GHz was projected. A maximum gain as high as 19.3 dB was also measured at 18 GHz. At 59 GHz, the devices have demonstrated a minimum noise figure of 2.3 dB with an associated gain of 6.5 dB from one wafer, and 2.5 dB noise figure with 8.0 dB associated gain from another. At 94 GHz, ∼7 dB small signal gain was also measured from a single-stage amplifier. These are the best gain and noise results reported to date for FETs.