Noise performance of submicrometer AlInAs-GaInAs HEMTs

Record DC and RF performance of AlInAs-GaInAs lattice matched to InP HEMTs (high-electron-mobility transistors) with nominally 0.2- and 0.1- mu m gate lengths have been achieved. The devices were fabricated on material grown by MBE (molecular-beam epitaxy) on Fe-doped InP substrates. The epitaxial layers consisted of an undoped AlInAs spacer, a highly doped AlInAs donor layer, an undoped Schottky-enhancing AlInAs layer, and, finally, a highly doped GaInAs layer contact layer. 50- mu m-wide devices with 0.2- and 0.1- mu m-long T-gates were fabricated. The 0.2- mu m gate-length devices were tested at V-band. The single-stage amplifier (waveguide to waveguide with no correction) exhibited a minimum noise figure F/sub min/ of 1.8 dB with an associated gain 7.5 dB at 63.0 GHz. This translates to an amplifier noise measure of 2.10 dB. The corresponding device performance was a minimum noise figure of 1.4 dB with an associated gain of 8.5 dB. This corresponds to a device noise measure of 1.6 dB.<
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