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The dc and microwave results of Si/sub 0.2/Ge/sub 0.8//Si/sub 0.7/Ge/sub 0.3/ pMODFETs grown on silicon-on-sapphire (SOS) substrates by ultrahigh vacuum chemical vapor deposition are reported. Devices with L/sub g/=0.1 /spl mu/m displayed high transconductance (377 mS/mm), low output conductance (25 mS/mm), and high gate-to-drain breakdown voltage (4 V). The dc current-voltage (I-V) characteristics were also nearly identical to those of control devices grown on bulk Si substrates. Microwave characterization of 0.1/spl times/50 /spl mu/m/sup 2/ devices yielded unity current gain (f/sub T/) and unilateral power gain (f/sub max/) cutoff frequencies as high as 50 GHz and 116 GHz, respectively. Noise parameter characterization of 0.1/spl times/90 /spl mu/m/sup 2/ devices revealed minimum noise figure (F/sub min/) of 0.6 dB at 3 GHz and 2.5 dB at 20 GHz.