A narrow-channel, 0.2- mu m gate-length, double-quantum-well pseudomorphic MODFET with high power gain at millimeter-wave frequencies

State-of-the-art pseudomorphic MODFETs were developed with metallurgical gate lengths between 0.22 and 0.25 mu m, very short source-to-drain spacings of 0.7 mu m, and a double-quantum-well material structure. S-parameter measurements were performed on these 60- mu m gate-width devices up to 40 GHz. From these S-parameter measurements, an extrapolated value of 82 GHz was estimated for F/sub t/. Modeling of the power gain as a function of frequency indicates that F/sub max/ may be as high as 305 GHz.>