High performance 50 nm T-gate In/sub 0.52/Al/sub 0.48/As/In/sub 0.53/Ga/sub 0.47/As metamorphic high electron mobility transistors

We report the performance of 50 nm gate length metamorphic GaAs HEMTs with maximum transconductance (g/sub m/) of 1520 mS/mm and current cut-off frequency(f/sub T/) of 350 GHz, to our knowledge the highest g/sub m/ and f/sub T/ of a GaAs-based HEMT transistor. The devices were fabricated with a novel UVIII/PMMA T-gate resist stack and a non-selective "digital" wet etch gate recess technology which results in a highly uniform, high yield sub-100 nm HEMT technology.