Low noise In/sub 0.32/(AlGa)/sub 0.68/As/In/sub 0.43/Ga/sub 0.57/As metamorphic HEMT on GaAs substrate with 850 mW/mm output power density

A double-pulse-doped InAlGaAs/In/sub 0.43/Ga/sub 0.57/As metamorphic high electron mobility transistor (MHEMT) on a GaAs substrate is demonstrated with state-of-the-art noise and power performance, This 0.15 μm T-gate MHEMT exhibits high on- and off-state breakdown (V/sub ds/>6 V and V/sub dg/>13 V, respectively) which allows biasing at V/sub ds/>5 V. The 0.6 mm device shows >27 dBm output power (850 mW/mm) at 35 GHz-the highest reported power density of any MHEMT. Additionally, a smaller gate periphery 2×50 μm (0.1 mm) 43% MHEMT exhibits a F_min=1.18 dB and 10.7 dB associated gain at 25 GHz, and also is the first noise measurement of a -40% In MHEMT. A double recess process with selective etch chemistries provides for high yields.