Metamorphic GaAs HEMTs with f/sub T/ of 200 GHz

We report the RF performance of 0.12 /spl mu/m T-gate GaAs based metamorphic HEMTs with a composite In/sub 0.53/Ga/sub 0.47/As/In/sub 0.30/Ga/sub 0.70/As channel. 2/spl times/50 /spl mu/m wide devices demonstrated an f/sub T/ of 200 GHz, the highest of any three terminal GaAs based device reported to date. In addition, 2/spl times/25 /spl mu/m devices demonstrated 9.0 dB MAG at 94 GHz showing the W-band capability of GaAs based metamorphic HEMTs.