A high performance 0.12 um T-shape gate Ga0.5In0.5As/Al0.5In0.5As MODFET grown by MBE lattice mis-matched on a GaAs substrate

We report on the first successful fabrication of high performance GalnAs/AlInAs MODFETs of 0.12 µm gate length grown lattice mismatched on a GaAs substrate. A peak extrinsic DC transconductance of 585 mS/mm and a saturated channel current of 370 mA/mm are achieved at room temperature. A high unity current gain cut-off frequency fT, of 107 GHz has been demonstrated. Parasitic conduction which may be the result of the dislocations present under the large-area FET bonding pads and possibly under the active FET channel, however, serverely limits the peak fmaxto 125 GHz.