High-linearity high-current-drivability ga0.51in0.49p/gaas misfet using ga0.51in0.49p airbridge gate structure grown by gsmb

A novel structure Ga0.51In0.49P/GaAs MISFET with an undoped Ga0.51In0.49P layer serving as the airbridge between active region and gate pad was first designed and fabricated. Wide and flat characteristics of gmand fmaxversus drain current or gate voltage were achieved. The device also showed a very high maximum current density (610 mA/mm) and a very high gate-to-drain breakdown voltage (25 V). Parasitic capacitances and leakage currents were minimized by the airbridge gate structure and thus high fTof 22 GHz and high fmaxof 40 GHz for 1 μm gate length devices were attained. To our knowledge, both were the best reported values for 1 μm gate GaAs channel FETs.