HIGH-PERFORMANCE GA0.51IN0.49P GAAS AIRBRIDGE GATE MISFETS GROWN BY GAS-SOURCE MBE/

Ga0.51In0.49P/GaAs MISFET's, in which a Ga0.51In0.49P insulating layer was inserted between the gate metal and the channel layer, were compa red with MESFET's experimentally and theoretically in terms of de and microwave performance, Devices performance were evaluated by varying t he thickness of the insulating layer, Wide and flat characteristics of g(m), f(t), and f(max), versus drain current (or gate voltage) togeth er with a high maximum current density (above 610 mA/mm) were achieved for devices with insulating layer thickness of 50 nm and 100 nm, More over, the maximum values of f(t)'s and f(max)'s for a 1-mu m gate leng th device both occurred when t was between 50 and 100 nm, We also obse rved that parasitic capacitances and gate leakage currents were minimi zed by using the airbridge gate structure, and thus high-frequency and breakdown characteristics were greatly improved. These results demons trate that Ga0.51In0.49P/GaAs airbridge gate MISFET's with insulating layer thickness between 50 and 100 mm were very suitable for microwave high-power device applications.