Microwave performance of InGaAs/InAlAs/InP SISFETs

Microwave S-parameter measurements and equivalent-circuit modeling of In/sub 0.53/Ga/sub 0.47/As/In/sub 0.52/Al/sub 0.48/As/InP semiconductor-insulator-semiconductor FETs (SISFETs) of 1.1- mu m gate length are discussed. The devices incorporated wide-bandgap buffers, self-aligned contact implants, and refractory air-bridge gates. Their DC I-V characteristics displayed sharp pinchoff, good output conductance of 10-20 mS/ss, and extrinsic transconductance up to 220 ms/mm at room temperature. The maximum unity-current-gain frequency was 27 GHz. Gate resistance was found to be the dominant factor limiting microwave power gain.<
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