DC and microwave characteristics of InAlAs/InGaAs single-quantum-well MODFETs with GaAs gate barriers

The design and performance of In/sub 0.53/Ga/sub 0.47/As/In/sub 0.52/Al/sub 0.48/As modulation-doped field-effect transistors (MODFETs) have been optimized by incorporating a single In/sub 0.53/Ga/sub 0.47/As quantum-well channel and a thin strained GaAs gate barrier layer. These help to lower the output conductance and gate leakage current of the device, respectively. The DC performance of 1- mu m-gate devices is characterized by extrinsic transconductances of 320 mS/mm at 300 K and 450 mS/mm at 77 K and a best value of f/sub T/=35 GHz is derived from S-parameter measurements.<
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