Gate-length dependence of DC and microwave properties of submicrometer In/sub 0.53/Ga/sub 0.47/As HIGFETs

In/sub 0.52/Al/sub 0.48/As/In/sub 0.53/Ga/sub 0.47/As/InP heterostructure insulated-gate field-effect transistors (HIGFETs) with gate lengths from 1.1 and 0.3 mu m have been fabricated, and their electrical performance is characterized at DC and microwave frequencies. The refractory-gate self-aligned process, applied to devices with In/sub 0.53/Ga/sub 0.47/As channels, yields an unprecedented combination of very-high speed and excellent uniformity. HIGFETs with L/sub g/=0.6 mu m showed average peak transconductance g/sub m/ of 528 mS/mm and unity-current-gain cutoff frequency f/sub t/ of 50 GHz. The uniformity of g/sub m/ was better than 1%, and the voltage of the g/sub m/ peak was uniform to +or-30 mV. HIGFETs with L/sub g/=0.3 mu m showed f/sub 1/ up to 63 GHz, but suffered from serious short-channel effect, due to excessive thickness of the InGaAs channel layer. A self-aligned technique for gate resistance reduction is shown to substantially improve microwave power gain.<
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