Ga₂O₃(Gd₂O₃)/InGaAs enhancement-mode n-channel MOSFETs

We have demonstrated the first Ga2O3(Gd2O3) insulated gate n-channel enhancement-mode In/sub 0.53/Ga/sub 0.47/As MOSFET's on InP semi-insulating substrate. Ga2O3(Gd2O3) was electron beam deposited from a high purity single crystal Ga5Gd3O/sub 12/ source. The source and drain regions of the device were selectively implanted with Si to produce low resistance ohmic contacts. A 0.75-μm gate length device exhibits an extrinsic transconductance of 190 mS/mm, which is an order of magnitude improvement over previously reported enhancement-mode InGaAs MISFETs. The current gain cutoff frequency, fT, and the maximum frequency of oscillation, fmax, of 7 and 10 GHz were obtained, respectively, for a 0.75×100 μm2gate dimension device at a gate voltage of 3 V and drain voltage of 2 V.