A 0.4- mu m gate-length AlGaAs/GaAs P-channel HIGFET with 127-mS/mm transconductance at 77 K

WN-gate, p-channel AlGaAs-GaAs heterostructure insulated-gate field-effect transistors (HIGFETs) fabricated on a metalorganic vapor-phase epitaxy (MOVPE) wafer are discussed. A self-aligned Mg ion implantation (80 keV, 6*10/sup 13/ cm/sup -2/) annealed at 850 degrees C in an arsine atmosphere and the control of the SiO/sub 2/ sidewall dimensions allow the fabrication of p-channel HIGFETs with a gate length smaller than 0.5 mu m with low subthreshold current. P-channel HIGFETs with 0.4- mu m gate lengths exhibit extrinsic transconductances as high as 127 mS/mm at 77 K and 54 mS/mm at 300 K.<
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