A 630-mS/mm GaAs MESFET with Au/WSiN refractory metal gate

GaAs MESFET's with a gate length as low as 0.2 mu m have been successfully fabricated with Au/WSiN refractory metal gate n/sup +/-self-aligned ion-implantation technology. A very thin channel layer with high carrier concentration was realized with 10-keV ion implantation of Si and rapid thermal annealing. Low-energy implantation of the n/sup +/-contact regions was examined to reduce substrate leakage current. The 0.2- mu m gate-length devices exhibited a maximum transconductance of 630 mS/mm and an intrinsic transconductance of 920 mS/mm at a threshold voltage of -0.14 V.<
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