High K-value LDD GaAs MESFET's with SiF/sub 3/-implanted shallow channels

High K-value self-aligned GaAs MESFETs with a reduced short-channel effect that were developed using both shallow SiF/sub 3/-implanted channels annealed with a WSiN refractory metal cap and a lightly doped drain (LDD) structure are discussed. The 0.5- mu m-gate device has a maximum transconductance of 360 mS/mm and a K-value of 504 mS/Vmm with a threshold voltage of 60 mV. The threshold voltage shift was only 90 mV when the gate length was reduced from 2.0 to 0.5 mu m. In addition, more precise control of the threshold voltage was obtained.<
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