Velocity overshoot in ultra-short-gate-length GaAs MESFETs

GaAs MESFETs with ultrashort gates between 0.035 and 0.065 mu m were fabricated to determine trends in their DC transconductance as a function of gate length. It is found that overshoot in the channel causes a considerable increase in the average electron velocity. An approximation based on the gradual channel approximation becomes valid at ultrashort gate lengths due to an increased percentage of the channel that is velocity-saturated.<
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