Characteristics including electron velocity overshoot for 0.1- mu m-gate-length GaAs SAINT MESFET's

Short-channel effects, substrate leakage current, and average electron velocity are investigated for 0.1- mu m-gate-length GaAs MESFETs fabricated using the SAINT (self-aligned implantation for n/sup +/-layer technology) process. The threshold-voltage shift was scaled by the aspect ratio of the channel thickness to the gate length (a/L/sub g/). The substrate leakage current in a sub-quarter-micrometer MESFET is completely suppressed by the buried p layers and shallow n/sup +/-layers. The average electron velocity for 0.1- to 0.2- mu m-gate-length FETs is estimated to be 3*10/sup 6/ cm/s from the analysis of intrinsic FET parameters. This high value indicates electron velocity overshoot. Moreover, a very high f/sub T/ of 93.1 GHz has been attained by the 0.1- mu m SAINT MESFET.<
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