Design and realization of sub 100 nm gate length HEMTs
Standard layer structure InAlAs/InGaAs/EnP designed for 100 nanometer gate length High Electron Mobility Transistors (HEMTs) become inadequate, if we reduce the gate length under 100 nm. An InAlAs/InGaAs/InP layer structure optimized for 50 nanometer gate length HEMTs has been realized. DC and microwave characteristics are reported on HEMTs realized on a standard layer and an optimized layer, with similar gate length. Comparable cutoff frequencies f/sub T/ are obtained for both devices. The main result is a large improvement of maximum oscillation frequency f/sub max/, which is 260 GHz and 470 GHz for respectively the standard and the optimized devices. This behavior is attributed to the reduction of short channel effects.