Proceedings of the First European Workshop on Low Temperature Electronics
J. Phys. IV France 04 (1994) C6-171-C6-176
High electric field transport effects on low temperature operation of pseudomorphic HEMTsF. Aniel1, P. Crozat1, A. De Lustrac1, R. Adde1 and Y. Jin2
1 IEF, URA 22 du CNRS, Bat. 220, Université Paris-Sud, 91405 Orsay, France
2 L2M/CNRS LP20, 196 rue de Ravera, 92220 Bagneux, France
High electric field effect in very small pseudomorphic High Electron Mobility Transistor (HEMT) Al0.22Ga0.78As/In0.2Ga0.8As/GaAs and their influence at low temperature are investigated for 0.1µm up to 0.4µm gate lengths. The extent of transport improvement at low temperature and performance degradation associated with gate length reduction are underlined. Limitations in performance improvement appear at low temperature due to trapping effects and to an enhancement of the mechanisms responsible of short channel effects. In pulsed drain operation the evolutions of drain current versus time in the 10ns-600µs range illustrate the influence of trapping centers and self heating of the lattice in the device. We analyze the variation of gate current versus temperature at high drain bias (>3V) and the influence of impact ionization.
© EDP Sciences 1994