n(+) self-aligned-gate AlGaAs/GaAs heterostructure FET

The n(+) self-aligned gate technology employing rapid lamp annealing has been studied and successfully applied to the AlGaAs/GaAs high-mobility two-dimensional electron gas FET integrated circuits (HEMT IC). Large transconductances of 330 mS/mm at 300 K and 530 mS/mm at 77 K were obtained for a 0.7 micron gate length device by reducing the source resistance to 0.6 ohm-mm. The minimum delay time of 18.7 ps was obtained with a power dissipation of 9.1 mW at 300 K. The small delay time standard deviation of 1.1 ps suggests that the n(+) self-aligned gate process is a key one for HEMT IC fabrication.