Ion implantation and annealing of undoped (Al,Ga)As/GaAs heterostructures

Electrical measurements of n+-GaAs/π-(Al,Ga)As/π-GaAs semiconductor-insulator-semiconductor (SIS) heterostructure capacitors and field-effect transistors (FET's) show that the (Al,Ga)As/GaAs heterojunction abruptness is well preserved for an arsine flash anneal of 1 s at temperatures up to ∼900°C. The heterostructure stability is also preserved for a low-dose silicon implant across the (Al,Ga)As/GaAs heterojunction and subsequent annealing. Arsenic overpressure is found to be necessary, even for short time annealing, to prevent excessive As loss from a GaAs or (Al,Ga)As surface. High mobility enhance-deplete heterostructure SISFET's with sharp current versus voltage (I-V) turn-on characteristics have been fabricated using ion implantation and arsine flash anneal.