Rapid Thermal Annealing with Arsenic Overpressure for Processing of Self-Aligned GaAs MESFET's

Processing of the self-aligned GaAs MESFET's involves high temperature annealings for activation of the ion implanted species. The refractory gate, serving as a mask for the channel is present on the wafer surface at the time of annealing. The rapid thermal annealing (RTA, typically 900C for 20 sec) is a desirable dopant activation technique due to reduction of short channeling effect and gate/substrate interaction. This paper presents data on surface morphology, carrier concentration and mobility in the implanted substrates as a function of capping layers and arsenic overpressure during annealing.