Effect of F co-implant during annealing of Be-implanted GaAs

Abstract

F+ co-implantation at different doses and energies was performed into GaAs already implanted with Be+ at high dose (1015 cm−2) and low energy (20 keV), in order to reduce the beryllium diffusion during post-implant annealing. The redistribution behavior of Be and associated electrical effects were studied by secondary-ion mass spectrometry, transmission electron microscopy (TEM), Hall effect measurements, and current-voltage profiling. Be outdiffusion was reduced by co-implantation of F; more than 80% of the implanted Be was retained during rapid thermal annealing up to 850 °C. The dose and energy of the F implant strongly influenced Be electrical activation efficiency. High activation, up to 48.5%, was obtained when F was co-implanted at high dose (1015 cm−2) and low energy (10 keV). Hole profiles shown reduced electrical activation in the region where F and Be profiles overlapped and TEM studies indicated the formation of {111} coherent plates, possibly BeF2 precipitates, in the same region. The reduction of Be outdiffusion in F co-implanted samples led to high activation after annealing, and was believed to be due to chemical interaction between Be and F.

Development of InxGa1−xAs-based ohmic contacts for p-type GaAs by radio-frequency sputtering

“…5 In x Ga 1-x As-based ohmic contacts which showed excellent contact properties for n-GaAs were demonstrated to be applicable to p-GaAs ohmic contacts. Ion implantations were carried out at room temperature for the GaAs wafers which were tilted 7° off the ion-beam direction to reduce ion channeling in a crystalline target.…”

“…5 After the implant activation, the Si 3 N 4 cap layer was removed by immersing in buffered HF. The activation of the implanted Be was performed by annealing at 850°C for 5 s in an atmosphere of flowing argon gas using a rapid thermal annealer (RTA).…”

n-type ion implantation doping of AlxGa1−xAs (0⩽x⩽0.7)

“…One approach that has been applied to both Si ͑Ref. 7͒ and acceptor [15][16][17][18] implantation in GaAs, is to employ the coimplantation of a column V element ͑As or P͒ overlaying the Si profile. This technique is thought to increase the probability of Si for occupying a Ga-lattice site and thereby act as a donor by one of two mechanisms.…”