Hall Effect Measurements of Zn Implanted GaAs

The isochronal annealing behavior of the effective surface carrier concentration and effective Hall mobility of Zn-implanted layers in GaAs has been investigated. Ion implantation has been performed with 60 keV Zn ion at various doses up to 1016/cm2 at room temperature and 400°C. An annealing stage for effective Hall mobility exsists between 600 and 700°C. After annealing at 700°C and above, ionized-impurity scattering is a dominant mechanism affecting the mobility. The highest mobility obtained is 170 cm2/V sec. The maximum effective surface carrier concentration is achieved after annealing at temperatures around 700°C. Samples implanted with doses up to 1015/cm2 show a 100% doping efficiency and those implanted with heavier doses show a saturation tendency in the effective surface carrier concentration.