Abstract
The purpose of this study has been to investigate the possibility of doping germanium using the technique of ion implantation. Elements from groups IIIa and Va of the periodic table have been used for implantation - namely, gallium, indium, thallium, antimony, and bismuth - together with some "control" implantations with argon and carbon. The majority of implantations were carried out at 70keV The Rutherford backscattering and channelling technique, using MeV alpha particle has been applied to the implants to determine the gross lattice damage as a function of implantation dose and annealing temperature,, The same technique has been used to determine the position of the implanted atoms within the re-ordered lattice unit-cell following annealing. The electrical effects of the radiation damage (in the case of p-type dopants) and the implanted ions have been determined using the Van der Pauw four point probe technique. The annealing temperature at which implantation damage disappeared was found to be a function of ion dose, for ion doses up to 1014 ions/cm-2. For higher doses an annealing temperature of it 400°C was required to restore lattice order" The electrical effects caused by ion implantation were dominated by radiation damage below 400°C and by the implanted dopants at slightly higher temperatures. The electrical activity of the Implanted ion was also roughly proportional to dose, except at high doses, Rutherford backscattering indicated that the implanted ions were mainly on substitutional lattice sites, in the range 450°C to 600°C, with no significant interstitial component. At temperatures above 600°C, significant outdiffusion was observed.