High-dose magnesium implantations in InP activated by rapid thermal annealing

Highly doped, near 1019 cm−3, p-type layers have been obtained in InP by ion implantation of magnesium and the use of rapid thermal annealing with proximity encapsulation. The resulting doping profiles can be qualitatively accounted for by considering the interstitial/substitutional diffusion model and the stoichiometric imbalance created by implantation-induced knock-on of phosphorus. The upper limit for substitutional incorporation of magnesium is found to be of the order of 1019 cm−3. Although coimplantation of P and Mg has an effect on the activation and distribution of Mg, it is not as important as in the case of As/Mg in GaAs. The results have important implications for the design of implanted contacts to optoelectronic devices.