Implantation isolation in n-type InP bombarded with He+ and B+

An extensive study has been carried out to investigate the changes in the electrical properties of n-type InP, doped in the range 2.5 × 1016−1 × 1018 cm−3, and bombarded with 55 keV He+ and 125 keV B+. The carrier concentration initially decreases with ion dose and reaches a minimum at a dose of ∼ 5 × 1013 cm−2 for He+ and 1 × 1013 cm−2 for B+ irradiation. The dose where the minimum occurs for each ion and the magnitude of the minimum carrier concentration is independent of the initial carrier concentration. However, at doses below this minimum the carrier removal rate is directly dependant on the carrier concentration. At higher doses the electrical properties are dominated by radiation defects and are independent of initial doping. These results are discussed in terms of the production of defects and defect/dopant interactions.