Na+ ion implanted ZnSe epitaxial layers grown by atmospheric pressure metalorganic vapor phase epitaxy

Abstract

We have introduced Na impurities by ion implantation into undoped ZnSe heteroepitaxial layers grown at 250 °C by atmospheric pressure metalorganic vapor phase epitaxy. The implanted Na impurity forms not only an acceptor level but also a deep level. The formation of implanted Na acceptor levels begins to increase at relatively low annealing temperatures (less than 450 °C). Annealing between 451 and 557 °C is the optimum condition to form acceptor levels effectively while generating a low density of deep levels. Annealing of temperatures significantly higher than 550 °C does not form Na acceptors, but generates deep levels.