Incorporation of N into GaAsN under N overpressure and underpressure conditions

Abstract

GaAsN was grown by molecular beam epitaxy equipped with a radio frequency nitrogen plasma source. The N incorporation behaviors were investigated using a series of samples grown at different growth rates, As4/Ga ratios, and nitrogen fluxes within a growth temperature range from 420 to 560 °C. It was found that, for the GaAsN grown at higher growth rates (0.4–1.3 ML/s), the N concentration increased linearly following a decrease in growth rate, and kept independent of the arsenic pressure. For the GaAsN grown at lower growth rate (0.1–0.3 ML/s), the N concentration was significantly influenced by the arsenic pressure, and the increase in N concentration with decreasing growth rate follows a sublinear manner. We propose a model based on the incorporation competition of group V elements (N and As) under N underpressure and overpressure conditions, which can explain the different behaviors well.