Isotope effect on the reactivation of neutralized Si dopants in hydrogenated or deuterated GaAs: The role of hot electrons

Room-temperature bias stress and annealing experiments have been performed on hydrogenated and deuterated Si doped n-type GaAs Schottky diodes. From a careful analysis of capacitance–voltage characteristics, we have studied the variation of the active doping concentration and the reactivation of neutralized dopants. In thermal annealing experiments at 250 °C, the Si–H complex dissociation rate does not vary significantly by incorporating deuterium rather than hydrogen. On the contrary, by applying high reverse bias voltages to the Schottky diodes at room temperature, a strong isotope effect is observed on the dissociation rate. In this case, the dopant reactivation should be due to hot electron excitations.