Concentration of interstitial and substitutional nitrogen in GaNxAs1-x

The interstitial to substitutional nitrogen atoms as a function of concentration in GaNAs were determined by nuclear reaction analysis utilizing the 14N(d,p)15N and 14N(d,α)12C reactions using ion channeling technique. The GaNAs films with mean nitrogen concentration between 0.3% and 3%, measured with secondary ion mass spectrometry and time-of-flight elastic recoil detection analysis, were grown using gas-source molecular-beam epitaxy. The fraction of nitrogen atoms occupying substitutional sites was observed to increase linearly with increasing nitrogen amount, while the concentration of interstitial nitrogen was nearly constant at 2×1019 cm−3 throughout the concentration region. Annealing at 750 °C decreases the concentration of interstitial nitrogen.