The ratio of interstitial to substitutional N atoms, as a function of concentration, was determined by nuclear reaction analysis involving the 14N(d,p)15N and 14N(d,α)12C reactions and ion channelling techniques. Films with mean N concentrations of between 0.3 and 3%, measured by secondary ion mass spectrometry and time-of-flight elastic recoil detection analysis, were grown by means of gas-source molecular-beam epitaxy. The fraction of N atoms which occupied substitutional sites was observed to increase linearly with increasing N content, while the concentration of interstitial N was almost constant at 2 x 1019/cm3 throughout the concentration region. Annealing at 750C decreased the concentration of interstitial N.

Concentration of Interstitial and Substitutional Nitrogen in GaNxAs1–x. T.Ahlgren, E.Vainonen-Ahlgren, J.Likonen, W.Li, M.Pessa: Applied Physics Letters, 2002, 80[13], 2314-6