Mechanisms of nitrogen incorporation in GaAsN alloys

We have investigated nitrogen incorporation mechanisms in dilute nitride GaAsN alloys grown by plasma-assisted molecular-beam epitaxy. A comparison of nuclear reaction analysis and Rutherford backscattering spectrometry in channeling and nonchanneling conditions reveals significant composition-dependent incorporation of N into nonsubstitutional sites, presumably as either N-N or N-As split interstitials. Furthermore, we identify the (2x1) reconstruction as the surface structure which leads to the highest substitutional N incorporation, likely due to the high number of group V sites per unit area available for N-As surface exchange. (C) 2004 American Institute of Physics.