Hubert Valencia - Ab initio study of GaAs(100) surface stability over As2, H2 and N2 as a model for vapor-phase epitaxy of GaAs1−xNx

Version 2

      Publication Details (including relevant citation   information):

      Hubert Valencia, Yoshihiro Kangawa, and Koichi Kakimoto, J.   Cryst. Growth 432, pp. 6–14 (2015)

      Abstract:

      GaAs(100) c(4×4) surfaces were examined by ab initio   calculations, under As2, H2 and   N2 gas mixed conditions as a model for   GaAs1−xNx vapor-phase epitaxy   (VPE) on GaAs(100). Using a simple model consisting of   As2 and H2 molecules adsorptions and As/N   atom substitutions, it was shown to be possible to examine the   crystal growth behavior considering the relative stability of the   resulting surfaces against the chemical potential of   As2, H2 and N2 gases. Such   simple model allows us to draw a picture of the temperature and   pressure stability domains for each surfaces that can be linked   to specific growth conditions, directly. We found that, using   this simple model, it is possible to explain the different   N-incorporation regimes observed experimentally at different   temperatures, and to predict the transition temperature between   these regimes. Additionally, a rational explanation of   N-incorporation ratio for each of these regimes is provided. Our   model should then lead to a better comprehension and control of   the experimental conditions needed to realize a high quality VPE   of   GaAs1−xNx.

      Address (URL): http://dx.doi.org/10.1016/j.jcrysgro.2015.09.005