The effect of surface reconstruction upon the surface morphology during  in situ  layer-by-layer etching of the (001) surface with AsBr3 was studied by means of reflection high-energy electron diffraction measurements. Although the etching was initially layer-by-layer, an originally smooth surface became considerably rougher; depending upon the stoichiometry which was associated with the surface reconstruction. The best morphology after removing 250nm was found for the Ga-rich 3 x 1 reconstruction region, close to the phase transition boundary to As-rich 2 x 4. This was confirmed by scanning electron microscopy and atomic force microscopy data.

M.Ritz, T.Kaneko, K.Eberl: Applied Physics Letters, 1997, 71[5], 695-7