CHEMICAL BONDING FEATURES FOR FAULTILY STACKED INTERFACES OF GAAS(111)

The electronic states for normally stacked and faultily stacked layers on the GaAs{111} A, B surfaces are calculated by use of the discrete variational X alpha cluster method and the plane wave nonlocal pseudop otential method. The results show that chemical bondings between atoms are not as ionic in the faultily stacked layer of (111) B as they are in the (111)A case, and that on the (111) A surface more attractive C oulomb interaction energy is gained in the faulty stacking layer than in the normal stacking one. These results explain well the more freque nt emergence of in-plane faults in the (111) A surface, which is well known in GaAs{111} A, B growth experiments. The total energy calculati ons also provide quantitative interpretation of such growth features. (C) 1998 American Vacuum Society.