ATOMIC-STRUCTURE OF GA AND AS ATOMS ON GAAS(110)

Atomic structures of Ga and As atoms on GaAs(110) were examined employ ing a first-principles pseudopotential method. Both Ga and As atoms re side in the center of a triangle consisting of a surface Ga and two su rface As atoms in the single-atom chemisorbed state. Adsorption energi es for Ga and As atoms are 3.1 and 3.5 eV, respectively, Energy barrie r heights of Ga and As atoms for the migration along the path through the interstitial channel were found to be 0.6 and 1.0 eV, respectively . Simulations on the deposition of two atoms reveal that a pair format ion is stable against separate single-atom chemisorptions.