INFLUENCE OF OXYGEN ON SURFACE-MORPHOLOGY OF METALORGANIC VAPOR-PHASEEPITAXY-GROWN GAAS(001)

Atomic force microscopy has been used to investigate the influence of controlled oxygen incorporation on the surface morphology of GaAs film s grown by metalorganic vapor phase epitaxy (MOVPE). Oxygen influences the periodic morphology observed in GaAs surfaces, with concentration s about 10(18) cm(-3) leading to a breakup of the periodicity. To acco unt for these observations, we propose a model in which oxygen prefere ntially attaches at steps with a subsequent reduction in step mobility and a concomitant increase in the surface roughness. (C) 1996 America n Institute of Physics.