Step-edge kinetics driving the formation of atomically flat (110) GaAs surfaces

Atomically flat (110) GaAs surfaces fabricated by the cleaved-edge overgrowth method and high-temperature growth-interrupt annealing are characterized at the atomic scale. We observe atomically flat (110) surfaces extending over areas more than 100 mum in size. Moreover, deposition of slightly less or more than integral monolayers (MLs) causes the appearance of characteristic step-edge shapes such as 1-ML-deep pits, or 2-to-3-ML-high isolated islands. Statistical analysis on the size and shape distribution of the 1-ML-deep pits supports a simple model based on the stability of Ga and As atoms on step edges with different bonding configurations, and reveals driving force to form an atomically flat (110) surface. (C) 2003 American Institute of Physics.