Step Motion and Structure Transition on InAs and GaAs (001) Surfaces Observed by Scanning Tunneling Microscopy

Abstract
The step motion and structure transition on InAs and GaAs (001) surfaces are directly observed by scanning tunneling microscopy at high temperatures. A stable (2×4) structure is observed for the InAs surface even at temperatures high enough to cause the motion of monomolecular steps and kinks. At higher temperatures, domains with an In stable (4×2) structure (As desorbed region) are clearly observed surrounded by As stable (2×4) structures. These results differ from those for GaAs surfaces and indicate strong lateral interaction in (2×4) structures on InAs.