Enabling electron diffraction as a tool for determining substrate temperature and surface morphology

The reconstruction transitions for the GaAs(001) surface have been identifi ed as a function of the band gap-derived substrate temperature and As-4 bea m equivalent pressure. Surface morphology measurements using in situ scanni ng tunneling microscopy reveal that the surface spontaneously forms a rando m distribution of two-dimensional islands. The onset of island formation is coincident with the reflected high-energy electron diffraction pattern cha nging from the beta to alpha subphase of the (2x4) reconstruction. An elect ron diffraction-based method for determining the substrate temperature and engineering the surface morphology with a desired amount of roughness is pr esented. (C) 2001 American Institute of Physics.