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

The reconstruction transitions for the GaAs(001) surface have been identified as a function of the band gap-derived substrate temperature and As₄ beam equivalent pressure. Surface morphology measurements using in situ scanning tunneling microscopy reveal that the surface spontaneously forms a random distribution of two-dimensional islands. The onset of island formation is coincident with the reflected high-energy electron diffraction pattern changing from the β to α subphase of the (2 × 4) reconstruction. An electron diffraction-based method for determining the substrate temperature and engineering the surface morphology with a desired amount of roughness is presented