ATOMIC-SCALE NATURE OF THE (3X3)-ORDERED GAAS(001)N SURFACE PREPARED BY PLASMA-ASSISTED MOLECULAR-BEAM EPITAXY

In situ scanning tunneling microscopy and time-resolved reflection hig h-energy electron diffraction measurements were performed to study the nitridation process of the As-terminated GaAs(001)-(2x4) surface by u sing electron cyclotron resonance plasma-assisted molecular-beam epita xy. We report the real-space atomic structure of the coherently strain ed (3x3)-ordered GaN monolayer on GaAs(001) after a limited-exposure n itridation process and the atomically smooth morphology of this nitrid ed surface. The unique (3x3) phase is found consisting of nitrogen dim ers and a regular array of missing nitrogen rows in both [<(1)over bar 10>] and [110] directions. (C) 1997 American Institute of Physics.