The reconstructions of the Ga polarity GaN(0 0 0 1) surface with and without trace amounts of arsenic and prepared by molecular beam epitaxy (MBE) have been studied with in situ reflection high-energy electron diffraction (RHEED) and scanning tunneling microscopy (STM). Various reconstructions are observed with RHEED by analyzing patterns while the substrate is exposed to a fixed NH3 flux or after depositing known amounts of Ga as a function of substrate temperature. In situ STM images reveal that only a few of these reconstructions yield long-range periodicity in real space. The controversial role of arsenic on Ga induced reconstructions was also investigated using two independent MBE chambers and X-ray photoelectron spectroscopy.
@article{arxiv.1501.00143,
title = {Origins of GaN(0 0 0 1) surface reconstructions},
author = {S. Vezian and F. Semond and J. Massies and D. W. Bullock and Z. Ding and P. M. Thibado},
journal= {arXiv preprint arXiv:1501.00143},
year = {2015}
}