Structure of clean and arsenic-covered GaN(0 0 0 1) surfaces V. Ramachandran C. D. Lee Randall Feenstra A. R. Smith J. E. Northrup David Greve 10.1184/R1/6508184.v1 https://kilthub.cmu.edu/articles/journal_contribution/Structure_of_clean_and_arsenic-covered_GaN_0_0_0_1_surfaces/6508184 <p>The effect of trace arsenic on the growth and surface structure of GaN(0 0 0 1) has been studied. We find that a partial pressure of only 10<sup>−9</sup> Torr of arsenic during molecular beam epitaxial growth significantly modifies the growth kinetics. Such a small background pressure of arsenic leads to an arsenic-terminated surface displaying a 2×2 reconstruction <em>during growth</em> which is absent for the clean surface. First-principles theoretical calculations show that As-terminated surfaces are energetically more favorable than Ga-terminated surfaces for arsenic pressures of 10<sup>−9</sup> Torr, and structural models for the As-adatom 2×2 reconstruction are presented.</p> 2000-02-01 00:00:00 GaN Arsenic Surface 2×2 RHEED Auger