Date of Original Version
Journal of Crystal Growth Volume 209, Issues 2–3, February 2000, Pages 355–363
Abstract or Table of Contents
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 10−9 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 during growth 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 10−9 Torr, and structural models for the As-adatom 2×2 reconstruction are presented.