Compositional changes on GaN surfaces under low-energy ion bombardment studied by synchrotron-based spectroscopies
Date
2003-12-15
Authors
Deenapanray, Prakash N. K.
Petravić, M.
Kim, K.-J.
Kim, B.
Li, G.
Journal Title
Journal ISSN
Volume Title
Publisher
American Institute of Physics
Abstract
We have investigated compositional changes on GaNsurfaces under Ar-ion bombardment using synchrotron-based high-resolution x-rayphotoemission (PES) and near-edge x-ray absorption fine structure(NEXAFS)spectroscopy. The low-energy ion bombardment of GaN produces a Ga-rich surface layer which transforms into a metallic Ga layer at higher bombarding energies. At the same time, the photoemissionspectra around N 1s core levels reveal the presence of both uncoordinated nitrogen and nitrogen interstitials, which we have analyzed in more details by x-rayabsorption measurements at N K edge. We have demonstrated that PES and NEXAFS provide a powerful combination for studying the compositional changes on GaNsurfaces. A mechanism for the relocation and loss of nitrogen during ion bombardment in agreement with some recent experimental and theoretical studies of defect formation in GaN has been proposed.
Description
Keywords
Keywords: Absorption spectroscopy; Composition effects; Defects; Emission spectroscopy; Ion bombardment; Nitrogen; Reaction kinetics; Surface chemistry; Synchrotron radiation; X ray spectroscopy; Compositional changes; Defect formation; High resolution x ray photoe
Citation
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Source
Applied Physics Letters
Type
Journal article