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Surface composition changes in GaN induced by argon ion bombardment
Author(s) -
Kovač J.,
Zalar A.
Publication year - 2002
Publication title -
surface and interface analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 90
eISSN - 1096-9918
pISSN - 0142-2421
DOI - 10.1002/sia.1294
Subject(s) - argon , x ray photoelectron spectroscopy , sputtering , ion , semiconductor , substrate (aquarium) , diode , materials science , thin film , band gap , analytical chemistry (journal) , atomic physics , chemistry , optoelectronics , nanotechnology , physics , oceanography , organic chemistry , nuclear magnetic resonance , chromatography , geology
Abstract The wide‐bandgap GaN semiconductor has been used to fabricate efficient blue–green light‐emitting diodes, laser diodes and high‐power/high‐temperature electronic devices since the many problems regarding the life‐time characteristics were resolved in recent years. Knowledge of ion‐bombardment‐induced surface composition changes is important in quantitative AES/XPS analysis. We investigated the dependence of preferential sputtering of components on ion energies and on the angle of incidence of argon ions. Thin films of GaN prepared on a smooth Si substrate and GaN single crystals were bombarded with argon ions of energy 0.5–5 keV at incidence angles of 10–72° with respect to the surface normal. The N KLL and Ga LMM AES signals were acquired after the steady‐state surface composition was reached. The results show that nitrogen is sputtered preferentially. This effect is more pronounced for higher ion energies and smaller incidence angles. The experimental results are discussed in the framework of models of preferential sputtering and compared with computer simulations. Copyright © 2002 John Wiley & Sons, Ltd.