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XPS analysis of aluminum nitride films deposited by plasma source molecular beam epitaxy
Author(s) -
Rosenberger Leland,
Baird Ronald,
McCullen Erik,
Auner Gregory,
Shreve Gina
Publication year - 2008
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.2874
Subject(s) - x ray photoelectron spectroscopy , nitride , binding energy , molecular beam epitaxy , analytical chemistry (journal) , crystallography , oxygen , chemical bond , aluminium , materials science , chemistry , epitaxy , nanotechnology , chemical engineering , metallurgy , atomic physics , organic chemistry , layer (electronics) , physics , engineering
Abstract Ten samples of crystalline aluminum nitride (AlN) film were deposited on sapphire and silicon substrates by a plasma source molecular beam method. The samples were analyzed using X‐ray photoelectron spectroscopy (XPS) depth profiling and high‐resolution X‐ray diffraction. Oxygen levels were observed to decrease exponentially from the surface into the bulk film. Aluminum, nitrogen and oxygen peaks were fitted with subpeaks in a consistent manner and the subpeaks were assigned to chemical states. AlN subpeaks were observed at 73.5 eV for Al2p and 396.4 eV for N1s. An N1s subpeak at 395.0 eV was assigned to NN defects. No direct NO bonds are assigned; rather it is proposed that an NAlO bond sequence is the source of higher binding energy N1s subpeaks. The observations in this study support a model in which oxygen is bound only to aluminum in the form of AlO octahedral complexes dispersed or clustered throughout the main AlN matrix or as AlO bonds on the crystal grain boundaries. The data also suggest that the AlN lattice parameters are related to oxygen content, since the c‐axis is observed to increase with increasing oxygen content. Copyright © 2008 John Wiley & Sons, Ltd.