@article {Katsikini:2010:1533-4880:6260,
title = "Local Bonding Geometry of Oxygen Implanted in GaN: A Depth-Dependent Study",
journal = "Journal of Nanoscience and Nanotechnology",
parent_itemid = "infobike://asp/jnn",
publishercode ="asp",
year = "2010",
volume = "10",
number = "9",
publication date ="2010-09-01T00:00:00",
pages = "6260-6265",
itemtype = "ARTICLE",
issn = "1533-4880",
eissn = "1533-4899",
url = "https://www.ingentaconnect.com/content/asp/jnn/2010/00000010/00000009/art00117",
doi = "doi:10.1166/jnn.2010.2611",
keyword = "OXYGEN, X-RAY ABSORPTION, FEFF SIMULATIONS, NEXAFS, IMPLANTATION, GAN, AMORPHOUS, GALLIUM OXYNITRIDE",
author = "Katsikini, M. and Boscherini, F. and Paloura, E. C.",
abstract = "The bonding environment of oxygen implanted in GaN is studied using near edge X-ray absorption fine structure spectroscopy at the O-K-edge. The 70 keV oxygen ions form a 200 nm-thick subsurface layer that is highly defective or amorphous depending on the implantation fluence which ranges
from 1 \texttimes 1015 cm2 to 1 \texttimes 1017 cm2. The information depth of the fluorescence photons varies from 50 to 63 nm, depending on the angle of incidence. The spectra are simulated using the FEFF8 code and assuming various models,
e.g., O interstitial, O substitutional in N sites, Ga and N vacancies, and various polymorphs of Ga2O3. The lattice disorder is modelled by displacing atoms from their equilibrium positions by adding to their Cartesian coordinates random numbers that belong to normal
distributions. The simulation results reveal that at the low fluence limit, the O atoms occupy interstitial sites preferentially in the empty channels aligned to the c-axis and in the atomic planes containing the Ga atoms. When the fluence is equal to 1 \texttimes 1016 cm2
the O atoms substitute N while at 1 \texttimes 1017 cm2 they form mixed GaO
x
N
y
phases with the N/O ratio decreasing with increasing depth, i.e., as we approach the peak of the implanted O profile.",
}