https://doi.org/10.1051/epjap:2004089
Luminescence and EPR studies of defects in Si-SiO2 films
1
Institute of Semiconductor Physics, National Academy of Sciences
of Ukraine, 45 Prospect Nauky, Kyiv 03028, Ukraine
2
Racah Institute of Physics, Hebrew University, Givat Ram, 91904 Jerusalem,
Israel
Corresponding author: kors@lumin.semicond.kiev.ua
Received:
2
July
2003
Accepted:
15
December
2003
Published online: 15 July 2004
Co-sputtered Si-rich SiO2 films annealed at 1150 °C are studied by photoluminescence and EPR methods. It is found that the emission spectrum of as-prepared samples contains one broad infrared band. It is shown that one-year aging in ambient air and low-temperature annealing in an oxygen atmosphere leads to an increase in the infrared band intensity and the appearance of additional bands with maxima at 1.7 eV, 2.06 eV and 2.3 eV while annealing in a hydrogen atmosphere results in the decrease of the 1.7 eV and 2.06 eV band intensities. A correlation between the 1.7-eV band intensity and the EPR signal from EX-centers is found to exist. The decrease of crystallite sizes results in a high-energy shift of the infrared band while the peak positions of the other ones (at 1.7 eV, 2.06 eV and 2.3 eV) do not change. The infrared band is ascribed to recombination in Si crystallites while the others are attributed to silicon oxide defects, the 1.7-eV and 2.06-eV bands being due to oxygen-excess defects such as EX-center and NBOHC.
PACS: 61.46.+w – Nanoscale materials: clusters, nanoparticles, nanotubes, and nanocrystals / 61.72.Hh – Indirect evidence of dislocations and other defects (resistivity, slip, creep, strains, internal friction, EPR, NMR, etc.) / 78.55.-m – Photoluminescence, properties and materials / 78.66.-w – Optical properties of specific thin films
© EDP Sciences, 2004
