Oxygen '96
Early Stages of Oxygen Precipitation in Silicon
SOME PROPERTIES OF OXYGEN-RELATED RADIATION INDUCED DEFECTS
IN SILICON AND GERMANIUM
L. Khirunenko
V. Shakhovtsov and V. Yashnik
Institute of Physics of the National Academy of Sciences of Ukraine
252650, Kiev-22, Pr.Nauki 46, Ukraine
Keywords: oxygen, silicon, germanium, vacancy, irradiation
In this work, new data is presented showing peculiarities in the
behaviour of the main oxygen-related defects (A-centres). These are
created by high energy particle irradiation in Si and Ge, and then
modified during annealing.
The CZ-grown Si and Ge crystals were irradiated by either 3.5 MeV
electrons, or reactor neutrons. The measurements were made using IR
Fourier spectroscopy.
Annealing of A-centres in Si leads to the formation of
VO2-centres, as well as the gradual appearance of many
other component structures in the same absorption range. It is shown
that these structures correspond to the formation of 3 new types of
oxygen related centre. The energies of activation for annealing of
these centres are 2.35, 2.59 and 2.68 eV respectively.
Piezospectroscopic investigation of these three line groups show them
to have different dichroisms.
We find the process of VO2-centre formation differs
depending on whether fast electron or neutron irradiation of Si is
used. Assuming that in electron irradiated Si, VO2-centres
are formed by direct diffusion of A-centres to interstitial oxygen,
then in neutron irradiated crystals formation occurs via an
intermediate stage. This stage leads to the formation of new centres
which have absorption bands at 919.6 and 1008.9 cm-1.
It is shown that the formation and annealing of A-centres in Ge is
fundamentally different from that of Si. Using isotopically enriched
Ge, these processes were examined. The EPR spectral lines
corresponding to VO and VO2-centres were distinguished via
comparison between EPR and IR absorption spectra. Values of the
g-factors for bands corresponding to VO and VO2-centres are
estimated.
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Last modified: Wed Feb 28 17:02:45 GMT 1996
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