Oxygen '96
Early Stages of Oxygen Precipitation in Silicon
PROPERTIES OF OXYGEN AND OXYGEN-RELATED DEFECTS IN
SILICON DETERMINED FROM STRESS-INDUCED ALIGNMENT STUDIES
George D. Watkins
Department of Physics, Lehigh University, Bethlehem, PA, USA
The application of uniaxial stress to a crystal can produce
preferential alignment of an anisotropic defect, which, in turn, can
be monitored by a variety of spectroscopic techniques. One of the
earliest uses of this approach was for isolated interstitial oxygen in
silicon, the sense of the alignment monitored by its IR LVM absorption
confirming its squeezed position between two normally bonded silicon
atoms, and the kinetics for reorientation supplying a highly accurate
measure for its diffusion properties. Also very early was the study
of substitutional oxygen in silicon (the A-centre), formed when
interstitial oxygen traps a vacancy. In this case, simultaneous study
via IR and EPR led to a remarkably detailed atomic model for the
defect. Another interesting example is the carbon-oxygen pair, formed
when interstitial oxygen traps a mobile interstitial carbon atom,
which can be monitored by LVM, electronic excitation spectroscopy, and
EPR. Direct stress alignment of the defect, plus indirect alignment
achieved by first aligning the oxygen before the trapping event, has
led to a detailed atomic model for the defect and its mechanism for
production. Finally, we will discuss several informative clues as to
the structure, identity and formation mechanism for the thermal donors
that result from the application of stress during formation, plus the
kinetics for recovery, as monitored by EPR and resolved electronic
excitation spectra.
Full list of abstracts | participants
list | main page.
Last modified: Mon Feb 19 12:10:49 GMT 1996
JG