Chemical and structural characterization of oxygen

zhangcunbiao

Chemical and structural characterization of oxygen
precipitates in silicon by infrared spectroscopy and TEM
O. De Gryse
a,
*, P. Clauws
a
, O. Lebedevb
, J. Van Landuyt
b
, J. Vanhellemont
c
,
C. Claeys
d
, E. Simoend
a
University of Gent, Krijgslaan 281 (S1), B-9000 Gent, Belgium
b
RUCA-EMAT, Groenenborgerlaan 171, B-2020 Antwerpen, Belgium
c
Ministry of Flanders, AWI, Boudewijnlaan 30, B-1000 Brussel, Belgium
d
IMEC, Kapeldreef 75, B-3001 Leuven, Belgium
Abstract
Infrared absorption spectra of polyhedral and platelet oxygen precipitates are analyzed using a modified Day–Thorpe
approach (J. Phys.: Condens. Matter 11 (1999) 2551). The aspect ratio has been determined by TEM measurements.
The reduced spectral function and the stoichiometry are extracted from the absorption spectra and the concentration of
precipitated interstitial oxygen. One set of spectra reveal a Fr . ohlich frequency around 1100 cm
1
and another around
1110–1120 cm
1
. It is shown that the shift in the Fr . ohlich frequency is not due to a different stoichiometry, but due to
the detailed structure in the reduced spectral function. The oxygen precipitates consist of SiOg with gE1:121:270:1:
r 2001 Elsevier Science B.V. All rights reserved.