Chemical and structural characterization of oxide precipitates in heavily boron doped silicon by infrared spectroscopy and transmission electron microscopy
Faculty of Sciences. Physics
S.l. , 2002
Proceedings of the 7th International Symposium on High Purity Silicon held at the 202nd Meeting of the Electrochemical Society, October 20-25, 2002, Salt Lake City, Utah
University of Antwerp
Infrared absorption spectra of oxygen precipitates in boron doped silicon with a boron concentration between 10(17) and 10(19) cm(-3) are analyzed, applying the spectral function theory of the composite precipitates. The aspect ratio of the platelet precipitates has been determined by transmission electron microscopy measurements. Our analysis shows that in samples with moderate doping levels (<10(18) B cm(-3)) SiOgamma precipitates are formed with stoichiometry as in the lightly doped case. In the heavily (>10(18) cm(-3)) boron doped samples, however, the measured spectra of the precipitates are consistent with a mixture of SiO2 and B2O3. with a volume fraction of B2O3 as high as 0.41 in the most heavily doped case.