CHARACTERISATION OF DEFECTS IN SILICON USING FTIR ABSORPTION SPECTROSCOPY

Abstract

The work presented in this dissertation comprises a study of the infrared absorption characteristics of the vibrational modes in silicon using FTIR spectroscopy in the wavenumber range 4600-400 cm I , All the measurements were performed at room temperature with the spectral resolution of 1 cm-I , Silicon samples used in this investigation were grown by two different growth techniques, Czochralski (CZ) and Float-zone (PZ) techniques. The FTIR absorption spectra are divided into two categories. The category A consists of the spectra obtained on the float-zone samples and category B is the spectra obtained on the sample grown by Czochralski technique. The FTIR spectra of our silicon samples show some important features in the spectral range from 1400-400 cm I . On the basis of the comparison with the available literature, we conclude that our samples show the well known absorption peaks due to the substitutional carbon (Cs), interstitial oxygen (Oi), B II and (B II _Sb). Some other, smaller peaks have also been observed by us.