• Christopoulos, Stavros-Richard G.
• Chroneos, Alexander
• Potsidi, Marianna S.
• Kuganathan, Navaratnarajah
• Sarlis, Nicholas V.
• Angeletos, Theoharis
• Londos, Charalampos A.

Abstract

<p>We investigated, experimentally as well as theoretically, defect structures in electron irradiated Czochralski-grown silicon (Cz-Si) containing carbon. Infrared spectroscopy (IR) studies observed a band at 1020 cm⁻¹ arisen in the spectra around 300^◦C. Its growth occurs concomitantly with the decay out of the well-known vacancy-oxygen (VO) defect, with a Local Vibrational Mode (LVM) at 830 cm⁻¹ and carbon interstitial-oxygen interstitial (C_iO_i) defect with a LVM at 862 cm⁻¹, in silicon (Si). The main purpose of this work is to establish the origin of the 1020 cm⁻¹ band. One potential candidate is the carbon interstitial-dioxygen (C_iO_2i) defect since it is expected to form upon annealing out of the C_iO_i pair. To this end, systematic density functional theory (DFT) calculations were used to predict the lowest energy structure of the (C_iO_2i) defect in Si. Thereafter, we employed the dipole–dipole interaction method to calculate the vibrational frequencies of the structure. We found that C_iO_2i defect has an LVM at ~1006 cm⁻¹, a value very close to our experimental one. The analysis and study of the results lead us to tentatively correlate the 1020 cm⁻¹ band with the C_iO_2i defect.</p>

Topics

• density
• impedance spectroscopy
• Carbon
• theory
• Oxygen
• Silicon
• density functional theory
• annealing
• interstitial
• defect structure
• infrared spectroscopy
• vacancy