Comparative mid- and far-infrared spectroscopy of nitrogen-oxygen complexes in silicon

A comparative infrared absorption study between electronic and vibrational states of nitrogen-oxygen related shallow donors has been performed in nitrogen-doped Czochralski silicon. Quasi-thermodynamic equilibrium conditions have been established by long-term annealing between 600 and 1000 degrees C. Different members of the N-O shallow donor family show a specific thermal decay in this temperature range, in disagreement with present theoretical modeling. Based on this characteristic behavior, we find two local vibrational modes at 1070 and 860 cm(-1) which can be assigned to the most prominent shallow-donor species with the chemical composition NO(2). The implication on the microscopic structure of this complex is discussed. (C) 2009 Elsevier By. All rights reserved.