ICDS Conference, Sendai, Japan, 7.95

FIRST PRINCIPLES INVESTIGATION OF VACANCY OXYGEN DEFECTS IN Si

C. P. Ewels, R. Jones,

Department of Physics, University of Exeter, Exeter, EX4 4QL, UK.

S. Öberg

Department of Mathematics, University of Luleå, Luleå, S95187, Sweden.

Abstract

Ab initio techniques are used to study vacancy oxygen complexes in Si. Substitutional oxygen is found to be an off-site defect in agreement with experiment. It possesses one high frequency O-related LVM at 788 cm-1. The VO_2 defect has D_2d symmetry and only one O-related high frequency IR active mode at 807 cm-1. The VO_3 defect has three high frequency IR active modes. The V_2O defect has one such LVM. These results provide strong support for the assignment of the 889 cm-1 (300 K) local vibrational mode to VO_2.

Keywords: ab initio theory, silicon, oxygen, vacancy, defect