Defect site competition for metal atoms in intrinsically gettered silicon: Numerical model

Abstract

Intrinsic gettering of silicon immobilizes metal atoms at oxide precipitates and other crystal defects in the bulk of a wafer. The competition for metal atoms between these bulk gettering sites and near-surface defect sites is investigated with simple models. Metal-decorated near-surface defect sites lead to dark or leakage currents that limit semiconductor-device performance. The calculations indicate the circumstances under which bulk gettering sites are predicted to be successful in competing for metal atoms. Numerical results are shown for variations in the number of near-surface sites, the metal atom capacity of a bulk site, and the number of initial metal atoms. Predicted profiles of free and trapped metal atoms are presented.