Decoration of defects in silicon with gold, and related subjects

The decoration of defects with gold is introduced as a novel technique for detecting and localizing defects in moderately imperfect silicon crystals. In contrast to the well-known decoration with copper precipitates, the decoration with gold is based on an enhancement of the concentration of substitutionally dissolved gold in the vicinity of defects acting as sinks for self-interstitials. This effect is a consequence of the so-called kick-out mechanism, by which the diffusion of gold in silicon takes place. In practice, defect-decoration studies with gold are done by the diffusion of gold into silicon and subsequent monitoring of defect-induced peaks of the gold concentration by neutron-activation analysis in combination with serial sectioning or, more conveniently, by spreading-resistance measurements. The power of the method is demonstrated by presenting results on the decoration of dislocations and stacking faults as well as of hitherto undetected microdefects in both, FZ and CZ silicon.