Influence of contamination on the electrical activity of crystal defects in silicon
It is shown by EBIC that dislocation activity is controlled by the degree of metal contamination. The activity can be affected by external gettering and hydrogenation. DLTS investigations showed that the occurrence and features of the dislocation-related C1 line also depend on the amount of contamination. In small amounts, the impurities are believed to be tightly bonded to the dislocation core, resulting in a rather sharp energetic distribution of levels of the C1 line. At larger concentrations, the impurities are accommodated as a cloud in the dislocation strain field, giving rise to a broad energetic distribution of levels of C1. It is suggested that only impurity atoms in the cloud can be removed by external gettering and/or passivated by hydrogenation.
electrical activity silicon dislocations gettering passivation