Recombination activity of contaminated dislocations in silicon: A electron-beam-induced current contrast behavior - art. no. 115208

Existing experimental data give many evidences that the recombination rate of minority charge carriers at dislocations in silicon depends strongly on dislocation decoration by transition metal impurities. Here, we present a m odel that allows a quantitative description of the recombination of minorit y carriers at decorated dislocations. It assumes that shallow dislocation b ands, induced by the strain field, and deep electronic levels, caused by im purity atoms, which have segregated at the dislocation, or by core defects, can exchange electrons and holes. As a consequence, the recombination of c arriers captured at dislocation bands can be drastically enhanced by the pr esence of even small concentrations of impurity atoms at the dislocation co re. The model allows us not only to explain experimentally observed depende nces of the recombination rate on temperature and excitation level, but als o to estimate the concentration of deep level impurities at dislocations.