Electrical properties of gold in dislocated silicon

We present results of the electrical properties of gold-decorated dislocations in silicon studied by means of Deep Level Transient Spectroscopy (DLTS). We investigated the effect of the gold by measuring DLTS spectra from Schottky diodes having different gold concentrations but same thermal history. We found three point-defect-like deep levels which occurrence could be attributed to the gold. After gold in-diffusion the well-known A-, B- and C-lines of dislocated n-type silicon could hardly be measured, whereas another gold-induced line appeared. This line has nearly the same emission characteristics as the gold acceptor level in non-dislocated silicon but shows a logarithmic dependence on capture time typical for extended defects. In the lower half of the band gap we measured at least two gold-induced levels. One of them shows very similar emission characteristics to the gold donor level in non-dislocated silicon. Both amplitudes are logarithmically dependent on the capture time. We tentatively attribute this behaviour to substitutional dissolved gold accumulated in the vicinity of the dislocations and in dislocation core.