Dresden 2006 – wissenschaftliches Programm

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HL: Halbleiterphysik

HL 32: Photovoltaic

HL 32.13: Vortrag

Mittwoch, 29. März 2006, 17:45–18:00, BEY 118

Electronic structure of gold- and iron-decorated dislocations in silicon — •Oliver Voß¹, Vitaly Kveder², and Michael Seibt¹ — ¹IV. Physikalisches Institut der Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen — ²permanent address: Institute of Solid State Physics RAS, Chernogolovka,*142432 Moscow reg., Russia

The recombination activity of dislocations in silicon strongly depends on their decoration with transition metal impurities in different states e.g. as precipitates or as isolated point defects. In this study the influence of Au and Fe as decoration of dislocations in fz-Si was measured by deep level transient spectroscopy (DLTS). We compared the effects of different Au concentrations. In addition to the DLTS-lines of dislocated n-Si we found a line with the emission characteristics of the Au-acceptor-level but with a capture barrier only with a high Au concentration. In dislocated p-Si we found comparable results for a defect similar to the Au-donor-level and an additional line whose amplitude depends in the same way on the Au concentration. It was shown that these lines are point-defect-like lines with a logarithmic capture dependence. We tentatively attribute this behaviour to substitutional Au atoms in the strain field of dislocations. After indiffusion of Fe into dislocated p-Si and storage of 30 hours we found two point-defect DLTS-lines: the FeB-pair-line and the intertitial Fe line. After soft annealing both lines almost disappeared, another capture dependent line appeared and the total amount of active sites was significantly reduced.