Electrical Effects of Point Defect Clouds at Dislocations in Silicon, Studied by Deep Level Transient Spectroscopy

摘要

We have investigated the shape of one prominent line observed by deep level transient spectroscopy (DLTS) and associated with dislocations. This is the C-line in n-type Si, that has been observed by various authors. Its shape exhibits in some experiments nearly symmetrical broadening, in others a strongly asymmetrical broadening with long low-temperature tails. While symmetric broadening presumably arises from point defects in the dislocation core, the low-temperature tails of line C remained without explanation so far. We show that point defect clouds, formed in the strain field of edge-type dislocations, can account for these tails. We therefore propose that the C-line can represent both, points defects in the core and in far-field region of dislocations.