Influence of the Dislocation Travel Distance on the DLTS Spectra of Dislocations in Cz-Si

Abstract

We investigated the development of dislocation-related DLTS spectra in n-CZ-Si crystals with small (about 7.104 cm-2) number of long individual dislocations depending on the distance L that dislocations traveled during deformation at 600oC and on the velocity of dislocations. We found that a typical dislocation-related DLTS signal appeared only when dislocations traveled a significant distance that is more than 150-200μm, and it depended strongly on dislocation velocity. The results were interpreted on the assumption that the DLTS signal corresponds to some core defects and atomic impurities accumulated on the dislocations during their slow motion. At high concentration of deep level defects on dislocations a strange “negative DLTS” signal was observed. This can be explained by electron tunneling between deep defects along dislocations.

On the nature of defects produced by motion of dislocations in silicon

“…Note that according to Refs. , the C‐line corresponds to some impurities at dislocations. It means that the AlG should strongly decrease concentration of those defects in our samples.…”

“…Most of such investigations are focused on interaction of impurities with dislocations and on electronic properties of real dislocations with impurities and defects in their cores (e.g., see Refs. ).…”

Gettering Processes and the Role of Extended Defects

“…Additional evidence supporting the idea that C-defects correspond to some impurity atoms at dislocations were demonstrated [174] by the observed dependence of DLTS spectra on the velocity of dislocations. A few thousand dislocation loops were generated in n-type silicon at 600 • C from indentation pits.…”

“…Deep dislocation-related energy levels have been intensively investigated by DLTS (see, e.g., [170][171][172][173][174][175][176][177]). However, the exact origin of the defects responsible for even well known dislocation-related energy states detected by DLTS is not yet completely clear.…”

Interaction of Chromium Atoms with Dislocations and as‐Grown Vacancy Complexes and its Impact on the Electronic Properties of FZ‐Si

“…But, a mc‐Si usually contains high concentration of dislocations and some other defects that can significantly influence a behavior of transition metal atoms. This stimulates a great interest to investigations of interaction of impurities with dislocations and to electronic properties of dislocations contaminated by the impurities …”