Quasi-particle optical signatures in silicon defects
Abstract
Extended 311 defects and interstitial clusters in silicon are commonly believed to play important roles in dopant transient enhanced diffusion. In experiments, DLTS signals correspond to both localized and extended defects are observed in the silicon band gap. We perform GWA calculation for the quasi-particle levels of some of the important defects. For extended defects, we find a defect level 0.56 eV above the valence band maximum in the 311 /II/ structure, in agreement with the experimental DLTS signature at 0.5 eV. On the other hand, the lowest level in 311 /IO/ structure is 1.2 eV above the valence band maximum. Furthermore, the calculation of optical transition matrix elements shows that only the transition between the valence band maximum and the 0.56 eV level is allowed. This result strongly supports that the 0.56 eV level corresponds to the DLTS signal in experiments. Also, the spatial density of the optical transition matrix element shows the transition is localized in a region 0.9 nm around the defect. Possible signatures in localized defects will also be discussed.
- Publication:
-
APS March Meeting Abstracts
- Pub Date:
- March 2004
- Bibcode:
- 2004APS..MARS10003C