Abstract
Positron annihilation spectroscopy was applied to study relaxed P-doped -type and undoped layers with up to 0.30. The as-grown layers were found to be defect free and annihilation parameters in a random alloy could be represented as superpositions of annihilations in bulk Si and Ge. A proton irradiation with a fluence was used to produce saturated positron trapping in monovacancy related defects in the -type layers. The defects were identified as V-P pairs, the center. The distribution of Si and Ge atoms surrounding the center was the same as in the host lattice. The process leading to the formation of V-P pairs therefore does not seem to have a significant preference for either Si or Ge atoms. In undoped we find that a similar irradiation produces a low concentration of divacancies or larger vacancy defects and found no evidence of monovacancies surrounded by several Ge atoms.
- Received 25 January 2006
DOI:https://doi.org/10.1103/PhysRevB.73.165209
©2006 American Physical Society