Electron Microscope Study of Defects in Annealed Boron Implanted Silicon.
Abstract
Transmission electron microscopy was used to characterize defects observed in silicon, following boron implantation through an oxide film and annealing in nitrogen or argon to 950 C. Rod defects, believed by some to be boron precipitates, are formed upon annealing from 600 to 700 C. Most of these defects disappear upon annealing to 950 C when maximum electrical activity is achieved. At this point, most of the defects consist of narrow dislocation dipoles or loops. In this study, we observed at 950 C rows of closely spaced loops similar in diameter and in length to the rod defects. This led us to the belief that they were derived directly by the dissolution of the rod defects. Small precipitate particles were sometimes attached to the single loops. Contrast within some of the residual rod defects suggested partial dissolution. These observations can be explained by assuming that the rod defects are rows of boron atoms which, upon dissolution, leave a narrow dipole or loop which may pinch off into smaller loops forming rows of the type observed. Loop formation can be explained by the mechanism suggested by Bicknell where, as the boron atoms of which the rods are composed move into substitutional positions, interstitial silicon atoms are formed. These coalesce to form dipolar loops which may pinch off into loop rows. A small percentage of the boron atoms may form silicon borides at the sites of dislocation loops.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1976
- Accession Number
- ADA037956
Entities
People
- Joseph J. Comer
- Sven A. Roosild
Organizations
- Rome Laboratory