Interaction between implanted fluorine atoms and point defects in preamorphized silicon

✍ Scribed by G. Impellizzeri; J.H.R. dos Santos; S. Mirabella; E. Napolitani; A. Carnera; F. Priolo

• Publisher: Elsevier Science
• Year: 2005
• Tongue: English
• Weight: 217 KB
• Volume: 230
• Category: Article
• ISSN: 0168-583X
• DOI: 10.1016/j.nimb.2004.12.044

✦ Synopsis

We have studied, by means of B diffusion analyses, the effect of F on the point defect density in preamorphized Si. Through molecular beam epitaxy (MBE) Si samples containing a special B multi-spike were grown. These samples were amorphized to a depth of 550 nm by implanting Si at liquid nitrogen temperature and then enriched with F at different energies (65-150 keV) and fluences (0.7-5 • 10 14 /cm 2 ). After solid phase epitaxy (SPE) of the samples, we induced, by thermal annealing at 850 °C, the emission of Si self-interstitials (Is) from the end-of-range (EOR) defects. We studied the diffusion of the B spikes, demonstrating that F effectively reduces the B diffusion. This reduction is shown to be caused not by a direct B-F chemical interaction, but by a F interaction with point defects. In particular, F is able to reduce the density of Is, which are responsible for the B diffusion. Still, we showed that F does not appreciably influence the Is emission from the EOR defects, but a local interaction occurs between F atoms and Is after the release of these defects from the EOR region. This interaction results in a consistent reduction of B diffusivity in F enriched regions.