Abstract
The evolution of vacancy-type defects has been studied by variable-energy positron annihilation spectroscopy (VEPAS) in samples of high-quality FZ p-type (001) silicon wafers implanted with 4 MeV Si 2+ ions at room temperature to doses of 10 12 -10 14cm -2. The average vacancy concentration increases as (ion dose) 0.70±0.06. Progressive isochronal annealing measurements show that open-volume point defects (having a VEPAS signature close to that for divacancies) anneal between 500-600°C. VEPAS with enhanced depth sensitivity (via progressive etching) verified that single 30 min anneals to 550 and 600°C lead to the formation of buried clusters V N with an average N of 3.5 lying between depths of 2.2 and 3.6 μm (both ± 2 μm), close to the peak of vacancy damage just shallower than the ion range predicted by simulation. The concentration of these clusters increases as (ion dose) 2.6±0.1. Single anneals to higher temperatures reduce all open-volume point defect concentrations to below the limit detectable by VEPAS.
Original language | English |
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Pages (from-to) | 695-700 |
Number of pages | 6 |
Journal | Journal of Materials Science: Materials in Electronics |
Volume | 18 |
Issue number | 7 |
DOIs | |
Publication status | Published - Jul 2007 |