کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1816661 | 1525270 | 2006 | 4 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Early SiO2 precipitates in Si: Vacancy-oxygen versus interstitial-oxygen clusters
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
فیزیک و نجوم
فیزیک ماده چگال
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
Oxygen precipitation in Si strongly depends on the undergoing thermal treatment. Between 350 and 450 °C thermal donor formation is activated by a 1.4-1.6 eV barrier. On the other hand, at T>500âC, SiO2 cluster formation is limited by the interstitial oxygen (Oi) migration barrier of â¼2.5eV. Volumetric arguments imply that the formation of silica precipitates during anneals of oxygen-rich Si crystals, must be accompanied by the ejection of approximately one Si self-interstitial (Sii) per SiO2 unit that is formed. We report on ab-initio density-functional studies of small oxygen aggregates in Si, to show that the OnâVOn+Sii reaction is exothermic for n⩾4. The large energy barrier required to form an intermediate Sii defect prevents the formation of VOn complexes at temperatures as low as 450 °C. Our results imply that thermal donors are not thermodynamically stable clusters, and their formation is driven by kinetics. Infra-red absorption studies can discriminate VOn and On defects. We report their local vibrational modes and compare them with the available experimental data.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Physica B: Condensed Matter - Volumes 376â377, 1 April 2006, Pages 109-112
Journal: Physica B: Condensed Matter - Volumes 376â377, 1 April 2006, Pages 109-112
نویسندگان
V.J.B. Torres, J. Coutinho, R. Jones, M. Barroso, S. Ãberg, P.R. Briddon,