Browse by author
Lookup NU author(s): Professor Patrick Briddon
Full text for this publication is not currently held within this repository. Alternative links are provided below where available.
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>500°C, SiO2 cluster formation is limited by the interstitial oxygen (Oi) migration barrier of ∼2.5eV. 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 SiO 2 unit that is formed. We report on ab-initio density-functional studies of small oxygen aggregates in Si, to show that the On→VOn+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. © 2005 Elsevier B.V. All rights reserved.
Author(s): Torres VJB, Coutinho J, Jones R, Barroso M, Oberg S, Briddon PR
Publication type: Conference Proceedings (inc. Abstract)
Publication status: Published
Conference Name: Physica B: Condensed Matter. 23rd International Conference on Defects in Semiconductors
Year of Conference: 2006
Pages: 109-112
ISSN: 0921-4526
Publisher: Elsevier BV
URL: http://dx.doi.org/10.1016/j.physb.2005.12.029
DOI: 10.1016/j.physb.2005.12.029
Library holdings: Search Newcastle University Library for this item
ISBN: 18732135
