A computational study of SiaH bonds as precursors for neutral Ea2Ea2 centres in amorphous silica and at the Si/SiO2 interface

Using computational modelling we investigate whether SiaH Bonds can serve as precursors for neutral Ea2Ea2 centre formation in amorphous silica and at the Si/SiO2 interface. Classical inter-atomic potentials are used to construct models of a-SiO2 containing SiaH bonds. We then investigate the mechan...

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Bibliographic Details
Published in:Microelectronic engineering 2013-09, Vol.109, p.310-313
Main Authors: Ling, Sanliang, El-Sayed, Al-Moatasem, Lopez-Gejo, Francisco, Watkins, Matthew, Afanasaev, V V, Shluger, Alexander
Format: Article
Language:English
Subjects:
Charging
Computation
Defects
Precursors
Silicon
Silicon dioxide
Silicon substrates
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Summary:Using computational modelling we investigate whether SiaH Bonds can serve as precursors for neutral Ea2Ea2 centre formation in amorphous silica and at the Si/SiO2 interface. Classical inter-atomic potentials are used to construct models of a-SiO2 containing SiaH bonds. We then investigate the mechanism of dissociation of a SiaH bond to create a neutral Ea2Ea2 defect, that is a 3-coordinated silicon with an unpaired electron localised on it. We show that the SiaH bond is extremely stable, but as a result of hole injection it is significantly weakened and may dissociate, creating a neutral Ea2Ea2 centre and a proton attached to one of the nearby oxygen atoms. The proton can diffuse around the Ea2Ea2 centre and has a profound effect on the defect levels. We show that at a Si/SiO2 interface, the position of the proton can facilitate electron transfer from the Si substrate onto the defect, making it negatively charged.
ISSN:0167-9317
DOI:10.1016/j.mee.2013.03.028