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Diffusion of cesium in silicon during SIMS experiments investigated by numerical simulations
Author(s) -
Philipp Patrick,
Barry Peter,
Wirtz Tom
Publication year - 2014
Publication title -
surface and interface analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 90
eISSN - 1096-9918
pISSN - 0142-2421
DOI - 10.1002/sia.5608
Subject(s) - caesium , silicon , diffusion , chemistry , molecular dynamics , atom (system on chip) , density functional theory , lattice diffusion coefficient , surface diffusion , chemical physics , atomic diffusion , ab initio , molecular physics , materials science , computational chemistry , effective diffusion coefficient , thermodynamics , crystallography , inorganic chemistry , medicine , physics , organic chemistry , radiology , adsorption , computer science , magnetic resonance imaging , embedded system
In the present paper, we focus on the diffusion behaviour of cesium atoms implanted into silicon. This aspect has not been investigated directly up to now but is of utmost importance to understand the ionisation mechanisms in more detail. Density functional theory calculations combined with ab initio molecular dynamics simulations have been used to study the different aspects of cesium diffusion to the sample surface as a function of cesium concentration and sample temperature. In general, the solubility of cesium atoms in a silicon matrix is small, and the diffusion of the cesium atoms towards the surface is almost immediate, depending on how and where the cesium atom is incorporated in the silicon lattice. Depending on the defects introduced into the Si substrate, the diffusion could be largely reduced or cannot be observed during the few picosecond time range that can be explored by ab initio molecular dynamics simulations. Copyright © 2014 John Wiley & Sons, Ltd.