Article
Correlation of local structure and electrical activation in arsenic ultrashallow junctions in silicon
Journal of Applied Physics
(2008)
Abstract
The understanding of the behavior of arsenic in highly doped near surface silicon layers is of crucial importance for the formation of NN-type ultrashallow junctions in current and future very large scale integrated technology. This is of particular relevance when studying recently developed implantation and annealing methods. Past theoretical as well as experimental investigations have suggested that the increase in As concentration, and therefore the reciprocal proximity of several As atoms, leads to a drastic increase in electrically inactive defects giving only marginal reduction in sheet resistance. Monoclinic SiAs aggregates as well as various arsenic-vacancy clusters contribute to the deactivation of arsenic. This study aims to correlate between the results of electrical activation measurements and x-ray absorption fine structure measurements. Samples were doped with a nominal fluence of 1×1015–3×1015atoms/cm21, implanted at 2 keV, and annealed by rapid thermal treatments, laser submelt treatments, and a combination of both. Hall effect and sheet resistance measurements have been performed to obtain the density of charge carriers. Secondary ion mass spectrometry has been employed to measure the depth profile and the total retained fluences. The percentage of substitutional arsenic has been obtained by least-squares fits of the measured x-ray absorption spectra with simulated spectra of relaxed structures of the defects obtained by density functional theory. A good agreement with the Hall effect measured electrically active dose fraction has been obtained and a quantification of the population of the different defects involved has been attempted.
Disciplines
Publication Date
November 15, 2008
DOI
10.1063/1.3026706
Citation Information
Damiano Giubertoni, Stephen Kelty, Salvatore Gennaro, Massimo Bersani, et al.. "Correlation of local structure and electrical activation in arsenic ultrashallow junctions in silicon" Journal of Applied Physics Vol. 104 Iss. 10 (2008) ISSN: 0021-8979 Available at: http://works.bepress.com/stephen_kelty/3/