Neutron Reflectometry for the Investigation of Self-Diffusion in Amorphous Silicon

Abstract:

We present experiments based on neutron reflectometry in combination with ²⁹Si/^natSi isotope multilayers in order to investigate the self-diffusion in amorphous silicon. Such experiments allow the detection of diffusion processes in the amorphous state on length scales below 10 nm. First results at 650 °C show a continuous decrease of the artificial Bragg peak produced by the multilayer, corresponding to a diffusivity of (1.1 ± 0.4) x 10^-20 m²/s on a length scale of 2 - 7 nm. The diffusivity is not time-dependent for annealing times between 3 min and 1 h. Compared to recent measurements in silicon single crystals by the same method, the diffusivity is higher by a factor of about 10⁵.

• Periodical: Defect and Diffusion Forum (Volume 363)
• Pages: 225-230
• DOI: https://doi.org/10.4028/www.scientific.net/DDF.363.225
• Online since: May 2015
• Authors: Florian Strauß, Thomas Geue, Jochen Stahn, Harald Schmidt
• Keywords: Amorphous Silicon, Isotope Multilayers, Neutron Reflectometry, Self-Diffusion

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