Liu, A. Y.Sun, C.Markevich, V. P.Peaker, A. R.Murphy, J. D.Macdonald, D.2026-07-032026-07-030021-8979ORCID:/0000-0001-5792-7630/work/219174022ORCID:/0000-0003-4579-5495/work/219175252https://hdl.handle.net/1885/733812703It is known that the interstitial iron concentration in silicon is reduced after annealing silicon wafers coated with plasma-enhanced chemical vapour deposited (PECVD) silicon nitride films. The underlying mechanism for the significant iron reduction has remained unclear and is investigated in this work. Secondary ion mass spectrometry (SIMS) depth profiling of iron is performed on annealed iron-contaminated single-crystalline silicon wafers passivated with PECVD silicon nitride films. SIMS measurements reveal a high concentration of iron uniformly distributed in the annealed silicon nitride films. This accumulation of iron in the silicon nitride film matches the interstitial iron loss in the silicon bulk. This finding conclusively shows that the interstitial iron is gettered by the silicon nitride films during annealing over a wide temperature range from 250 °C to 900 °C, via a segregation gettering effect. Further experimental evidence is presented to support this finding. Deep-level transient spectroscopy analysis shows that no new electrically active defects are formed in the silicon bulk after annealing iron-containing silicon with silicon nitride films, confirming that the interstitial iron loss is not due to a change in the chemical structure of iron related defects in the silicon bulk. In addition, once the annealed silicon nitride films are removed, subsequent high temperature processes do not result in any reappearance of iron. Finally, the experimentally measured iron decay kinetics are shown to agree with a model of iron diffusion to the surface gettering sites, indicating a diffusion-limited iron gettering process for temperatures below 700 °C. The gettering process is found to become reaction-limited at higher temperatures.This work has been supported by the Australian Renewable Energy Agency (ARENA) through project RND009. Author C. Sun acknowledges the financial support from Australian Centre for Advanced Photovolatics. The work in the UK was supported by the Engineering and Physical Sciences Research Council via the SuperSilicon PV project (EP/M024911/1). Access to the low-energy ion implantation system at the Department of Electronic Materials Engineering (ANU) is greatly appreciated. The authors would like to thank Dr. Yimao Wan (ANU) for sharing his knowledge on the PECVD silicon nitride deposition processes and film properties.enPublisher Copyright: © 2016 Author(s).2016-11-2110.1063/1.496791484998892661