Nanopatterning of metal-coated silicon surfaces via ion beam irradiation: Real time x-ray studies reveal the effect of silicide bonding

Osman El-Atwani, Birck Nanotechnology Center, Purdue University
Sean Gonderman, Purdue University
Alexander DeMasi, Boston University
Anastassiya Suslova, Purdue University
Justin Fowler, Purdue University
Mohamad El-Atwani, Purdue University
Karl Ludwig, Boston University
Jean Paul Allain, Birck Nanotechnology Center, Purdue University

Date of this Version



J. Appl. Phys. 113, 124305 (2013)


Copyright (2013) American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in J. Appl. Phys. 113, 124305 (2013) and may be found at . The following article has been submitted to/accepted by Journal of Applied Physics. After it is published, it will be found at Copyright (2013)Osman El-Atwani, Sean Gonderman, Alexander DeMasi, Anastassiya Suslova, Justin Fowler, Mohamad El-Atwani, Karl Ludwig and Jean Paul Allain. This article is distributed under a Creative Commons Attribution 3.0 Unported License.


We investigated the effect of silicide formation on ion-induced nanopatterning of silicon with various ultrathin metal coatings. Silicon substrates coated with 10 nm Ni, Fe, and Cu were irradiated with 200 eV argon ions at normal incidence. Real time grazing incidence small angle x-ray scattering (GISAXS) and x-ray fluorescence (XRF) were performed during the irradiation process and real time measurements revealed threshold conditions for nanopatterning of silicon at normal incidence irradiation. Three main stages of the nanopatterning process were identified. The real time GISAXS intensity of the correlated peaks in conjunction with XRF revealed that the nanostructures remain for a time period after the removal of the all the metal atoms from the sample depending on the binding energy of the metal silicides formed. Ex-situ XPS confirmed the removal of all metal impurities. In-situ XPS during the irradiation of Ni, Fe, and Cu coated silicon substrates at normal incidence demonstrated phase separation and the formation of different silicide phases that occur upon metal-silicon mixing. Silicide formation leads to nanostructure formation due the preferential erosion of the non-silicide regions and the weakening of the ion induced mass redistribution. (C) 2013 American Institute of Physics. []


Nanoscience and Nanotechnology