Structural Properties of Iron Silicide Nanostructures Grown by Reactive Deposition Epitaxy

Abstract

Iron silicide particles were grown on Si(100) by reactive deposition epitaxy. By maintaining the thickness of the deposited Fe down to 2 nm, silicide particles with diameters of less than 100 nrn were formed on Si(I 00) substrates. Type B FeSi(CsCI) or gamma-FeSi(2) nanoparticles and a few beta-FeSi(2) nanoparticles were formed at 500 degrees C. Type A and B gamma-FeSi(2), alpha-FeSi(2), and beta-FeSi(2) nanoparticles coexisted in the samples deposited at 600 degrees C. The alpha-FeSi(2) phase was predominant in the sample that was deposited at 700 degrees C. Among these iron silicide nanoparticles, alpha-FeSi(2) and beta-FeSi(2) nanoparticles tended to protrude out of the Si substrate and FeSi(CsCI) and gamma-FeSi(2) nanoparticles preferred to embed in the Si substrate. The mechanism of the formation of a faceted nanoparticle was discussed on the basis of the minimization of total surface energy. (C) 2009 The Japan Society of Applied Physics