Haberl, BiancaBradby, J. E.Ruffell, S.Williams, J. S.Munroe, P.2015-10-012015-10-010021-8979http://hdl.handle.net/1885/15751The deformation behavior of ion-implanted (unrelaxed) and annealed ion-implanted (relaxed) amorphous silicon(a-Si) under spherical indentation at room temperature has been investigated. It has been found that the mode of deformation depends critically on both the preparation of the amorphous film and the scale of the mechanical deformation.Ex situmeasurements, such as Raman microspectroscopy and cross-sectional transmission electron microscopy, as well as in situ electrical measurements reveal the occurrence of phase transformations in all relaxed a-Si films. The preferred deformation mode of unrelaxed a-Si is plastic flow, only under certain high load conditions can this state of a-Si be forced to transform. In situ electrical measurements have revealed more detail of the transformation process during both loading and unloading. We have used ELASTICA simulations to obtain estimates of the depth of the metallic phase as a function of load, and good agreement is found with the experiment. On unloading, a clear change in electrical conductivity is observed to correlate with a “pop-out” event on load versus penetration curves.http://www.sherpa.ac.uk/romeo/issn/0021-8979..."Publishers version/PDF may be used on author's personal website, institutional website or institutional repository" from SHERPA/RoMEO site (as at 2/10/15). Copyright 2006 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 Journal of Applied Physics and may be found at https://doi.org/10.1063/1.2210767Keywords: Amorphous films; Annealing; Computer simulation; Ion implantation; Phase transitions; Temperature distribution; Transmission electron microscopy; Mechanical deformation; Raman microspectroscopy; Room temperature; Spherical indentation; Amorphous silicon2006-07-1210.1063/1.22107672015-12-12