Nano-scale elastic–plastic properties and indentation-induced deformation of amorphous silicon carbide thin film

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalNot applicablepeer-review

9 Scopus Citations
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Author(s)

Detail(s)

Original languageEnglish
Pages (from-to)385-391
Journal / PublicationCeramics International
Volume43
Issue number1
Publication statusPublished - 1 Jan 2017

Abstract

Controllable low-temperature (500 °C) deposition of amorphous a-SiC ceramic films on Si(100) was achieved using a pulsed dc-magnetron puttering system in a mixture of CH4/Ar. The nanoscale elastic-plastic response of the film upon contact loading was systematically characterized and analyzed by depth sensing nanoindentation technique using a Berkovich tip indenter. The mean values for elastic modulus and hardness were found to be 170±10 and 11.0±0.8 GPa, respectively. The onset of elastic-plastic transition occurred with contact loading of 70 µN at a depth of 10 nm. By coupling the Hertzian contact theory and Johnson's cavity model, the critical shear stress (7.7 GPa), yielding strength (14.4 GPa), plastic zone size (30–300 nm), and plastic work ratio (0.18–0.40) of a-SiC thin film under nanoindentation were determined. Based on the experimental results, the resolved shear stress analysis and deformation behavior were found to be consistent with the interpretation that the deformation behavior was associated with local readjustment of small clusters of atoms. The deformation mechanism was also explained on the basis of shear transformation zones (STZs) amorphous plasticity theory.

Research Area(s)

  • Elastic-plastic deformation, Mechanical properties, Nanoindentation, SiC thin film