Micro/nanomechanical behavior of magnetron sputtered Si–C–N coatings through nanoindentation and scratch tests

Abstract

Si-C-N/Si based MEMs are advantageous to conventional MEMS because of their ease of fabrication and high temperature sustainability. The failure mechanism of such systems has to be known for their efficient performance. Nanoindentation and scratch behavior were performed on Si-C-N coatings deposited on silicon substrates by RF magnetron sputtering. Crack growth and propagation were studied using optical and SEM views of the deformed region. Different failure mechanisms were observed and analyzed. The crack deflection was due to nanocrystalline phases in the Si-C-N nanocomposite film, as no such deflection was observed in the amorphous CNx film. A different failure mechanism in the form of tensile and conformal cracking was observed. The films' failure mechanism changes from cohesive failure at lower loads to adhesive failure at higher loads during nanoscratching.

Nanoindentation Stress–Strain for Fracture Analysis and Computational Modeling for Hardness and Modulus

“…To extend the research further we assigned other geometrical shapes to the crack region. We observed crack branching phenomenon in nanoindentation as well as reported earlier [16]. The ratio E/H is nanoindentation is usually of the order of 10 which gives χ ~ 0.05.…”

“…In an energetic context, toughness is the ability of a material to absorb energy during deformation up to fracture. Nanoindentation performed at higher loads caused fracture surrounding the indentation impression [5][6][7]. However there are also some internal cracks not visible on the surfaces which arise due to high shear stress of the indenter.…”

Emerging materials for microelectromechanical systems at elevated temperatures

“…Bright et al pursued a similar route using hot isostatic pressing. 69 Soft lithography methods, 72,73 PECVD, 74 and even sputtering 75,76 have also been explored, but these ultimately limit the potential aspect ratio.…”

Influence of Si contents on tribological characteristics of CrAlSiN nanocomposite coatings

“…Furthermore, the significant distinction in the worn volume was mainly resulted from the different nanostructures between both coatings. Bhattacharyya et al [19] illustrated a wear model for Si-C-N nanocomposite coatings. Crack deflection was due to nanocrystalline phases in Si-C-N nanocomposite films, as no such deflection was observed in amorphous CN x films.…”