In situ scanning electron microscopy indentation studies on multilayer nitride films: Methodology and deformation mechanisms

Abstract

Systematic studies of the deformation mechanisms of multilayer transition metal nitride coatings TiN/CrN, TiN/NbN, and NbN/CrN, and corresponding reference coatings of TiN, NbN, and CrN deposited by a direct current (dc) magnetron sputtering process onto silicon 〈100〉 have been performed. Mechanical characterization was conducted using a combination of microindentation and nanoindentation in the load range 30 to 150 mN and 0.5 to 3.5 mN, respectively. For both load ranges, scanning electron microscopy (SEM) in situ indentation was used to observe the indentation process including any pileup, sink-in, and fracture mechanisms specific to each coating. The coatings’ microstructure, both before and after indentation, was analyzed using transmission electron microscopy (TEM). It was possible to both correlate the indentation load–displacement response to surface roughness effects and fracture modes (substrate and film cracking) and observe deformation mechanisms within the coatings.