Substrate composition effects on the interfacial fracture of tantalum nitride films

Abstract

In this study we combined nanoscratch testing with a multilayer sapphire and aluminum nitride single-substrate system to determine the effects of interface composition and structure on susceptibility to fracture of hard, thin tantalum nitride films. Nanoindentation tests showed that the elastic moduli of the tantalum nitride and aluminum nitride films, as well as the sapphire substrate, were essentially equal at 400 GPa. On both portions of the substrate, these tests also showed that near surface hardness was near 35 GPa. Nanoscratch tests triggered long blisters and circular spalls on both the sapphire and aluminum nitride portions of the substrate. The blisters showed that the tantalum nitride film was subjected to a compressive residual stress of 26.7 GPa. The spalls showed that failure occurred along the tantalum nitride film-substrate interface regardless of substrate composition. Most importantly, the blisters and spalls showed that the mode I component of the fracture energies was essentially equal on both substrate materials at a value near 3.1 J͞m 2 . These energies are on the order of the energies for metallic bonding.

Structural and mechanical properties of compositionally gradient CrNx coatings prepared by arc ion plating

“…To minimize the effect of substrate and film thickness, nanoindentation tests were performed to evaluate film hardness, and the indentation depth was adopted at 120 nm, equal to or less than 20% of film thickness [19,20]. Film thickness was obtained by SEM observation.…”

Nanoindentation and nanoscratch behaviors of DLC coatings on different steel substrates

“…This is likely an artifact of the data reduction method -when the penetration depth is sufficiently shallow, the load-depth curve shows almost complete elastic recovery [4]. Variations in surface topography also led to the scatter in measured values within 50 nm of the coating surface [5]. The hardness and modulus values of 40CrNiMo and 9Cr18 were approximately independent of indentation depths.…”

Quantifying improvements in adhesion of platinum films on brittle substrates

“…Scratch testing continuously measures the force and displacement of the microprobe, generally a diamond tip, to generate an interfacial crack and spalling. 21 Tymiak et al 22 studied the role of plasticity as a possible mechanism for increasing the interfacial fracture energy and others [23][24][25] have studied interface chemistry effects. Four-point bend and sandwich specimens test a macroscopic sample that incorporates a thin film into its structure.…”