Low-load indentation behavior of HfN thin films deposited by reactive rf sputtering

Deformation of HfN thin films deposited by the reactive sputtering method on silicon and alumina substrates has been investigated using depth-sensing indentation. The experiments performed in a low load range (2-50 mN) revealed that even extremely shallow indentations were affected by the elastic/plastic response of the substrate. The analysis of the shape of the indentation load-depth hysteresis loops and of conventional hardness data was supplemented by considerations based on the recently proposed energy principle of indentation.