Determination of effective nanoindentation range for hard (Ti,Al)N thin film

In this study, a theoretical approach to determine effective nanoindentation range was conducted. The tip radius was first calculated from the experimental contact area function. Then a minimal indentation depth, at which the tip rounding effect can be negligible, was determined. As a representative system for the hard film on the soft substrate, the (Ti,Al)N film on the Si substrate was selected. The yield strengths were estimated for the evaluation of the substrate effect. The minimal indentation depth, at which the substrate effect can be negligible, was determined using the yield strength and tip radius. Finally, the effective nanoindentation range was estimated for the sample. The elastic modulus and the hardness of the film were also numerically verified.