Cross-sectional nanoindentation for thin film interfacial adhesion characterization

Cross sectional nanoindentation (CSN) is a technique recently developed to study thin film interface decohesion in a microscopic scale. Controlled interfacial microcracks are induced at the interfaces of interest by indenting in a cross section of a multilayer thin film structure. The correlation between the observed cracking phenomena and the corresponding load vs, indenter tip displacement curves is discussed. An additional benefit of the CSN technique is the low scatter of results obtained for the mean interfacial crack lengths produced by identical tests. The observation of the interfacial crack front by scanning electron microscopy shows clear differences between the interfacial fracture micro-mechanisms present in samples with good and bad adhesion behaviour.