Nanoindentation and nanoscratch are two common techniques for measuring the interfacial adhesion thin film/substrate systems. There are multiple ways in which these techniques are used for interfacial adhesion characterization, but all are based on supplying a well-known stress to the film/substrate interface and identifying delamination events though sudden changes in probe/film contact conditions. During a nanoindentation test, interfacial adhesion is determined using site-specific material properties and the dimensions of the delaminated region, either caused by buckling or indentation-induced blister formation. Nanoscratch testing increases the normal force acting on the scratch probe as it is translated tangential to the sample surface. The normal force at which delamination occurs during a nanoscratch test is known as the critical load of interfacial adhesion and is closely tied to the film/substrate interfacial adhesion energy. Both nanomechanical testing techniques provide fast, reliable, and quantitative interfacial adhesion characterization of thin films in their as-deposited state.
Bruker is the industry-leader for thin film interfacial adhesion measurements. Bruker’s patented electrostatic transducer technologies provide high-sensitivity force and displacement measurements, critical to detecting the initial onset of delamination during the nanomechanical test. In-situ SPM imaging capabilities enable high resolution topography mapping post-test to quickly measure the size of the delamination and observe material deformation behavior. Algorithms built into the TriboScan™ software package automatically identify critical loads of interfacial adhesion values and automated measurement routines allow rapid nanoscale mapping of adhesion properties across blanket thin films. Bruker technologies enable quantitative measurement of the interfacial adhesion characteristics of ultra-thin films, down to a couple nanometers in thickness.