Nanoindentation, Scratching and Wear Testing Using Scanning Probe Microscopy (AN13)

Nanoindentation is an option for Digital Instruments MultiMode® and Dimension™ Series Scanning Probe Microscopes (SPMs). Using TappingMode™ AFM and an AFM diamond tip mounted to a metal-foil cantilever, you can indent a surface and immediately image the indentation. This eliminates the need to move the sample, switch AFM tips, relocate the indenting area for scanning, or use an entirely different instrument to image the indentation. Although indentation cantilevers have higher spring constants than typical imaging cantilevers, it is still possible to image soft samples with relatively low forces. This is possible using TappingMode AFM, which requires less force to image a sample than does contact mode AFM. The diamond tips are sufficiently sharp to provide good image resolution. The same cantilever/tip also allows scratching and wear tests. This option allows characterization of mechanical properties of thin films, such as diamond-like carbon, using indentation to investigate hardness, and scratching or wear testing to investigate film adhesion and durability. Recent studies have been done on chemical mechanical polishing (post CMP) wafers, polymers, and biological samples such as bovine and human sperm nuclei.