Agar Scientific Provides Source for SPM Accessories

Agar is well known for its accessories for electron and light microscopy but perhaps is less well known for providing excellent calibration materials for scanning probe microscopy (SPM). As SPMs become more commonly used, the need for accessible and traceable standards is of great importance.

Agar supplies a range of ultra sharp silicon gratings for calibration and distortion checking of SPMs. The gratings, which have different profiles for different measurements, are manufactured using microfabrication techniques.

Gratings are available in different sizes to match user applications, for example, stepped gratings may be used for z axis calibration and non linearity measurement. Different step heights are available including 20 nm and 100 nm which are NIST traceable. Triangular gratings are used for lateral calibration, non linearity detection, assessment of angular distortion and determination of the radius of curvature of cantilever tips.

Chess pattern gratings with sharp undercut edges are very useful when studying certain semiconductor structures. These test patterns may be used to look at lateral calibration and non linearity, hysteresis and piezoceramic creep effects of scanners.

Using standards in SPM is vital for users wishing to produce quantitative data from their instruments. In the semiconductor world, atomic force microscopes (AFMs) are accepted as standard metrology tools while in the life sciences, AFM are being used to measure quantitative forces between molecules, cells and surfaces.