ISO/TC 201/SC 9 - Scanning probe microscopy

This document describes a procedure for the determination of elastic modulus for compliant materials using atomic force microscope (AFM). Force-distance curves on the surface of compliant materials are measured and the analysis uses a two-point method based on Johnson-Kendall-Roberts (JKR) theory. This document is applicable to compliant materials with elastic moduli ranging from 100 kPa to 1 GPa. The spatial resolution is dependent on the contact radius between the AFM probe and the surface and is typically approximately10-20 nm.

This document specifies methods for characterizing and calibrating the scan axes of scanning-probe microscopes (SPMs) for measuring geometric quantities at the highest level. It is applicable to those providing further calibrations and is not intended for general industry use, where a lower level of calibration might be required. This document has the following objectives: — to increase the comparability of measurements of geometrical quantities made using SPMs by traceability to the unit of length; — to define the minimum requirements for the calibration process and the conditions of acceptance; — to ascertain the instrument's ability to be calibrated (assignment of a "calibrate-ability" category to the instrument); — to define the scope of the calibration (conditions of measurement and environments, ranges of measurement, temporal stability, transferability); — to provide a model, in accordance with ISO/IEC Guide 98-3, to calculate the uncertainty for simple geometrical quantities in measurements using an SPM; — to define the requirements for reporting results.

ISO 11775:2015 describes five of the methods for the determination of normal spring constants for atomic force microscope cantilevers to an accuracy of 5 % to 10 %. Each method is in one of the three categories of dimensional, static experimental, and dynamic experimental methods. The method chosen depends on the purpose, convenience, and instrumentation available to the analyst. For accuracies better than 5 % to 10 %, more sophisticated methods not described here are required.

ISO 13083:2015 describes a method for measuring the spatial (lateral) resolution of scanning capacitance microscopes (SCMs) or scanning spreading resistance microscopes (SSRMs), which are widely used in imaging the distribution of carriers and other electrical properties in semiconductor devices. The method involves the use of a sharp-edged artefact.

ISO 13095:2014 specifies two methods for characterizing the shape of an AFM probe tip, specifically the shank and approximate tip profiles. These methods project the profile of an AFM probe tip onto a given plane, and the characteristics of the probe shank are also projected onto that plane under defined operating conditions. The latter indicates the usefulness of a given probe for depth measurements in narrow trenches and similar profiles. This International Standard is applicable to the probes with radii greater than 5u0, where u0 is the uncertainty of the width of the ridge structure in the reference sample used to characterize the probe.

ISO 11039:2012 defines terms and specifies measurement methods for characterizing the drift rates of scanning-probe microscopy (SPM) instruments in the X- and Y-directions and, for SPM instruments measuring topography, the drift rate in the Z-direction. Though the behaviour of the long-term drift rate might be nonlinear, both that and the behaviour of the short-term drift rate after a user-defined settling time can be characterized by either typical average or typical maximum drift rates. This International Standard is suitable for evaluating the drift rate based on SPM images. It is intended to help manufacturers quote drift figures in specifications in a meaningful and consistent manner and to aid users to characterize the drift behaviour so that effective experiments can be designed. These measurements are not designed for image correction.

ISO 27911:2011 describes a method for determining the spatial (lateral) resolution of an apertured near-field scanning optical microscope (NSOM) by imaging an object with a size much smaller than the expected resolution. It is applicable to aperture-type NSOMs operated in the transmission, reflection, collection or illumination/collection mode.

ISO 11952:2014 specifies methods for characterizing and calibrating the scan axes of scanning-probe microscopes for measuring geometric quantities at the highest level. It is applicable to those providing further calibrations and is not intended for general industry use, where a lower level of calibration might be required.