Some time ago, an interferometer-based metrological scanning probe microscope (SPM) was developed at the Institute of Process Measurement and Sensor Technology of the Ilmenau University of Technology, Germany. The specialty of this SPM is the combined deflection detection system that comprises an interferometer and a beam deflection. Due to this system it is possible to simultaneously measure the displacement, bending and torsion of the probe (cantilever). The SPM is integrated into a nanopositioning and nanomeasuring machine (NPM machine) and allows measurements with a resolution of 0.1 nm over a range of 25 mm × 25 mm × 5 mm. Excellent results were achieved for measurements of calibrated step height and lateral standards and these results are comparable to the calibration values from the Physikalisch-Technische Bundesanstalt (PTB) (Dorozhovets N et al 2007 Proc. SPIE 6616 661624–1–7). The disadvantage was a low attainable scanning speed and accordingly large expenditure of time. Control dynamics and scanning speed are limited because of the high masses of the stage and corner mirror of the machine. For the vertical axis an additional high-speed piezoelectric drive is integrated in the SPM in order to increase the measuring dynamics. The movement of the piezoelectric drive is controlled and traceable measured by the interferometer. Hence, nonlinearity and hysteresis in the actuator do not affect the measurement. The outcome of this is an improvement of the bending control of the cantilever and much higher scan speeds of up to 200 µm s−1.

An interferometer-based metrological scanning probe microscope (SPM) is successfully integrated into our nanopositioning and nanomeasuring machine (NPM machine) for high-precision measurements with nanometre uncertainty over a range of 25 mm × 25 mm × 5 mm. Both devices were developed at the Institute of Process Measurement and Sensor Technology of Ilmenau University of Technology, Germany. Outstanding results were achieved for different measurement tasks. With the NPM machine, truly long-range and long-term measurements are possible. Due to the tip wear, an automatic SPM cantilever replacement is preferable. Such a tip replacement is also required for the integration of multifunctional nanoanalytics. For example, for Kelvin probe force microscopy (KPFM), the measurement of topography and surface potential with different SPM tips is necessary. For this purpose, an electromagnetic tip changer was designed. The tip changer comprises three SPM probes. In order to retrieve the previous tip positions, additional fiducial marks were developed. The repeatability of relocation is less than 10 nm. The automatic tip changer and fiducial marks are integrated into a sample holder. The tip changer in combination with fiducial marks allows scanning distances three times longer (with the same type of SPM probes) and multifunctional nanoanalytics (with different SPM probes with special properties). Sample KPFM measurements are demonstrated. The developed tip changer, including special fiducial marks, improves the performance and functionality of the NPM machine crucially.

Continuing engineering progress in precision fabrication technologies, especially in the diversified micro-and nanotechnology, stimulates the advance in precision metrology, particularly in nanopositioning and nanomeasuring technology. Structures reach atomic dimensions, and becoming more and more complex. Consequently, measurements are required -to an increasing extend -of larger surface regions and sidewalls with higher aspect ratios as well as fully 3D micro-and nanostructures. Therefore, the resolution of nanomeasuring machines approaches the picometre level and the frequency stability of the laser sources the range of 10-10 to provide multiscale accuracy. Area-measuring optical sensors provide vast amount of data (> 5 Tbyte). Lateral highly resolved measurements are only possible by tip-based AFM single point probes but are extremely time consuming. Here, adaptive intelligent algorithms for optimum hierarchical measurement strategies are necessary. Multisenor instrumentation and multiparameter characterization provide additional challenges also in profoundly parallel data processing.

Nanomeasuring machines are devices for solving various positioning and measuring problems in a range of several millimetres with sub-nanometre resolution. These devices are used for positioning, probing and measurements. The combination of this machine with a scanning force microscope leads to improved quality in the calibration of standards. The measurement accuracy and stability of the scanning force microscope are important for the achievable measurement uncertainty. Many systems are influenced by the creep, hysteresis and bending of the included piezo actuators. A scanning force microscope head with a combined deflection detection system that comprises an interferometer and a beam deflection system was developed. Due to this system, it is possible to simultaneously measure the displacement, bending and torsion of the cantilever with only one focussed beam. An additional high-speed piezoelectric actuator for the vertical motion of the cantilever was integrated and is controlled by the bending signal. The outcome of this additional control system is a much higher scan speed. The interferometer system can be used for precise measurement of the vertical cantilever motion. Hence, non-linearity and hysteresis in the actuator do not affect the measurement. The device was used for several calibration measurements on step height and lateral standards. This article deals with the set-up, function and application of a scanning force microscope head for dimensional metrology with the nanomeasuring machines.

This paper presents different possibilities of determination of cantilever deflection using the beam theory and finite element method. It is proved that the cantilever can be described as an elementary beam with the force point within the neutral fibre, and its deflection can be determined according to Euler–Bernoulli beam theory. The determined analytical relationship between the inclination angle of the cantilever beam and displacement of its end is used for further calculations of the output signal of the atomic force microscope (AFM) position detector optical lever. Such position detectors as an interferometer, optical lever, and focus sensor are compared for application in an AFM. Analytical and numerical position detector models are developed here for determination of characteristic curves of detector output signals and their sensitivities. The comparison shows that the interferometer is by far the most sensitive and the optical lever is similarly sensitive to the focus sensor. Furthermore, a combined deflection-detection system that contains a homodyne Michelson interferometer and an optical lever is discussed.