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With the nanopositioning and nanomeasuring machine (NPM-Machine) developed at the Technische Universität Ilmenau, subnanometre resolution and nanometre uncertainty in a measuring volume of 25 × 25 × 5 mm3 have been demonstrated in the last few years. This machine allows the most various measuring problems to be solved. In practice, however, there are too many different requirements for sensing surfaces or for detecting structures. So, this paper deals with the development and also the improvement of several optical and tactile probes for application in the NPM-Machine. A focus probe with a spot size of approximately 0.5 µm, a working distance of 1.5 mm and a resolution of less than 1 nm was developed and adopted in the NPM-Machine. In the next step, the working distance was improved to exploit the full vertical range of the NPM-Machine of 5 mm. To realize tactile sensing, an atomic force probe and tactile stylus probe were developed on the basis of the focus probe. These probing systems can acquire measuring data only by scanning the surface sequentially and point-by-point. To increase data acquisition, we realized a sensor based on a white-light interference microscope and parallel sampling of 1600 × 1200 data points. First results of fringe evaluation with laser interferometer reference are presented.

Kelvin probe force microscopy (KPFM) is a method to detect the surface potential of microand nanostructured samples using a common atomic force microscope (AFM). The electrostatic force has a very long range compared to other surface forces. By using AFM systems under ambient conditions, KPFM measurements are performed using a non-contact regime at surface distances greater than 10 nm. This paper deals with a method to deconvolve the measured KPFM data with the objective to increase the lateral resolution. The KPFM signal is a convolution of an effective surface potential and a microscopic intrinsic point spread function, which allows the restoration of the measured data by linear deconvolution. In contrast to other papers [4], we have developed a new method to use the measured AFM tip shape as a basis to construct the point spread function. The linear shift-invariant channel is introduced as a signal formation model and a Wiener-supported deconvolution algorithm is applied to the measured data. The new method was demonstrated on a nanoscale test stripe pattern for lateral resolution and calibration of length scales (BAM-L200) manufactured by the Federal Institute for Materials Research and Testing, Germany. For the first time, a two-dimensional deconvolution of the KPFM data was able to be demonstrated. An increase in the lateral resolution compared to Strassburg et al (2005 Rev. Sci. Instrum. 76 083705) was accomplished. The results demonstrate the necessity of deconvolving the virtually topography-free probe data under ambient conditions.

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