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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This article presents white light interferometry as a new application for the nanopositioning and nanomeasuring machine (NPMM). The NPMM was developed under the leadership of the Institute of Process Measurement and Sensor Technology at the Technische Universität Ilmenau (Germany) and allows highly exact dimensional and traceable positioning with a resolution of 0.1 nm within a volume of 25 mm x 25 mm x 5 mm.An application of white light interferometry was developed on the basis of these features which can utilize the device's very high precision and large effective range, which enables the stitching of partitioned results without overlapping measurements and expensive matching methods.In order to extract height data from the interferograms, a robust, precise and fast method using matched filters in the frequency domain has been put into practice. The filter templates are calculated according to a model function or are directly sampled from the light source power spectrum, which has been previously analyzed once. Thus, light sources with different spectral forms can be used.

This article discusses methods to measure samples up to 25 × 25 mm 2 using the NPMM [1] as an atomic force microscope (AFM) [2]. An entire scan at full resolution (10 nm) and 10 μm/s scan speed would take about 200 years. Therefore, overview scans with the AFM can be done to reduce the scan time, but these scans can induce aliasing artifacts due to subsampling. This paper gives a solution to that problem. The AFM camera is used for approximate orientation in the scan field. From an automatic optical area scan stitching software creates an overview image of about 2.6 GPixel with 0.5 μm resolution. The GEOtiff standard [3] is introduced to enable orientation in such big images. This format includes positioning information in the image and is used to solve the nano-orientation problem. This article further presents routines to create an overview image and a segmentation routine to detect structure domains. Since a combination of an AFM and optical scanning leads to higher positioning performance, both measurements are merged.Zusammenfassung In diesem Artikel werden Methoden zur hochauflösenden Messung von sehr großen Proben (bis zu 25 × 25 mm 2 Fläche) an der Nanopositionier-und Messmaschine [1] in Kombination mit einem Rastersondenmikroskop (AFM) [2] vorgestellt. Die geschätzte Messzeit für einen vollständigen Oberflächenscan mit einer lateralen Auflösung von 10 nm und einer Messgeschwindigkeit von 10 μm/s beläuft sich auf über 200 Jahre. Grobaufgelöste Übersichtsscans können bei der Orientierung im Messvolumen helfen, jedoch treten in Abhängigkeit von der Oberflächentopographie aufgrund der Unterabtastung AliasingStörungen in den Messdaten auf. Eine Lösung bietet die Einbeziehung der Mikroskopkamera am AFM zur Orientierung im Messvolumen. Über automatisierte Stitchingverfahren wird der komplette Messbereich in einem Übersichtsbild abgebildet. Bei einer Pixelauflösung von 0,5 μm erreicht das Übersichts-bild eine Größe von 2,6 GPixel. Die Transformationsdaten vom Bild-in das Maschinenkoordinatensystem werden über den in das Übersichtsbild integriert, um so eine Orientierung im Messbereich zu gewährleisten. Durch eine automatische Segmentierung werden zusammenhängende Regionen auf der Probe separiert, aus denen die interessanten Messbereiche nach vorgegebenen Merkmalen selektiert werden. Diese ausgewählten Bereiche können dann gezielt angefahren und hochaufgelöst mit dem AFM-Sensor gemessen werden. Die Kombination von Übersichtsbild und AFM ermög-licht eine bessere Performance zur Messung von Proben, welche aufgrund ihrer Größe nicht vollständig hochaufgelöst abgetastet werden können.