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The 3D transfer characteristics of interference microscopes and their effect on the interference signals occurring at surface slopes are studied. The interference image stacks acquired during a depth scan are 3D Fourier transformed. This allows a comprehensive frequency domain analysis of the interferograms. The double foil model introduced in a previous publication enables the interpretation of the signal spectra and the underlying transfer behavior of the interferometer using the concept of the Ewald sphere, which is limited by the numerical aperture (NA) of the imaging system. Analysis in the 3D spatial frequency domain directly discloses that the lateral dimensions of the transfer function depend on the axial spatial frequency. In this contribution we investigate measuring objects produced by Nanoimprint-Lithography. The corresponding signal spectra bear information that can be utilized to optimize the subsequent signal processing algorithms. These include envelope and phase evaluation procedures of the interference signals. A narrow bandpass filter is used to actively select certain frequency components in order to improve the robustness of the estimation of the envelope position. Although the shape and width of the envelope are affected, this procedure increases the reliability of the evaluation process and improves the accuracy of the measured topography especially at steeper surface slopes.

The 3D transfer characteristics of interference microscopes and their effect on the interference signals occurring at surface slopes are studied. The interference image stacks acquired during a depth scan are 3D Fourier transformed. This allows a comprehensive frequency domain analysis of the interferograms. The double foil model introduced in a previous publication enables the interpretation of the signal spectra and the underlying transfer behavior of the interferometer using the concept of the Ewald sphere, which is limited by the numerical aperture (NA) of the imaging system. Analysis in the 3D spatial frequency domain directly discloses that the lateral dimensions of the transfer function depend on the axial spatial frequency. In this contribution we investigate measuring objects produced by Nanoimprint-Lithography. The corresponding signal spectra bear information that can be utilized to optimize the subsequent signal processing algorithms. These include envelope and phase evaluation procedures of the interference signals. A narrow bandpass filter is used to actively select certain frequency components in order to improve the robustness of the estimation of the envelope position. Although the shape and width of the envelope are affected, this procedure increases the reliability of the evaluation process and improves the accuracy of the measured topography especially at steeper surface slopes.

Tailored 3D microparticles and nanostructures lead to increasing possibilities in semiconductor industry or biomedical applications. In an interdisciplinary study we investigate the parallel production of such particles by using nanoimprint lithography in combination with their characterization based on interference microscopy. In this Letter we report on a metrological inspection, which tends to a universal measurement solution comparing the sample optically to a master object produced in the same way as the sample.

Optical measurement systems are an important part of the portfolio of 3D topography sensors. By precise, contactless and rapid measurements these sensors constitute an alternative to tactile instruments. In this contribution the principle of a laser interferometric distance sensor is presented, which in combination with lateral scan axes acts as a topography sensor and also as distance sensor for the compensation of vibrations in a coherence scanning Linnik interferometer. An advantage of this distance sensor is its high acquisition rate of height values, which in case of working as a topography sensor enables high scan velocities as it is demonstrated at a chirp standard measured with a scan velocity of 80 mm/s. This is much higher than the scan velocity of tactile instruments, which are typically limited up to 1 mm/s. In addition, the compensation of vibration disturbances demonstrates the capability of the fast distance measurement.

Die Charakterisierung eines Messinstruments zur Topographiemessung erfolgt durch die Messung bekannter Strukturen oder durch den Vergleich mit Referenzgeräten. Exakte Vergleichsmessungen bei unterschiedlicher Aufspannung des Messobjektes gestalten sich in der Praxis jedoch als schwierig, da Umgebungseinflüsse, Winkel zwischen Messobjekt und Messgerät, sowie die Position des Messfeldes nicht immer exakt übereinstimmen.

Die Charakterisierung eines Messinstruments zur Topographiemessung erfolgt durch die Messung bekannter Strukturen, oder durch den Vergleich mit Referenzgeräten. Exakte Vergleichsmessungen bei unterschiedlicher Aufspannung des Messobjektes gestalten sich in der Praxis jedoch als schwierig, da Umgebungseinflüsse, Winkel zwischen Messobjekt und Messgerät, sowie Position des Messfeldes nicht immer exakt übereinstimmen. In diesem Beitrag wird ein bislang neuartiges Multisensor- Mess- und Referenzsystem vorgestellt. Dieses Messsystem ermöglicht Vergleichsmessungen zwischen verschiedenen Sensoren in einer Aufspannung. Dabei werden zwei kommerzielle Sensoren (AFM und Konfokalmikroskop) als Referenzmessgeräte und zwei in Eigenentwicklung entstandene Interferometer (Mirau-Interferometer und fasergekoppelter High-Speed-Punktsensor) verwendet. Vergleichsmessungen mit den Referenzsensoren erlauben die Charakterisierung und Verbesserung der Interferometer, sowie die Untersuchung auftretender optischer Effekte an kritischen Messoberflächen. Neben dem Gesamtkonzept des Multisensor-Messsystems wird auf die Funktionsweise der eingesetzten Sensoren eingegangen. Darauf basierend werden von den unterschiedlichen Sensoren gemessene Oberflächentopographien präsentiert, welche die Schwierigkeiten einer genauen Wiedergabe der Oberfläche demonstrieren. Hinsichtlich der dargestellten Messergebnisse, liegen die Schwerpunkte auf dem Mirau-Interferometer und dem fasergekoppelten High- Speed-Punktsensor.