Bühler (Germany)

Ion beam machining has a long tradition in the fabrication of classical high-end optical components, enabling deterministic and highly reproducible surface correction on a broad range of optical materials. From sophisticated telescopic assemblies to lithographic projection systems, focused ion beam figuring (IBF) has delivered nanometer-level precision and sub-angstrom micro-roughness for decades. Today, industrial and research environments in precision optics and semiconductors demand not only equal or better optical performance but also markedly higher throughput, consistency, and process resilience. We outline methods for integrating high-resolution beam control with multi-axis motion to achieve productivity and precision concurrently. The result is a future-proof IBF approach capable of addressing both global form and higher-frequency content for next-generation optical and semiconductor applications.

Kunsthaus Bühler in einer Doppelausstellung vom 18. Januar bis zum 2. Februar 2002 das Gesamtwerk der aus Stuttgart stammenden Künstlerin, die sich zunächst in den USA und dann wieder in Stuttgart einen Namen gemacht hat und heute auf ein reiches Schaffen zurückblicken kann. 1947 gelingt es der gerade 17-jährigen Rose Alber, ohne das eigentlich erforderliche Abitur, an der Stuttgarter Akademie das Studium der Malerei bei Willi Baumeister und Erich Fuchs aufzunehmen. Baumeister, der das malerische Talent seiner Schülerin erkannte, förderte sie großzügig, obwohl sie sich nie der von ihm propagierten abstrakten Kunst zuwenden wollte und von Anfang an einen eigenen künstlerischen Weg suchte, der nicht auf die Anregung durch die konkreten Erfahrungen der Umwelt verzichten wollte. Man sieht dies an dem bereits 1951 entstandenen Gemälde «Am See», in dem eine

We have assessed and reduced the particle count in coatings from a magnetron sputter coater used for production of optical coatings for applications in photonics and semiconductor industry. Results for particle levels in single layers from Al₂O₃, SiO₂, Nb₂O₅, Ta₂O₅, and TiO₂ showed semiconductor grade particle levels for the upgraded deposition system. Moreover, particle levels were also investigated for optical filter stacks deposited on bare Si, glass substrates and actual CMOS device wafers, which were used for the manufacturing of hyperspectral imaging (HSI) sensors. In all cases, low particle counts were detected in the optical filters as expected from the results obtained for the single layer. It could be shown that the coating on the device wafers had no negative impact on the production yield of the HSI sensors.

Piezoresponse force microscopy (PFM) is widely used for characterization and exploration of the nanoscale properties of ferroelectrics. However, quantification of the PFM signal is challenging due to the convolution of various extrinsic and intrinsic contributions. Although quantification of the PFM amplitude signal has received considerable attention, quantification of the PFM phase signal has not been addressed. A properly calibrated PFM phase signal can provide valuable information on the sign of the local piezoelectric coefficient-an important and nontrivial issue for emerging ferroelectrics. In this work, two complementary methodologies to calibrate the PFM phase signal are discussed. The first approach is based on using a standard reference sample with well-known independently measured piezoelectric coefficients, while the second approach exploitsthe electrostatic sample-cantilever interactions to determine the parasitic phase offset. Application of these methodologies to studies of the piezoelectric behavior in ferroelectric HfO2 -based thin-film capacitors reveals intriguing variations in the sign of the longitudinal piezoelectric coefficient, d33,eff . It is shown that the piezoelectric properties of the HfO2 -based capacitors are inherently sensitive to their thickness, electrodes, as well as deposition methods, and can exhibit wide variations including a d33,eff sign change within a single device.

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Optical monitoring is a go to method for complex filters deposition; however, it can be easily shown that filter performance is dependent on monitoring strategy. When a non-quarter wave design needs to be deposited, usually one or minimal number of monitoring wavelengths is selected. This allows to use correction algorithms based on swing that are compatible with level-cut monitoring to a great extent. This approach has a significant drawback that it is very difficult to find one or few wavelengths that can be used for all layers of a complex filter. We present a different approach that relies on the selection of the best monitoring wavelength for each layer using pre-defined criteria that secure minimized thickness errors for each individual layer. Wavelength selection process uses several important criteria, such as monitoring wavelength sensitivity to errors in previous layers, transmittance evolution speed versus layer thickness growth, noise of measurement setup… We show that an additional important criteria is spectral resolution of the optical monitoring system and its impact on filter’s spectral response after each layer. Last, to ensure stable deposition we show that some precautions must be made to avoid false turning point detections. Using a binary approach for each criteria (pass or fail), monitoring wavelengths then can be selected automatically based on criteria defined above. In this work we demonstrate that such an approach can be implemented on stable deposition technique such as plasma assisted reactive magnetron sputtering (Bühler HELIOS machine) for different types of filters with various complexities. We illustrate our results for example on an 8-layer beamsplitter, a 37 layer D65 compensation filter, or a 100 layer custom shape spectral filter that are all very sensitive even to small thickness errors. Similar or better spectral performances are achieved compared with classical optical monitoring approaches but with an automatically determined optical monitoring strategy.

Variable filters, in which the bandpass central wavelength shifts along a dimension of the component, is a promising way to simplify and to miniaturize imaging spectrophotometer systems for spatial observation. In this paper, we present a new method for the fabrication of variable filters with different spatial profiles based on plasma assisted reactive magnetron sputtering. Variable filters are based on the variation of the thickness of the layers deposited on the substrate. The layers are manufactured using a Bühler HELIOS machine. To insure a non-uniformity of the deposited layers, adapted masks are placed in front of the targets for the low and high refractive index materials. The uniformity of these layers is measured via a homemade set-up allowing a local measurement of the transmission over the component surface. We demonstrate the fabrication of a narrow variable filter where all the thicknesses of all layers are changing, resulting in an overall shift of the filter.

This position paper is based on the current German and international guideline recommendations [1] [2] [3] and serves as a short, clinically-oriented guideline for the diagnosis and treatment of patients with diabetes mellitus and peripheral arterial disease (PAD).

Abstract Die neue Rührwerkskugelmühle Visconomic+ wurde speziell für die Verarbeitung von hochviskosen Produkten entwickelt. Die neue Spaltgeometrie sorgt zusammen mit der Stiftanordnung für eine maximale Strömungsbelastbarkeit. Durch diese Kombination werden eine frühzeitige Kompaktierung der Mahlkörper und eine Überhitzung des Produkts vermieden. Die Rotor‐ und Statorkühlung gewährleistet zudem eine optimale Temperaturführung.