TY - JOUR A1 - Emmerich, Florian A1 - Thielemann, Christiane T1 - Real-space measurement of potential distribution in PECVD ONO electrets by Kelvin probe force microscopy JF - Nanotechnology N2 - Multilayers of silicon oxide/silicon nitride/silicon oxide (ONO) are known for their good electret properties due to deep energy traps near the material interfaces, facilitating charge storage. However, measurement of the space charge distribution in such multilayers is a challenge for conventional methods if layer thickness dimensions shrink below 1 μm. In this paper, we propose an atomic force microscope based method to determine charge distributions in ONO layers with spatial resolution below 100 nm. By applying Kelvin probe force microscopy (KPFM) on freshly cleaved, corona-charged multilayers, the surface potential is measured directly along the z-axis and across the interfaces. This new method gives insights into charge distribution and charge movement in inorganic electrets with a high spatial resolution. KW - electret, multilayer, charge distribution, Kelvin probe force microscopy KW - Kelvin-Sonde KW - Rasterkraftmikroskopie Y1 - 2016 VL - 2016 IS - 27 SP - 1 EP - 10 ER - TY - CHAP A1 - Emmerich, Florian A1 - Thielemann, Christiane T1 - Observation of Thermal Discharge in Nanopatterned Electrets by Kelvin-Probe-Microscopy T2 - 14th International Symposium on Elecrets, 2011, Montpellier, France KW - Elektret Y1 - 2014 SN - 978-1-4577-1023-0 SN - 2153-3253 SP - 149 EP - 150 ER - TY - CHAP A1 - Emmerich, Florian A1 - Thielemann, Christiane T1 - Direct Visualisation of Stored Charges in PECVD ONO-Layers by Kelvin-Probe-Force-Microscopy T2 - 15th International Symposium on Electrets ISE KW - Kelvin-Sonde KW - Rasterkraftmikroskop Y1 - 2014 VL - 2014 CY - Baltimore, USA ER - TY - GEN A1 - Uhrig, Janis A1 - Emmerich, Florian T1 - Study on different template-based production processes for magnetic nanowires T2 - 22nd International Student Conference on Electrical Engineering POSTER 2018 N2 - Nickel-iron (NiFe) nanowires with a high contentof nickel and large aspect-ratio show promising characteris-tics for applications in modern micro-systems. In this study,nanowires with well-controlled diameter, height and compo-sition are fabricated using nanoporous poly-carbonate (PC)and anodized aluminum-oxide (AAO) membranes. Differ-ences between potentiostatic and pulsed deposition methodswere studied with regard to their flexibility and a recommen-dation for the best use of the individual types is given. Withthe application of the presented processes, future technolo-gies as magnetic energy-harvesting or nano-fluxgate sensorscan be improved. N2 - Poster KW - magnetic nanowires KW - MEMS KW - template-based KW - electroplating KW - Nanodraht Y1 - 2018 VL - 2018 IS - POSTER 2018 SP - 1 EP - 5 ER - TY - JOUR A1 - Emmerich, Florian A1 - Thielemann, Christiane T1 - Optimizing dimensions of unipolar Teflon-FEP piezoelectrets with micro-system-technology JF - Journal of Physics: Conference Series N2 - In this work we present a new micro-system-technology based production process for unipolar ferroelectrets. Theoretical analysis of the influence of the air-gap size on the electric field distribution as well as on the induced charge on the electrodes shows superior performance of unipolar piezoelectrets with small air-gaps. For the production of these small air-gaps we developed a new design using a photoresist thermoforming master, an integrated micro-heater and shadow masks for metallization. Unipolar piezoelectrets produced with this technology exhibit increased d33-coefficients compared to designs in previous publications. These piezoelectrets are highly preferable for energy-harvesting applications, as they promise high electric power output. KW - Mikrosystemtechnik Y1 - 2017 VL - 2018 IS - 1052 SP - 1 EP - 4 ER - TY - GEN A1 - Emmerich, Florian A1 - Ciba, Stefan T1 - Thin-film Micro-Heater for Fusion Bonding of Teflon-FEP Foils T2 - 21th International Student Conference on Electrical Engineering POSTER 2017 N2 - MEMS-based Micro-Heaters, in combination with thin-film temperature sensors, are often used for providing the necessary amount of thermal energy for sensor-applications. In this work, we propose an integrated micro-heater as actuator for fusion bonding of polymers, which can optimize the production process of electret-based micro-energy-harvesters. By adjusting the design parameters of thermoforming-molds, we can implement thin-film micro-heaters that are capable of generating temperatures of above 300°C for numerous cycles. Utilizing the integrated micro-heater allows local fusion bonding of Fluoroethylenepropylene (Teflon-FEP) foils on a micrometer-scale while reducing unnecessary thermal stress. This is beneficial for the longevity of the micro-energy-harvesters, while simultaneously improving its performance. N2 - Poster KW - Energy-Harvesting KW - Fusion Bonding KW - Micro-Heater KW - SU-8 KW - Teflon-FEP KW - Mikrosystemtechnik Y1 - 2017 VL - 2017 IS - POSTER 2017 SP - 1 EP - 5 ER - TY - CHAP A1 - Emmerich, Florian A1 - Thielemann, Christiane T1 - Patterning of PMMA by gold-nanoparticle initiated localized decomposition T2 - 2015 International Conference on Manipulation, Manufacturing and Measurement on the Nanoscale (3M-NANO), Changchun, China N2 - The need for manipulating matter at its smallest scale has been a hot topic in research for the last decades. As the final goal of arranging single atoms has been achieved, research focuses on two targets: firstly, improving the capabilities of existing technologies towards nanometer resolution and secondly, finding new methods for producing nanostructures in a fast and easy way. Here, we present a new maskless method for sub-micro-patterning of poly(methyl methacrylate) (PMMA) thin films. By applying atomic-force-microscope (AFM) assisted nano-xerography, electric charges were locally injected with an AFM-tip into PMMA. The resulting electrostatic patterns attracted charged gold-nanoparticles, which were selectively deposited onto the PMMA layers with lateral dimensions below 200 nm. In a second step, heat treatment at 275 °C initiated a selective decomposition of the PMMA layer, only observed in PMMA-areas covered with nanoparticles, whereas uncovered areas were not modified by the heat treatment. Analyzing the grooves with the AFM, we found that lines with a width in the sub-micrometer range to several micrometers have successfully been realized. We propose this new and promising method to manufacture nano-grooves used as masking for lift-off processes, for functionalization of underlying areas, or for micro-contact-printing. KW - Nanoparticles KW - Gold KW - Thermal stability KW - Heating KW - Electrostatics KW - Polymethylmethacrylate KW - Dünnschichttechnik Y1 - 2015 U6 - https://doi.org/10.1109/3M-NANO.2015.7425480 ER - TY - CHAP A1 - Nick, Christoph A1 - Hock, Christina A1 - Emmerich, Florian A1 - Belle, Stefan A1 - Thielemann, Christiane A1 - Asmus, Tim A1 - Loose, Thomas A1 - Wienand, Karlheinz T1 - Ultrathin gold as sensor platform for biomolecules T2 - 2015 International Conference on Manipulation, Manufacturing and Measurement on the Nanoscale (3M-NANO), Changchun, China N2 - Due to the increasing number of diabetes patients worldwide there is an enormous need for accurate, fast and someday also continuous or even closed loop monitoring of blood glucose level. More than 50 years after Clark and Lyons proposed the first glucose enzyme electrodes this concept is still widely in use today. Most concepts use the enzyme glucose oxidase (GOx) that reacts with glucose. These reactions cause a current that is proportional to the amount of glucose present at the sensor. Thus, if the sample volume is known, the blood sugar level can be measured. Although these electrodes have been in use for so long they have the disadvantage of a limited shelf time. In this work we present an enzyme free approach for glucose detection applying ultrathin gold films. According to the basic Fuchs-Sondheimer-theory and other more sophisticated models the resistivity of ultrathin metal films is dominated by scattering effects at their surface. Chemical reactions at the metallic surface are expected to change the conductivity properties and thus these changes can be used to detect molecules. This can be done by creating a self-assembled monolayer at the gold surface. When molecules such as glucose bind to the end groups of this layer the electron scattering and thus the conductivity of the film is expected to change. Ultrathin gold films with a thickness of 6 nm show the largest relative change in resistivity and are thus the preferred film thickness for this application. These gold films show a significant change in resistance when model molecules sodium sulfide and dextran are present, whereas the resistance of a platinum reference electrode does not change significantly. KW - ultrathin gold KW - biosensor KW - glucose KW - enzyme free glucose sensor KW - Biosensor KW - Dünne Schicht KW - Gold Y1 - 2015 U6 - https://doi.org/10.1109/3M-NANO.2015.7425462 ER - TY - CHAP A1 - Döhring, Thorsten A1 - Probst, Anne-Catherine A1 - Emmerich, Florian A1 - Stollenwerk, Manfred A1 - Stehlikova, Veronika A1 - Friedrich, Peter A1 - Damm, Christine T1 - Development of iridium coated X-ray mirrors for astronomical applications T2 - Proceedings of the International Society for Optics and Photonics (SPIE) N2 - Future space-based X-ray observatories need to be very lightweight for launcher mass constraints. Therefore they will use a reduced mirror thickness, which results in the additional requirement of low coating stress to avoid deformation of the initial precisely shaped mirror substrates. Due to their excellent reflection properties iridium coatings are sometimes applied for grazing incidence mirrors in astronomical X-ray telescopes. At Aschaffenburg University of Applied Sciences the coating of thin iridium films by an RF-magnetron sputtering technique is under development. The work is embedded in collaborations with the Max-Planck-Institute for Extraterrestrial Physics in Germany, the Czech Technical University in Prague, the Osservatorio Astronomico di Brera in Italy, the German Leibniz Institute for Solid State and Materials Research in Dresden, and the French Institute Fresnel. Sputtering with different parameters leads to iridium films with different properties. The current work is focused on the microstructure of the iridium coatings to study the influence of the substrate and of the argon gas pressure on the thin film growing process. Correlations between coating density, surface micro-roughness, the crystalline structure of the iridium layers, and the expected reflectivity of the X-ray mirror as well as coating stress effects are presented and discussed. The final goal of the project is to integrate the produced prototype mirrors into an X-ray telescope module. On a longer timescale measurements of the mirror modules optical performance are planned at the X-ray test facility PANTER. KW - X-ray KW - telescope KW - mirror KW - iridium KW - coating KW - Iridium KW - Röntgenteleskop Y1 - 2017 U6 - https://doi.org/10.1117/12.2273988 VL - 2017 IS - 10399 SP - 103991C-1 EP - 103991C-8 PB - SPIE ER - TY - CHAP A1 - Döhring, Thorsten A1 - Probst, Anne-Catherine A1 - Stollenwerk, Manfred A1 - Emmerich, Florian A1 - Stehlíková, Veronika A1 - Inneman, Adolf ED - Hudec, René ED - Pina, Ladislav T1 - Prototyping iridium coated mirrors for X-ray astronomy T2 - Proceedings of the International Society for Optics and Photonics N2 - X-ray astronomy uses space-based telescopes to overcome the disturbing absorption of the Earth´s atmosphere. The telescope mirrors are operating at grazing incidence angles and are coated with thin metal films of high-Z materials to get sufficient reflectivity for the high-energy radiation to be observed. In addition the optical payload needs to be light-weighted for launcher mass constrains. Within the project JEUMICO, an acronym for “Joint European Mirror Competence”, the Aschaffenburg University of Applied Sciences and the Czech Technical University in Prague started a collaboration to develop mirrors for X-ray telescopes. The X-ray telescopes currently developed within this Bavarian- Czech project are of Lobster eye type optical design. Corresponding mirror segments use substrates of flat silicon wafers which are coated with thin iridium films, as this material is promising high reflectivity in the X-ray range of interest. The deposition of the iridium films is based on a magnetron sputtering process. Sputtering with different parameters, especially by variation of the argon gas pressure, leads to iridium films with different properties. In addition to investigations of the uncoated mirror substrates the achieved surface roughness has been studied. Occasional delamination of the iridium films due to high stress levels is prevented by chromium sublayers. Thereby the sputtering parameters are optimized in the context of the expected reflectivity of the coated X-ray mirrors. In near future measurements of the assembled mirror modules optical performances are planned at an X-ray test facility. KW - X-ray KW - iridium KW - mirror KW - lightweight optic KW - Lobster Eye KW - Iridium KW - Röntgenastronomie KW - Spiegelteleskop Y1 - 2017 U6 - https://doi.org/10.1117/12.2265931 VL - 2017 IS - 10235 SP - 1023504-1 EP - 1023504-8 PB - SPIE International Society for Optics and Photonics CY - Bellingham WA ER - TY - JOUR A1 - Büttner, Andre A1 - Probst, Anne-Catherine A1 - Emmerich, Florian A1 - Damm, Christine A1 - Rellinghaus, Bernd A1 - Döhring, Thorsten A1 - Stollenwerk, Manfred T1 - Influence of Sputtering Pressure on the Microstructure and Layer Properties of Iridium Thin Films JF - Thin Solid Films N2 - Iridium layers with low stress, high density, and low surface roughness find widespread use in different high-technology applications. This paper presents a study of the influence of the sputtering pressure on the properties of iridium thin films and of its effect on the substrate surface microstructure. We analysed the dependence of the microstructure, crystalline structure, electrical resistivity, and deposition rate on the sputtering pressure and surface defects of the substrate. For the latter, plasma etching of the substrate was performed for different processing times and its effect on the surface roughness of substrates and, subsequently, on the grown iridium films, was examined. The sputtering pressure and the substrate plasma etching time both had a strong influence on the microstructure and surface roughness. These microstructural changes are in good agreement with the tendency described in the Thornton Structure-Zone Model for different sputtering pressures and the microstructure phase map of Alvarez. The electrical resistivity, deposition rate, and crystalline structure were highly dependent on the sputtering pressure. KW - Iridium KW - microstructure KW - TEM KW - sputtering KW - thin films KW - Iridium KW - Dünne Schicht Y1 - 2018 UR - https://doi.org/10.1016/j.tsf.2018.06.056 SN - 0040-6090 VL - 2018 IS - 662 SP - 41 EP - 46 ER - TY - JOUR A1 - Probst, Anne-Catherine A1 - Stollenwerk, Manfred A1 - Emmerich, Florian A1 - Büttner, Andre A1 - Zeising, Sebastian A1 - Stadtmüller, Johannes A1 - Riethmüller, Franziska A1 - Stehlikova, Veronika A1 - Mingwu, Wen A1 - Proserpio, Laura A1 - Damm, Christine A1 - Rellinghaus, Bernd A1 - Döhring, Thorsten T1 - Influence of sputtering pressure on the nanostructure and the X-ray reflectivity of iridium coatings JF - Surface and Coatings Technology N2 - Reflective mirror coatings made of iridium are used in X-ray telescopes of the Chandra X-ray Observatory (CXO) launched in 1999 by the National Aeronautics and Space Administration (NASA) to investigate astronomical sources at photon energies below 10. keV. These coatings were produced in a DC magnetron sputtering process and have so far proven their suitability for space-based applications. We are considering in the present paper the processing of thin iridium films for lightweight telescopes using the radio frequency magnetron sputtering technique with an oblique angle deposition. The coating development presented here is focused on the influence of total sputtering pressure on film properties as well as on its impact on the mirror's performance. Characterisation methods such as X-ray diffractometry, X-ray reflectometry, atomic force microscopy and transmission electron microscopy have been used. Correlations between morphology, density, surface micro-roughness, crystal structure of the iridium layer and the expected reflectivity of the X-ray mirror are described and discussed. KW - Iridium KW - sputtering KW - microstructure KW - coating KW - X-ray KW - Iridium KW - Röntgenteleskop Y1 - 2017 UR - https://doi.org/10.1016/j.surfcoat.2017.10.062 SN - 0257-8972 VL - 2017 IS - 343 SP - 101 EP - 107 ER - TY - JOUR A1 - Probst, Anne-Catherine A1 - Begou, Thomas A1 - Döhring, Thorsten A1 - Zeising, Sebastian A1 - Stollenwerk, Manfred A1 - Stadtmüller, Johannes A1 - Emmerich, Florian A1 - Lumeau, Julien ED - Publishing OSA, T1 - Coating stress analysis and compensation for iridium-based x-ray mirrors JF - Applied Optics N2 - Iridium-based coatings for mirrors of x-ray telescopes are studied. In particular, stress-induced deformation is characterized and shown to be compressive and equal to −1786  MPa. Two methods for stress compensation are then studied. One relies on the deposition of silica on the back surface of the substrate and a second one relies on the deposition of a chromium sublayer. Advantages and drawbacks of each of these techniques are presented. KW - iridium KW - coating stress KW - X-ray KW - mirror KW - astronomy KW - Röntgenteleskop KW - Iridium KW - Spiegelteleskop Y1 - 2018 UR - https://doi.org/10.1364/AO.57.008775 VL - 2018 IS - 57 (29) SP - 8775 EP - 8779 ER - TY - THES A1 - Emmerich, Florian T1 - Eigenschaften und Anwendungen von Dünnschicht-Elektretmaterialien KW - Dünnschichttechnik KW - Elektret Y1 - 2020 U6 - https://doi.org/10.25534/tuprints-00012056 ER - TY - JOUR A1 - Flachs, Dennis A1 - Emmerich, Florian A1 - Thielemann, Christiane T1 - Fabrication process for FEP piezoelectrets based on photolithographically structured thermoforming templates JF - Microsystem Technologies N2 - Piezoelectrets fabricated from fluoroethylenepropylene (FEP)-foils have shown drastic increase of their piezoelectric properties during the last decade. This led to the development of FEP-based energy harvesters, which are about to evolve into a technology with a power-generation-capacity of milliwatt per square-centimeter at their resonance frequency. Recent studies focus on piezoelectrets with solely negative charges, as they have a better charge stability and a better suitability for implementation in rising technologies, like the internet of things (IOT) or portable electronics. With these developments heading towards applications of piezoelectrets in the near future, there is an urgent need to also address the fabrication process in terms of scalability, reproducibility and miniaturization. In this study, we firstly present a comprehensive review of the literature for a deep insight into the research that has been done in the field of FEP-based piezoelectrets. For the first time, we propose the employment of microsystem-technology and present a process for the fabrication of thermoformed FEP piezoelectrets based on thermoforming SU-8 templates. Following this process, unipolar piezoelectrets were fabri� cated with air void dimensions in the range of 300–1000 lm in width and approx. 90 lm in height. For samples with a void size of 1000 lm, a d33-coefficient up to 26,508 pC/N has been achieved, depending on the applied seismic mass. Finally, the properties as energy harvester were characterized. At the best, an electrical power output of 0.51 mW was achieved for an acceleration of 1 � g with a seismic mass of 101 g. Such piezoelectrets with highly defined dimensions show good energy output in relation to volume, with high potential for widespread applications. KW - Mikrosystemtechnik Y1 - 2022 UR - Microsystem Technologies https://doi.org/10.1007/s00542-022-05405-6 U6 - https://doi.org/doi.org/10.1007/s00542-022-05405-6 VL - 2022 IS - November SP - 0 EP - 0 ER - TY - JOUR A1 - Flachs, Dennis A1 - Emmerich, Florian A1 - Roth, Gian-Luca A1 - Hellmann, Ralf A1 - Thielemann, Christiane T1 - Laser-bonding of FEP/FEP interfaces for a flexiblemanufacturing process of ferroelectrets JF - Journal of Physics: Conference Series N2 - This paper presents an optimized laser-bonding process for piezoelectric energy-harvesters based on thin fluorinated-ethylene-propylene (FEP) foils, using an ultra-short-pulse(USP) laser. Due to the minimized thermal stress in the material during bonding, achieved bypulse durations of few picoseconds, we created seams down to 40μm width without generatingholes in the 12.5μm thick FEP-foils. Using a galvanometer scanning system allowed for fastbonding-speed up to several centimeters per second, making the process also suitable for largestructures and areas. The achieved bond strength of the seams under influence of shearingstress was examined using tensile testing, which showed a sufficient strength of about 25 % of the maximum strength of an unbonded, single layer of FEP. KW - Ultrakurzzeitlaser KW - Piezoelektrizität Y1 - 2019 U6 - https://doi.org/10.1088/1742-6596/1407/1/012107 VL - 1407 IS - 012107 SP - 1 EP - 5 ER -