Progress of nanopositioning and nanomeasuring machines for cross-scale measurement with sub-nanometre precision. - In: Measurement science and technology, ISSN 1361-6501, Volume 31 (2020), number 8, 085005, Seite 1-8
https://doi.org/10.1088/1361-6501/ab848c
Model-based dimensional optical metrology. - In: Optics and Photonics for Advanced Dimensional Metrology, (2020), S. 113520P-1-113520P-13
https://doi.org/10.1117/12.2554517
Demonstration of aberration-robust high-frequency modulated Differential Confocal Microscopy with an oscillating Pinhole. - In: Optics and Photonics for Advanced Dimensional Metrology, (2020), S. 113520N-1-113520N-10
Metrological stages such as the nano-positioning and nano-measurement machine (NPMM) can position single-digit nanometer accurately on centimeter working volumes. However, their measurement system requires a feedback to the arbitrary shaped specimen by another probe. The differential confocal microscopy (DCM) offers the possibility to have a sensitivity down to that single-digit nanometers but suffers from noise and aberration. Recently the principle of the LockIn filtering could be successfully adapted in DCM and therefore achieved a high SNR. Contrary to the there employed acoustically driven tunable GRIN lens (TAG lens) at the objective, we demonstrate a microelectromechanical system (MEMS), an AFM cantilever, as an ultrafast oscillating pinhole in front of the detector. Its first resonance at 96kHz makes it very competitive regarding acquisition speed, but the low oscillation amplitude lowers contrast. By principle inheriting the possibility to compensate a change in reflectivity, we present another advancement for the evaluation of the resulting differential signal to make it robust against sample induced systematic depth errors, e.g. a tilt-angle. This could be advantageous for DCM with static beam-paths, as well. Potentially, the highest improvement can be achieved in conjunction with the NPMMs highly accurate measurement interferometers, because the residual error for the depth of a specimen under the influence of varying aberration is kept below 20nm.
https://doi.org/10.1117/12.2555558
Scanning wavefront detection coherent Fourier scatterometry (SCFS). - In: Optics and Photonics for Advanced Dimensional Metrology, (2020), S. 1135214-1-1135214-11
https://doi.org/10.1117/12.2554526
Nanopositioning and nanomeasuring machine for multi-sensor applications. - In: Measuring Equipment and Metrology, ISSN 2617-846X, Bd. 81 (2020), 2, S. 17-24
In micro- and nanotechnology, the demands placed on measurement technology are increasing. The structures to be measured are becoming more complex with smaller structure widths, increasingly larger surface regions, and thousands of inspection features. To solve the problems, it has become desirable and even necessary to combine multi-sensor technology with high precision nanopositioning and nano measuring technology. The Nanopositioning and Nanomeasuring Machine NMM-1 with a measuring range of 25 mm × 25 mm × 5 mm and sub-nanometer resolution allow the application of several optical, tactile and atomic force probes. The combination of several sensor technologies in a multi-sensor approach for application with the NMM-1 is demonstrated.
https://doi.org/10.23939/istcmtm2020.02.017
Structural and local electronic properties of clean and Li-intercalated graphene on SiC(0001). - In: Surface science, ISSN 1879-2758, Bd. 699 (2020), 121638
https://doi.org/10.1016/j.susc.2020.121638
The revised International System of Units (SI) and the resulting new potentials :
Das erneuerte Internationale Einheitensystem (SI) und seine Potenziale. - In: Technisches Messen, ISSN 2196-7113, Bd. 87 (2020), 4, S. 223-225
Editorial
https://doi.org/10.1515/teme-2020-0007
New ways to calibrate E2 mass standards and realization of forces up to 10 N :
Neue Wege zur Kalibrierung von E2-Massenormalen und Darstellung von Kräften bis 10 N. - In: Technisches Messen, ISSN 2196-7113, Bd. 87 (2020), 4, S. 280-293
https://doi.org/10.1515/teme-2019-0143
Tip- and laser-based nanofabrication up to 100 mm with sub-nanometre precision. - In: Novel Patterning Technologies for Semiconductors, MEMS/NEMS and MOEMS 2020, (2020), S. 113240A-1-113240A-17
Although the field of optical lithography is highly investigated and numerous improvements are made, structure sizes smaller than 20 nm can only be achieved by considerable effort when using conventional technology. To cover the upcoming tasks in future lithography, enormous exertion is put into the development of alternative fabrication technologies in particular for micro- and nanotechnologies that are capable of measuring and patterning at the atomic scale in growing operating areas of several hundred square millimetres. Many new technologies resulted in this process, and are promising to overcome the current limitations^1, 2, but most of them are demonstrated in small areas of several square micrometers only, using state-of-the-art piezo stages or the like. At the Technische Universitat Ilmenau, the NanoFabrication Machine 100 (NFM-100) was developed, which serves as an important experimental platform for basic research in the field of scale-spanning AFM tip-based and laser-based nanomeasuring and nanofabrication for simultaneous subnanometre measuring and structuring on surfaces up to Ø100 mm. This machine can be equipped with several probing systems like AFM, laser focus probes and 3D-micro probes as well as tools for different nanofabrication technologies like tip-based technologies, optical technologies and mechanical two-dimensional technologies in a large working range with subnanometre reproducibility and uncertainty. In this paper, the specifics and advantages of the NFM-100 will be described as well as nanofabrication technologies that are currently worked on e.g. advanced scanning proximal probe lithography based on Fowler-Nordheim-electron-field emission, direct laser writing and UV-nanoimprint lithography.
https://doi.org/10.1117/12.2551044
Cryogenic etching for pattern transfer into silicon of Mix-and-Match structured resist layers. - In: Microelectronic engineering, Bd. 227 (2020), 111325, insges. 5 S.
A Mix-and-Match lithography method for a high-resolution, high-precision and cost effective lithography tool using DLW and FE-SPL was developed and successfully realized. The pattern transfer from the photoresist to the silicon substrate is done by so-called "cryogenic etching". It means that the substrate is cooled down to cryogenic temperatures. In contrast to etching processes at standard room temperature, the cryogenic temperatures (below -100 ˚C) enable a highly anisotropic etching process. The difference between etching at room temperature compared to cryogenic etching is carried out in this work. The advantages of the etching process are highlighted for the pattern transfer from Mix-and-Match-structured samples. Therefore, the used photoresist mr-P 1201LIL (microresist technologies GmbH) has been examined concerning its silicon-to-resist selectivity which could be determined to be 6:1 for the applied etching recipe. Using cryogenic etching, we are now able to transfer the Mix-and-Match-structured patterns into silicon with appreciable high selectivities. This opens a novel pathway for the manufacturing of quantum devices on large wafers. The paper discusses current research results based on the TU Ilmenau Nanopositioning and Nanomeasuring Machines (NPMM) including the novel application of nanofabrication. First, the basic setup and the resulting benefits of the NPMMs for measuring and fabrication in a working volume of up to 200 mm × 200 mm × 25 mm while abiding nanometer accuracy is described. This is in contradiction to state-of-the-art AFM scanners, which have a limited working range of appr. 100 [my]m × 100 [my]m. Next, the principle and the results of different nanofabrication technologies are shown. These include Scanning Probe Lithography (SPL), Direct Laser Writing (DLW) and UV-nanoimprint lithography (NIL). Last, efforts for further improving the feature placement accuracy of the NPMMs as well as attempts to combine several fabrication technologies to improve their throughput are touched on.
https://doi.org/10.1016/j.mee.2020.111325