Micro- and nanofabrication technologies using the nanopositioning and nanomeasuring machines. - In: Optical Measurement Systems for Industrial Inspection XI, (2019), S. 1105637-1-1105637-13
To keep up with Moore's law in future, the critical dimensions of device features must further decrease in size. Thus, the nano-electronics and nano-optics manufacturing is based on the ongoing development of the lithography and encompasses also some unconventional methods. In this context, we use the Nanopositioning and Nanomeasuring Machine (NPMM) to generate features in resist layers by means of Direct Laser Writing (DLW),1 Field Emission Scanning Probe Lithography (FE-SPL)2 and Soft UV-Nanoimprint Lithography (Soft UV-NIL)3 with highest accuracy. The NPMM was collaboratively developed by TU Ilmenau and SIOS Meßtechnik GmbH.4 The tool provides a large positioning volume of 25 mm × 25 mm × 5 mm with a positioning resolution of 0.1 nm and a repeatability of less than 0.3 nm over the full range. Previously a single electron transistor (SET) working at room temperature generated by FE-SPL has been demonstrated.5 However, the throughput is limited because of the serial writing scheme making Tennant's law (At R5 ) valid.6 Here, At is the areal throughput and R the lithographic resolution. Thus, patterning of the whole NPMM positioning area by FE-SPL is very time consuming. In order to address this problem, different strategies and/or combinations are conceivable. In this work a so-called Mix-and-Match lithography is conducted. A fast generation of structures in the sub-micron range is possible by means of DLW. By this, features such as electrical wires, contact patches for bonding or labels are generated in resist. Subsequently, we use FE-SPL in order to define the actual nano-scaled features for quantum or single electron devices. In combination, DLW and FE-SPL are maskless lithography strategies, hence, offering completely novel opportunities for rapid nanoscale prototyping of largescale resist patterns. An explanation of this technique is given in a previous publication.7 Furthermore, after reactive ion etching, the sample can be used as template for Soft UV-NIL, thus resulting in a high-throughput process chain for future quantum and/or single electron devices.
https://doi.org/10.1117/12.2528136
Intrinsic surface feature based subaperture stitching of freeform wavefront. - In: Modeling Aspects in Optical Metrology VII, (2019), S. 1105708-1-1105708-10
The subaperture stitching technique requires the registration of freeform subapertures into global coordinate frame before stitching in order to compute entire freeform wavefront. A scanning Shack-Hartman Sensor (SHS) utilizes translation stages to scan the freeform surface in XY plane and measure the slope data of various subapertures. The measured slope data is then integrated using weighted cubic spline (WCSLI) based integration method to compute the phase data. The positioning error during scanning causes misalignments between the measured subapertures and their nominal values. The least square based subaperture stitching methods are not capable to minimize lateral misalignment errors of freeform subapertures and therefore degrade the performance of subaperture stitching process. In this work, we have utilized fiducial added planes for correction of angular and rotation misalignments of an extended cubic phase plate. An intrinsic surface feature (ISF) based registration method is used for lateral misalignment corrections. Gaussian curvature is used as an intrinsic pattern which can be defined as one of the fundamental second order geometric properties of a surface. Any shift in the peaks of the Gaussian curvature of reference and measured subaperture corresponds to lateral misalignments in X and Y directions and need to be minimized before registration of subaperture into global frame of reference. After precise registrations, all the subapertures are stitched with consistent overlapping area by using least square fitting method. A numerical validation of the proposed scheme is carried out which demonstrates the effectiveness of the proposed method to improve the subaperture stitching accuracy.
https://doi.org/10.1117/12.2526037
Evaluation of absorber configuration for a low clutter environment for over-the-air automotive radar testing. - In: 2019 IEEE MTT-S International Conference on Microwaves for Intelligent Mobility (ICMIM), (2019), insges. 4 S.
https://doi.org/10.1109/ICMIM.2019.8726691
Ultra-fast moving coil actuator for power switches in medium-voltage grids. - In: The journal of engineering, ISSN 2051-3305, (2019), 17, S. 4085-4089
https://doi.org/10.1049/joe.2018.8212
System distortion model for the cross-validation of millimeter-wave channel sounders. - In: 2019 13th European Conference on Antennas and Propagation (EuCAP), (2019), insges. 5 S.
https://ieeexplore.ieee.org/document/8739821
Numerical study of differential temperature measurement in human muscle tissue using UWB radar. - In: 2019 13th European Conference on Antennas and Propagation (EuCAP), (2019), insges. 4 S.
https://ieeexplore.ieee.org/document/8740020
Spherical wave expansion applied to the measured radiation patterns of automotive antennas in the installed state in the GHz range. - In: 2019 13th European Conference on Antennas and Propagation (EuCAP), (2019), insges. 5 S.
https://ieeexplore.ieee.org/document/8739832
Measurement based determination of parameters for in-stationary TDL models with reduced number of taps. - In: 2019 13th European Conference on Antennas and Propagation (EuCAP), (2019), insges. 5 S.
https://ieeexplore.ieee.org/document/8740077
Ultra-wideband temperature dependent dielectric spectroscopy of blood in the microwave frequency range. - In: 2019 13th European Conference on Antennas and Propagation (EuCAP), (2019), insges. 4 S.
https://ieeexplore.ieee.org/document/8740004
Experimental and analytical characterization of time-variant V2V channels in a highway scenario. - In: 2019 13th European Conference on Antennas and Propagation (EuCAP), (2019), insges. 5 S.
https://ieeexplore.ieee.org/document/8739792