High spatial resolution nanomechanical mapping of materials: from proteins to magnetic media

Tesis Doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Física de la Materia Condensada. Fecha de Lectura: 01-09-202

Miniaturized Electron Optics based on Self-Assembled Micro Coils

Zahlreiche Geräte, die in den Naturwissenschaen, in der Industrie und im Gesundheitswesen unverzichtbar sind, basieren auf Strahlen schneller geladener Teilchen. Dazu zählen unter anderem Elektronen- und Ionenmikroskope, entsprechende Lithographiestrahlanlagen und Röntgenstrahlungsquellen. Magnetische Optiken, die Strahlen geladener Teilchen ablenken, formen und fokussieren, sind das Rückgrat aller Geräte die mit hochenergetischen Teilchen arbeiten, da sie im Vergleich zu Optiken, die auf elektrischen Feldern basieren, bei hohen Teilchengeschwindigkeiten eine überlegene optische Leistung aufweisen. Konventionelle makroskopische magnetische Optiken sind jedoch groß, teuer und platzraubend, nicht hochfrequenzfähig und erfordern aktive (Wasser-)Kühlung zur Wärmeabfuhr. Sie sind daher für Mehrstrahlinstrumente, miniaturisierte Anwendungen und schnelle Strahlmanipulation ungeeignet, die für zukünftige Fortschritte in der Nanofabrikation und -analyse gebraucht werden. Im Rahmen dieser Arbeit wurden die ersten magnetischen selbst-assemblierenden Mikro-Origami-Elektronenoptiken entwickelt, hergestellt und charakterisiert. Mit dem verwendeten Miniaturisierungsansatz können, bei ähnlicher optischer Leistung, alle oben genannten Nachteile von konventionellen magnetischen Optiken überwunden werden. Die außergewöhnlichen Eigenschaften dieser optischen Elemente werden durch die einzigartigen Merkmale der Mikrospulen ermöglicht: geringe Größe, geringe Induktivität und geringer Widerstand. Im Rahmen dieser Arbeit wurden unter anderem adaptive Phasenplaen hergestellt, die Elektronenvortexstrahlen mit einem bislang unerreichten Bahndrehimpuls von bis zu mehreren 1000 ̄h erzeugen. Des Weiteren wurden schnelle Elektronenstrahldeflektoren zur Strahlablenkung, zum zweidimensionalen Rastern und für stroboskopische Experimente gefertigt. Sie besitzen eine Ablenkleistung im mrad-Bereich für 300 kV Elektronen und einen Frequenzdurchgang bis zu 100 MHz. Darüber hinaus wurden miniaturisierte adrupollinsen mit Brennweiten kleiner als 46 mm für 300 kV Elektronen entwickelt. Diese drei Arten elektronenoptischer Elemente sind von großem Interesse für verschiedenste Anwendungen in der Nanofabrikation und -analyse, da sie unter anderem als integrale Bestandteile von zu entwickelnden Mehrstrahlinstrumenten, miniaturisierten Geräten und stroboskopischen Messaufbauten dienen können.:1 Introduction 1.1 Charged Particle Optics 1.2 Miniaturized Charged Particle Optics 1.3 Phase Plates for Transmission Electron Microscopy 2 Charged Particle Optics 2.1 Hamiltonian Formalism 2.2 Gaussian Matrix Optics 2.3 Transfer Matrices of Magnetic Elements 2.3.1 Single Quadrupole 2.3.2 Quadrupole Multiplets 2.3.2.1 Quadrupole Doublet 2.3.2.2 Quadrupole Triplet 2.3.2.3 Higher Order Quadrupole Multiplets 2.4 Scaling Laws for Charged Particle Optics 2.4.1 Thin Film 2.4.2 Electrostatic Scaling Laws 2.4.3 Magnetic Scaling Laws 3 Design and Fabrication of Miniaturized Electron Optics 3.1 Basics of Polymer-Based Self-Assembly Technology 3.2 Basic Coil Design and Magnetic Field Simulations 3.3 CoFeSiB-Pyrex Core-Shell Micro Wires 3.4 Fabrication of Self-Assembled Micro Coil Devices 4 Optical Properties of Self-Assembled Miniaturized Electron Optics 4.1 Electron Vortex Phase Plate 4.1.1 Projected Magnetic Fields 4.1.2 Vortex Beam Characteristics 4.2 Miniaturized Deflector 4.3 Quadrupole Focusing Optic 4.4 High Frequency Characteristics of Self-Assembled Electron Optics 5 Summary and Outlook 5.1 Applications of Electron Vortex Beams with Large OAM 5.2 Optics of Large Optical Power for Pulsed Instruments 5.3 Stroboscopic TEM Measurements 5.4 Miniaturized Wigglers, Undulators and Free Electron Lasers 5.5 Towards Integrated Electron Optical SystemsBeams of highly accelerated charged particles are essential for numerous indispensable devices used throughout natural sciences, industry and the healthcare sector, e.g., electron and ion microscopes, charged particle lithography machines and X-ray radiation sources. Magnetic charged particle optics that deflect, shape and focus high-energy charged particles are the backbone of all such devices, because of their superior optical power compared to electric field optics at large particle velocities. Conventional macroscopic magnetic optics, however, are large, costly and bulky, not high frequency capable and require active cooling for heat dissipation. They are therefore unsuitable for fast beam manipulation, multibeam instrumentation, and miniaturized applications, much desired for future advances in nanofabrication and analysis. The first on-chip micro-sized magnetic charged particle optics realized via a self-assembling micro-origami process were designed, fabricated and characterized within the frame of this work. The utilized micro-miniaturization approach overcomes all the aforementioned obstacles for conventional magnetic optics, while maintaining similar optical power. The exceptional properties of these optical elements are rendered possible by the unique features of strain-engineered micro-coils: small size, small inductance and small resistivity. Within the frame of this work, adaptive phase plates were fabricated, which generate electron vortex beams with an unprecedented orbital angular momentum of up to several 1000 ̄h. Furthermore, fast electron beam deflectors for beam blanking, two-dimensional scanning and stroboscopic experiments were manufactured. They possess a deflection power in the mrad regime for 300 kV electrons and a high frequency passband up to 100 MHz. Additionally, miniaturized strong quadrupole lenses with focal lengths down to 46 mm for 300 kV electrons have been developed. These three types of electron optical elements are of great interest for a wide range of applications in nanofabrication and analysis, as they serve as integral components of future multibeam instruments, miniaturized devices, and stroboscopic measurement setups to be developed.:1 Introduction 1.1 Charged Particle Optics 1.2 Miniaturized Charged Particle Optics 1.3 Phase Plates for Transmission Electron Microscopy 2 Charged Particle Optics 2.1 Hamiltonian Formalism 2.2 Gaussian Matrix Optics 2.3 Transfer Matrices of Magnetic Elements 2.3.1 Single Quadrupole 2.3.2 Quadrupole Multiplets 2.3.2.1 Quadrupole Doublet 2.3.2.2 Quadrupole Triplet 2.3.2.3 Higher Order Quadrupole Multiplets 2.4 Scaling Laws for Charged Particle Optics 2.4.1 Thin Film 2.4.2 Electrostatic Scaling Laws 2.4.3 Magnetic Scaling Laws 3 Design and Fabrication of Miniaturized Electron Optics 3.1 Basics of Polymer-Based Self-Assembly Technology 3.2 Basic Coil Design and Magnetic Field Simulations 3.3 CoFeSiB-Pyrex Core-Shell Micro Wires 3.4 Fabrication of Self-Assembled Micro Coil Devices 4 Optical Properties of Self-Assembled Miniaturized Electron Optics 4.1 Electron Vortex Phase Plate 4.1.1 Projected Magnetic Fields 4.1.2 Vortex Beam Characteristics 4.2 Miniaturized Deflector 4.3 Quadrupole Focusing Optic 4.4 High Frequency Characteristics of Self-Assembled Electron Optics 5 Summary and Outlook 5.1 Applications of Electron Vortex Beams with Large OAM 5.2 Optics of Large Optical Power for Pulsed Instruments 5.3 Stroboscopic TEM Measurements 5.4 Miniaturized Wigglers, Undulators and Free Electron Lasers 5.5 Towards Integrated Electron Optical System

Molecular lithography

Die Quantenmechanik kann als das präziseste physikalische Modell angesehen werden, das je entwickelt wurde. Sie fungiert als Triebkraft für technologischen Fortschritt und Wohlstand. Sie berschreitet etablierte philosophische Konzepte der Realität und dient als reiche Quelle für revolutionäres, wissenschaftliches Denken. Und trotzdem ist sie mit unseren klassischen Vorstellungen nicht vereinbar. Der Welle-Teilchen Dualismus im Besonderen ist ein Meilenstein der Quantenphysik und nimmt einen zentralen Platz in unserem modernen physikalischen Weltbild ein. Seit jeher ist er Gegenstand hitziger Debatten. Materiewellen-Interferometrie stellt sich als geeignetes Werkzeug heraus, die fundamentalen Konzepte der Wellennatur von massiven Teilchen elegant darzustellen. Diese Methode wurde nun entscheidend durch die Kombination der molekularen Quantenoptik mit nanotechnologischen Verfahren erweitert: Das molekulare Interferenzmuster wird lithographisch auf eine Siliziumoberfläche geprägt. Die Verwendung eines Rastertunnelmikroskops ermöglicht überdies die Auswertung der aufgenommenen Interferenz mit atomarer Auflösung. Die quantenphysikalische Wellennatur massiver Teilchen erscheint so in einem völlig neuen Licht. Während des Experiments verlassen großen Kohlenstoff-Fullerene mit komplexer innerer Struktur als einzelne, lokalisierte Teilchen die Quelle und werden als solche auch auf der Oberfläche deponiert. Doch ihre Anordnung lässt auf ein Verhalten während des Durchgangs im Interferometer schließen, das als quantenphysikalische, räumlich ausgedehnte Welle interpretiert wird. Zusätzlich zur Demonstration dieser fundamentalen Quanteneffekte eröffnen sich einzigartige Möglichkeiten für neue technologische Anwendungen der Materiewellen-Interferometrie. Innovative Verbesserungen in Bezug auf den bestehenden Vakuumapparat und die Justage des Interferometers haben genauso zu einem erfolgreichen Experiment beigetragen, wie das wertvolle Wissen und die Erfahrungen, die durch die Arbeit mit einem Rastertunnelmikroskop gesammelt werden konnten. Darüber hinaus wurden neuartige Methoden zur Geschwindigkeitsselektion eines molekularen Strahles und zur Positionierung der Tunnelspitze entwickelt. So wird in dieser Arbeit erstmalig ein topgraphisches Abbild molekularer Interferenz mit atomarer Auflösung präsentiert.Quantum mechanics is the most precise theory ever developed and acts as a driving force for technological progress and wealth. It transcends established philosophical concepts of reality and functions as a rich source for revolutionary scientific research. And yet it remains counter intuitive. In particular, the wave particle duality is a cornerstone of quantum physics and lies in the heart of our modern physical world view. It has remained subject of fiery debates until present times. A suitable tool that demonstrates the fundamental concepts of the wave nature of massive particles in a beautiful way can be seen in matter-wave interferometry. This concept has now been significantly extended by combining the field of molecular quantum optics with nanotechnological methods. Namely, the imprinting of nanometer-scale interference patterns onto silicon surfaces. The use of a scanning tunneling microscope to evaluate the recorded interference with single atom resolution, elucidates the quantum wave-nature of massive particles in its most distinct form. Large and internally complex carbon fullerenes leave the source as single, localized particles and are revealed as individual molecules deposited on a surface, but structured in a way that they have to be described by a delocalized quantum wave during their propagation through an interferometer. Apart from this fundamental approach, the use of quantum interference to deposit nanostructures composed of single, complex molecules onto silicon surfaces offers unique possibilities for novel technological applications. Thus, we trespass the mere demonstration of fundamental quantum effects to approach a novel technological application of matter-wave interferometry. Innovative improvements regarding the existing vacuum apparatus and alignment of the interferometer, coupled with crucial knowledge gained concerning the imaging with atomic resolution and exceptional, novel inventions dealing with the velocity selection of a molecular beam and accurate tip positioning, make it possible to present the first image of a quantum interferogram of large molecules directly visualized with single atom resolution

Performance-driven control of nano-motion systems

The performance of high-precision mechatronic systems is subject to ever increasing demands regarding speed and accuracy. To meet these demands, new actuator drivers, sensor signal processing and control algorithms have to be derived. The state-of-the-art scientific developments in these research directions can significantly improve the performance of high-precision systems. However, translation of the scientific developments to usable technology is often non-trivial. To improve the performance of high-precision systems and to bridge the gap between science and technology, a performance-driven control approach has been developed. First, the main performance limiting factor (PLF) is identified. Then, a model-based compensation method is developed for the identified PLF. Experimental validation shows the performance improvement and reveals the next PLF to which the same procedure is applied. The compensation method can relate to the actuator driver, the sensor system or the control algorithm. In this thesis, the focus is on nano-motion systems that are driven by piezo actuators and/or use encoder sensors. Nano-motion systems are defined as the class of systems that require velocities ranging from nanometers per second to millimeters per second with a (sub)nanometer resolution. The main PLFs of such systems are the actuator driver, hysteresis, stick-slip effects, repetitive disturbances, coupling between degrees-of-freedom (DOFs), geometric nonlinearities and quantization errors. The developed approach is applied to three illustrative experimental cases that exhibit the above mentioned PLFs. The cases include a nano-motion stage driven by a walking piezo actuator, a metrological AFM and an encoder system. The contributions of this thesis relate to modeling, actuation driver development, control synthesis and encoder sensor signal processing. In particular, dynamic models are derived of the bimorph piezo legs of the walking piezo actuator and of the nano-motion stage with the walking piezo actuator containing the switching actuation principle, stick-slip effects and contact dynamics. Subsequently, a model-based optimization is performed to obtain optimal drive waveforms for a constant stage velocity. Both the walking piezo actuator and the AFM case exhibit repetitive disturbances with a non-constant period-time, for which dedicated repetitive control methods are developed. Furthermore, control algorithms have been developed to cope with the present coupling between and hysteresis in the different axes of the AFM. Finally, sensor signal processing algorithms have been developed to cope with the quantization effects and encoder imperfections in optical incremental encoders. The application of the performance-driven control approach to the different cases shows that the different identified PLFs can be successfully modeled and compensated for. The experiments show that the performance-driven control approach can largely improve the performance of nano-motion systems with piezo actuators and/or encoder sensors

MEMS Technology for Biomedical Imaging Applications

Biomedical imaging is the key technique and process to create informative images of the human body or other organic structures for clinical purposes or medical science. Micro-electro-mechanical systems (MEMS) technology has demonstrated enormous potential in biomedical imaging applications due to its outstanding advantages of, for instance, miniaturization, high speed, higher resolution, and convenience of batch fabrication. There are many advancements and breakthroughs developing in the academic community, and there are a few challenges raised accordingly upon the designs, structures, fabrication, integration, and applications of MEMS for all kinds of biomedical imaging. This Special Issue aims to collate and showcase research papers, short commutations, perspectives, and insightful review articles from esteemed colleagues that demonstrate: (1) original works on the topic of MEMS components or devices based on various kinds of mechanisms for biomedical imaging; and (2) new developments and potentials of applying MEMS technology of any kind in biomedical imaging. The objective of this special session is to provide insightful information regarding the technological advancements for the researchers in the community

Frontiers in Ultra-Precision Machining

Ultra-precision machining is a multi-disciplinary research area that is an important branch of manufacturing technology. It targets achieving ultra-precision form or surface roughness accuracy, forming the backbone and support of today’s innovative technology industries in aerospace, semiconductors, optics, telecommunications, energy, etc. The increasing demand for components with ultra-precision accuracy has stimulated the development of ultra-precision machining technology in recent decades. Accordingly, this Special Issue includes reviews and regular research papers on the frontiers of ultra-precision machining and will serve as a platform for the communication of the latest development and innovations of ultra-precision machining technologies