Cette étude a pour but la mise au point d'un procédé de dépôt en vue de réaliser des fibres piézoélectriques. Ces fibres pourront être utilisées soit comme jauge de déformation (extensomètre) soit comme système de récupération d'énergie liée au mouvement d'un utilisateur (tissu) pour alimenter un dispositif d'électronique embarqué. Une fibre piézoélectrique constituée d'un dépôt cylindrique d'oxyde de zinc sur un fil d'acier inoxydable a été réalisée par pulvérisation magnétron à impulsion de haute puissance (HiPIMS) à l'aide d'un prototype de traitement au défilé conçu, réalisé et décrit lors de cette étude. Une caractérisation précise des échantillons réalisés dans différentes conditions expérimentales a permis de décrire et comprendre en partie les mécanismes de croissance des dépôts, ceci de manière, en particulier, à déterminer les conditions de fonctionnement optimum pour l'élaboration de dépôts possédant une orientation cristalline préférentielle hors plan. Pour envisager le traitement de fibres ne supportant pas les hautes températures nous avons montré qu'il était possible de contrôler cette température en ajustant certains paramètres du procédé, tel que la pression et la puissance moyenne. Un mécanisme de germination préférentielle suivi d'une croissance par auto-épitaxie a été proposé afin d'expliquer la très forte orientation préférentielle des films réalisés à faible température. Pour des fortes valeurs de courant crête, le phénomène de germination préférentielle associé à la croissance évolutionnaire pourrait favoriser l'orientation (101)*. Pour les plus fortes valeurs de courant, aucune orientation préférentielle n'est observée et les fortes contraintes mesurées ont été attribuées à l'excès d'oxygène détecté dans les couches.

My dissertation focuses on (i) the development sputtered films for solid phase microextraction (SPME) and (ii) the comprehensive characterization of materials using a suite of analytical techniques. Chapter 1 reviews the basics of SPME. This chapter also contains (i) a discussion of various sputtering techniques, (ii) a discussion of two techniques I focused on most of my work: spectroscopic ellipsometry (SE) and X-ray photoelectron spectroscopy (XPS). Chapter 2 focuses the major part of my work, which is to prepare new solid phases/adsorbents for SPME via silicon sputtering followed by thermal deposition of a polymer, polydimethylsiloxane (PDMS). PDMS was deposited by a simple gas phase technique which has never before been applied to prepare SPME stationary phases. The coatings were characterized by time-of-flight mass spectrometry (ToF-SIMS), XPS, scanning electron microscopy (SEM), SE, and contact angle goniometry. The extraction efficiencies of ca. 1.8 µm sputtered, PDMS-coated fibers were compared to a commercial fiber (7 µm PDMS) for a series of polycyclic hydrocarbons (PAHs). Large carry-over and phase bleed peaks are observed in case of commercial PDMS-based SPME coatings, which decrease the lifetime and usefulness of these fibers. It is of great significance that our sputtered fibers exhibit very small or negligible carry-over peaks and phase bleed peaks under the same conditions. Chapter 3 focuses on the multi-instrument characterization of copper and tungsten films sputtered by direct current magnetron sputtering (DCMS) and high-power impulse magnetron sputtering (HiPIMS) using a modern sputter source. The resulting films were characterized by energy dispersive X-ray spectroscopy (EDX), XPS, SEM, atomic force microscopy (AFM), SE, and X-ray diffraction (XRD). By EDX and XPS, all the sputtered films only showed the expected metal peaks. By XPS, the surfaces sputtered by DCMS were richer in oxygen than those produced by HiPIMS. By AFM, both surfaces were quite smooth. By SEM, the HiPIMS films exhibited smaller grain sizes, which was further confirmed by XRD. The crystallite sizes estimated by XRD are as follows: 18.2 nm (W, HiPIMS), 27.3 nm (W, DCMS), 40.2 nm (Cu, HiPIMS), and 58.9 nm (Cu, DCMS). By SE, the HiPIMS surfaces showed higher refractive indices, which suggested that they were denser and less oxidized than the DCMS surfaces. Chapter 4 reports characterization of liquid PDMS via SE, which required some experimental adaptations. The transmission measurements were obtained via a dual cuvette approach that eliminated the effects of the cuvettes and their interfaces. Only the reflection measurements were modeled with a Sellmeier function which produced decent fits. Chapters 5 consists of contributions to Surface Science Spectra (SSS) of near-ambient XPS spectra of various unconventional materials including cheese, kidney stone, sesame seeds, clamshell, and calcite. This dissertation also contains appendices of tutorial articles I wrote on ellipsometry and vacuum equipment.

Thermochromic vanadium dioxide based materials undergo a metal-to-semiconductor transition. This ability can reduce the energy consumption in buildings with windows or glass facades, especially for passive cooling in warmer climates. In dependence on the temperature, the transmittance of the material for infrared light changes reversibly, regulating the amount of the solar heat transmitted into buildings. Although thermochromic vanadium dioxide based coatings have been extensively studied at laboratory scale, there are still fundamental challenges for industrial manufacturing. The present work aims to explore the prospects of the deposition of a tungsten-doped vanadium dioxide based coating onto ultra-thin glass in an upscaled roll-to-roll process. An existing laboratory scale layer stack design enabled the achievement of high performance using unipolar pulsed and high power impulse magnetron sputtering. For this purpose, a new oxygen control system was developed. Furthermore, the optical and structural properties of the deposited coatings were characterized, as well as the doping content, and further the potential for energy savings. A newly designed optical model allowed calculation of the dispersion relation of the layers and their electrical properties.:1 Introduction 1 2 Topic of the thesis 4 3 State of the art 6 3.1 Thermochromism . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 3.2 Vanadium dioxide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 3.2.1 Crystalline Structure . . . . . . . . . . . . . . . . . . . . . . . . . 9 3.2.2 Phase transition – Band structure . . . . . . . . . . . . . . . . . . 12 3.2.3 Literature review of thermochromic VO2 coatings . . . . . . . . . 13 3.2.4 Limitations of VO2 in smart window applications . . . . . . . . . 14 3.2.5 Using multifunctional layers . . . . . . . . . . . . . . . . . . . . . 15 3.2.6 Reducing the transition temperature . . . . . . . . . . . . . . . . 15 3.3 Magnetron sputtering of thermochromic coatings . . . . . . . . . . . . . 17 3.3.1 Sputtering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 3.3.2 Magnetron sputtering . . . . . . . . . . . . . . . . . . . . . . . . . 21 3.3.3 Reactive magnetron sputtering . . . . . . . . . . . . . . . . . . . 22 3.3.4 Sputtering using multi-component targets . . . . . . . . . . . . . 24 3.3.5 Pulsed magnetron sputtering . . . . . . . . . . . . . . . . . . . . . 26 3.3.6 High-power impulse magnetron sputtering . . . . . . . . . . . . . 27 3.4 Layer growth and ion assistance . . . . . . . . . . . . . . . . . . . . . . . 30 3.5 Thin film optics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 3.5.1 Interaction of light with surfaces . . . . . . . . . . . . . . . . . . . 34 3.5.2 Models for thin film optics . . . . . . . . . . . . . . . . . . . . . . 36 4 Methodology 39 4.1 Deposition process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 4.1.1 Roll-to-roll process . . . . . . . . . . . . . . . . . . . . . . . . . . 39 4.1.2 FOSA labX 330 Glass . . . . . . . . . . . . . . . . . . . . . . . . 39 4.1.3 Rotatable magnetrons . . . . . . . . . . . . . . . . . . . . . . . . 41 4.1.4 Materials used . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 4.1.5 Oxygen flow controls . . . . . . . . . . . . . . . . . . . . . . . . . 43 4.1.6 Challenges of the roll-to-roll deposition process on UTG . . . . . 46 4.2 Deposition of ZrO2 multifunctional layer . . . . . . . . . . . . . . . . . . 47 4.3 Deposition of ZrO2/V1-xWxO2/ZrO2 with HiPIMS . . . . . . . . . . . . . 48 4.3.1 The investigation of the effect of oxygen partial pressure . . . . . 48 4.3.2 Deposition of thermochromic layers with optical emission spec- troscopy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 4.4 Deposition of ZrO2/V1-xWxO2/ZrO2 with unipolar pulsed magnetron sputtering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 4.5 Coating characterisation . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 4.5.1 UV-Vis-NIR spectrophotometry . . . . . . . . . . . . . . . . . . . 51 4.5.2 Determination of the film properties with optical modelling . . . . 52 4.5.3 Scanning electron microscopy . . . . . . . . . . . . . . . . . . . . 55 4.6 Determination of the film thickness . . . . . . . . . . . . . . . . . . . . . 55 4.6.1 Resistivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 4.6.2 X-ray diffraction . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 4.6.3 Atomic force microscopy . . . . . . . . . . . . . . . . . . . . . . . 58 4.6.4 Rutherford backscattering . . . . . . . . . . . . . . . . . . . . . . 59 5 Results and discussion 61 5.1 Bottom and top ZrO2 layers for thermochromic V1-xWxO2 coating . . . . 61 5.2 Process design for the deposition of thermochromic V1-xWxO2 coating with HiPIMS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 5.2.1 The effect of oxygen partial pressure . . . . . . . . . . . . . . . . 70 5.2.2 Deposition of the layer system with optical emission spectroscopy 72 5.2.3 Determination of the W content in the thermochromic films . . . 80 5.2.4 Resistivity measurements and structure assumption . . . . . . . . 86 5.2.5 Dependence of the doping concentration in the target on the film thickness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 5.2.6 Influence of the deposition temperature on the thermochromic properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 5.2.7 Influence of the film thickness on the thermochromic properties . 90 5.3 Thermochromic V1-xWxO2 coating deposited with uPMS . . . . . . . . . 93 5.4 Comparison of HiPIMS (two-layer vs three-layer systems) and uPMS for V1-xWxO2 coating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97 6 Summary and outlook 101 6.1 Research goal and achievements . . . . . . . . . . . . . . . . . . . . . . . 101 6.2 Layer deposition and results overview . . . . . . . . . . . . . . . . . . . . 102 6.3 Outlook . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103 7 Appendix 105 8 Abbreviations 108 9 Formula symbols 109 Literature 118

This thesis report presents a new design of a synchronization unit for high power impulse magnetron sputtering (HiPIMS) applications used for depositing thin films. The proposed system is composed of two major hardware parts: a microcontroller unit (MCU) and a field-programmable gate array (FPGA). The control range of the new system is increased by at least ten times compared to existing synchronization unit designed by Ionautics AB.In order to verify the system and benchmark its innovations, several batches of the thin film have been deposited using the new technology. It is shown that HiPIMS with synchronized pulsed substrate bias can effectively improve coating performance. Pulsed substrate bias with user-defined pulse width and delay time is possible to use in the new control mode proposed by this master thesis work; Bias mode. As a result, this master thesis work enables users to flexibly control the HiPIMS processes.

Grâce à ses excellentes propriétés physiques et chimiques (stable thermiquement, bon conducteur électrique et de chaleur, ductile, très dur mécaniquement, bonne inertie chimique), le matériau tantale et son nitrure TaNx sont utilisés comme revêtement de surface des outils, résistance électrique, barrière de diffusion au cuivre, croissance de nanotubes par un procédé chimique catalytique en phase vapeur. C'est ce matériau et son nitrure que nous avons étudiés lors de cette thèse.Aujourd'hui les exigences des industriels nécessitent que la pulvérisation cathodique magnétron (PCM) puisse être appliquée aux pièces de formes complexes. La principale limitation de cette méthode de dépôt est que la plupart des particules pulvérisées sont neutres. Pour contrôler l'énergie et la trajectoire des particules pulvérisées, des nouveaux procédés IPVD (Ionized Physical Vapor Deposition) ont été développés pour ioniser les atomes pulvérisés. Le procédé RF-IPVD (Radio-Frequency Ionized Physical Vapor Deposition) permet, grâce à une boucle placée entre la cible et le substrat et polarisée en RF, de créer un second plasma permettant d'ioniser la vapeur pulvérisée. Un autre procédé a été développé : nommé HIPIMS (High Power Impulse Magnetron Sputtering), ce procédé utilise une alimentation fournissant des impulsions de courte durée et de forte puissance au lieu d'une alimentation DC. Les particules pulvérisées peuvent être ionisées dans le plasma magnétron qui est très dense lors des impulsions. Nous avons réalisé des couches minces de Ta par PCM, RF-IPVD et HIPIMS, et des couches minces de TaNx par PCM et HIPIMS. Les différentes propriétés des décharges et des couches minces sont étudiées et comparées dans ce mémoire.

Vibration control requires high dynamic stiffness in mechanical structures for a reliable performance under extreme conditions. Dynamic stiffness composes the parameters of stiffness (K) and damping (η) that are usually in a trade-off relationship. This thesis study aims to break the trade-off relationship. After identifying the underlying mechanism of damping in composite materials and joint interfaces, this thesis studies the deposition technique and physical characteristics of nano-structured HDS (high dynamic stiffness) composite thick-layer coatings. The HDS composite were created by enlarging the internal grain boundary surface area through reduced grain size in nano scale (≤ 40 nm). The deposition process utilizes a PECVD (Plasma Enhanced Chemical Vapour Deposition) method combined with the HiPIMS (High Power Impulse Magnetron Sputtering) technology. The HDS composite exhibited significantly higher surface hardness and higher elastic modulus compared to Poly(methyl methacrylate) (PMMA), yet similar damping property. The HDS composites successfully realized vibration control of cutting tools while applied in their clamping interfaces. Compression preload at essential joint interfaces was found to play a major role in stability of cutting processes and a method was provided for characterizing joint interface properties directly on assembled structures. The detailed analysis of a build-up structure showed that the vibrational mode energy is shifted by varying the joint interface’s compression preload. In a build-up structure, the location shift of vibration mode’s strain energy affects the dynamic responses together with the stiffness and damping properties of joint interfaces. The thesis demonstrates that it is possible to achieve high stiffness and high damping simultaneously in materials and structures. Analysis of the vibrational strain energy distribution was found essential for the success of vibration control.

The requirements of the consumer market on high frequency devices have been more and more demanding over the last decades. Thus, a continuing enhancement of the devices’ performance is required in order to meet these demands. In a macro view, changing the design of the device can result in an improvement of its performance. In a micro view, the physical properties of the device materials have a strong influence on its final performance. In the case of high frequency devices based on piezoelectric materials, a natural way to improve their performance is through the improvement of the properties of the piezoelectric layer. The piezoelectric material studied in this work is AlN, which is an outstanding material among other piezoelectric materials due to its unique combination of material properties. This thesis presents results from experimental studies on the synthesis of AlN thin films in view of telecom, microelectronic and sensor applications. The main objective of the thesis is to custom design the functional properties of AlN to best suit these for the specific application in mind. This is achieved through careful control of the crystallographic structure and texture as well as film composition. The piezoelectric properties of AlN films were enhanced by doping with Sc. Films with different Sc concentrations were fabricated and analyzed, and the coupling coefficient (kt2) was enhanced a factor of two by adding 15% of Sc to the AlN films. The enhancement of kt2 is of interest since it can contribute to a more relaxed design of high frequency devices. Further, in order to obtain better deposition control of c-axis tilted AlN films, a new experimental setup were proposed. When this novel setup was used, films with well-defined thicknesses and tilt uniformity were achieved. Films with such characteristics are very favorable to use in sensors based on electroacoustic devices operating in viscous media. Studies were also performed in order to obtain c-axis oriented AlN films deposited directly on Si substrates at reduced temperatures. The deposition technique used was HiPIMS, and the results indicated significant improvements in the film texture when comparing to the conventional Pulsed DC deposition process.

My dissertation is primarily divided into two parts. The first deals with the preparation, functionalization, and characterization of carbon surfaces prepared by direct current magnetron sputtering (DCMS) and high power impulse magnetron sputtering (HiPIMS) as substrates for bioarrays. Part two discusses applications of XPS peak fitting in surface chemical analysis. Chapter 1, the introduction, includes (i) a discussion of the construction of bioarrays and the preparation of sputtered surfaces, e.g., by DCMS and HiPIMS, and also functionalization (bioconjugate) chemistry with special emphasis on the importance of covalent functionalization of surfaces, and (ii) a discussion of the surface characterization techniques and accompanying analysis methods I have primarily used, which include X-ray photoelectron spectroscopy (XPS), near-ambient pressure XPS (NAP-XPS), XPS peak fitting, and contact angle goniometry (wetting). Chapter 2 discusses the preparation, characterization, and functionalization of DCMS and HiPIMS carbon surfaces for bioarrays. Here, two functionalization chemistries are explored, where the activity of DCMS and HiPIMS carbon towards amidation and amination is compared. Chapter 3 focuses on the use of Gaussian-Lorentzian sum (GLS) and Gaussian-Lorentzian product (GLP) line shapes in the context of peak fitting XPS narrow scans. This discussion includes a comparison of the GLS and GLP line shapes with the Voigt function. Chapters 4 and 5 discuss the applications of XPS peak fitting in materials characterization. Chapter 4 talks about XPS data analysis in the context of the chemical vapor deposition of various aminosilanes and their effect on peptide stability and purity. Chapters 5 describes the surface chemical analysis of various materials by NAP-XPS, including accompanying data analysis and/or peak fitting. The materials probed here cannot be analyzed at ultra-high vacuum by conventional XPS, hence, they are analyzed by NAP-XPS. Chapter 5 is divided into 5 sections. Section 5.1.1 discusses the characterization and analysis of a solution of bovine serum albumin (BSA) by peak fitting the C 1s and O 1s peak envelopes. Section 5.1.2 discusses the analysis of polytetrafluoroethylene (PTFE) at different pressures. Here, the effect of increasing background pressure and X-ray illumination time on the equivalent widths of the F 1s narrows scans is shown. Environmental charge compensation is also discussed here. Section 5.1.3 includes the analysis of poly(γ-benzyl L-glutamate) (PBLG), where the C 1s and O 1s peak envelopes were peak fitted to determine/confirm the structure and composition of this polymer. Section 5.1.4 contains an analysis and comparison of three different human hair samples: (i) untreated, (ii) colored, and (iii) bleached. Here, a comparison of the Si 2p, S 2p, and C 1s peaks illustrates the effects of the different treatments. Section 5.1.5 shows the characterization and analysis of liquid and solid phosphate buffered saline (PBS). Chapter 6 presents conclusion of my work and discusses future work.

The aim of this thesis is to determine the mechanical properties of copper, titanium and carbon thin films deposited on foil substrates, and identify how the properties are affected by the deposition process. This is important when such coated foils are subjected to mechanical deformation during applications. Three coating materials, Cu, Ti, and C, were evaluated on PET and Al foils. The materials were deposited by direct current magnetron sputtering (DCMS) and high-power impulse magnetron sputtering (HiPIMS). The crack initiation and propagation during tensile tests were investigated in-situ by a SEM. The coatings’ crack onset strain (COS), cohesive strength, interfacial shear strength (IFSS), and Weibull shape and scale parameters were successfully determined from the experimental data. The results showed the Cu coatings had similar cohesive strengths and IFSS, independent of the deposition process. The main difference was the COS, where thin films deposited with ion assistance displayed a higher value. The coatings also displayed different morphologies that clearly influenced the crack propagation. Larger grains hindered the crack propagation and resulted in a more ductile fragmentation, with coatings displaying short and tortuous cracks. All Ti films displayed similar fragmentation and thus mechanical properties, despite small differences in morphology. However, the surface roughness of the Al foil influences the results. Localized stresses arise in the rolling tracks from the foil production and facilitates the crack propagation, thus affecting the fragmentation of the coatings. Lastly, it could be shown that the addition of a thin Ti adhesion layer resulted in a fully adherent C film.

La pulvérisation cathodique magnétron est un procédé plasma très répandu dans l'industrie pour le dépôt de couches minces. Néanmoins, les exigences des nouvelles applications nécessitent de mieux comprendre, contrôler et maîtriser les processus fondamentaux gouvernant le transport de la matière pour optimiser le procédé. Ce travail de thèse porte sur l'étude du transport des atomes pulvérisés de tungstène (W) en décharge magnétron continu (DC direct current) et pulsée haute puissance (HiPIMS_high power impulse magnétron sputtering). La fluorescence induite par diode laser (TD-LIF) a été mise au point afin de mesurer les fonctions de distribution en vitesse des atomes W pulvérisés. Les mesures ont été calibrées par absorption laser et validées en corrélant avec les vitesses de dépôt. En procédé DC, l'étude de l’influence des paramètres de la décharge (puissance, tension, mélange gazeux Ar/He, distance par rapport à la cible, etc.) a mis en évidence l'évolution spatiale des régimes de transport balistique (atomes énergétiques), diffusif (atomes thermalisés), et mixte (balistique+diffusif). Pour l'étude du procédé HiPIMS, le plasma pulsé a nécessité de développer la TD-LIF résolue en temps (TR-TDLIF). Le degré de liberté supplémentaire qu'offre la dimension temporelle du plasma HiPIMS a permis de mieux comprendre le transport mixte qui représente le cas le plus compliqué. En effet, cela a permis de mesurer la cinétique du transport des atomes pulvérisés en ayant la possibilité de séparer les temps caractéristiques des différents processus / Magnetron sputter deposition is an established and widely used method for the growth of thin films. Nevertheless, the high level of expectations regarding new applications require a better understanding, controlling, mastering of basic processes governing atoms transport in the view of process optimization. This work consist in the study of transport of sputtered W atoms in direct current and high power impulse magnetron discharges (DC and HiPIMS). A tunable diode laser induced fluorescence technique (TD-LIF) has been developed, in order to measure W sputtered atom velocity distribution function. Measurements were calibrated using laser absorption and were corroborated by deposition rate. In DC, the study of the influence of discharge parameters (power, voltage, Ar/He gas mixture, and distance from target, etc.) highlighted spatial evolution of different regimes of transport: ballistic (energetic atoms), diffusive (thermalized atoms), and mixed (ballistic + diffusive). In HiPIMS, pulsed plasma required to develop a time resolved TD-LIF technique (TR-TDLIF). The additional degree of freedom, given by time dimension allowed for a better understanding of mixed transport which represents the most complicated situation. This technique allowed to measure the kinetic of sputtered W atoms while at the same time providing the possibility to separate characteristic time scales of different processes