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Thin films of Ga₂O₃ and ZnGa₂O₄ are of technological interest due to their applications in wide bandgap electronic and optoelectronic devices. In this study, we report on the deposition of amorphous and crystalline thin films (d ̅ = 260 nm) of Ga₂O₃ and ZnGa₂O₄ by reactive pulsed direct current magnetron sputtering from a liquid gallium target onto fused (f-) quartz and c plane (c-) sapphire substrates, where the temperature of the substrate is varied from room temperature (RT) to 800°C. Nonstoichiometric ZnGa₂O₄ thin films, covering a wide range of Ga:Zn atomic ratios (≈ 0.3 – 5.7), were deposited by co-sputtering solid Zn target next to liquid Ga target. The composition was controlled by varying the sputtering power of the Zn target and monitoring the process with plasma optical emission spectroscopy. Composition analysis shows no traces of impurities and a slight oxygen deficiency in the films. The static deposition rate of Ga₂O₃ (up to 37 nm/min at RT on f-quartz and 5 nm/min at 800 °C on c-sapphire) is two to five times higher than the rates reported in the literature for radio frequency sputtering. When deposited onto unheated substrates, the films are X-ray amorphous. Well-defined X-ray diffraction peaks of β-Ga₂O₃ begin to appear at a substrate temperature of 500°C, and ZnGa₂O₄ peaks at 300°C. Electron microscopy images reveal a dense and void-free microstructure. The thin films are highly transparent in the visible light range (≈ 84%) and the optical band-gap varies between approximately 3.9 eV and 5.1 eV, depending on the amount of Zn in the composition.

https://doi.org/10.14332/svc24.proc.0064

This article presents the integration of predictive maintenance strategies with vacuum transducers designed for measuring rough to ultra-high vacuum. Offering innovative solutions for various industrial sectors worldwide, the transducers combine digital precision with durability and intelligence, featuring modern combination sensors and interfaces like RS485, EtherCat, or PROFINET.
Predictive maintenance is crucial in industrial environments, aiming to prevent costly breakdowns, increase equipment longevity, boost performance, assure product quality, and maximize return on investment. Vacuum transducers can support predictive maintenance through continuous monitoring, analysis of sensor wear, and providing operating hour data. By leveraging these insights, industries can optimize maintenance schedules, reduce downtime, and enhance overall operational efficiency.
Furthermore, the transducers facilitate seamless integration into industry 4.0 environments, complying with OPC UA standards and enabling bidirectional data transfer. With the support of corresponding software and their PROFINET interface, the transducers contribute to efficient data management, downstream process optimization, and maintenance cycle enhancement.
In conclusion, the integration of predictive maintenance with vacuum transducers offers a proactive approach to optimize performance, reliability, and longevity of vacuum systems in industrial settings. Embracing predictive maintenance as a strategic priority empowers industries to stay competitive in today's dynamic business landscape.

https://doi.org/10.14332/svc24.proc.0040

Bipolar pulsed sputter deposition provides a robust method for depositing insulating coatings like oxides and nitrides. For several years, both sine-wave and squarewave generators have been utilized for these processes. Different applications demand stringent and distinct coating requirements, and pulse mode provides an additional variable enabling a user to optimize film microstructure and thereby film properties. This presentation shows a comparative study of three types of bipolar pulsed modes: symmetric sinusoidal pulsing, symmetric square pulsing and the new asymmetric square pulsing mode called dynamic reverse pulsing. The three modes were tested on reactive sputter deposition of silicon nitride films in an industrial drum coater. The aim is to provide a comprehensive understanding of the different modes and their influence on the film properties in terms of deposition rate, heat load at the substrate, residual stress and optical properties. We show that the different pulse modes have inherent differences in plasma behavior and we outline their benefits.

https://doi.org/10.14332/svc24.proc.0024

In-situ layer thickness can be determined from the broad band spectral reflectivity of the growing film. While this technique is fairly common in many vacuum coating applications, its accuracy relies heavily on the correct refractive indices of the materials involved.
Typically, the refractive indices are determined from ex-situ measurements on witness samples coated in the production process. Such measurements however may deviate from the in-situ values for various reasons. The refractive index may be different because the ambient conditions during the ex-situ measurement (temperature, humidity) differ from the process conditions. Furthermore, the process condition may vary from batch to batch, e.g. because of the buildup of coating material on the chamber walls.
A more accurate value for the in-situ refractive index can be obtained by combining the reflectivity analysis with real-time data from plasma monitoring based on broad band emission spectroscopic. Changes in the plasma composition are detected instantly and can be used to adjust the value of the refractive index used for reflectivity modelling. This approach has been implemented in the EMICON system and applied to a variety of typical industrial coating process covering PECVD for solar cell production, nanocrystalline diamond coatings and amorphous carbon films (aC:H) for tribological applications.
In this presentation, application examples are presented that show how intentional as well as unwanted process changes do impact the precision of the film thickness measurement and how this can be avoided by suitable combination of the different in-situ data sources.

https://doi.org/10.14332/svc24.proc.0063

Magnetron sputtering devices have a wide range of uses in the coatings industry, where they are used for optical coatings, metallization in integrated circuits, and coatings for wear resistance. Numerical simulations can aid in the design of such systems, as computation can allow one to predict the figures of merit, eliminating the need to test each conceived configuration on the path to the final design. Such figures of merit include the uniformity and extent of the distribution of sputtered material, the power consumption of the system, and the erosion of the cathode. Such computations must be self-consistent and kinetic, i.e., they must follow particle trajectories, since fluid approximations make simplifying assumptions that may not be valid (especially at low pressure) and only a kinetic approach can properly account for the critical physics, including the energy-angle distribution of the impacting sputterers and the resulting distribution. The Particle-In-Cell, Monte Carlo Collision (PIC-MCC method) is ideal for this, as it can properly account for the above physics as well as the physics involved in plasma creation, electron trapping by the magnetic field, and even dynamics that occurs in High Power Impulse Magnetron Sputtering (HIPIMS). Unfortunately, these calculations can take significant computing time, as the time scales for relaxation to steady-state are long compared with plasma processes. This talk presents computations using multiple techniques to speed up these calculations. The methods include using a circuit model that allows one to rapidly get to the final state, steady-state relaunch, where the results of one simulation that has reached steady-state are used to initialize another, and physics minimization, where initial analysis using a global model minimizes the number of included collisional processes. Results are compared with those available in the literature.

https://doi.org/10.14332/svc24.proc.0034

Austenitic steels are known for their high corrosion resistance but at the same time have low wear resistance and high interfacial contact resistance (ICR), which limits their application e. g. as bipolar plates in Proton Exchange Membrane Fuel Cells (PEMFC). Plasma diffusion treatment, especially the well-known plasma nitriding, improves the hardness and interfacial contact resistance but mostly worse the corrosion behavior in PEMFC environment. Aim of this study is to evaluate the less known plasma carburizing as a suitable process for functionalization austenitic stainless steels. For this purpose, a number of processes were executed under specific variation of temperature ranging from 360 °C to 450 °C and duration of 10 to 16 h. The samples were analyzed using x-ray diffractometer, x-ray photoelectron spectroscopy, SEM, Vickers micro-indentation, potentiodynamic polarization and ICR measurements. It could be shown that the corrosion current density (1.78 μA·cm^-2) of the treated samples are an order of magnitude lower than those of the reference (17.38 μA·cm^-2). The ICR was also reduced from > 1000 mΩ·cm^-2 down to 31 mΩ·cm^-2. After corrosion, even lower values around 15 mΩ·cm^-2 were achieved. The targets according to DOE ( < 1 μA·cm^-2 and < 10 mΩ·cm^-2) were almost achieved. A comparison to the plasma-nitrided samples was also performed and shows the high potential of plasma carburizing.

https://doi.org/10.14332/svc24.proc.0050

The Vera C. Rubin Observatory construction is poised to be completed, finishing the Integration phase and starting the Commissioning phase. The Coating Plant is delivering the coated main science mirrors to the project. The M2 mirror was coated with protected Silver in 2019 and the M1M3 mirror coated in 2024 with protected Silver as well, both coatings achieving the main project requirements. This paper describes the main project milestones in terms of construction, assembly and integration, the coating results on both mirrors. This paper also describes a characterization of the Coating Plant and its ancillary equipment, a characterization of the coating delivered by us, the coating tests that we made prior of the final coating recipe decision, and the final coating results over the main telescope mirrors, finishing with the future projects related to this Coating System.

https://doi.org/10.14332/svc24.proc.0025

processes. Ampres has developed a new generation of scalable closed drift gas ionizers. These sources provide an economical tool for the deposition of complex high quality multilayer thin film coatings. The gas ionizers provide very high ionization rates in a compact fully scalable design. They are used to supply ionized reactive gas for enhanced magnetron sputtering processes and for a unique hybrid PVD–PECVD process.
These sources are ideally suited to deliver ionized reactive gases like Oxygen, Nitrogen and Fluorine direct to the substrate surface to form metal oxide, metal nitride and other complex thin film coatings. They also can be used as standalone plasma sources for PECVD and plasma etching applications.

https://doi.org/10.14332/svc24.proc.0023

Vacuum coating from roll to roll is an established technology in the web processing industry. The applications are manifold. Complex multilayer stacks can be applied with R2R coating systems equipped with a precisely defined set of e.g. magnetron sputter sources. Examples of applications include low emissivity layer stacks for energy control, anti-reflective and decorative coatings, or electronic applications such as solar and electro chromatic applications or flexible printed circuit boards. Architectural, transportation, consumer goods and other industries benefit from this wide range of applications and coating equipment.
A number of these processes require high productivity to produce a high volume of product at competitive costs. This presentation will highlight the automation and modularity of the FLC1600 R2R system to increase productivity. One, two or more main coating modules can be integrated. The modules can be arranged and configured to increase the versatility of the process or the productivity of the system. The applicability of the system platform for high product versatility and productivity will be demonstrated. Furthermore, productivity is gained by increasing the coating speed. With modern process automation, oxidic processes are set stable at a high deposition rate. The presentation introduces the use of the Plasmaster program for R2R coating automation of flexible products.

https://doi.org/10.14332/svc24.proc.0060

Gravitational-wave detectors (GWD) are ultra-sensitive, large-scale facilities whose successful operation depends critically -among various factors- on the performance of high-reflective mirrors. These consist of doublets of high- and low-refractive-index amorphous oxide coatings deposited by ion beam sputtering (IBS). Their performance, defined in terms of high reflectivity, low optical absorption and low thermal noise, can be enhanced by optimizing the constituent materials, the deposition and post-deposition processes such as the thermal annealing. In this contribution, an implementation of real-time spectroscopic ellipsometry is proposed as a convenient tool to understand the evolution of coatings properties during the post-deposition thermal annealing. The amorphous titania-tantala coating and the annealing protocol considered here match those currently used in mirrors for GWD. In-situ analysis shows the evolution of the coating refractive index and thickness throughout the annealing, including the heating and cooling ramps. Results indicate that the current annealing protocol leaves room for further possible modifications in the coatings properties and suggest ways to optimize it. The in-situ analysis discussed here can be beneficial to screen and validate other coating materials as well as to test new annealing protocols to enhance the properties of mirror coatings for GWD applications.

https://doi.org/10.14332/svc24.proc.0029