A5077711237- Metal and Thin Film Mechanics
- Copper Interconnects and Reliability
- Microstructure and mechanical properties
- Aluminum Alloys Composites Properties
- Advanced materials and composites
- Acoustic Wave Resonator Technologies
- Advanced ceramic materials synthesis
- Electronic Packaging and Soldering Technologies
- Advanced Welding Techniques Analysis
- High-Temperature Coating Behaviors
- Aluminum Alloy Microstructure Properties
- nanoparticles nucleation surface interactions
- High-pressure geophysics and materials
- Extraction and Separation Processes
- 3D IC and TSV technologies
- Nanotechnology research and applications
- Semiconductor materials and interfaces
- Mechanical and Optical Resonators
- Chemical and Physical Properties of Materials
- Tribology and Wear Analysis
- Thermal properties of materials
- Force Microscopy Techniques and Applications
- Optical Coatings and Gratings
- Diamond and Carbon-based Materials Research
- Environmental Impact and Sustainability
Swiss Federal Laboratories for Materials Science and Technology
2021-2025
University of St. Gallen
2023
Politecnico di Milano
2022
University of Padua
2022
Many technologies, such as surface-acoustic-wave (SAW) resonators, sensors, and piezoelectric MEMS require highly-oriented textured functional thin films. The best results are typically achieved for on-axis sputter geometries, but in some scenarios, this is not feasible, during co-deposition from multiple magnetrons or when coating substrates with high aspect ratios. Ionized physical vapor deposition (PVD) techniques HiPIMS can be used to accelerate the film-forming species onto growing film...
ABSTRACT The changes in the local chemical state of W interfacial atoms at buried W/Cu, W/Cr, and W/Mo interfaces multilayers cosputtered alloys have been investigated by analysis using situ XPS/HAXPES. An Auger parameter shift is found to depend on degree miscibility interface being maximum for Mo/W system. This experimental trend cannot be rationalized electronegativity differences between W, Cu, Cr, Mo. nonuniformity electron density studied with (and possible also structural mismatch...
The internal stress and microstructure in nanomultilayers strongly affect their reliability performance, especially towards higher service temperatures. initial can be controlled during the growth by opportunely changing deposition parameters. intrinsic state tuned to achieve states ranging from compressive tensile. In present work, Cu/W with opposite (tensile compressive) were fabricated magnetron sputtering. is found correlated disorder, as measured X-ray diffraction photoemission....
Interface stress is a fundamental descriptor for interphase boundaries and defined in strict relation to the interface energy. In nanomultilayers with their intrinsically high density, functional properties are dictated by structure, which governed delicate interaction of residual volume stresses. present work, experimental estimations Cu/W NMLs were compared corresponding theoretical values as calculated using DFT (adopting an incoherent bcc W{110}/fcc Cu{111} variable in-plane strain). The...
Controlling growth stresses during thin film fabrication is of paramount importance to solve reliability issues operation functional films in harsh environments. A combination different methods for thin-film stress determination, such as situ wafer curvature and ex x-ray diffraction, usually required reveal tailor systems, well extract interface contributions multilayered coatings. In this article, the tuning intrinsic Cu W, grown by magnetron sputtering, was performed varying Ar pressure...
Residual stresses are one of the key factors for tuning properties, microstructure, and reliability thin films nanomultilayers, but their measurement evaluation challenging. in nanomultilayers with {1 1 0} out-of-plane texture exhibit a dependence on in-plane crystal orientation, which complicates using X-ray diffraction. The residual were investigated two representative immiscible materials fcc/bcc structure: Cu/Mo Cu/Nb grown Si substrate an amorphous silicon nitride layer. Both...
Thermal annealing experiments evidence opposite effect on the degradation kinetics of Cu/W nano-multilayers from compressive to tensile in-plane strain. Besides higher activation energy, with strains degrade nanocomposites faster than those strains. By assuming a vacancy-driven diffusion mechanism degradation, we applied ab initio calculations quantify different contributions corresponding coefficients in relation The average vacancy formation energy increases as strain changes tensile,...
The microstructural evolution of Cu/Mo nanomultilayers upon annealing was investigated by X-ray diffraction and transmission electron microscopy. isothermal process in the temperature ranges 300 – 850°C conducted to understand thermal behavior sample follow transformation into a nanocomposite. Annealing at 600°C led initiation grain grooving nanomultilayer, it degraded spheroidized nanocomposite structure 800°C. kept as-deposited Cu {111}//Mo{110} fiber texture up 850°C. residual stress...
The properties and thermal stability of thin films nano-multilayers (NMLs) are generally governed by the in-depth stress (strain) gradients rather than average state. effect strain gradient variation in Cu/W NMLs on between 400 800 °C was investigated. distribution NML stacks varied combining bilayers with different Cu W thicknesses either 3 or 10 nm. A recently developed method based in-plane grazing X-ray diffraction adopted to extract depth profiles. In addition, evolution during growth...
The combination of the high wear resistance and mechanical strength W with thermal conductivity Cu makes Cu/W system an attractive candidate material for heat sinks in plasma experiments radiation tolerance applications. However, resulting properties multilayers coatings strongly depend on microstructure layers. In this work, nanomultilayers different densities internal interfaces are systematically investigated two opposite in-plane stress states critically discussed comparison literature....
Smart microstructure and interface design in nanomultilayers allows to tailor physical properties like thermal stability, conductivity directional metal outflow for targeted applications. In this work, selected examples of nanomultilayer systems, constituted alternating nanolayers metals and/or nitrides, as precisely fabricated with variable textures, microstructures, grain sizes internal stresses are presented. The role the stress state on functional is shown.
In this work we report on the extensive characterization of amorphous silicon carbide ($a$-SiC) coatings prepared by physical deposition methods. Our investigation is performed within perspective application $a$-SiC as an optical material for high-precision experiments and, in particular, gravitational wave interferometry. We compare results obtained with two different sputtering systems [a standard radio frequency (rf) magnetron and ion-beam sputtering] to grasp impact setups repeatability...
The intrinsic stress in nanomultilayers (NMLs) is typically dominated by interface stress, which particularly high immiscible Cu/W NMLs. Here, atomistic simulations with a chemically-accurate neural network potential reveal the role of interfacial intermixing and metastable phase formation on levels. These results rationalize an experimentally-reported compressive- to-tensile transition as function NML deposition conditions extremely stresses under some conditions.
Abstract Steel production is one of the most carbon-intensive industrial sectors, responsible for 8% European CO2 emissions. While traditional furnaces strongly rely on consumption coal or natural gas, potential opportunities decarbonization stand in adoption alternative technologies such as hydrogen-based Direct Reduction Iron (DRI) coupled with Electric Arc Furnaces (EAF). This work focuses Italian steel sector and aims at assessing economic environmental impact a switch towards...
Download This Paper Open PDF in Browser Add to My Library Share: Permalink Using these links will ensure access this page indefinitely Copy URL DOI
Download This Paper Open PDF in Browser Add to My Library Share: Permalink Using these links will ensure access this page indefinitely Copy URL DOI
Abstract In this study, we have investigated the feasibility of localized, focused ion beam (FIB)-stimulated Cu outflow in Cu/W nanomultilayers (NMLs) for manufacturing heterogeneous micro-/nanojoints. Sub-micron-sized trenches were created on nanomultilayer surface prior to heat treatment with aim directing diffusion locally defined NML regions. was triggered by annealing at 500 °C a reducing atmosphere and lead formation (sub-)micron-sized particles that are firmly joined W-terminated NML....
Many technologies require highly-oriented and textured functional thin films. The most common synthe-sis approaches use on-axis sputter geometries. However, in some scenarios, sputtering is not feasible. During ionized physical vapor deposition (PVD), contrast to conventional PVD, the film-forming species can be accelerated onto growing film using substrate-bias potentials. This increas-es ad-atom mobility, but also deflects trajectory of ions towards substrate increasing texture film....
Thermal annealing experiments evidence opposite effect on the degradation kinetics of Cu/W nano-multilayers from compressive to tensile in-plane strain. Besides higher activation energy, with strains degrade nanocomposites faster than those strains. By assuming a vacancy-driven diffusion mechanism degradation, we applied ab initio calculations quantify different contributions corresponding coefficients in relation The average vacancy formation energy increases as strain changes tensile,...
Interface stress is a fundamental descriptor for interphase boundaries and defined in strict relation to the interface energy. In nanomultilayers with their intrinsically high density, functional properties are dictated by structure, which governed delicate interaction of residual volume stresses. present work, experimental estimations Cu/W NMLs were compared corresponding theoretical values as calculated using DFT (adopting an incoherent bcc W{110}/fcc Cu{111} variable in-plane strain). The...