PUBLICATIONS

Scientific reports

Oxide semiconductors and related devices produced by high power impulse magnetron sputtering and selective area atomic layer deposition methods

Christy Fadel1, Stéphane Cuynet1, Claudia De Melo1, Marcos Soldera2,
Jean-François Pierson1, Frank Müklich3, David Horwat1

1. Institut Jean lamour, Nancy, France / 2. Institut für Fertigungstechnik, Dresden,Germany / 3. Lehrstuhl für Funktionswerkstoffe, Saarbrücken, Germany

Abstract

Zinc oxide (ZnO) and Al-doped ZnO (AZO) are widely used as n-type
semiconductors and transparent electrodes due to the abundance and low cost of Zn and Al in addition to their high optical and electrical properties. An important technique for depositing (AZO) films is the High Impulse Magnetron Sputtering (HiPIMS) method that allows us to deposit highly conductive and transparent films on large surfaces and at low temperatures [1]. Another important technique is the Atomic Layer Deposition (ALD) which is used for depositing high-quality films with excellent surface coverage on high aspect ratio structures; this method enables us to combine metallic Cu films with semiconductor oxides (ZnO, Cu2O, or both) leading to many applications in different fields related with optoelectronics, catalysis, gas sensing and photovoltaics [2]…

Applying Ultrashort Pulsed Direct Laser Interference Patterning for Functional Surfaces

Daniel Wyn Müller,Tobias Fox, Philipp G. Grützmacher, Sebastian Suarez & Frank Mücklich

Abstract

Surface structures in the micro- and nanometre length scale exert a major influence on performance and functionality for many specialized applications in surface engineering. However, they are often limited to certain pattern scales and materials, depending on which processing technique is used. Likewise, the morphology of the topography is in complex relation to the utilized processing methodology. In this study, the generation of hierarchical surface structures in the micro- as well as the sub-micrometre scale was achieved on ceramic, polymer and metallic materials by utilizing Ultrashort Pulsed Direct Laser Interference Patterning (USP-DLIP)…

Towards control of TiO2 thickness film in R-HiPIMS process with a coupled optical and electrical monitoring of plasma

D.Boivin, A.NajahR.Jean-Marie-Désirée, C.Noël, G.Henrion, S.Cuynet,
L.De Poucques

Université de Lorraine, CNRS, IJL, F-54000 Nancy, France

Abstract

In this work, optical emission spectroscopy and electrical measurements are implemented to investigate a reactive HiPIMS TiO2 deposition process running at duty cycles lower than 16% and at a repetition rate of 1 kHz. Investigations focus on both the effect of the discharge pulse duration and the reactive gas (O2) content in an Ar/O2 gas mixture at fixed working pressures. It is shown that a competition occurs between the pulse duration and the target poisoning, the latter being favored with short pulse duration although the mean power is kept constant. An unusual hysteresis shape observed between the two sputtering modes is also discussed. From combined analyses of Ti emission line intensity, discharge current and deposited TiO2 coating thickness, it is established that plasma diagnostics can be used effectively to control the deposition rate and to precisely manage the transition between metal and composite sputtering modes. Using these to calibrate a power feedback control loop could provide a better response compared to gas feedback control loop.

Magnetron Sputtering vs. Electrodeposition for Hard Chrome Coatings: A Comparison of Environmental and Economic Performances

Antoine Merlo, Grégoire Leonard

Department of Chemical Engineering, University of Liège, Quartier Agora B6a Sart-Tilman, 4000 Liège, Belgium

Abstract

The coating of materials with specific films is widely used to improve material properties and many technologies exist to perform it. In the last few years, the replacement of wet electrodeposition processes has been continuously encouraged in the EU due to the problematic waste management linked to those processes. In this paper, magnetron sputtering is studied as an alternative to conventional electrodeposition by comparing the technologies’ environmental impacts and costs. From the study, it appears that while magnetron sputtering greatly reduces hexavalent chromium emissions over the production, it has an increased electricity consumption mostly due to its lower production capacity, thus leading to more greenhouse gas emissions. Furthermore, a short discussion on the quantification of the impact of hexavalent chromium emissions is conducted. Regarding costs, the electrodeposition process has a lower cost of investment and of consumables, but requires more work time for the different steps of the process, making the total price per functional unit roughly equal. However, the cost per functional unit strongly depends on assumptions on the required work time, for which a sensitivity study is performed. Finally, the impacts of these two competing coating processes are discussed to complete the technological comparison for the case of hard chromium deposition.

Impact of temperature on chlorine contamination and segregation for Ti(C,N) CVD thin hard coating studied by nano-SIMS and atom probe tomography

Idriss ElAzhariabJeniferBarrireroaNathalieVallecJoséGarcíadLinusvon FieandtdMichaelEngstleraFlavioSolderaaLuisLlanesbFrankMücklicha

a
Chair of Functional Materials, Department of Materials Science, Saarland University, Campus D 3.3, D-66123 Saarbrücken, Germany
b
CIEFMA – Department of Materials Science and Engineering, EEBE – Campus Diagonal Besòs, Universitat Politècnica de Catalunya – BarcelonaTech, 08019 Barcelona, Spain
c
Materials Research and Technology Department, Luxembourg Institute of Science and Technology, 41 rue du Brill, 4422 Belvaux, Luxembourg
d
AB Sandvik Coromant R&D, Lerkrogsvägen 19, SE-126 80 Stockholm, Sweden
 

Abstract

High resolution characterization by Atom Probe Tomography (APT) and Secondary Ion Mass Spectrometry (SIMS) imaging were combined to highlight the nature of chlorine contamination and impact of deposition temperature for chemical vapor deposited Ti(C,N) thin hard coating. It is highlighted that chlorine is spread and segregates exclusively at the grain boundaries. With increasing temperature (at 930°C), columnar grains of Ti(C,N) become coarser and chlorine segregation at the grain boundaries is reduced about 3 times in comparison to lower temperature (at 885°C). It also appears that chlorine is less homogeneously distributed with chlorine rich/free regions as it is demonstrated by the powerful combination of nano-SIMS and APT which gave a great insight of the spatial distribution of segregating elements at grain boundaries at nano- and micrometric scales..

Magnetron Sputtering vs. Electrodeposition for Hard Chrome Coatings: A Comparison of Environmental and Economic Performances

J Minguela 1D W Müller 2F Mücklich 2L Llanes 3M P Ginebra 4,                   J J Roa 3C Mas-Moruno 5

Department of Chemical Engineering, University of Liège, Quartier Agora B6a Sart-Tilman, 4000 Liège, Belgium

Abstract

A dual approach employing peptidic biofunctionalization and laser micro-patterns on dental zirconia was explored, with the aim of providing a flexible tool to improve tissue integration of restorations. Direct laser interference patterning with a femtosecond Ti:Sapphire laser was employed, and two periodic grooved patterns were produced with a periodicity of 3 and 10 μm. A platform containing the cell-adhesive RGD and the osteogenic DWIVA peptides was used to functionalize the grooved surfaces. Topography and surface damage were characterized by confocal laser scanning (CLSM), scanning electron and scanning transmission electron microscopy techniques. The surface patterns exhibited a high homogeneity and subsurface damage was found in the form of nano-cracks and nano-pores, at the bottom of the valleys. Accelerated tests in water steam were carried out to assess hydrothermal degradation resistance, which slightly decreased after the laser treatment. Interestingly, the detrimental effects of the laser modification were reverted by a post-laser thermal treatment. The attachment of the molecule was verified trough fluorescence CLSM and X-ray photoelectron spectroscopy. Finally, the biological properties of the surfaces were studied in human mesenchymal stem cells. Cell adhesion, morphology, migration and differentiation were investigated. Cells on grooved surfaces displayed an elongated morphology and aligned along the patterns. On these surfaces, migration was greatly enhanced along the grooves, but also highly restricted in the perpendicular direction as compared to flat specimens. After biofunctionalization, cell number and cell area increased and well-developed cell cytoskeletons were observed. However, no effects on cell migration were found for the peptidic platform. Although some osteogenic potential was found in specimens grooved with a periodicity of 10 μm, the largest effects were observed from the biomolecule, which favored upregulation of several genes related to osteoblastic differentiation in all the surfaces.

 

The poster

PULSATEC
Application of pulsed plasma surface treatment technologies to complex 3D surfaces.
Project cost : 2 107 789€
ERDF cost : 1 114 911€

The flyer

First platform for cross-border collaboration in the Greater Region in the field of surface treatment technologies.