Critical angles in DC magnetron glad thin films

The objective of this study is to examine the sudden drop in properties of aluminum, titanium and chromium thin films prepared by the glancing angle deposition method. The thin films were deposited by DC magnetron sputtering under identical deposition conditions. A substrate-holder with seven different orientations with respect to the target normal was used. The thickness and the column tilt angles (β) of the thin films were determined by scanning electron microscopy. The residual stress of the thin films was evaluated using the wafer curvature technique and calculated by the Stoney's formula. The thickness variation and column tilt angle versus the orientation of the substrate indicated that the critical point is around 60° for all metallic materials and a critical angle of 60° is also found for the residual stress. Simulations of the particles transport are compared to the experimental data and moderate the critical angles analyses.Frnch Ministry of Higher Education and Researc

A study of the tribological behavior of duplex treatment

The objective of this study is to determine the influence of duplex treatment (low pressure thermochemical treatment and PVD coating) on tribological properties. The carbide and carbonitride coatings are deposited by dual RF magnetron sputtering on the reference steel 18CrMo4 and the carburized and carbonitrided one (respectively). The low-pressure carburized and carbonitrided samples present 0.72 and 0.69 w. % carbon content at their surface respectively and a hardness of about 700 Hv0.1. The carburizing and carbonitriding layer are respectively 540 and 390 µm thick, while TiWC and TiWCN were 2.8 and 3.4 µm thick respectively. Tribological tests were performed by a Pin-on-Disk rotative tribometer with alumina and steel (100Cr6) balls. A comparison of the friction coefficient and the wear rate for each sample has been made. The adhesion of the coatings has been performed by analyzing the wear track using optical profilometry, optical microscopy and scanning electron microscopy equipped with an energy-dispersive X-ray spectrometer. The best tribological performances were observed by combining carbides coatings and carburized 18CrMo4 or reference steel. In contrast, the TiWCN thin film completely delaminated

Numerical and experimental study of thin films’ growth deposited by reactive sputtering.

L’objectif de ce travail est de déterminer expérimentalement les paramètres d’entrée des logiciels de simulation, puis de comparer les résultats expérimentaux et numériques pour différents métaux ainsi que pour leurs oxydes. La configuration GLAD a été volontairement choisie pour les structures inclinées particulières qu’elle permet.Le processus de formation de dépôt en phase vapeur (PVD) peut être divisé en trois étapes : l'éjection d'atomes de la cible, le transport vers le substrat et la croissance des couches minces. Chacune est simulée par un logiciel : SRIM pour l’éjection de matière de la cible suite à l’impact avec un ion, SIMTRA pour le transport des atomes de la cible jusqu’au substrat et Simul3D pour la croissance des dépôts. L’évolution des propriétés des couches inclinées (angle d’inclinaison des colonnes β, épaisseur de la couche, contraintes résiduelles, etc) en fonction de la position et de l’angle d’orientation du substrat est étudiée.Les résultats expérimentaux et numériques se complètent mutuellement et permettent une meilleure compréhension des nombreux aspects de l’étude.The objective of the present work is to determine experimentally the input parameters of the modelling software and then to compare experimental and numerical results in the case of different metals and their oxides. The GLAD configuration was deliberately chosen for the particular angled structures it allows.The Physical Vapor Deposition (PVD) process can be divided in three steps: ejection of atoms from the target, transport to the substrate and growth of the thin films. Different softwares have been developed for each step: SRIM is a computer program that calculates the interactions of energetic ions; SIMTRA simulates the transport of the atoms from the target to the substrate and Simul3D simulates the growth of the film. The evolution of the thin angled films’ properties (column tilt angles β, thickness, residual stress, etc.) versus the orientation of the substrate is studied.The experimental and numerical results complement each other and allow a better understanding of the many aspects of the study

Etude numérique et expérimentale de la croissance de couches minces déposées par pulvérisation réactive.

The objective of the present work is to determine experimentally the input parameters of the modelling software and then to compare experimental and numerical results in the case of different metals and their oxides. The GLAD configuration was deliberately chosen for the particular angled structures it allows.The Physical Vapor Deposition (PVD) process can be divided in three steps: ejection of atoms from the target, transport to the substrate and growth of the thin films. Different softwares have been developed for each step: SRIM is a computer program that calculates the interactions of energetic ions; SIMTRA simulates the transport of the atoms from the target to the substrate and Simul3D simulates the growth of the film. The evolution of the thin angled films’ properties (column tilt angles β, thickness, residual stress, etc.) versus the orientation of the substrate is studied.The experimental and numerical results complement each other and allow a better understanding of the many aspects of the study.L’objectif de ce travail est de déterminer expérimentalement les paramètres d’entrée des logiciels de simulation, puis de comparer les résultats expérimentaux et numériques pour différents métaux ainsi que pour leurs oxydes. La configuration GLAD a été volontairement choisie pour les structures inclinées particulières qu’elle permet.Le processus de formation de dépôt en phase vapeur (PVD) peut être divisé en trois étapes : l'éjection d'atomes de la cible, le transport vers le substrat et la croissance des couches minces. Chacune est simulée par un logiciel : SRIM pour l’éjection de matière de la cible suite à l’impact avec un ion, SIMTRA pour le transport des atomes de la cible jusqu’au substrat et Simul3D pour la croissance des dépôts. L’évolution des propriétés des couches inclinées (angle d’inclinaison des colonnes β, épaisseur de la couche, contraintes résiduelles, etc) en fonction de la position et de l’angle d’orientation du substrat est étudiée.Les résultats expérimentaux et numériques se complètent mutuellement et permettent une meilleure compréhension des nombreux aspects de l’étude

Temperature effect on hydrogenated amorphous carbon leading to hydrogenated graphene by pulsed laser deposition

International audienceA direct synthesis of hydrogenated graphene at a reduced temperature of 400◦ C using pulsed laser ablation technique is reported. Here, we have investigated the effect of the substrate temperature. Therefore, hydrogenated carbon thin films were elaborated under the same conditions of laser fluence and CH4 pressure but at different substrate temperatures ranging from room temperature to 600 ◦C. The Raman and X-ray photoelectron spectroscopy revealed a structural change induced by the substrate temperature increase. Indeed the elaborated thin films evolved from amorphous carbon to hydrogenated graphene as the substrate temperature increases. The elastic recoiled detection analysis and the Rutherford backscattering measurements indicated a decrease in the hydrogen content as well as a thickness reduction along with the substrate temperature increase. We have concluded that the structural change can be ascribed to the increase in the species mobility during the growth