GDR Matepi

Post-Doctoral fellowship in multi-scale modeling of the growth of polycrystalline thin films.

Dr. Cédric MASTAIL

Post-Doctoral fellowship in multi-scale modeling of the growth of polycrystalline thin films
From 12/1st/2023 (24 month)
Section CNU : 28
Theme / axis: Condensed matter physics or materials science
PhD degree


The objective of this post-doctoral position is to model the growth and microstructural evolution of polycrystalline metallic thin films by developing a numerical simulation code based on kinetic Monte Carlo (kMC) which considers the specificities of energetic physical vapor deposition (PVD) such as magnetron sputtering. It is part of the DREAM project funded by ANR and Région Nouvelle Aquitaine. To this end, the candidate will have to link the deposition parameters (deposited energy, particle flux, substrate temperature and the chemical reactivity at the substrate interface to the microstructure (grain size, texture) and morphology (roughness, faceting) evolution of the growing layer. Specific attention will be also placed on the creation of defects due to energetic bombardment in the polycrystalline metallic layer.


The candidate will extend the current kMC code (developed by the group), dedicated to the simulation of a 3D growth
of Cu/Cu(001) under energetic conditions, to the case of Cu/substrate interface of different chemistry, and to polycrystalline systems in order to account for the issue of GB formation and grain misorientation. First, the candidate will become familiar with the current code, based on a single rigid lattice, and will study the dewetting of Cu(001) films.

Subsequently, the growth of polycrystalline films will be approached through the implementation of the multi-lattice kinetic Monte Carlo code (mn-kMC). This evolution of the code could be achieved by using several rigid networks following the work of Huang1

. Particular emphasis will be placed on the dynamics of GB formation and the role of energetic species on metal and/or silicon diffusion. Also, defect annihilation at the free surface and at the GB will be implemented leading to thin film stress relaxation2.

This will give a comprehensive picture of the microstructural changes of polycrystalline films, and will allow for the identification of the origin of the structural and morphological evolution. Beyond this, the final objective is to address the origin and evolution of intrinsic stress during thin film growth using off-lattice kMC.
Therefore, the second part of the work will be dedicated to investigate at atomic scale, the crucial role of GBs on the dynamic stress evolution (generation and/or relaxation) during growth by means of a comprehensive description of the diffusion mechanisms near GBs. One suitable approach is the combination of the developed mn-kMC code with kinetic Activation- Relaxation Technique (k-ART) 3

code, which is an off-lattice, self-learning, on-the-fly
identification and evaluation of activation barriers. The fulfilment of this objective will be facilitated thanks to close
collaboration with the developper of the k-ART code, Pr N. Mousseau (University of Montreal, Canada).
The outcome will be benchmarked against experimental validations (structural, electrical and optical layer properties)
thanks to the unique palette of in situ and real-time diagnostics available at Pprime Institute

(1) H. Huang and L. G. Zhou, “Atomistic simulator of polycrystalline thin film deposition in three dimensions”, Journal of Computer-Aided Materials Design 11, 59 (2004). 
(2) E. Chason ,P. Guduru, “Tutorial: Understanding residual stress in polycrystalline thin films through real-time measurements and physical models”, Journal of Applied Physics 119, 191101 (2016)./ E Chason, M Karlson, J. J Colin, D Magnfält, K Sarakinos, G Abadias, “A kinetic model for stress generation in thin films grown from energetic vapor fluxes”, Journal of Applied Physics 119, 145307 (2016).
(3) F. El-Mellouhi, N. Mousseau, L. J. Lewis, “Kinetic activation-relaxation technique: An off-lattice self-learning kinetic Monte Carlo algorithm”, Physical Review B 78, 153202 (2008). / 0scar A. Restrepo, N. Mousseau, F. El-Mellouhi, O. Bouhali, M. Trochet, C. S. Becquart, “Diffusion properties of Fe–C systems studied by using kinetic activation–relaxation technique”, Computational Materials Science 112, Part A, 96 (2016). / G. K. N’Tsouaglo, L. K. Béland, J. – F. Joly, P. Brommer, N. Mousseau, P. Pochet, “Probing potential energy surface exploration strategies for complex systems”, Journal of Chemical Theory and Computation 11, 1970 (2015).

Main Skills Required

– PhD degree in condensed matter physics or materials science
Prior experience (PhD thesis, post-doctorate) in atomic-scale simulation (Ab initio and/or MD) with a good knowledge of associated simulation software (VASP and/or LAMMPS) or Monte Carlo
Strong programming language skills (Fortran, C, Python, etc.), Linux.
Sufficient level of English for writing and understanding scientific articlesBien que les modélisations et les prédictions dans le domaine de l’épitaxie et des interactions aient connu des progrès significatifs, des défis subsistent. La complexité des interactions atomiques et les limites des modèles théoriques nécessitent une amélioration constante des méthodes de simulation. De plus, les évolutions rapides des matériaux et des technologies nécessitent une mise à jour régulière des bases de données et des modèles. Malgré ces défis, les modélisations et les prédictions continueront à jouer un rôle crucial dans la conception de nouveaux matériaux épitaxiés et dans l’accélération des découvertes scientifiques et technologiques.- PhD degree in condensed matter physics or materials science
– Prior experience (PhD thesis, post-doctorate) in atomic-scale simulation (Ab initio and/or MD) with a good knowledge of associated simulation software (VASP and/or LAMMPS) or Monte Carlo
– Strong programming language skills (Fortran, C, Python, etc.), Linux.


Numerous studies have demonstrated a complex dependence of the deposition conditions (4)
(i.e. the kinetic energy of the particles deposited, the nature and the temperature of the substrate) and characteristics (5) (surface mobility, chemical reactivity) on the evolution of the microstructure of metallic thin films and their properties. This is illustrated in some of our recent work on thin films of copper or columnar structures of TiN obtained by grazing incidence deposition (6).

Therefore, the need for a deterministic approach leading to a better understanding of the elementary growth processes
is highly desirable. Computational modelling based on numerical simulation offers a comprehensive approach to
fulfil this goal and contributes to provide a predictive and reliable tool towards end-users. To simulate the full growth
process, from condensation of the vapor flux to the nucleation stage and towards the formation of thicker layers, over
a realistic time scale comparable (order of seconds or minutes) with the experiments, requires a multi-scale modelling.
Understanding initial growth stages and their influence on the evolution of film microstructure (grain size and texture)
and properties (stress state, defect density, mechanical attributes) is the main objective of the DREAM project funded
by the ANR and the Nouvelle Aquitaine Region.
One important aspect of the DREAM project is to implement a robust and reliable multiscale computational modelling
of thin film growth over realistic time scales with the ultimate goal to address stress generation and relaxation
processes into a single, multi-methods simulation package. This computational-driven approach is based on a kinetic
Monte Carlo (kMC) scheme, which will encompass both on-lattice and off-lattice models to address all
interdependent issues of defect creation, chemical intermixing and grain boundaries (GB) formation/migration
during polycrystalline film growth. Specifically, the project will address fundamental aspects of the growth process of polycrystalline thin films with emphasis laid on the GB formation/evolution, surface faceting, stress relaxation and the defect creation/evolution
related to energetic deposition process, as also the early growth stages such as interfacial reaction, nucleation and

(4) G. Abadias, A. Fillon, J.J. Colin, A. Michel, C. Jaouen, “Real-time stress evolution during early growth stages of sputter-deposited metal films: Influence of adatom mobility”, Vacuum 100, 36 (2014). / G. Abadias, E. Chason, et al., “Review Article: Stress in thin films and coatings: Current status, challenges, and prospects”, Journal of Vacuum Science & Technology A 36, 020801 (2018)
(5) C. Furgeaud, L. Simonot, A. Michel, C. Mastail,G. Abadias., Impact of Ge alloying on the early growth stages, microstructure and stress evolution of sputter-deposited Cu-Ge thin films, Acta Materialia. 159, 286 (2018)
(6) B. Bouaouina, C.Mastail, et al , “Nanocolumnar TiN thin film growth by oblique angle sputter-deposition: Experiments vs. simulations”, Materials & Design 160, 338 (2018)

Main Skills Required


Nos axes

Épitaxie et interactions

Ingénierie de matériaux épitaxiés, nouvelles fonctions et applications industrielles