The “INTEGRAL” project aims to develop a robust, reliable and realistic multiscale computational modelling of metallic thin film growth when using physical vapor deposition, and in particular under energetic conditions such as sputtering deposition scales with the ultimate goal to study stress generation and relaxation processes. Elementary mechanisms at the atomistic level, adsorption and diffusion, and the corresponding energy barrier heights will be identified using both ab initio DFT and molecular dynamics calculations. These events will then be implemented in a kinetic Monte Carlo (kMC) code, so as to depict realistic growth conditions in magnetron sputtering (energy and angular distribution of incoming particles). The resulting simulation code will be capable of seamlessly bridging length and time scales, and predicting evolution of physical quantities, roughness, density and/or morphology, with the ultimate goal to address intrinsic stress generation and relaxation processes into a single, multi-physics simulation package.
The initial growth stages are of prime importance for subsequent microstructure development, therefore the cases regarding high mobility metals (as Cu) and low mobility metals (as Mo) will be studied in parallel, as experimental observations point to different adopted growth modes, 3D vs 2D, respectively. Chemical reactivity at the interface between metal and crystalline silicon will be investigated to gain insight in the mechanisms of silicide formation. In a final step, polycrystalline growth and grain boundary formation will be addressed, highlighting the relation between grain boundary evolution and diffusion of point defects.
The computational approach will encompass both on-lattice and off-lattice kMC models to resolve the interdependent issues of defect creation, chemical intermixing and grain-boundary formation during polycrystalline film growth. Stress modelling will be addressed using kinetic activation-relaxation technique (k-ART), an off-lattice self-learning kMC algorithm, in collaboration with the group of Prof. Mousseau at Montreal University. Data collection from growth experiments for in situ structural analysis will be conducted within the Pprime laboratory as well as externally, using Synchrotron facilities. The strength of the INTEGRAL project is the direct experimental validation on structural, electrical and optical properties of thin films, using a unique palette of in situ and real-time studies during growth that is available to the research group.
The ultimate purpose of the project is to simulate the stress build-up during growth under energetic conditions, as this has yet to be achieved. The fundamental knowledge obtained during the INTEGRAL implementation will provide a more clear view of the relationship between the evolution of the film microstructure (grain size and texture) and its properties (stress state, defect density, mechanical attributes). It will make accessible new paths for fundamental and technological concept design and implementation, and it will greatly reduce the time required from concept to industrial product.
Monsieur Cedric MASTAIL (Institut P' : Recherche et Ingénierie en Matériaux, Mécanique et Energétique)
The author of this summary is the project coordinator, who is responsible for the content of this summary. The ANR declines any responsibility as for its contents.
Pprime Institut P' : Recherche et Ingénierie en Matériaux, Mécanique et Energétique
Help of the ANR 256,947 euros
Beginning and duration of the scientific project: March 2020 - 48 Months