Multiscale simulation of PVD coating on complex objects in motion. From gas phase modelling to atomic scale film growth.

Efficient thin film deposition by PVD can be challenging in numerous situations like complex-shaped objects or systems of multiples objects in competition due to shadowing. As an example, we can think about deposition of hard coating on cutting tools.

In this work, we are investigating thin films deposited by magnetron sputtering process on drill bits placed on a holder in motion. The aim is to show if and how the conformality of such coating can be obtained with such process.

The deposition process is modelled by combining Computational Fluid Dynamic (CFD), Monte-Carlo algorithm and ray-tracing (using the software Virtual Coater) to be able to predict the fluxes deposited on the meshed 3D objects. This modelling tool is coupled to an atomic scale kinetic Monte-Carlo model to simulate the time dependent growth of the film at different positions of the samples. A special attention is paid to the influence the kind of motion or the number of pieces in the chamber on the conformality of the coating.

This approach allows to reduce substantially the R&D time which is necessary to find optimal process parameters. Moreover, such modelling workflow can be extended to any study implying PVD deposition on large number of objects in motion, like in e.g. hard coating on ball bearing for medical applications, or coating of micron-scale particles in the domain of battery.