Simulation of deposition of thin layers on 3D rotating substrates with complex geometry. Application to the deposition by magnetron sputtering

One of the main challenges of thin films deposition is to obtain a high thickness uniformity. Indeed, the collision between metal and gas atoms, the cathodes racetrack, the substrates complex geometries, have as effect a relatively low thickness uniformity (effects of the angular distribution, shadowing…). To fix it, there are several possibilities: the multi-axis substrate rotation to expose each surface to the atoms flux, other modes of magnetrons discharges, alternatives devices geometry... The question then arise of “What are the optimal parameters to obtain the more uniform thickness layer?”. Testing lots of possibilities with different gas pressures, angular velocities, inclinations, etc. is a solution but can become very slow and expensive. We want then to simulate numerically the deposition rate of matter on rotating 3D complex shapes. Several software’s simulate the thin films growth. The process including lots of complex phenomena (diffusion, reflection, etc.) but the actual simulations are very slow and/or concern a microscopic description of the layer instead of the uniformity (a macroscopic characteristic). Moreover, the simulations are rarely made for substrate rotation. Simulations with rotating substrates have been made for the growth of multilayers but the strong hypothesis (zero pressure, plane samples…) give the simulation not much generalizable for the study of deposition rate on complex shapes (the substrate considered are little plane surfaces).