Numerical simulation of metallic film thickness distribution deposited by electron beam co-evaporation under vacuum

This study deals with Monte Carlo simulation of the physical phenomena involved during the transport of three metals (aluminium, copper and titanium) evaporated simultaneously from independent sources under a vacuum atmosphere (5 × 10−2 Pa). The model allows the simulation of the particle trajectories and therefore the theoretical thickness distribution on a rotating substrate located above the sources. As the deposition is performed under vacuum, we suppose that there is no collision between ambient and evaporated particles. The first stage has consisted in the checking of the assumption according to which there is no interaction between the particles emanating from the different sources. Then, we have determined precisely the space distribution function of the evaporated metallic atoms which follows a cosnθ law. Finally, and to validate the model, simulated and measured thickness distribution profiles have been compared. The good agreement obtained shows that the model is able to predict correctly the thickness distribution profile during a co-evaporation deposition process under vacuum.