Uniform film in large areas deposited by magnetron sputtering with a small target

To grow uniform films on a large substrate by magnetron sputtering with a small target, a new theoretical model has been proposed, implemented and confirmed. The model was based on a magnetron sputtering system containing a rotation substrate holder and a step-moving target. There were two critical parameters, namely the target stay time and the target moving step, affecting film thickness distribution in this model. The relationship between the thickness distribution and the parameters was obtained. The simulated results showed that when the target stay time was proportional to the target scanning area at the rotating substrate, the film thickness was more uniform than other conditions. The deviation of film thickness distribution decreased with a decrease in target moving step. A magnetron sputtering system containing a rotation substrate holder and an Φ 50 mm step-moving target has been established by us. When target stay time was proportional to the target scanning area at the rotating substrate and target moving step was 5 mm, the relative deviation of film thickness distribution was less than 5% within a diameter of Φ 300 mm. The numerical results agreed well with measurements, which demonstrated that our model was applicable to depositing large uniform film. It was expected that our model was also applicable to magnetron sputtering systems with other dimensions.

► A new model about magnetron sputtering was established to deposit the uniform film.
► The target stay time and the target moving step are critical parameters in the model.
► The relation between the thickness distribution and the parameters was discussed.
► A uniform Al film was deposited on an Φ 300 mm glass wafer by this method.