Optical TiO2 layers deposited on polymer substrates by the Gas Injection Magnetron Sputtering technique

This work presents decorative TiO2, TiO2/Al layers deposited on poly(methyl methacrylate) (PMMA) substrates. We chose the Gas Injection Magnetron Sputtering (GIMS) technique for layer deposition. Choosing this technique, we expected a lower thermal load of polymer substrate than in other commonly used magnetron techniques. The pulse plasma, generated in the GIMS method, is controlled by a periodical injection of gas dosages in the region of the magnetron target. The process of deposition operated with a 1 Hz frequency of a plasma generation and the life time of plasma was ∼500 ms. Under these conditions, the energetic impact into the substrate, integrated over the time, is lower than during the continuous process, so it should not cause any damage to the polymer surface. For our experiment we deposited a thick ∼700 nm aluminum layer and thin 17-116 nm TiO2 films, which exhibited the interference effect, on non - heated PMMA substrates. The optical properties of the prepared systems were investigated by spectroscopic ellipsometry and spectrophotometric measurements.