Influence of the method of gas supply to the chamber on the processes of reactive magnetron sputtering of Ti–Al composite target

The paper demonstrates study results of the processes of reactive magnetron sputtering of a Ti–Al composite target in an Ar/O$_2$ gas mixture with various methods of gas supply to the chamber. It has been established that, regardless of the method of gas supply, when changing the oxygen concentration in the Ar/O$_2$ gas mixture, the ratio of the Al and Ti content in the deposited Ti$_{1-x}$Al$_x$O$_y$ films changes. The metal content ratio in the deposited films varies in proportion to the change in the ratio of the control lines intensities of the optical emission of aluminum AlI (396.15 nm) and titanium TiI (395.82 nm) in plasma. This makes it possible to effectively use the method of optical emission spectroscopy to predict and control the content of metals in deposited films. Based on studies of the dielectric characteristics of deposited Ti$_{1-x}$Al$_x$O$_y$ films, it was discovered that with separate gas supply (Ar is supplied to the target region, O$_2$ is supplied to the substrate region), in contrast to the joint gas supply (the Ar/O$_2$ gas mixture is supplied to the target region), it is possible to deposit dielectric films in the transient mode at relatively high sputtering rates. In this case, the oxygen supply to the substrate region makes it possible to increase the oxygen content in the films up to 60–64%.