Square-wave low-frequency modulation of the discharge current for high rate deposition of stoichiometric ceramic films

Low-frequency modulation of the discharge current is as a convenient way of overcoming the drawbacks associated with unstable behaviour, i.e. the hyst eresis effect, often encountered in reactive magnetron sputtering. In this paper, we present the main trends of a square-wave low-frequency modulation of the discharge current. Particular attention is paid to the description of the characteristic times of poisoning and cleaning of the target surface , at the origin of the process stabilisation close to the elemental or reac tive sputtering mode. Finally, we focus on the characteristic time at the s urface of the substrate, where it is shown that the high-rate deposition of stoichiometric titanium dioxide is obtained by depositing a sub-stoichiome tric layer at the end of the step high of the modulation, which reoxidises during the following step low. (C) 2001 Elsevier Science B.V. All rights re served.