Including substrate temperature in Berg model for reactive sputtering

Abstract

Reactive magnetron sputtering deposition can be qualitatively simulated by the well known Berg model. However, such model does not take into account explicitly the dependence of the substrate temperature on the sticking coefficient. The substrate temperature plays a major role in film properties and also affects the hysteresis curves. In order to analyze the effect of substrate heating on the hysteresis curves, the Berg model equations were rewritten by using both the Langmuir and the Kisliuk adsorption models. The theoretical results show that a raise on substrate temperature causes variations in the first critical point, but the adsorptions models exhibit different temperature dependences. In the experimental hysteresis curves obtained for Ti and Al targets using N2 and O2 as reactive gases, the effects of substrate temperature are very small, therefore, negligible.