Partially reactive d.c. magnetron sputtering — a key to new understanding of reactive plasma sputter deposition?

Abstract

This paper deals with reactive gas incorporation during d.c. magnetron sputtering under process conditions resulting in undersaturated films, defined as partially reactive. Besides a reactive gas incorporation via classic adsorption, a four-stepped reaction sequence is discussed consisting of: (1) ionization; (2) ion bombardment of the target and, simultaneously, formation of a coverage by plating; (3) removal of this coverage by sputtering; (4) condensation on the substrate. The reaction course is mirrored by simple macrokinetic rate equations as demonstrated with different reactive gases and a CrSi target. Because of the simplicity of the relationships, and a possibly wide transferability, it is considered that investigations into partially reactive d.c. magnetron depositions could become important also for more complex reaction conditions.