Systematic study of the evolution of texture and electrical properties of ZrN_x thin films by reactive DC magnetron sputtering

The ZrN_x thin films are synthesized by Reactive DC magnetron sputtering and the detailed evolution of atomic ratio, phase, texture and electrical property in the thin films are systematically studied with various growth parameters including N₂ flux ratio, applied DC power, target-to-substrate distance and substrate bias by four-point probe, EPMA and XRD. It is found that each of the growth parameters not only affects the crystallinity, texture and oxygen impurity content in the thin films to different degrees but also alters the composition of the constituent elements in the films in different ways. The formations of Zr-rich, stoichiometry and N-rich zirconium nitride films can be obtained by varying N₂ flux ratio or substrate bias. The growth window for the stoichiometry ZrN phase is narrow and its occurrence corresponds exactly to the minimum resistivity and the highest 200 texture coefficient. The formation of metastable Zr ₂N phase is also demonstrated by varying the substrate bias for a given N₂ flux ratio. The influence of each growth parameter on the film properties is discussed in the paper.