Self-regulating gas dosage for reactive RF sputtering of composition spread Hf oxy- nitride combinatorial layers

Abstract

We aimed to prepare single sample concept composition-spread metal oxy-nitride layers by reactive radiofrequency sputtering for a highly efficient characterization of their optical properties in a wide range of O/N ratios. Affinity of metals requires oxygen proportion, in the Ar-O-N plasma, be set orders of magnitude lower compared to nitrogen. The required low partial pressure range of oxygen was covered by a new concept self-regulating gas inlet assembly based on a peristaltic pump delivering gas from a finite volume vial. We proved the suitability of our combinatorial method by both energy dispersive spectrometry mapping and ellipsometry of the correlated refractive indices along a 3-component composition-spread HfON sample.