Yttrium oxide coatings and their formation methods

Abstract

A yttrium oxide film and a method thereof are provided to suppress plasma resistance reduction due to abnormal growth originating from foreign matter. In the yttrium oxide film formed on a substrate, in a cross-section of the film including the thickness direction, the average ratio of the major axis to the minor axis of each of the plurality of yttrium-dominant particles present in the film when approximated by an ellipse is greater than 1.5.