Fluorine and oxygen plasma exposure behavior of yttrium oxyfluoride ceramics

Abstract

Abstract Yttrium oxyfluoride ceramics, YOF and Y 5 O 4 F 7 , are promising materials with plasma durability and they are expected to be suitable for plasma etching equipment. In this study, high energy fluorocarbon and oxygen plasma exposure behavior of YOF and Y 5 O 4 F 7 was evaluated. Due to simultaneous sputtering and chemical reaction, etching rates depended not on materials but on plasma conditions. Surfaces of Y 2 O 3 , YOF and Y 5 O 4 F 7 showed crater-like patterns after exposure to high-energy plasmas. Morphological observation and line roughness evaluation showed good durability of Y 5 O 4 F 7 because it had a flatter surface than YOF and Y 2 O 3 after plasma irradiation. TEM cross-sectional observation confirmed a disordered lattice pattern on Y 2 O 3 and YOF after fluorocarbon plasma and oxygen plasma exposure.