Contamination particle behavior of aerosol deposited Y 2 O 3 and YF 3 coatings under NF 3 plasma

Abstract

The internal coatings of chambers exposed to plasma over a long period of time are subject to chemical and physical damage. Contamination particles that are produced by plasma damage to coatings are a major contribution to poor process reliability. In this study, we investigated the behavior of contamination particles produced from plasma damage to Y 2 O 3 and YF 3 protective coatings, which were applied by an aerosol deposition method. The coating materials were located at the powered electrode, the grounded electrode, and the grounded wall, which were exposed to a NF 3 plasma. The mass loss at the powered electrode, which was exposed to the NF 3 plasma etching under an applied bias, showed that the YF 3 etching rate was higher than that of Y 2 O 3 . Conversely, the mass of coating increased at the grounded electrode and the grounded wall, which were exposed to NF 3 plasma etching under zero bias. The mass of the Y 2 O 3 coating increased more than that of the YF 3 coating. X-ray photoelectron spectroscopy analysis showed that the Y 2 O 3 coating corroded to YO x F y in the NF 3 plasma, and YF 3 existed as YFx. Light scattering sensor analysis showed that the YF 3 coating produced fewer contamination particles than did the Y 2 O 3 coating.