Yttrium oxide (Y2O3) and yttrium oxyfluoride (YO0.6F2.1) protective coatings were prepared by an atmospheric plasma spraying technique. The coatings were exposed to a NF3 plasma. After the NF3 plasma treatment, the mass loss of the coatings showed that the etching rate of YO0.6F2.1 was larger than that of the Y2O3. X-ray photoelectron spectroscopy revealed that YO0.5F1.9 was present in the Y2O3 coating, whereas YO0.4F2.2 was present in the YO0.6F2.1 coating. Transmission electron microscope analysis conducted on contamination particles generated during the plasma etching showed that both coatings were mainly composed of YFx. The contamination particles estimated by in-situ particle monitoring sensor revealed that the YO0.6F2.1 compared with the Y2O3 coatings produced 65% fewer contamination particles.

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 Y2O3 and YF3 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 NF3 plasma. The mass loss at the powered electrode, which was exposed to the NF3 plasma etching under an applied bias, showed that the YF3 etching rate was higher than that of Y2O3. Conversely, the mass of coating increased at the grounded electrode and the grounded wall, which were exposed to NF3 plasma etching under zero bias. The mass of the Y2O3 coating increased more than that of the YF3 coating. X-ray photoelectron spectroscopy analysis showed that the Y2O3 coating corroded to YOxFy in the NF3 plasma, and YF3 existed as YFx. Light scattering sensor analysis showed that the YF3 coating produced fewer contamination particles than did the Y2O3 coating.

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