Plasma-Erosion Properties of Ceramic Coating Prepared by Plasma Spraying

Abstract

Application of plasma sprayed ceramic coatings with a high purity of more than 99.9% has been sharply increasing in semiconductor and liquid-crystal-display (LCD) production equipments in the last few years. The size of the equipments becomes larger with increasing Si wafer size and the LCD size that promotes the replacement from conventional techniques, such as alumite film and bulk ceramics, to plasma spray coatings, where the high durability against the plasma erosion (anti-plasma erosion resistance) is required. However, as far as we know, no systematic studies on the plasma-erosion properties are reported. In this work, durability of plasma sprayed alumina and yttria coatings against CF₄/O₂ plasma are investigated by reactive ion etching (RIE) system and are compared to that of the conventional techniques. The erosion mechanism and the effect of the powder properties are discussed through the micro-structural analysis.