Axial Suspension Plasma Sprayed Ceramic coatings for Semiconductor Applications

The size of semiconductor and flat-panel-display (FPD) production equipment for dry etching and sputtering has been increasing due to the increased size of Si wafer and the FPD. Plasma treatment is used for micro~nano fabrication especially in dry etching, and a higher plasma power is needed to fabricate the large scaled substrates with high etching rate. This trend presents higher requirements on the plasma erosion resistant coatings on the inside wall of the chamber. High-purity oxide ceramics such as alumina (Al2O3) and yttria (Y2O3) are good coating materials against plasma erosion. These coatings have been used primarily applied with plasma spraying agglomerated-and-sintered powders. In this study, Al2O3 and Y2O3 coatings were sprayed using axial suspension plasma spraying with fine powders. The resulting coatings were harder, denser and smoother with improved plasma erosion resistance and dielectric properties compared to traditional plasma coatings. The effect of the powder properties on the coating structure were investigated, and their erosion resistance and dielectric properties are discussed.