Masakatsu Kiyohara

Plasma Exposure Behavior of Yttrium Oxide Film Formed by Aerosol Deposition Method

Aerosol deposition (AD) method is technique for forming high density ceramic films on substrate material surface at room temperature. The yttrium oxide films formed by the AD method (AD-Y₂O₃ films) have been developed as plasma resistance coating used for the plasma etching equipment. In recent years, plasma eroded particles from chamber components of the etching devices are regarded as a serious issue that they reduce the semiconductor device yield rate. AD-Y₂O₃ films which have excellent plasma resistance can reduce the eroded particles in the plasma etching equipment and greatly have contributed to manufacturing high integrated semiconductor devices. In this paper, the plasma erosion behavior of AD-Y₂O₃ films were investigated compared with sintered Al₂O₃, sintered Y₂O₃ and thermal splayed Y₂O₃ in order to clarify the reason why AD Y₂O₃ films were superior as plasma resistance material. The plasma etching rates of AD-Y₂O₃ films were not significantly different from other samples. It was assumed that the etching rates were dependent on the chemical stability to fluorine plasma of material. On the other hand, the surface roughness difference before and after plasma exposure of AD-Y₂O₃ films were much smaller than other samples. It was assumed that the surface roughness difference is dependent on the crystalline size of material. The structure of AD-Y₂O₃ films, which had high density and nano-crystalline structure, were eroded homogeneously and smoothly. It suggests AD-Y₂O₃ films do not generate large eroded particles and are superior to reduce the eroded particles in the etching devices.