Zirconium sputtering by argon–hydrogen and argon–oxygen plasma

The effects on the sputtering of zirconium by mixing hydrogen or oxygen with argon plasma were investigated. Plasmas were generated by electron cyclotron resonance (ECR) heating. The zirconium target was cylindrical, 7 cm in diameter, 2 cm in length and 0.1 mm in thickness, and was set on the downstream side from the ECR point. The zirconium sputtering rate was evaluated from the amount of zirconium deposited onto the copper sample collector, which was dissolved with aqua regia after plasma sputtering experiments, and then the zirconium concentration was measured by ICP-AES. The chemical sputtering effect is discussed based on comparison with the physical sputtering effect. It was found that the sputtered zirconium flux depends on the oxygen partial pressure. It is concluded that the sputtering of zirconium in Ar–O2 is governed by chemical interaction between oxygen radicals and the zirconium target.