Hydrophilization treatment of copper surface usingan atmospheric damage-free plasma source

Summary form only given. In recent years, atmospheric plasma sources have been developed for industrial applications such as surface treatment, CVD, hazardous waste treatment or elemental analysis. It does not use vacuum pumping system or chambers and high-density plasma can be generated so it is beneficial to industrial applications. However, metal surface treatment by usual atmospheric plasma source was difficult because arc discharge is generated when the metal target is placed in close to the source. So in our group, a damage-free plasma source for high-speed metal surface cleaning/treatment has been developed. With the damage-free plasma source, outer electrode that has 100 times 1 mm slit is grounded and the plasma gas flows out from the slit so the discharge does not generate to target surface. 27.12 MHz of RF power is applied to the electrodes through a matching network. The generated plasma can be touched because electrical discharge does not occur outside the plasma source and the plasma is low temperature. Argon or helium gas is used as a plasma gas and oxygen or air is used as an additional gas. In the metal surface cleaning, organic substance remains on the metal surfaces are chemically removed by oxygen or hydroxyl radicals generated in the plasma. Then, the metal surface is hydrophilized. In this study, copper surface treatment by the plasma source is tested. The surface was hydrophilized 36 to 73 dyn/cm in sub second. Hydrophilization speed of copper surface was increased with the flow rate of the plasma gas and the RF input power. Oxygen mixed helium plasma shows the highest processing speed. The measured spectroscopic properties of the plasma and results of copper surface treatment will be reported.