Local modification of thin film metal by laser peening

点击翻译按钮获取中文摘要

Laser peening (LP) is a surface treatment method for improving mechanical properties. Conventionally, LP has been applied to bulk material and the treatment is conducted under water medium to prevent expansion of plasma.In this research, to apply this treatment to thin film metals is objective. The LP has possibility to be a novel treatment method of thin film metal, however the conventional wet-condition treatment is not suitable for thin films. Therefore, LP under dry condition is proposed.Dry LP uses transparent solid material instead of water for medium. Glass is chosen for the solid medium of dry LP because it shows higher improvement of hardness than that of conventional wet LP. In addition, air gap between specimen and solid medium is considered. As results, the peening effect is confirmed less than 0.1mm of the gap thickness. Finally, the proposed dry LP is applied to thin copper film deposited by sputtering and hardness of the film is improved.