In this paper we reported the results of investigation on surface deformation caused by thermal effect during excimer laser ablation of polyimide. Obvious surface deformation around the hole entrance was observed during the experiment. The surface topology and cross-section of the ablated holes were analyzed using Zygo and SEM. It was shown that ring feature of 17 to 150 nm in height and 1 to 3 micrometers in width was formed above the level of the unablated surface. The deformed surface showed rough and color-changed characteristics. An optical diffraction model was employed to explain the causing of this kind of deformation. It was found that the ablating and heating by near- and under-threshold laser beam became thermal effect to polyimide material ablation, which was contributed by diffraction effect of optical projection system.

Date Published: 29 October 2001
PDF: 6 pages
Proc. SPIE 4595, Photonic Systems and Applications, (29 October 2001);

Published in SPIE Proceedings Vol. 4595:
Photonic Systems and Applications
Yakov S. Sidorin; Ding Yuan Tang, Editor(s)