Observation of Species Ablated from Fused Silica by F2-KrF Multiwavelength Excitation Process

Abstract

Dynamics of ablation of fused silica by multiwavelength excitation process using F2 and KrF excimer laser has been investigated by energy analyzed mass spectrometry of ablated species. The number of generated Si+ ion by multiwavelength excitation process corresponds to that by single-F2 laser ablation and to approximately 2.1 times higher than that by single-KrF excimer laser ablation. In addition, kinetic energy distribution of Si+ ablated by multiwavelength excitation process shows almost same as that by single-F2 laser ablation. We regard that absorption of KrF excimer laser by excited state generated by F2 laser (excited-state absorption: ESA) causes effective photoionization, resulting in enhancement of Si+ with higher kinetic energy and then in high-quality ablation. © 2003, The Institute of Electrical Engineers of Japan. All rights reserved.