Phase Explosion and Marangoni Flow Effects during Laser Micromachining of Thin Metal

Hendijanifard, M., Willis, D.A., “Phase Explosion and Marangoni Flow Effects during Laser Micromachining of Thin Metal Films”, Proceedings of the SPIE, Vol. 6879, (Presented at Photonics West Conference, January, 2008).
Hendijanifard SPIE2008.pdf
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ABSTRACT
Phase explosion and Marangoni flow during laser micromachining of thin films are studied in this paper. The
purpose of this study is to improve understanding of the time scales by which these processes occur. The
study is based on time-resolved reflection imaging method. The effect of the Marangoni flow can be seen on
the starting/ending time scales of the ablation. The microscopic images make it clearer if the flow regime is
more Marangoni flow dominant or phase explosion dominant. Marangoni flow is mainly responsible for
removal of the outer layers of the melt pool, while phase explosion begins in the center of the sample. The
other difference is the speed of material removal from the sample which shows that phase explosion occurs on
a shorter time scale than Marangoni flow. This difference may result in new applications by controlling the
fluence of the laser in both Marangoni and phase explosion regions. Phase explosion phenomenon may be
used for instant removal of material from the sample and Marangoni flow may be used for fine and more
controlled material removal from the sample.