Ablation of silicon by focusing a femtosecond laser through a subwavelength annular aperture structure

Y. Y. Yu, C. K. Chang, M. W. Lai, L. S. Huang, C. K. Lee

研究成果: Conference contribution

1 引文 斯高帕斯(Scopus)


We experimentally examined the effect of laser energy fluence on the ablation of a silicon wafer using a Ti:sapphire femtosecond laser system. A femtosecond laser was focused through an oxide-metal-oxide (Al2O 3/Al/Al2O3) film engraved with a subwavelength annular aperture (SAA) structure, i.e., a Bessel beam composed of a femtosecond laser created using a SAA. The optical performance, such as depth-of-focus (DOF) and focal spot of the SAA structure, was simulated using finite-difference time domain (FDTD) calculations. We found that a far-field laser beam propagating through the SAA structure possesses a sub-micron focal spot as well as high focus intensity. The experimental results demonstrated that silicon can be ablated using an input ablation threshold of an order of 0.05 J/cm2 with a pulse duration at around 120fs. We found the obtained surface hole to have a diameter smaller than 1μm. Different surface ablation results obtained by using different threshold fluences of input laser energy are shown. Possible applications of this technique includes executing high aspect ratio laser drilling for thin film microfabrication undertaking thru silicon via (TSV) for 3DIC, etc.

主出版物標題Laser Beam Shaping XI
出版狀態Published - 2010 10月 28
事件Laser Beam Shaping XI - San Diego, CA, United States
持續時間: 2010 8月 22010 8月 2


名字Proceedings of SPIE - The International Society for Optical Engineering


ConferenceLaser Beam Shaping XI
國家/地區United States
城市San Diego, CA

All Science Journal Classification (ASJC) codes

  • 電子、光磁材料
  • 凝聚態物理學
  • 電腦科學應用
  • 應用數學
  • 電氣與電子工程


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