Journal of the Korean Society for Precision Engineering (한국정밀공학회지)

Korean Society for Precision Engineering (한국정밀공학회)
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Micromachining of the Si Wafer Surface Using Femtoseocond Laser Pulses

펨토초 레이저를 이용한 실리콘 웨이퍼 표면 미세가공 특성

  • 김재구 (한국기계연구원 나노공정장비연구센터) ;
  • 장원석 (한국기계연구원 나노공정장비연구센터) ;
  • 조성학 (한국기계연구원 나노공정장비연구센터) ;
  • 황경현 (한국기계연구원 나노공정장비연구센터) ;
  • 나석주 (한국과학기술원 기계공학과)
  • Published : 2005.12.01
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Abstract

An experimental study of the femtosecond laser machining of Si materials was carried out. Direct laser machining of the materials for the feature size of a few micron scale has the advantage of low cost and simple process comparing to the semiconductor process, E-beam lithography, ECM and other machining process. Further, the femtosecond laser is the better tool to machine the micro parts due to its characteristics of minimizing the heat affected zone(HAZ). As a result of line cutting of Si, the optimal condition had the region of the effective energy of 2mJ/mm-2.5mJ/mm with the power of 0.5mW-1.5mW. The polarization effects of the incident beam existed in the machining qualities, therefore the sample motion should be perpendicular to the projection of the electric vector. We also observed the periodic ripple patterns which come out in condition of the pulse overlap with the threshold energy. Finally, we could machined the groove with the linewidth of below $2{\mu}m$ for the application of MEMS device repairing, scribing and arbitrary patterning.

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References

  1. Madow, M. J., 'Fundamentals of microfabrication,' 2nd ed. CRC Press, 2001
  2. Rethfeld, B., Sokolowski-Tinten, K., Von der linde, D., Anisimov, S. I., 'Timescales in the response of materials to femtosecond laser excitation,' Appl. Phys. A 79, pp. 767-769, 2004 https://doi.org/10.1007/s00339-004-2805-9
  3. Rosenfeld, A., Lorenz, M., Stoian, R., Ashkenasi, D., 'Ultrashort-laser-pulse damage threshold of transparent materials and the role of incubation,' Appl. Phys. A 69, pp. 373-376,1999 https://doi.org/10.1007/s003390051419
  4. Schaffer, C. B., 'Interaction of femtosecond laser pulse with transparent materials,' Ph.D. thesis, Harvard University, 2001
  5. Park, S. H., Lim, T. W., Yang, D. Y, Kong, H. J., 'Directly Nano-precision Feature Patterning on Thin Metal Layer using Top-down Building Approach in nRP Process,' J. of KSPE, Vol. 21, No.6, pp. 153-159,2004
  6. Barsch, N., Korber, K., Ostendorf, A., Tonshoff, K. H., 'Ablation and cutting of planar silicon devices using femtosecond laser pulses,' Appl. Phys. A 77, pp. 237-242, 2003
  7. Bauerle, D., 'Laser processing and chemistry,' 3rd ed. Springer, pp. 574-586,2000