Abstract
Controlling precisely the depth in glass micro-drilling by spark assisted chemical engraving (SACE) remains challenging, particularly for low depths. The possibility of using an electrically conductive material as an etch-stop layer for SACE gravity-feed drilling is investigated in this paper. Micromachining with constant DC and pulsed DC of 30–35 μm thick SiO2 deposited on low resistive silicon substrate demonstrated the etch-stop function of the conductive silicon. Measurements of etch rates and hole profiles along with scanning electron microscope imaging revealed the mechanism underlying the etch-stop process. Low resistive silicon is demonstrated to be a good etch-stop layer for SACE gravity-feed drilling. Demonstration of machining of SiO2 layer on silicon as a substrate and an etch-stop layer opens up new possibilities to adapt SACE for developing devices on silicon platform.
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Acknowledgments
This work was supported by the Canadian Institute for Photonics Innovations (CIPI) and the Natural Sciences and Engineering Research Council of Canada (NSERC). The authors acknowledge the technical support provided by Enablence Inc. Ottawa, Canada.
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Ozhikandathil, J., Morrison, A., Packirisamy, M. et al. Low resistive silicon substrate as an etch-stop layer for drilling thick SiO2 by spark assisted chemical engraving (SACE). Microsyst Technol 17, 373–380 (2011). https://doi.org/10.1007/s00542-011-1248-4
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DOI: https://doi.org/10.1007/s00542-011-1248-4