Abstract
This paper presents the different processing steps of a new generic surface micromachining module for MEMS hermetic packaging at temperatures around 180 °C based on nickel plating and photoresist sacrificial layers. The advantages of thin film caps are the reduced thickness and area consumption and the promise of being a low-cost batch process. Moreover, sealing happens by a reflow technique, giving the freedom of choosing the pressure and atmosphere inside the cavity. Sacrificial etch holes are situated above the device allowing shorter release times compared to the state-of-the-art. With the so-called over-plating process, small etch holes can be created in the membrane without the need of expensive lithography tools. The etch holes in the membrane have been shown to be sufficiently small to block the sealing material to pass through, but still large enough to enable an efficient release.
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Acknowledgments
The authors would like to thank Bert Du Bois for helpful discussions and for SEM analysis.
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Hellín Rico, R., Celis, JP., Baert, K. et al. A new generic surface micromachining module for MEMS hermetic packaging at temperatures below 200 °C. Microsyst Technol 13, 1451–1456 (2007). https://doi.org/10.1007/s00542-006-0351-4
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DOI: https://doi.org/10.1007/s00542-006-0351-4