Research on the Protrusions Near Silicon-Glass Interface during Cavity Fabrication
Abstract
:1. Introduction
2. Experiment Details
3. Results and Discussion
3.1. Chemical Composition
3.2. Etching Mechanisms
4. Optimized Fabrication Scheme
- (a)
- At first, the sample was immersed in the HF-based solution with added HCl for 5 s to remove the part of glass about 80 nm higher than silicon to avoid the effect of ion reflection on the glass slope. The oxide layer thermally grown on the silicon sidewalls was simultaneously exposed.
- (b)
- Then, the silicon was etched for 24 s to the depth of 1 μm by ICP dry etching technology. During etching, the plasma groups consisting of energetic ions accumulated at the interface to accelerate the etching of the oxide layer. Since plasma accumulation accelerated etching and the ion reflection at glass edges attenuated, much less material remained near the interface to form the protrusions.
- (c)
- Afterwards, without the shield effect of silicon at the interface, 1 μm glass was etched completely, which exposed the protrusions near the interface completely.
- (d)
- One micrometer of silicon was etched away again, as in step (b). During the silicon etching process, the protrusions that were completely exposed were etched more quickly than before in order to be minimized further.
- (e)
- Finally, the glass was also etched to same depth as silicon, as in step (c). By this time, a 2 μm-deep cavity with tiny protrusions was prepared. It should be mentioned that 2-min BHF wet etching could be adopted to further make the step between glass and silicon become smoother. Cavity with other depths could be fabricated by adjusting the number of the etching steps and the etching depth in each step in the optimized process flow in Figure 8.
5. Conclusions
Author Contributions
Funding
Conflicts of Interest
References
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Element | Oxygen | Silicon | Sodium | Aluminum | ||
---|---|---|---|---|---|---|
wt% | ||||||
Location | ||||||
A_glass | 58.335 | 35.83 | 3.94 | 1.895 | ||
B_interface | 19.48 | 77.027 | 2.01 | 1.483 | ||
C_interface | 12.45 | 85.45 | 1.12 | 0.98 | ||
D_silicon | 0 | 100 | 0 | 0 |
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Zhang, M.; Yang, J.; He, Y.; Yang, F.; Zhao, Y.; Xue, F.; Han, G.; Si, C.; Ning, J. Research on the Protrusions Near Silicon-Glass Interface during Cavity Fabrication. Micromachines 2019, 10, 420. https://doi.org/10.3390/mi10060420
Zhang M, Yang J, He Y, Yang F, Zhao Y, Xue F, Han G, Si C, Ning J. Research on the Protrusions Near Silicon-Glass Interface during Cavity Fabrication. Micromachines. 2019; 10(6):420. https://doi.org/10.3390/mi10060420
Chicago/Turabian StyleZhang, Meng, Jian Yang, Yurong He, Fan Yang, Yongmei Zhao, Fen Xue, Guowei Han, Chaowei Si, and Jin Ning. 2019. "Research on the Protrusions Near Silicon-Glass Interface during Cavity Fabrication" Micromachines 10, no. 6: 420. https://doi.org/10.3390/mi10060420
APA StyleZhang, M., Yang, J., He, Y., Yang, F., Zhao, Y., Xue, F., Han, G., Si, C., & Ning, J. (2019). Research on the Protrusions Near Silicon-Glass Interface during Cavity Fabrication. Micromachines, 10(6), 420. https://doi.org/10.3390/mi10060420