A Novel Method to Dicing Anodically Bonded Silicon Glass MEMS Wafers Based on UV Laser Technique

Abstract:

UV laser dicing has many advantages such as mechanical stress-free and dicing shape-free, but it is seldom used to dice multi-layer MEMS wafers because of the deposition of a lot of debris and heat affected zones around the dicing lines. In this paper, a novel UV laser dicing method for anodically bonded wafers is presented. The heat caused split of the bonded silicon and glass around the dicing line is prevented by fabricating recesses on either the glass wafer or the silicon wafer. The Finite Element Method (FEM) in the ANSYSTM software was utilized to analyze the temperature and thermal stress distributions during the dicing process. The thermal stress is minimized sharply due to the fabrication of the recesses beneath the dicing line. The thicknesses of the glass and silicon wafers are 500μm and 250μm, respectively. The anodically bonding temperature is 360oC, and the bonding voltage is 400V. Dicing experiments show that the huge thermal stress caused by the laser can split the originally bonded silicon from glass around the dicing line. After recesses are fabricated along the dicing line, no heat caused split happens. The experiment results are in a good agreement with the FEM simulation. Compared with other methods, this research can provide a more reliable, flexible and cheaper laser dicing process for thick anodically bonded silicon/glass MEMS wafers, especially for multi-layer wafers with free shape.

• Periodical: Applied Mechanics and Materials (Volumes 511-512)
• Pages: 3-7
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.511-512.3
• Online since: February 2014
• Authors: Zhi Sheng Jing, Ze Long Zhou*, Chen Mei, Xiang Yong Su, Zhuo Yang, Yi Tao
• Keywords: Anodically Bonding, Dicing, Heat Affection, MEMS, Shape-Free, UV Laser

References

[1] Y. Izawa, S. Tanaka, H. Kikuchi, Debris-free In-air Laser Dicing for Multi-layer MEMS by Perforated Internal Transformation and Thermally-induced Crack Propagation, in: Proceedings of MEMS 2008, Tucson, AZ, USA, 13-17 January, 2008, pp.822-827.

DOI: 10.1109/memsys.2008.4443783

[2] S.F. Liu, T.H. Ma, W. Hou, Design and fabrication of a new miniaturized capacitive accelerometer, Journal of Sensors and Actuators A. 147 (2008) 70-74.

DOI: 10.1016/j.sna.2008.03.016

[3] R.A. Dias, E. Cretu, et al., Pull-in-based μg-resolution accelerometer: Characterization and noise analysis, Journal of Sensors and Actuators A. (2011), doi: 10. 1016/j. sna. 2011. 01. 027.

DOI: 10.1016/j.sna.2011.01.027

[4] S.E. Alper, K. Azgin, T. Akin, A high-performance silicon-on-insulator MEMS gyroscope operating at atmospheric pressure, Journal of Sensors and Actuators A. 135 (2007) 34-42.

DOI: 10.1016/j.sna.2006.06.043

[5] Z.Y. Guo, L.T. Lin, et al., A lateral-axis microelectromechnical tuning-fork gyroscope with decoupled comb drive operating at atmospheric pressure, Journal of Microelectromechanical Systems. 19 (2010) 458-468.

DOI: 10.1109/jmems.2010.2046477