微機電系統(MEMS)的封裝是一個將原本在研究領域的微機電元件帶入實際產品的重要技術。而隨著對高深寬比(High-Aspect-Ratio) 結構的需求量增加，製程簡單且結構強壯的SOI(Silicon-on-Insulator)-MEMS晶片也被大量的使用，但SOI-MEMS晶片的封裝卻甚少被提及，其原因是在SOI-MEMS晶片中的導線即是結構層的單晶矽，而單晶矽又通常有數十微米以上的高度，如此大幅度的高度差並沒有一種封裝方式可以緊密的包覆而達到封裝的效果。本論文提出一利用垂直式導線與陽極接合封裝SOI-MEMS晶片的方法，利用垂直式導線不必跨過封裝介面的優點，將導線拉至晶圓背面，而讓控制電路的訊號從晶圓背面輸入，再利用康寧玻璃(型號Pyrex 7740)與結構層單晶細的高表面平整度達成高強度及氣密性的陽極接合(Anodic bonding)，整各封裝是在晶圓級(Wafer level)完成，不但可以減低封裝成本，整各封裝結構更相容於現今的表面接合技術(Surface Mount Technology)而有最高的後製程相容性。

Packaging of a Micro-Electron-Mechanical System (MEMS) is a key technology for MEMS. With an imperative need of High-Aspect-Ratio microstructures, SOI-MEMS technology is rapidly used because of its process simplicity and robust structures. But packaging of a SOI-MEMS wafer was rarely investigated. The main reason is that the interconnection which is been used in SOI-MEMS wafer have a step height of at least dozens of micrometers. None of existing MEMS packaging technologies can seal this range of step height without failed. This thesis bring up a SOI-MEMS packaging solution with through-wafer interconnections and anodic bonding with Pyrex 7740 glass. Taking advantage of through-wafer interconnections, electrical signals can input from backside of wafer, which is compatible with existing Surface Mount Technology. With anodic bonding of single-crystalline silicon and Pyrex 7740 glass, we can achieve high bonding strength and hermetic seal. Whole packaging process accomplishes at wafer-level, which represent lower cost and best post-process compatibility.

[1]MCNC MUMPs Process
http://www.memsrus.com/CIMSmain2ie.html

[2]Pister, K.S.J, “Hinged polysilicon structures with integrated CMOS TFTs,” Solid-State Sensor and Actuator Workshop, 1992. 5th Technical Digest., IEEE ,pp. 136 – 139,1992

[3] L.-S. Fan, Y.-C. Tai, and R. S. Muller, “IC-processed electrostatic micro-motor,” Technical Digest, IEEE Int. Electron Devices Meeting, San Francisco, CA, U.S.A. Dec. 1988, pp. 666-669.

[4] SUMMiT Process,
http://www.sandia.gov/mstc/index.html

[5] C. G. Keller and R. T. Howe, “HexSil tweezers for teleoperated micro-assembly,” MEMS’97, Nagoya, Japan, Jan. 1997, pp. 72-77.

[6] K.A. Shaw, Z.L. Chang, and N.C. MacDonald, “SCREAM I: A single mask, single-crystal silicon, reactive ion etching process for microelectromechanical Structures”, Sensors and Actuators A, vol.40, pp. 210-213, 1994.

[7] J.T. Nee, R.A. Conat, K.Y. Lau, and R.S. Muller, “Lightweight, optically flat micromirrors for fast beam steering,” 2000 IEEE/LEOS Int. Conference on Optical MEMS, Kauai, HI, 21-24 Aug. 2000, pp. 9-10.

[8] U. Krishnamoorthy, O. Solgaard, “Self-aligned vertical comb-drive actuators for optical scanning micromirrors,” Optical MEMS’01, Okinawa, Japan, Sep. 2001.

[9] H.D. Nguyen, D. Hah, P.R. Patterson, R. Chao, W. Piyawattanametha, E.K. Lau, and M.C. Wu, “Angular vertical comb-driven tunable capacitor with high-tuning capabilities,”J.MEMS, vol.13 , , June 2004 pp. 406 – 413.

[10] H. Toshiyoshi, M. Mita, and H. Fujita, “A MEMS Piggyback Actuator for Hard-Disk Drivers,” J.MEMS, vol.11 p. 648-654.

[11] A. Cao, J. B. Kim, T. Tsao, and L. Lin, “A Bi-Direectional Electrothermal Electromagnetic Actuator,” MEMS’04, Maastricht, The Netherlands, Jan. 2004, pp. 450-453.

[12] L. Lin, R. T. Howe, and A. P. Pisano, “Microelectromechanical filters for signal processing,” J. MEMS, vol.7, 1998, pp. 286-294.

[13] Y. C. Lee, B. Amir Parviz, J.A. Chiou, and S. Chen, “Packaging for microelectromechanical and nanoelectromechanical systems,” IEEE Transactions on Advanced Packaging, vol.26, Aug. 2003, pp. 217-226.

[14] T. Coreman, “Vacuum-sealed and gas-filled micromachined devices,” Ph.D. Thesis, Royal Institute of Technology, Stockholm, 1999.

[15] O. Oralkan, A. S. Ergun, C. H. Cheng, J. A. Johnson, M. Karaman, T. H. Lee, and B. T. Khuri-Yakubi, “Volumetric ultrasound imaging using 2-D CMUT arrays,” IEEE transactions on ultrasonics, ferroelectrics, and frequency control, vol.50, pp. 1581-1594, 2003.

[16]”Electrical through silicon wafer interconnects for high frequency photonic devices”
www.standford.edu/group/SPRC/Report/poster/cheng.pdf

[17] D. W. Lee, T. Ono, T. Abe, and M. Esashi, “Microprobe array with electrical interconnection for thermal imaging and data storage,” J.MEMS, vol.11, pp. 215-221, 2002.

[18] C. S. Premachandran, R. Nagarjan, C. Y. Xiolin, and C. S. Choong, “A novel electrically conductive wafer through hole filled vias interconnect for 3D MEMS packaging,” Electronic components and technology conference, 53rd, May. 2003, pp. 627-630

[19] Z. Li, Y. Hao, D. Zhang, T. Li, and G. Wu, “An SOI-MEMS technology using substrate layer and bonded glass as wafer-level package,” Sensor and Actuator A, vol.96, pp. 34-42, 2002.

[20] D.F. Lemmerhirt, and K. D. Wise, “Air-isolated through-wafer intereonnects for microsystem applications,” The 12th international conference on solid state sensors, actuators and microsystems, Boston, June 8-12, 2003, pp. 1067-1070.

[21] T. Sasayama, S. Suzuki, S. Tsuchitani, A. Koide, M. Suzuki, T. Nakazawa, and N. Ichikawa, “Highly reliable silicon micromachined physical sensors in mass production,” Proceeding of the IEEE Transducers ’95 and Eurosensors IX, Stockholm, Sweden, June 1995, pp. 687-690.

[22] T. Corman, P. Enokssou, and G. Stemme, “Gas damping of electrostatically excited resonators,” Sensor and Actuator A, vol.61, pp. 249-255, 1997.

[23] G. Stemme, “Resonant silicon sensors,” J. Micromech. Microeng., vol.1, pp. 113-125, 1991.

[24] X. Zhang, and W. C. Tang, “Viscous air damping in laterally driven microstructures,” MEMS’94, Jan 25-28, 1994, pp. 199-204.

[25] T. Veijola, H. Kuisma, J. Lahdenpera, and T. Ryhanen, “Equivalent-circuit model of the squeezed gas in a silicon accelerometer,” Sensor and Actuator A, vol.48, pp. 239-248, 1995.

[26] T. R. Anothony, “Forming electrical interconnections through semiconductors wafers,” J. Appl. Phys., Vol.52, pp. 5340-5349, 1981.

[27] R. V. W. Hofland, “The theory behind pulse plating reversal current,”
http://www.circuitree.com/CDA/ArticleInformation/features/BNP__Features__Item/0,2133,66303,00.html

[28] M. Despont, H. Gross, F. Arrouy, C. Stebler, and U. Staufer, “Fabrication of a silicon-Pyrex-silicon stack by a.c. anodic bonding,” Sensors and Actuators A, vol.55, pp. 219-224, 1996.

[29] A. Cozma, and B. Puers, “Characterization of the electrostatic bonding of silicon and Pyrex glass,” J. Micromech. Microeng., vol.5, pp. 98-102, 1995.

[30] P. C. Andricacos, C. Uzoh, J. O. Dukovic, J. Horkans, and H. Deligianni, “Damascene copper electroplating for chip interconnections,” IBM journal of research and development, vol.42, pp. 567-574, 1998.

[31] N. T. Nguyen, E. Boellaard, N. P. Pham, V. G. Kutchoukov, G. Craciun, and P. M. Sarro. “Through-wafer copper electroplating for three-dimensional interconnects,” J. Micromech. Microeng., vol.12, pp. 395-399, 2002.

[32] Y. Cheng, B. Y. Shew, C. Y. Lin, D. H. Wei, and M. K. Chyu, “Ultra-deep LIGA process,” J. Micromech. Microeng., vol.9, pp. 58-63, 1999.

[33] L. T. Romankiw, “A path: from electroplating through lithographic masks in electronics to LIGA in MEMS,” Electrochimica. Acta., Vol.42, pp. 2985-3005, 1997.