Th total thickness reduction of four adhesive tapes used to attach chips to chip holders due to the applied bonding loads was obtained using the same approach as measuring the reduction of distance between two bonded chips (see Figure 65). For this purpose, a flat metallic conductive disc was used instead of the bonded chips.
Figure 65. Thickness reduction of four adhesive tapes as a function of applied bonding load.
The bond interface width between two needle-like surfaces due to a bonding load was extracted by subtracting the actual distance between two bonded chips (the measured distance between two bonded chips, minus the measured total thickness reduction of the adhesive tapes) from the distance between two needle-like surfaces at their initial contact when no load applied on them. The distance between two interacting needle-like surfaces at their initial contact was considered as twice the maximum height of their needles (145. 2 µm for the surface 1, 52.4 µm for the surface 2, 54 µm for the surface 3, and 81.4 µm for the surface 4). Results are shown in Figures 66 - 69 and are in a good agreement with the ones measured and extracted optically through SEM images of cross-sections of bonded surfaces. They only showed a difference of about 5 - 10 %. The optically measured values are the average of
0 5 10 15 20 25
0 2 4 6 8 10 12 14
Shrinkage of 4 double sided tapes (µm)
Applied load (kg)
Circular Carbon tape Rectangular Tesa tape
155 measurement of the bond interface width through 16 SEM images along a cross-sectional view of a bonded interface.
Figure 66. Measured distance between two bonded chips and extracted bond interface width as a function of applied load for the needle-like surface 1.
Figure 67. Measured distance between two bonded chips and extracted bond interface width as a function of applied load for the needle-like surface 2.
0
156
Figure 68. Measured distance between two bonded chips and extracted bond interface width as a function of applied load for the needle-like surface 3.
Figure 69. Measured distance between two bonded chips and extracted bond interface width as a function of applied load for the needle-like surface 4.
0
157
Bibliography
[1] S. A. Campbell, Fabrication engineering at the micro- and nanoscale, 4th ed. New York: Oxford Univ. Press, 2013.
[2] S. Beeby, MEMS mechanical sensors. Boston: Artech House, 2004.
[3] J. A. Dziuban, Bonding in Microsystem Technology. Dordrecht: Springer, 2006.
[4] R. Nadipalli et al., “3D integration of MEMS and CMOS via Cu-Cu bonding with simultaneous formation of electrical, mechanical and hermetic bonds,” in 3D Systems Integration Conference (3DIC), 2011 IEEE International, 2012, pp. 1–5.
[5] S. Y. Kwang, J. C. Il, J. U. Bu, J. K. Chang, and Y. Euisik, “A surface-tension driven micropump for low-voltage and low-power operations,”
Microelectromechanical Systems, Journal of, vol. 11, no. 5, pp. 454–461, 2002.
[6] M. A. Schmidt, “Wafer-to-wafer bonding for microstructure formation,”
Proceedings of the IEEE, vol. 86, no. 8, pp. 1575–1585, 1998.
[7] Q.-Y. Tong and U. M. Gösele, Semiconductor wafer bonding: Science and technology. New York, NY: Wiley, 1999.
[8] C. Wang, E. Higurashi, and T. Suga, “Room Temperature Si/Si Wafer Direct Bonding in Air,” in 2007 8th International Conference on Electronic Packaging Technology, Shanghai, China, pp. 1–6.
[9] B. Bayram, O. Akar, and T. Akin, “Plasma-activated direct bonding of diamond-on-insulator wafers to thermal oxide grown silicon wafers,” Diamond and Related Materials, vol. 19, no. 11, pp. 1431–1435, 2010.
[10] M. R. Howlader, H. Itoh, T. Suga, and M. Kim, “Sequential Plasma Activated Process for Silicon Direct Bonding,” in 210th ECS Meeting, Cancun, Mexico, pp.
191–202, 2006.
[13] Xuan Xiong Zhang and J.-P. Raskin, “Low-temperature wafer bonding: A study of void formation and influence on bonding strength,” J. Microelectromech. Syst., vol.
14, no. 2, pp. 368–382, 2005.
158
[14] B. Warneke, M. Last, B. Liebowitz, and K. Pister, “Smart Dust: Communicating with a cubic-millimeter computer,” Computer, vol. 34, no. 1, pp. 44–51, 2001.
[15] C. S. Tan, R. J. Gutmann, and L. R. Reif, Eds., Wafer Level 3-D ICs Process Technology. Boston, MA: Springer-Verlag US, 2008.
[16] P. Jonnalagadda, U. Mescheder, A. Kovacs, and A. Nimoe, “Nanoneedles based on porous silicon for chip bonding with self-assembly capability,” Phys. Status Solidi C, vol. 8, no. 6, pp. 1841–1846, 2011.
[17] M. Stubenrauch et al., “Black silicon—new functionalities in microsystems,” J.
Micromech. Microeng., vol. 16, no. 6, pp. S82-S87, 2006.
[18] A. P. Russell, “A contribution to the functional analysis of the foot of the Tokay, Gekko gecko (Reptilia: Gekkonidae),” Journal of Zoology, vol. 176, no. 4, pp. 437– 476, 1975.
[19] D. IRSCHICK, “A comparative analysis of clinging ability among pad-bearing lizards,” Biological Journal of the Linnean Society, vol. 59, no. 1, pp. 21–35, 1996.
[20] K. Autumn et al., “Adhesive force of a single gecko foot-hair,” (eng), Nature, vol.
405, no. 6787, pp. 681–685, 2000.
[21] E. E. Williams and J. A. Peterson, “Convergent and alternative designs in the digital adhesive pads of scincid lizards,” (eng), Science, vol. 215, no. 4539, pp.
1509–1511, 1982.
[22] K. Autumn and A. M. Peattie, “Mechanisms of adhesion in geckos,” (eng), Integr.
Comp. Biol., vol. 42, no. 6, pp. 1081–1090, 2002.
[23] M. Steglich et al., “The structural and optical properties of black silicon by inductively coupled plasma reactive ion etching,” Journal of Applied Physics, vol.
116, no. 17, p. 173503, 2014.
[24] R. Legtenberg, “Anisotropic Reactive Ion Etching of Silicon Using SF6/O2/CHF3
Gas Mixtures,” J. Electrochem. Soc., vol. 142, no. 6, p. 2020, 1995.
[25] X. Liu et al., “Black silicon: Fabrication methods, properties and solar energy applications,” Energy Environ. Sci., vol. 7, no. 10, pp. 3223–3263, 2014.
[26] P. Kleimann, X. Badel, and J. Linnros, “Toward the formation of three-dimensional nanostructures by electrochemical etching of silicon,” Appl. Phys. Lett., vol. 86, no. 18, p. 183108, 2005.
[27] X. G. Zhang, “Porous Silicon Formation and Electropolishing of Silicon by Anodic Polarization in HF Solution,” J. Electrochem. Soc., vol. 136, no. 5, p. 1561, 1989.
159 [28] T. S. Chow, “Nanoscale surface roughness and particle adhesion on structured
substrates,” Nanotechnology, vol. 18, no. 11, p. 115713, 2007.
[29] Y. Rabinovich et al., “Capillary forces between surfaces with nanoscale roughness,” Advances in Colloid and Interface Science, vol. 96, no. 1-3, pp. 213– 230, 2002.
[30] P. Prokopovich and S. Perni, “Multiasperity contact adhesion model for universal asperity height and radius of curvature distributions,” (eng), Langmuir: the ACS journal of surfaces and colloids, vol. 26, no. 22, pp. 17028–17036, 2010.
[31] P. Prokopovich and S. Perni, “Comparison of JKR- and DMT-based multi-asperity adhesion model: Theory and experiment,” Colloids and Surfaces A:
Physicochemical and Engineering Aspects, vol. 383, no. 1-3, pp. 95–101, 2011.
[32] Rabinovich, Adler, Ata, Singh, and Moudgil, “Adhesion between Nanoscale Rough Surfaces,” (eng), J Colloid Interface Sci, vol. 232, no. 1, pp. 10–16, 2000.
[33] Greenwood JA, Tripp JH, Ed., The Contact of Two Nominally Flat Rough Surfaces: Institute of Mechanical Engineering, 1970.
[34] J. I. McCool, “Comparison of models for the contact of rough surfaces,” Wear, vol.
107, no. 1, pp. 37–60, 1986.
[35] U. Gösele et al., “Wafer bonding for microsystems technologies,” Sensors and Actuators A: Physical, vol. 74, no. 1-3, pp. 161–168, 1999.
[36] J. Wei, “Wafer Bonding Techniques for Microsystem Packaging,” J. Phys.: Conf.
Ser., vol. 34, pp. 943–948, 2006.
[37] R. Ghodssi and P. Lin, Eds., MEMS Materials and Processes Handbook. Boston, MA: Springer Science + Business Media LLC, 2011.
[38] C. Colinge, Ed., Semiconductor wafer bonding 11: science, technology, and applications - in honor of Ulrich Gösele: [presented in the symposium entitled
"Semiconductor Wafer Bonding 11: Science, Technology, and Applications - in Honor of Ulrich Gösele" held during the 218th meeting of the Electrochemical Society, in Las Vegas, Nevada from October 10 to 15, 2010]. Pennington, NJ:
Electrochemical Soc, 2010.
[39] M. Bergh, Wafer bonding: Problems and possibilities. Zugl.: Göteborg, Univ., Diss., 1998. Göteborg: Chalmers Univ. of Technol, 1998.
[40] V. Masteika, J. Kowal, N. S. J. Braithwaite, and T. Rogers, “A Review of Hydrophilic Silicon Wafer Bonding,” ECS Journal of Solid State Science and Technology, vol. 3, no. 4, pp. Q42-Q54, 2014.
160
[41] L. Rayleigh, “A Study of Glass Surfaces in Optical Contact,” Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, vol. 156, no.
888, pp. 326–349, 1936.
[42] D. Tabor and R. H. S. Winterton, “The Direct Measurement of Normal and Retarded van der Waals Forces,” Proceedings of the Royal Society A:
Mathematical, Physical and Engineering Sciences, vol. 312, no. 1511, pp. 435– 450, 1969.
[43] G. A. Antypas and J. Edgecumbe, “Glass−sealed GaAs−AlGaAs transmission photocathode,” Appl. Phys. Lett., vol. 26, no. 7, pp. 371–372, 1975.
[44] J. B. Lasky, S. R. Stiffler, F. R. White, and J. R. Abernathey, “Silicon-on-insulator (SOI) by bonding and ETCH-back,” in 1985 International Electron Devices Meeting, pp. 684–687.
[45] J. B. Lasky, “Wafer bonding for silicon‐on‐insulator technologies,” Appl. Phys.
Lett., vol. 48, no. 1, pp. 78–80, 1986.
[46] M. Shimbo, K. Furukawa, K. Fukuda, and K. Tanzawa, “Silicon‐to‐silicon direct bonding method,” Journal of Applied Physics, vol. 60, no. 8, pp. 2987–2989, 1986.
[47] C. G. Armistead, A. J. Tyler, F. H. Hambleton, S. A. Mitchell, and J. A. Hockey,
“Surface hydroxylation of silica,” J. Phys. Chem., vol. 73, no. 11, pp. 3947–3953, 1969.
[48] W. P. Maszara, G. Goetz, A. Caviglia, and J. B. McKitterick, “Bonding of silicon wafers for silicon-on-insulator,” Journal of Applied Physics, vol. 64, no. 10, pp.
4943–4950, 1988.
[49] R. Stengl, T. Tan, and U. Gösele, “A Model for the Silicon Wafer Bonding Process,” Japanese Journal of Applied Physics, vol. 28, no. 10R, p. 1735,1989.
[50] Qin-Yi Tong, G. Cha, R. Gafiteanu, and U. Gosele, “Low temperature wafer direct bonding,” J. Microelectromech. Syst., vol. 3, no. 1, pp. 29–35, 1994.
[51] S. Vincent, J.-D. Penot, I. Radu, F. Letertre, and F. Rieutord, “Study of the formation, evolution, and dissolution of interfacial defects in silicon wafer bonding,”
Journal of Applied Physics, vol. 107, no. 9, p. 93513, 2010.
[52] S. N. Farrens, “Chemical Free Room Temperature Wafer to Wafer Direct Bonding,” J. Electrochem. Soc., vol. 142, no. 11, p. 3949, 1995.
[53] P. Amirfeiz, S. Bengtsson, M. Bergh, E. Zanghellini, and L. Bo?rjesson,
“Formation of Silicon Structures by Plasma-Activated Wafer Bonding,” J.
Electrochem. Soc., vol. 147, no. 7, p. 2693, 2000.