The micro-structural characterization of thermosonic cu-al intermetallic compounds and modelling of its interface stress

Thermosonic bonding of the Cu wire on Al bond pad is a common technology used in semiconductor industry. However, recent research show voids formation at this bonding interface on micro-chip, after an annealing treatment of High Temperature Storage (HTS). This voids formation is believed due to the...

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Main Author: Chua, Kok Yau
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Published: 2015
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TS Manufactures
Chua, Kok Yau
The micro-structural characterization of thermosonic cu-al intermetallic compounds and modelling of its interface stress
description Thermosonic bonding of the Cu wire on Al bond pad is a common technology used in semiconductor industry. However, recent research show voids formation at this bonding interface on micro-chip, after an annealing treatment of High Temperature Storage (HTS). This voids formation is believed due to the volumetric changes of intermetallic compounds (IMCs) formed at the bonding interface. In previous research, effects of Cu free-air-ball and bonding temperature with high temperature storage (HTS) treatment on Cu-Al bonding interface are unclear. Besides, previous research provides inconclusive knowledge in the evolution of Cu-Al bonding interface due to inconsistent observations and variations in the bonding parameters. Research with statistical approach could be useful to address this limitation, however, it is yet to be established for Thermosonic Cu-Al interconnection. Besides, the void formation due to volumetric changes of IMC is discussed only qualitatively. A quantitative stress analysis could close the gap of research. Objectives of this research are (1) to analyse the correlation of wire bonding parameters, the interfacial micro-structure change and mechanical strength of the synthesized Cu-Al bonding interface, (2) to propose a theoretical model that describe quantitatively the stress due to volumetric changes originated from Cu-Al phase evolution, (3) to evaluate the stress generated by Cu-Al phase evolution at the bonding interface and its correlation to the void formation. Micro-structural characterizations were focused on crystallographic, compositional and mechanical analyses. It was found that bonding temperature resulted in an exponential increment for initial overall IMC thickness and average Cu content of the phases formed at the bonding interface. Moreover, HTS increase the overall IMC thickness by volume diffusion mechanism. The relationship between parameters, mechanical ball shear strength and IMC thickness were obtained statistically. A mathematical stress model based on assumptions of isotropic and elastic binary solid-solution was proposed. This model enabled an estimation of interfacial stresses from compositional measurements. It was found that the stress developed by interfacial Cu-Al IMC generally increased with the bonding temperature. Besides, forming gas supply was found to be less significant to affect the stress development, due to the oxide layers did not hinder much the interdiffusion of Cu and Al atoms. However, with HTS, the growth of Cu rich IMC increased the stress and caused gap within copper oxide layer. This work addressed the research gaps and offered a better understanding of the fundamental of Thermosonic Cu-Al interconnection. The results of the stress modelling could be a useful failure analysis technique for implementing Cu wire in the industry.
format Thesis
qualification_name Doctor of Philosophy (PhD.)
qualification_level Doctorate
author Chua, Kok Yau
author_facet Chua, Kok Yau
author_sort Chua, Kok Yau
title The micro-structural characterization of thermosonic cu-al intermetallic compounds and modelling of its interface stress
title_short The micro-structural characterization of thermosonic cu-al intermetallic compounds and modelling of its interface stress
title_full The micro-structural characterization of thermosonic cu-al intermetallic compounds and modelling of its interface stress
title_fullStr The micro-structural characterization of thermosonic cu-al intermetallic compounds and modelling of its interface stress
title_full_unstemmed The micro-structural characterization of thermosonic cu-al intermetallic compounds and modelling of its interface stress
title_sort micro-structural characterization of thermosonic cu-al intermetallic compounds and modelling of its interface stress
granting_institution Universiti Teknikal Malaysia Melaka
granting_department Faculty Of Manufacturing Engineering
publishDate 2015
url http://eprints.utem.edu.my/id/eprint/16883/1/The%20Micro-Structural%20Characterization%20Of%20Thermosonic%20Cu-Al%20Intermetallic%20Compounds%20And%20Modelling%20Of%20Its%20Interface%20Stress.pdf
http://eprints.utem.edu.my/id/eprint/16883/2/The%20micro-structural%20characterization%20of%20thermosonic%20Cu-Al%20intermetallic%20compounds%20and%20modelling%20of%20its%20interface%20stress.pdf
_version_ 1776103098248331264
spelling my-utem-ep.168832023-05-25T11:13:57Z The micro-structural characterization of thermosonic cu-al intermetallic compounds and modelling of its interface stress 2015 Chua, Kok Yau T Technology (General) TS Manufactures Thermosonic bonding of the Cu wire on Al bond pad is a common technology used in semiconductor industry. However, recent research show voids formation at this bonding interface on micro-chip, after an annealing treatment of High Temperature Storage (HTS). This voids formation is believed due to the volumetric changes of intermetallic compounds (IMCs) formed at the bonding interface. In previous research, effects of Cu free-air-ball and bonding temperature with high temperature storage (HTS) treatment on Cu-Al bonding interface are unclear. Besides, previous research provides inconclusive knowledge in the evolution of Cu-Al bonding interface due to inconsistent observations and variations in the bonding parameters. Research with statistical approach could be useful to address this limitation, however, it is yet to be established for Thermosonic Cu-Al interconnection. Besides, the void formation due to volumetric changes of IMC is discussed only qualitatively. A quantitative stress analysis could close the gap of research. Objectives of this research are (1) to analyse the correlation of wire bonding parameters, the interfacial micro-structure change and mechanical strength of the synthesized Cu-Al bonding interface, (2) to propose a theoretical model that describe quantitatively the stress due to volumetric changes originated from Cu-Al phase evolution, (3) to evaluate the stress generated by Cu-Al phase evolution at the bonding interface and its correlation to the void formation. Micro-structural characterizations were focused on crystallographic, compositional and mechanical analyses. It was found that bonding temperature resulted in an exponential increment for initial overall IMC thickness and average Cu content of the phases formed at the bonding interface. Moreover, HTS increase the overall IMC thickness by volume diffusion mechanism. The relationship between parameters, mechanical ball shear strength and IMC thickness were obtained statistically. A mathematical stress model based on assumptions of isotropic and elastic binary solid-solution was proposed. This model enabled an estimation of interfacial stresses from compositional measurements. It was found that the stress developed by interfacial Cu-Al IMC generally increased with the bonding temperature. Besides, forming gas supply was found to be less significant to affect the stress development, due to the oxide layers did not hinder much the interdiffusion of Cu and Al atoms. However, with HTS, the growth of Cu rich IMC increased the stress and caused gap within copper oxide layer. This work addressed the research gaps and offered a better understanding of the fundamental of Thermosonic Cu-Al interconnection. The results of the stress modelling could be a useful failure analysis technique for implementing Cu wire in the industry. 2015 Thesis http://eprints.utem.edu.my/id/eprint/16883/ http://eprints.utem.edu.my/id/eprint/16883/1/The%20Micro-Structural%20Characterization%20Of%20Thermosonic%20Cu-Al%20Intermetallic%20Compounds%20And%20Modelling%20Of%20Its%20Interface%20Stress.pdf text en public http://eprints.utem.edu.my/id/eprint/16883/2/The%20micro-structural%20characterization%20of%20thermosonic%20Cu-Al%20intermetallic%20compounds%20and%20modelling%20of%20its%20interface%20stress.pdf text en validuser https://plh.utem.edu.my/cgi-bin/koha/opac-detail.pl?biblionumber=96181 phd doctoral Universiti Teknikal Malaysia Melaka Faculty Of Manufacturing Engineering Thangaraj, Joseph Sahaya Anand 1. Abbasi, M., Karimi Taheri, a. and Salehi, M.T., 2001. Growth rate of intermetallic compounds in Al/Cu bimetal produced by cold roll welding process. Journal of Alloys and Compounds, 319(1-2), pp. 233–241. 2. Aghakhani, M., Mehrdad, E. and Hayati, E., 2011. Parametric Optimization of Gas Metal Arc Welding Process by Taguchi Method on Weld Dilution. 1(3). 3. Alyamani, A. and Lemine, O.M., 2012. FE-SEM Characterization of Some Nanomaterial. In: V. Kazmiruk, ed., Scanning Electron Microscopy. INTECH, pp.463–472. 4. Amistoso, J.O.S. and Amorsolo, A. V., 2010. Thermal Aging Effects on Cu Ball Shear Strength and Cu/Al Intermetallic Growth. Journal of Electronic Materials, 39(10), pp. 2324–2331. 5. Anoop, C.A. and Kumar, P., 2013. Application of Taguchi Methods and ANOVA in GTAW Process Parameters Optimization for Aluminium Alloy 7039. International Journal of Engineering and Innovative Technology, 2(11), pp. 54–58. 6. Antony, J. and Antony, F.J., 2001. Teaching the Taguchi method to industrial engineers. Work Study, 50(4), pp. 141–149. 7. Appelt, B.K., Tseng, A. and Lai, Y., 2010. Fine pitch copper wire bonding introduction to high volume production. In: 3rd Electronics System Integration Technology Conference ESTC. IEEE, pp.1–5. 8. Arnould, O. and Hild, F., 2007. On the measurement by EDX of diffusion profiles of Ni/Cu assemblies. Microscopy and Analysis, 33(March), pp. 13–15. 9. ASM, 1992. ASM Handbook: Volume 3: Alloy Phase Diagrams. 10th ed. ASM International, p.512. 10. Bendersky, L.A. and Gayle, W., 2001. Electron Diffraction Using Transmission Electron Microscopy. Journal of Research of the National Institute of Standards and Technology, 106(6), pp. 997–1012. 11. Birkholz, M., 2006. Principles of X-ray Diffraction. In: Thin Film Analysis by X-Ray Scattering. Weinheim: Wiley-VCH, pp.1–42. 12. Boettcher, T., Rother, M., Liedtke, S., Ullrich, M., Bollmann, M., Pinkernelle, A., Gruber, D., Funke, H.-J., Kaiser, M., Lee, K., Li, M., Leung, K., Li, T., Farrugia, M.L., O’Halloran, O., Petzold, M., Marz, B. and Klengel, R., 2010. On the intermetallic corrosion of Cu-Al wire bonds. In: 2010 12th Electronics Packaging Technology Conference. IEEE, pp.585–590. 13. Bogner, A., Jouneau, P.-H., Thollet, G., Basset, D. and Gauthier, C., 2007. A history of scanning electron microscopy developments: towards “wet-STEM” imaging. Micron (Oxford, England : 1993), 38(4), pp. 390–401. 14. Breach, C.D., 2010. What is the future of bonding wire? Will copper entirely replace gold? Gold Bulletin, 43(3), pp. 150–168. 15. Breach, C.D. and Wulff, F., 2004. New observations on intermetallic compound formation in gold ball bonds: general growth patterns and identification of two forms of Au4Al. Microelectronics Reliability, 44(6), pp. 973–981. 16. Breach, C.D., Wulff, F. and Tok, C.W., 2006. An unusual mechanical failure mode in gold ballbonds at 50μm pitch due to degradation at the Au–Au4Al interface during ageing in air at 175°C. Microelectronics Reliability, 46(2-4), pp. 543–557. 17. Breach, C.D. and Wulff, F.W., 2010. A brief review of selected aspects of the materials science of ball bonding. Microelectronics Reliability, 50(1), pp. 1–20. 18. Burgess, S., Li, X. and Holland, J., 2013. High spatial resolution energy dispersive X-ray spectrometry in the SEM and the detection of light elements including lithium | Microscopy and Analysis. Microscopy and Analysis. 19. Calister, W.D., 2004. Material Science and Engineering An Introduction. 6th ed. New York: John Wiley and Sons, Inc. 20. Carreon, M. a. and Guliants, V. V., 2005. Ordered Meso- and Macroporous Binary and Mixed Metal Oxides. European Journal of Inorganic Chemistry, 2005(1), pp. 27–43. 21. Charles, H.K., 2007. The Wirebonded Interconnect: A Mainstay for Electronics. In: E. Suhir, Y.C. Lee and C.P. Wong, eds., Micro- and Opto-Electronic Materials and Structures: Physics, Mechanics, Design, Reliability, Packaging Volume II Physical Design - Reliability and Packaging. Springer. 22. Charles, H.K., 2009. Advanced Wire Bonding Technology: Materials, Methods and Testing. In: D. Lu and C.P. Wong, eds., Materials for Advanced Packaging. New York: Springer, pp.113–179. 23. Chaudhari, D., Khedkar, S. and Borkar, N., 2011. Optimization of process parameters using Taguchi approach with minimum quantity lubrication for turning. International Journal of Engineering Research and Applications, 1(4), pp. 1268–1273. 24. Chen, J., Lai, Y.-S., Wang, Y.-W. and Kao, C.R., 2011. Investigation of growth behavior of Al–Cu intermetallic compounds in Cu wire bonding. Microelectronics Reliability, 51(1), pp. 125–129. 25. Cheng, D., Gosalvez, M.A., Shikida, M. and Sato, K., 2006. A Universal Parameter for Silicon Anisotropic Etching Inalkaline Solutions. In: 19th IEEE International Conference on Micro Electro Mechanical Systems. IEEE, pp.318–321. 26. Cheng, Y.-T. and Verbrugge, M.W., 2010. Diffusion-Induced Stress, Interfacial Charge Transfer, and Criteria for Avoiding Crack Initiation of Electrode Particles. Journal of The Electrochemical Society, 157(4), p. A508. 27. Chian, L.C., Chai, N.K., King, C.M., Seng, L.O. and Yau, C.K., 2006. Copper wire reliability and bonding integrity robustness on cratering sensitive bond pad structure. In: 2006 Thirty-First IEEE/CPMT International Electronics Manufacturing Technology Symposium. IEEE, pp.354–364. 28. Chu, J. and Lee, S., 1990. Diffusion-induced stresses in two-phase elastic media. International Journal of Engineering Science, 28(11), pp. 1085–1109. 29. Chylak, B., Ling, J., Clauberg, H. and Thieme, T., 2009. Next Generation Nickel-Based Bond Pads Enable Copper Wire Bonding. In: ECS Transactions. ECS, pp.777–785. 30. Clauberg, H., Backus, P. and Chylak, B., 2011. Nickel–palladium bond pads for copper wire bonding. Microelectronics Reliability, 51(1), pp. 75–80. 31. CoorsTek, 2014. Capillary Wire Bonding. 32. Cosemans, P., D’Haen, J., Witvrouw, A., Proost, J., D’Olieslaeger, M., De Ceuninck, W., Maex, K. and De Schepper, L., 1998. Study of Cu diffusion in an Al–1wt.%Si–0.5wt.%Cu bond pad with an Al–1wt.%Si bond wire attached using scanning electron microscopy. Microelectronics Reliability, 38(3), pp. 309–315. 33. Cowley, J.M., 2004. Applications of electron nanodifraction. Micron (Oxford, England : 1993), 35(5), pp. 345–60. 34. Crain, E.R., 2013. Crain’s Petrophysical Handbook. www.spec2000.net. 35. Davis, J.R. ed., 2001. Metallography and Microstructures of Beryllium-Copper Alloys. In: ASM Specialty Handbook: Copper and Copper Alloys. ASM International, pp.354–359. 36. Dehzangi, A., Larki, F., Majlis, B.Y. and Naseri, M.G., 2013. Impact of KOH Etching on Nanostructure Fabricated by Local Anodic Oxidation Method. 8, pp. 8084–8096. 37. Deley, M. and Levine, L., 2004. The emergence of high volume copper ball bonding. In: IEEE/CPMT/SEMI 29th International Electronics Manufacturing Technology Symposium. IEEE, pp.186–190. 38. Drozdov, M., Gur, G., Atzmon, Z. and Kaplan, W.D., 2008. Detailed investigation of ultrasonic Al–Cu wire-bonds: I. Intermetallic formation in the as-bonded state. Journal of Materials Science, 43(18), pp. 6029–6037. 39. Dybkov, V.I., 2002. Reaction diffusion and solid state chemical kinetics. IPMS Publications. 40. England, L. and Jiang, T., 2007. Reliability of Cu Wire Bonding to Al Metallization. In: 2007 Proceedings 57th Electronic Components and Technology Conference. IEEE, pp.1604–1613. 41. Eu, P.L., Poh, Z.S., Au, Y.K., Yong, C.C., Tran Tu, A., Arthur, J., Downey, H. and Mathew, V., 2010. A study on fine pitch Au and Cu WB integrity vs. Ni thickness of Ni/Pd/Au bond pad on C90 low k wafer technology for high temperature automotive. In: 2010 34th IEEE/CPMT International Electronic Manufacturing Technology Symposium. Malacca: IEEE, pp.1–7. 42. Fischer, A.C., Korvink, J.G., Roxhed, N., Stemme, G., Wallrabe, U. and Niklaus, F., 2013. Unconventional applications of wire bonding create opportunities for microsystem integration. Micromechanics and Microengineering, 23(8). 43. Fuji, T., 1960. Correlation of Some Physical Properties And Chemical Composition of Solid Solution. THE AMERICAN MINERALOGIST, 45(1), pp. 370 –382. 44. Fultz, B. and Howe, J., 2013. Transmission Electron Microscopy and Diffractometry of Materials. 2nd ed. Graduate Texts in Physics. Berlin, Heidelberg: Springer. 45. Funamizu, Y. and Watanabe, K., 1971. Interdiffusion in the Al-Cu System. Transactions of the Japan Institute of Metals, 12(3), pp. 147–152. 46. Gan, C.L., Francis, C., Chan, B.L. and Hashim, U., 2013. Extended reliability of gold and copper ball bonds in microelectronic packaging. Gold Bulletin, 46(2), pp. 103–115. 47. Gopalsamy, B.M., Mondal, B. and Ghosh, S., 2009. Taguchi method and ANOVA : An approach for process parameters optimization of hard machining while machining hardened steel. 68(August), pp. 686–695. 48. Gray, D.C., Butterbaugh, J.W., Hiatt, C.F., Lowing, A.S. and Sawin, H.H., 1995. Photochemical Dry Etching of Doped and Undoped Silicon Oxides. Journal of The Electrochemical Society, 142(11), p. 3859. 49. Guan, R., Hashimoto, H. and Kuo, K.H., 1985. Electron-microscopic study of the structure of metastable oxides formed in the initial stage of copper oxidation. III. Cu 64 O. Acta Crystallographica Section B Structural Science, 41(4), pp. 219–225. 50. Hang, C.J., Wang, C.Q., Mayer, M., Tian, Y.H., Zhou, Y. and Wang, H.H., 2008. Growth behavior of Cu/Al intermetallic compounds and cracks in copper ball bonds during isothermal aging. Microelectronics Reliability, 48(3), pp. 416–424. 51. Harman, G., 2010. Wire Bonding in Microelectronics. 3rd ed. McGraw Hill Professional, p.446. 52. He, Y., Zhi, W. and Rong, C., 2013. A Theoretical Investigation on the Electron Structures of Al-Based Intermetallic Compounds. Archives of Metallurgy and Materials, 58(4). 53. Hill, R., 1963. Elastic properties of reinforced solids: Some theoretical principles. Journal of the Mechanics and Physics of Solids, 11(5), pp. 357–372. 54. Hsueh, C.H., 2002a. Modeling of elastic deformation of multilayers due to residual stresses and external bending. Journal of Applied Physics, 91(12), p. 9652. 55. Hsueh, C.-H., 2002b. Modeling of elastic deformation of multilayers due to residual stresses and external bending. Journal of Applied Physics, 91(12), p. 9652. 56. Huang, S. and Zhang, X., 2006. Extension of the Stoney formula for film–substrate systems with gradient stress for MEMS applications. Journal of Micromechanics and Microengineering, 16(2), pp. 382–389. 57. Huerta, E., Oliva, A.I., Avilés, F., González-Hernández, J. and Corona, J.E., 2012. Elastic Modulus Determination of Al-Cu Film Alloys Prepared by Thermal Diffusion. Journal of Nanomaterials, 2012, pp. 1–8. 58. Imai, T., 2007. Molecular theory of partial molar volume and its applications to biomolecular systems. Condensed Matter Physics, 10(3), p. 343. 59. Janssen, G.C. a. M., Abdalla, M.M., van Keulen, F., Pujada, B.R. and van Venrooy, B., 2009. Celebrating the 100th anniversary of the Stoney equation for film stress: Developments from polycrystalline steel strips to single crystal silicon wafers. Thin Solid Films, 517(6), pp. 1858–1867. 60. Johal, K., Lamprecht, S. and Roberts, H., 2004. Electroless nickel/electroless palladium/immersion gold plating process for gold-and aluminum-wire bonding designed for high-temperature applications. In: SMTA 9th Annual Pan Pacific Microelectronics Symposium. 61. Juffs, L., Hughes, a. E., Furman, S. and Paterson, P.J.K., 2002. The use of macroscopic modelling of intermetallic phases in aluminium alloys in the study of ferricyanide accelerated chromate conversion coatings. Corrosion Science, 44(8), pp. 1755–1781. 62. Karpel, A., Gur, G., Atzmon, Z. and Kaplan, W.D., 2007. TEM microstructural analysis of As-Bonded Al–Au wire-bonds. Journal of Materials Science, 42(7), pp. 2334–2346. 63. Kelly, T. and Larson, D., 2000. Local electrode atom probes. Materials Characterization, 44, pp. 59–85. 64. Kim, D., Yoon, J., Lee, C. and Jung, S., 2003a. Reaction Diffusion and Formation of Cu11In9 and In27Ni10 Phases in the Couple of Indium-Substrates. Materials Transactions-JIM, 44(1), pp. 72–77. 65. Kim, H., Lee, J.Y., Paik, K., Koh, K., Won, J., Choe, S., Lee, J., Moon, J. and Park, Y., 2003b. Effects of Cu/Al intermetallic compound (IMC) on copper wire and aluminum pad bondability. IEEE Transactions on Components and Packaging Technologies, 26(2), pp. 367–374. 66. Kim, H.G., Kim, S.M., Lee, J.Y., Choi, M.R., Choe, S.H., Kim, K.H., Ryu, J.S., Kim, S., Han, S.Z., Kim, W.Y. and Lim, S.H., 2014. Microstructural evaluation of interfacial intermetallic compounds in Cu wire bonding with Al and Au pads. Acta Materialia, 64, pp. 356–366. 67. Kochure, P.G. and Nandurkar, K.N., 2012. Application of Taguchi Methodology in Selection of Process Parameters For Induction Hardening Of EN8 D Steel. 2(5), pp. 3736–3742. 68. Krzanowski, J.E., 1990. A transmission electron microscopy study of ultrasonic wire bonding. IEEE Transactions on Components, Hybrids, and Manufacturing Technology, 13(1), pp. 176–181. 69. Law, J.B.K. and Thong, J.T.L., 2007. Lateral ZnO nanowire growth on a planar substrate using a growth barrier. Nanotechnology, 18(5), p. 055601. 70. Lee, C.Y., Lee, C.C. and Lim, C.C., 2010. Relationship of Cu Oxidation and Hardness towards Cratering in Wirebonding. In: 2nd Infineon Technical Symposium. Malacca. 71. Lee, W.B., Bang, K.S. and Jung, S.B., 2005. Effects of intermetallic compound on the electrical and mechanical properties of friction welded Cu/Al bimetallic joints during annealing. Journal of Alloys and Compounds, 390(1-2), pp. 212–219. 72. Lejcek, P., 2010. Grain Boundaries: Description, Structure and Thermodynamics. In: Grain Boundary Segregation in Metals, Springer Series in Materials Science. Berlin, Heidelberg: Springer, pp.5–24. 73. Li, K., Er, E., Yeow, T. and Tang, D., 2006. Challenges in Barrier and Seed Layers Characterization of Cu Technology IC Devices. IEEE Transactions on Device and Materials Reliability, 6(2), pp. 283–287. 74. Liu, G.J., Jia, S.S., Zhu, Y.F., Hong, S.H., Lim, J.W., Mimura, K. and Isshiki, M., 2008. Annealing effect of hydrogen or argon atmosphere on corrosion resistance of CuAl dilute alloys at high temperature. Materials Science and Engineering: A, 472(1-2), pp. 235–241. 75. Liu, X. and Zhang, B., 2010. Properties of Cu-Al intermetallic compounds in copper wire bonding. In: 2010 11th International Conference on Electronic Packaging Technology & High Density Packaging. IEEE, pp.213–216. 76. Loh, W., Corfield, M., Lu, H., Hogg, S., Tilford, T. and Johnson, C.M., 2007. Wire Bond Reliability for Power Electronic Modules - Effect of Bonding Temperature. In: 2007 International Conference on Thermal, Mechanical and Multi-Physics Simulation Experiments in Microelectronics and Micro-Systems. EuroSime 2007. London: IEEE, pp.1–6. 77. Lu, D. and Wong, C.P., 2008. Materials for Advanced Packaging. Springer. 78. Lubarda, V.A., 2003. On the effective lattice parameter of binary alloys. Mechanics of Materials, 35(1-2), pp. 53–68. 79. Lubarda, V.A. and Richmond, O., 1999. Second-order elastic analysis of dilute distribution of spherical inclusions. Mechanics of Materials, 31(1), pp. 1–8. 80. Lum, I., Mayer, M. and Zhou, Y., 2006. Footprint study of ultrasonic wedge-bonding with aluminum wire on copper substrate. Journal of Electronic Materials, 35(3), pp. 433–442. 81. Milligen, B.P. Van, Bons, P.D., Carreras, B. a and Sánchez, R., 2005. On the applicability of Fick’s law to diffusion in inhomogeneous systems. European Journal of Physics, 26(5), pp. 913–925. 82. Mitra, A., 2010. Characterization of the Cu-Si System and Utilization of Metallurgical Techniques in Silicon Refining for Solar Cell Applications. University of Toronto. 83. Mitra, S., 2003. Sample Preparation Techniques in Analytical Chemistry. Chemical Analysis. Hoboken, NJ, USA: John Wiley & Sons, Inc. 84. Murali, S., Srikanth, N. and Vath, C.J., 2003. An analysis of intermetallics formation of gold and copper ball bonding on thermal aging. Materials Research Bulletin, 38(4), pp. 637–646. 85. Murali, S., Srikanth, N. and Vath, C.J., 2004. Effect of wire size on the formation of intermetallics and Kirkendall voids on thermal aging of thermosonic wire bonds. Materials Letters, 58(25), pp. 3096–3101. 86. Murali, S., Srikanth, N., Wong, Y.M. and Vath, C.J., 2006. Fundamentals of thermo-sonic copper wire bonding in microelectronics packaging. Journal of Materials Science, 42(2), pp. 615–623. 87. Muramatsu, N., Kimura, H. and Inoue, A., 2013. Microstructures and Mechanical Properties of Highly Electrically Conductive Cu-0.5, Cu-1 and Cu-2 at%Zr Alloy Wires. MATERIALS TRANSACTIONS, 54(2), pp. 176–183. 88. Na, S., Hwang, T., Park, J., Kim, J., Yoo, H. and Lee, C., 2011. Characterization of intermetallic compound (IMC) growth in Cu wire ball bonding on Al pad metallization. In: 61st Electronic Components and Technology Conference. Lake Buena Vista: IEEE, pp.1740–1745. 89. Najafi, S., Salmasnia, A., Kazemzadeh, R.B., Engineering, I. and Engineering, F., 2011. Optimization of Robust Design for Multiple Response Problem. Austrialian Journal of Basic and Applied Sciences, 5(9), pp. 1566–1577. 90. Nalbant, M., Gökkaya, H. and Sur, G., 2007. Application of Taguchi method in the optimization of cutting parameters for surface roughness in turning. Materials & Design, 28(4), pp. 1379–1385. 91. Nguyen, L., McDonald, D., Danker, A.R. and Ng, P., 1995. Optimization of copper wire bonding on Al-Cu metallization. IEEE Transactions on Components, Packaging, and Manufacturing Technology: Part A, 18(2), pp. 423–429. 92. Ni, H., Lee, H.J. and Ramirez, A.G., 2005. A robust two-step etching process for large-scale microfabricated SiO2 and Si3N4 MEMS membranes. Sensors and Actuators A: Physical, 119(2), pp. 553–558. 93. Nicolet, M.M.-A., 1978. Diffusion barriers in thin films. Thin Solid Films, 52(3), pp. 415–443. 94. Notthoff, C., Winterer, M., Beckel, A., Geller, M. and Heindl, J., 2013. Spatial high resolution energy dispersive X-ray spectroscopy on thin lamellas. Ultramicroscopy, 129, pp. 30–5. 95. Oliva, A.I., Corona, J.E. and Sosa, V., 2010. AlCu alloy films prepared by the thermal diffusion technique. Materials Characterization, 61(7), pp. 696–702. 96. Onuki, J., Koizumi, M. and Araki, I., 1987. Investigation of the Reliability of Copper Ball Bonds to Aluminum Electrodes. IEEE Transactions on Components, Hybrids, and Manufacturing Technology, 10(4), pp. 550–555. 97. Pan, J. and Fraud, P., 2004. Wire Bonding Challenges in Optoelectronics Packaging. In: Proceedings of the 1st SME Annual Manufacturing Technology Summit. Dearborn: Society of Manufacturing Engineers, pp.1–8. 98. Pelzer, R., Nelhiebel, M., Zink, R., Wöhlert, S., Lassnig, A. and Khatibi, G., 2012. High temperature storage reliability investigation of the Al–Cu wire bond interface. Microelectronics Reliability, 52(9-10), pp. 1966–1970. 99. Pennycook, S.J., Lupini, A.R., Carela, M., Borisevich, A.Y., Peng, Y., Oxley, M.P., Benthem, K. and Chisholm, M.F., 2007. Microscopy for Nanostructure. In: W. Zhou and Z.L. Wang, eds., Scanning Microscopy for Nanotechnology. New York: Springer, pp.152–191. 100. Pequegnat, a., Hang, C.J., Mayer, M., Zhou, Y., Moon, J.T. and Persic, J., 2009. Effect of EFO parameters on Cu FAB hardness and work hardening in thermosonic wire bonding. Journal of Materials Science: Materials in Electronics, 20(11), pp. 1144–1149. 101. Pignataro, S., Torrisi, A., Puglisi, O., Cavallaro, A., Perniciaro, A. and Ferla, G., 1986. Influence of surface chemical composition on the reliability of Al/Cu bond in electronic devices. Applied Surface Science, 25(1-2), pp. 127–136. 102. Prasad, S.K., 2004. Advanced Wirebond Interconnection Technology. Advanced Wirebond Interconnection Technology. Boston: Kluwer Academic Publishers. 103. Puh, F., Šegota, T. and Jurković, Z., 2012. Optimization of Hard Turning Process Parameters with PCBN Tool Based On the Taguchi Method. Tehnicki vjesnik, 19(2), pp. 415–419. 104. Qi, J., Hung, N.C., Li, M. and Liu, D., 2006. Effects of process parameters on bondability in ultrasonic ball bonding. Scripta Materialia, 54(2), pp. 293–297. 105. Qin, I., Shah, a., Huynh, C., Meyer, M., Mayer, M. and Zhou, Y., 2011. Role of process parameters on bondability and pad damage indicators in copper ball bonding. Microelectronics Reliability, 51(1), pp. 60–66. 106. Rao, R.S. and Padmanabhan, G., 2012. Application of Taguchi methods and ANOVA in optimization of process parameters for metal removal rate in electrochemical machining of Al / 5 % SiC composites. International Journal of Engineering Research and Applications, 2(3), pp. 192–197. 107. Ratchev, P., Stoukatch, S. and Swinnen, B., 2006. Mechanical reliability of Au and Cu wire bonds to Al, Ni/Au and Ni/Pd/Au capped Cu bond pads. Microelectronics Reliability, 46(8), pp. 1315–1325. 108. Rayne, J.A., Shearer, M.P. and Bauer, C.L., 1980. Investigation of interfacial reactions in thin film couples of aluminum and copper by measurement of low temperature contact resistance. Thin Solid Films, 65(3), pp. 381–391. 109. Reddy, K.H.P., 2011. A Study on Control of Microorganisms in Drinking Water Using Ag-Cu/C Catalysts. The Open Catalysis Journal, 4(1), pp. 47–53. 110. Roth, L. and Sandgren, G., 2004. Wire Encapsulation Improves Fine-Pitch Device Yield. Semiconductor International, 27(11), pp. 1–5. 111. Sahai, H. and Ageel, M.I., 2000. The analysis of variance : fixed, random and mixed models. Boston: Birkhauser. 112. Scheu, C., Gao, M., Oh, S.H., Dehm, G., Klein, S., Tomsia, a. P. and Rühle, M., 2006. Bonding at copper–alumina interfaces established by different surface treatments: a critical review. Journal of Materials Science, 41(16), pp. 5161–5168. 113. Schramm, L., Behr, G., Löser, W. and Wetzig, K., 2005. Thermodynamic Reassessment of the Cu-O Phase Diagram. Journal of Phase Equilibria & Diffusion, 26(6), pp. 605–612. 114. Senoo, M. and Hayashi, T., 1987. Elastic constants of Al-Cu solid-solution alloys and its variations by aging treatments. Transactions of the Japan Society of Mechanical Engineers Series A, 53(493), pp. 1762–1767. 115. Servais, G. and Brandenburg, S., 1991. Wire bonding–A closer look. In: 17th International Symposium for Testing & Failure Analysis. Los Angeles: ASM International, pp.525–529. 116. Shah, A., Mayer, M., Qin, I., Huynh, C., Zhou, Y. and Meyer, M., 2010. Ultrasonic friction power during thermosonic Au and Cu ball bonding. Journal of Physics D: Applied Physics, 43(32), pp. 1–8. 117. Shao, S., Xuan, F., Wang, Z. and Tu, S., 2009. Stress in film/substrate system due to diffusion and thermal misfit effects. Journal of Physics D: Applied Physics, 42(17), pp. 1–7. 118. Shieu, F.S., Chen, C.F., Sheen, J.G. and Chang, Z.C., 1999. Intermetallic phase formation and shear strength of a Au-In microjoint. Thin Solid Films, 346(1-2), pp. 125–129. 119. Singh, H., 2012. Review Article TAGUCHI OPTIMIZATION OF PROCESS PARAMETERS : A REVIEW AND CASE STUDY. International Journal of Advanced Engineering Research and Studies, 1(2), pp. 39–41. 120. Singh, I., On, J.Y. and Levine, L., 2005. Enhancing fine pitch, high I/O devices with copper ball bonding. In: Proceedings Electronic Components and Technology, 2005. IEEE, pp.843–847. 121. Singh, L.M., Student, M.T. and Kolkata, N., 2012. Optimization of welding parameters for maximization of weld bead widths for submerged arc welding of mild steel plates. International Journal of Engineering Research & Technology, 1(4), pp. 1–5. 122. Stephanie, F., Mike, O., Ben, T. and John, Z., 2006. Design of experiments via taguchi methods: orthogonal arrays. University of Michigan Chemical Engineering Process Dynamics and Controls Open Textbook. 123. Stephenson, G.B., 1988. Deformation during interdiffusion. Acta Metallurgica, 36(10), pp. 2663–2683. 124. Stokroos, I., Kalicharan, D., Van Der Want, J.J. and Jongebloed, W.L., 1998. A comparative study of thin coatings of Au/Pd, Pt and Cr produced by magnetron sputtering for FE-SEM. Journal of microscopy, 189(Pt 1), pp. 79–89. 125. Strachan, J.P., Pickett, M.D., Yang, J.J., Aloni, S., David Kilcoyne, A.L., Medeiros-Ribeiro, G. and Stanley Williams, R., 2010. Direct identification of the conducting channels in a functioning memristive device. Advanced materials, 22(32), pp. 3573–7. 126. Sturdivant, R., 2013. Microwave and Millimeter-Wave Electronic Packaging. Artech House, Inc. 127. Su, C.-T. and Yeh, C.-J., 2011. Optimization of the Cu wire bonding process for IC assembly using Taguchi methods. Microelectronics Reliability, 51(1), pp. 53–59. 128. Suzuki, A. and Mishin, Y., 2005. Atomic mechanisms of grain boundary diffusion: Low versus high temperatures. Journal of Materials Science, 40(12), pp. 3155–3161. 129. Swinnen, B., Ruythooren, W., De Moor, P., Bogaerts, L., Carbonell, L., De Munck, K., Eyckens, B., Stoukatch, S., Tezcan, D.S., Tokei, Z., Vaes, J., Van Aelst, J. and Beyne, E., 2006. 3D integration by Cu-Cu thermo-compression bonding of extremely thinned bulk-Si die containing 10µm pitch through-Si vias. In: 2006 International Electron Devices Meeting. San Francisco: IEEE, pp.1–4. 130. Tan, H., 2002. Experiment: Metallography Specimen Preparation and Examination. University of Aberdeen. 131. Tan, Y.Y. and Yong, F.K., 2010. Cu-Al IMC micro structure study in Cu wire bonding with TEM. In: 2010 17th IEEE International Symposium on the Physical and Failure Analysis of Integrated Circuits. IEEE, pp.1–4. 132. Taylor, R., 1990. Interpretation of the Correlation Coefficient: A Basic Review. Journal of Diagnostic Medical Sonography, 6(1), pp. 35–39. 133. Teb Pella, I., 2014. FIB Lift-Out Grids and Grid Boxes. Teb Pella, Inc. 134. Theint, E.P.P., Stephan, D., Goh, H.M., Pasamanero, E., Calpito, D.R.M., Wulff, F.W. and Breach, C.D., 2005. High Temperature Storage (HTS) Performance of Copper Ball Bonding Wires. In: 2005 7th Electronic Packaging Technology Conference. Singapore: IEEE, pp.602–607. 135. Tian, Y.H., Hang, C.J., Wang, C.Q., Ouyang, G.Q., Yang, D.S. and Zhao, J.P., 2011. Reliability and failure analysis of fine copper wire bonds encapsulated with commercial epoxy molding compound. Microelectronics Reliability, 51(1), pp. 157–165. 136. Vairis, A. and Petousis, M., 2009. Designing experiments to study welding processes : using the Taguchi method. Journal of Engineering Science and Technology Review, 2(1), pp. 99–103. 137. Vandenberg, J. and Hamm, R., 1982. An in situ X-ray study of phase formation in Cu-Al thin film couples. Thin Solid Films, 97, pp. 313–323. 138. Vermeulen, J.P., 2005. New developments in FESEM Technology Early developments. Advanced materials & processes, 163(8), pp. 33–36. 139. Walck, C., 2007. Handbook on statistical distributions for experimentalists. University of Stockholm. 140. Westbrook, J.H. and Fleischer, R.L., 2000. Basic Mechanical Properties and Lattice Defects of Intermetallic Compounds. New York: Wiley. 141. Weston, D., 1990. Microcorrosion of Al–Cu and Al–Cu–Si alloys: Interaction of the metallization with subsequent aqueous photolithographic processing. Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films, 8(3), p. 2025. 142. Wieczorek-Ciurowa, K., Oleszak, D. and Gamrat, K., 2008. Cu–Al/Al 2 O 3 cermet synthesized by reactive ball milling of CuO–Al system. Reviews on Advanced Material Science, 18, pp. 248–252. 143. Williams, K.R. and Muller, R.S., 1996. Etch rates for micromachining processing. Journal of Microelectromechanical Systems, 5(4), pp. 256–269. 144. Wlosiński, W., Olesińska, W. and Pietrzak, K., 1996. Bonding of alumina to steel using copper interlayer. Journal of Materials Processing Technology, 56(1-4), pp. 190–199. 145. Wood, M. a, Meredith, D.O., Owen, G.R., Richards, R.G. and Riehle, M.O., 2005. Utilizing atomic number contrast for FESEM imaging of colloidal nanotopography underlying biological cells. Nanotechnology, 16(9), pp. 1433–1439. 146. Wu, Y., Long, Z., Han, L. and Zhong, J., 2006. Temperature effect in thermosonic wire bonding. Transactions of Nonferrous Metals Society of China, 16(3), pp. 618–622. 147. Wulff, F., Breach, C., Stephan, D., Saraswati, T. and Dittmer, K.J., 2004. Characterisation of intermetallic growth in copper and gold ball bonds on aluminium metallization. In: Proceedings of 6th Electronics Packaging Technology Conference. IEEE, pp.348–353. 148. Xu, H., 2010. Thermosonic ball bonding: a study of bonding mechanism and interfacial evolution. Loughborough University. 149. Xu, H., Liu, C., Silberschmidt, V. V and Wang, H., 2008a. Effects of process parameters on bondability in thermosonic copper ball bonding. In: 2008 58th Electronic Components and Technology Conference. IEEE, pp.1424–1430. 150. Xu, H., Liu, C., Silberschmidt, V. V. and Chen, Z., 2009a. Growth of Intermetallic Compounds in Thermosonic Copper Wire Bonding on Aluminum Metallization. Journal of Electronic Materials, 39(1), pp. 124–131. 151. Xu, H., Liu, C., Silberschmidt, V. V., Pramana, S.S., White, T.J., Chen, Z., Sivakumar, M. and Acoff, V.L., 2010. A micromechanism study of thermosonic gold wire bonding on aluminum pad. Journal of Applied Physics, 108(11), p. 113517. 152. Xu, H., Liu, C. and Silberschmidt, V.V., 2008b. Effect of thermal aging on interfacial behaviour of copper ball bonds. 2008 2nd Electronics Systemintegration Technology Conference, pp. 891–896. 153. Xu, H., Liu, C., Silberschmidt, V.V., Chen, Z., Wei, J. and Sivakumar, M., 2011a. Effect of bonding duration and substrate temperature in copper ball bonding on aluminium pads: A TEM study of interfacial evolution. Microelectronics Reliability, 51(1), pp. 113–118. 154. Xu, H., Liu, C., Silberschmidt, V.V., Pramana, S.S., White, T.J. and Chen, Z., 2009b. A re-examination of the mechanism of thermosonic copper ball bonding on aluminium metallization pads. Scripta Materialia, 61(2), pp. 165–168. 155. Xu, H., Liu, C., Silberschmidt, V.V., Pramana, S.S., White, T.J., Chen, Z. and Acoff, V.L., 2011b. Behavior of aluminum oxide, intermetallics and voids in Cu–Al wire bonds. Acta Materialia, 59(14), pp. 5661–5673. 156. Xu, H., Qin, I., Clauberg, H., Chylak, B. and Acoff, V.L., 2013. Behavior of palladium and its impact on intermetallic growth in palladium-coated Cu wire bonding. Acta Materialia, 61(1), pp. 79–88. 157. Xuan, F.Z., Shao, S.S., Wang, Z. and Tu, S.T., 2010. Influence of residual stress on diffusion-induced bending in bilayered microcantilever sensors. Thin Solid Films, 518(15), pp. 4345–4350. 158. Yan-hong, T., Chun-qing, W. and Zhou, Y.N., 2007. Bonding mechanism of ultrasonic wedge bonding of copper wire on Au / Ni / Cu substrate. 159. Yeoh, L.S., 2007. Characterization of Intermetallic Growth for Gold Bonding and Copper Bonding on Aluminum Metallization in Power Transistors. In: 2007 9th Electronics Packaging Technology Conference. IEEE, pp.731–736. 160. Zhang, B.R., Jia, Z. and Duan, X.Z., 2013. Elastic Properties, Mechanical Stability, and State Densities of Aluminnides. Acta Physica Polonica A, 123(4), pp. 668–672. 161. Zhang, N.H., 2007. Thermoelastic stresses in multilayered beams. Thin Solid Films, 515(23), pp. 8402–8406. 162. Zhang, N.H. and Chen, J.Z., 2010. An alternative model for elastic thermal stresses in two materials joined by a graded layer. Composites Part B: Engineering, 41(5), pp. 375–379. 163. Zhang, N.-H. and Chen, J.-Z., 2008. An Alternative Two-Variable Model for Bending Problems of Multilayered Beams. Journal of Applied Mechanics, 75(4), p. 044503. 164. Zhong, Z.W., Ho, H.M., Tan, Y.C., Tan, W.C., Goh, H.M., Toh, B.H. and Tan, J., 2007. Study of factors affecting the hardness of ball bonds in copper wire bonding. Microelectronic Engineering, 84(2), pp. 368–374. 165. Zhou, W., Apkarian, R., Wang, Z. and Joy, D., 2007. Fundamentals of Scanning Electron Microscopy (SEM). In: W. Zhou and Z. Wang, eds., Scanning Microscopy for Nanotechnology. New York: Springer New York, pp.1–40. 166. ZOLLERN Foundry Technology, 2014. Copper Casting Alloys. 167. Zuo, J., 2005. Electron Nanocrystallography. In: N. Yao and Z.L. Wang, eds., Handbook of Microscopy for Nanotechnology. Springer, pp.567–599.