在許多傳統IC製程中，wire bond是作為chip與lead frame的電路連結，因此接點的好壞會影響整個IC元件的運作。本實驗主要是藉著高溫可靠度測試(HTSL，High Temperature Storage Life)以加速微接點的退化，再利用電子微探儀(EPMA)來觀察微接點界面的相變化反應，及相變過程所伴隨的void成長的機制，以了解微接點失效的反應機構。
在實驗中，Au wire/Al pad的界面反應初期主要有AuAl、Au2Al、Au5Al2、Au4Al四種相產生，而後轉為Au5Al2、Au4Al phase為主，但隨著時效時間的增加，Au5Al2 phase會消失，而全部轉為Au4Al phase。另外，在接合部邊緣處，由於Al原子的供應充足，故由內而外會依序生成Au4Al/ Au5Al2/Au2Al/ AuAl/ AuAl2 5種介金屬相。此外發現由於Au wire與Al pad的接合不良，在初始接合界面處所形成的voids line會隨著介金屬化合物的成長而往上移動，最後停留在Au4Al phase之間。並且在接合部外緣會因介金屬相的成長伴隨著annular voids的產生，高溫熱處理下，crack從annular voids沿著Au wire/介金屬相界面成長延伸，最後致使接點peeling off。
在Cu wire/Al pad試片中，所觀察到的界面有Cu9Al4、CuAl、CuAl2 3種相，而造成微接點失效的原因在於Cl離子對介金屬相進行腐蝕反應。

None

壹、 前言 1
1-1 研究背景 1
1-2 研究目的 2
貳、 文獻回顧 3
2-1 打線接合的技術 3
2-2 打線接合之材料及其性質 4
2-2-1 鋁 4
2-2-2 金 4
2-2-3 銅 4
2-3 Au-Al間介金屬化合物的微觀組織 4
2-4 Au-Al間介金屬化合物的反應機制 5
2-5 Au-Al微接點的退化機制 5
2-6 添加雜質對Au-Al intermetallic 的影響 7
2-7 Cu-Al間介金屬化合物的微觀組織 7
2-8 Au wire 與Cu wire 比較 7
2-8-1 Au wire 7
2-8-2 Cu wire 8
參、實驗方法 14
3-1 實驗目的 14
3-2 試片種類與時效處理 14
3-3 試片製作 14
3-4 試片分析 15
肆、結果 16
4-1 高溫時效對金鋁微接點的影響 16
4-1-1 175℃金鋁微接點的界面反應 16
4-1-2 金鋁微接點之void觀察 17
4-1-3 205℃金鋁微接點的界面反應 17
4-2 高溫時效對銅鋁微接點的影響 18
伍、討論 21
5-1 Au wire與Al pad接合後的時效機制 21
5-1-1 Phase transformation cross the ball bond 21
5-1-2 Phase transformation lateral the ball bond 21
5-2 Au wire/Al pad空孔的形成 21
5-3 Ball bond邊緣效應 24
5-4 Cu wire與Al pad接合後的時效機制 24
5-5 金鋁微接點與銅鋁微接點的比較 25
陸、結論 28
柒、參考文獻 30

1.George G. Harman, Wire Bonding in Microelectronic, second Edition.
2.Rao R. Tummala, Fundmentals of Microsystems Packaging, internation Edition 2001.
3.陳力俊, 微電子材料與製程,中國材料科學學會, 1990.
4.Gale WF and Totemeier TC, "Smithells Metals Reference Book, "8th ed. Elsevier, 2004.
5.V. Koeninger, H. H. Uchida, and E. Fromm, "Degradation of Gold-Aluminum Ball Bonds by Aging and Contamination," IEEE Transactions on Components, Packaging, and Manufacturing Technology, Part A, Vol. 18, No. 4, pp. 835-841, 1995.
6.T. Uno, K. Tataumi, and Y. Ohno, "Voids Formation and Reliability in Gold-Aluminum Bonding," Proceedings of the Joint ASME/JSME Advances in Electronic Packaging, Vol. 1-2, pp. 771-777, 1992.
7.E. Philofsky, "Intermetallic Formation in Gold-Alluminum System," Solid State Electronics, Vol. 13, pp. 1391-1399, 1970.
8.King-Ning Tu, James W. Mayer, Leonard C. Feldman," Electronic thin film science: for electrical engineers and materials scientist, " Macmillan Publishing Company, New York, 1992.
9.Da-Yuan Shin and Peter J. Ficalora, "The Reliability of Au-Al Intermetallic Formation and Electromigration in Hydrogen Environments," IEEE Transactions on Electron Devices, Vol. ED-26, No. 1, pp. 27-34, 1979.
10.G. Harsanyi, "Electronchemical Processes Resulting in Migrated Short Failures in Microcircuits, " IEEE Transactions on Components, Packaging, and Manufacturing Technology, Part A, Vol. 18, No. 3, 1995.
11.G. Harsanyi, "Effect of Bromine in Molding Compounds on Gold- Aluminum Bonds, " IEEE Transactions on Components, Hybrids, and Manufacturing Technology, Vol. CHMT-9. No. 4, 1986.
12.T. J. Rossiter, "Ambient Effects on Gold-Aluminum Bonds, "Proceedings, Annual Reliability Physics Symposium, pp. 186-190, 1970.
13.Nakane et al, "Fundamental Study for Microjoining in LSI," J. High Temperature Society, Vol. 13, pp. 248-255, 1987.
14.Suresh Kumar, Frank Wulff and Klaus Dittmer, "Intermetallic Growth in Small Ball Bonds, " Proc. SEMICON Singapore, Test, Assembly & Package, pp. 267-272, 1998.
15.Lisa Maiocco, Donna Smyer, Paul R. Munroe, and Ian Baker, "Correlation Between Electrical Resistance and Microstructure in Gold Wire Bonds on Aluminum Films," IEEE Transactions on Components, Hybrids, and Manufacturing Technology, Vol. 13, No. 3, pp. 592-935, 1990.
16.A. E. Gershinskii, B. I. Formin, E. I. Cherepov and F. L. Edelman, "Investigation of Diffusion in The Cu-Al Thin Film System, "Thin Solid Films, Vol. 42, pp. 269-275, 1977.
17.S. U. Campisano, E. Costanzo and F. Scaccianoce, "Growth Kinetics of The θ Phase in Al-Cu Thin Film Bilayers, "Thin Solid Films, Vol. 52, pp. 97-101, 1978.
18.R. A. Hamm and J. M. Vandenberg, "A study of the growth kinetics of the copper-aluminum thin-film interface reaction by in situ x-ray diffraction and Rutherford backscattering analysis, "J. Appl. Phys. Vol. 56, No. 2, pp.293-298, 1984.
19.Kenji Toyozawa, Kazuya Fujiya, Syozo Minamide and Takamichi Maeda, "Development of Copper Wire Bonding Application Technology, " IEEE Transactions on Components, Hybrids, and Manufacturing Technology, Vol. 13, No. 3, pp. 667-672, 1990.
20.Hyoung-Joon Kim, Joo Yeon Lee, Kyung-Wook Paik, "Effect of Cu/Al Intermetallic Compound (IMC) on Copper Wire and Aluminum Pad Bondability, " IEEE Transactions on Components and Packaging Technologies, Vol. 26, No. 2, pp.367-373, 2003.
21.S. Murali, N. Srikanth, Charles J. Vath III, "An analysis of intermetallic formation of gold and copper ball bonding on thermal aging, "Materials Research Bulletin , "Vol. 38, pp.637-646, 2003.
22.F. W. Wulff, C. D. Breach, D. Stephan, Saraswati and K. J. Dittmer, "Characterization of Intermetallic Growth in Copper and Gold Ball Bonds on Aluminum Metallization, "Presented at 6th EPTC, Pan Pacific Singapore: Dec. 2004.