臺灣博碩士論文加值系統

隨著電子元件對其效能與速度的要求不斷地提高，積體電路需不斷地微小化，晶圓中的金屬導線也需更微細化。因為導線線寬的縮小，導線間所產生的阻抗與容抗會有增加的現象，而造成訊號的延遲。為了改善訊號延遲，採用導電性佳的銅金屬，取代鋁金屬為元件間的導線是目前最佳的選擇。而電子封裝中銲線製程為連接晶片與導線架電力與電子訊號傳輸的重要製程，亦是整個封裝流程中發生破壞機率最高的製程。以現今銲線製程主流的熱音波銲接來進行銅導線的晶片的銲線製程，因銅金屬受高溫質地易軟化，對其他金屬層或元件等也易產生污染和破壞，故研究銅導線晶片熱音波銲線製程的界面微觀現象就格外的重要。
本研究根據熱音波銲線製程的作動原理，發展具鍍層表面接觸力學，由銲接界面之接觸面積、瞬閃溫度及界面能量等界面現象來探討熱音波銲接品質與製程參數的關係。在製程實驗方面針對銅金屬高溫易氧化的特性，分別應用惰性氣體屏障、晶片生成銅氧化膜作為障蔽層與濺鍍鈦金屬障蔽層的方法來改善其製程，並且以銲點強度及電阻量測作為銲接品質判定的標準。本研究結合製程實驗與界面微觀理論分析，有效地定出適銲區域範圍及最佳的製程參數組合。由銲點的能量飽和現象亦應証了能量飽和理論適用於銅導線晶片銲線製程，並由能量飽和理論的分析界定出最佳的適銲區域及提供銲線製程具物理意義的詮釋。本研究結合了理論分析與製程實驗方法，突破銅導線晶片銲線製程上的瓶頸，達到改善製程良率，提升銲接品質的目的。

The requirements for improved performance and reduced size have driven Copper to replace Aluminum interconnection for deep submicron integrated circuit. Copper has been identified as the best candidate to replace Aluminum due to its low resistivity, high electromigration resistance and likely lower processing cost. Thermosonic bonding of gold wire is the most popular joining technique in microelectronic packaging became of its advantages of high yield rate, fine pitch and easy for automatic operation. However, due to the material properties of Copper, thermosonic bonding on Cu Chip presents a major challenge for the electronic packaging industry.
This study used a microcontact approach to develop the thermosonic bonding technique for Cu Chips. Incorporating with the bonding parameter testing, the interfacial microcontact model had been developed, based on the interfacial energy model to identify the weldable range and elucidate the wire bonding phenomena. In order to improve the bonding quality for Cu Chip, this work presented three methods to overcome the bonding difficulty. These were inertia gas method, copper oxides growth method and titanium barrier layer method respectively. The bonding quality is based on the bonding strength and the circuit electric resistance. This study combines the analysis of microcontact theory and experiment results to determine optimal bonding parameter range by using the energy saturation theory. It also provides physical interpretation of thermosonic bonding of Cu pad from the viewpoint of interfacial micro contact phenomenon. This study constitutes a breakthrough in the wire bonding process for Cu Chip.

中文摘要 ...............................................I
英文摘要 ..............................................II
誌謝 .................................................III
目錄 ..................................................IV
表目錄 ...............................................VII
圖目錄 ..............................................VIII
符號表 ................................................XI
第一章 緒論...........................................1
1-1 前言...........................................1
1-2 電子構裝製程概述...............................2
1-3 銲接機理文獻回顧...............................4
1-4 熱音波銲線製程.................................5
1-5 銅晶片構裝製程簡介.............................7
1-6 界面微接觸理論模式與能量飽和理論...............9
1-7 研究動機與目的................................10
第二章 理論模式......................................13
2-1 表面接觸力學..................................13
2-1-1 彈性變形......................................15
2-1-2 塑性變形......................................16
2-1-3 彈塑性變形....................................17
2-2 具鍍層表面接觸力學............................18
2-2-1 有效複合微硬度................................20
2-2-2 彈性變形......................................21
2-2-3 塑性變形......................................22
2-2-4 彈塑性變形....................................23
2-3 界面溫度......................................23
2-4 界面能量......................................25
第三章 實驗流程與設備................................27
3-1 實驗材料......................................28
3-1-1 銅晶片之選用..................................28
3-1-2 導線架........................................28
3-1-3 金線..........................................29
3-1-4 鋼嘴..........................................30
3-2 實驗製成參數..................................30
3-3 實驗設備與方法................................32
3-3-1 熱音波銲線機..................................32
3-3-2 微型銲點強度測試機............................33
3-3-3 工具實體顯微鏡................................34
3-3-4 精密探針平台..................................34
3-3-5 電源供應器....................................35
第四章 研究結果與討論................................36
4-1 裸銅晶片熱音波銲線製程銲點品質分析............37
4-1-1 惰性氣體對銅晶片氧化的影響....................38
4-1-2 超音波發振功率與銲點強度之關係................39
4-1-3 實際接觸面積與銲點強度之關係..................40
4-1-4 界面溫度與銲點強度之關係......................42
4-1-5 界面能量與銲點強度之關係......................43
4-1-6 銲接負荷、超音波發振時間與銲點強度之關係......44
4-2 銅氧化膜對熱音波銲線製程銲點品質影響之分析....45
4-2-1 銅氧化膜厚度探討..............................46
4-2-2 超音波發振功率與銲點強度之關係................48
4-2-3 實際接觸面積與銲點強度之關係..................49
4-2-4 界面溫度與銲點強度之關係......................49
4-2-5 界面能量與銲點強度之關係......................50
4-3 迴路電阻分析..................................51
4-3-1 裸銅晶片迴路電阻..............................51
4-3-2 具氧化膜銅晶片迴路電阻........................51
4-4 鍍鈦銅晶片之銲點品質分析......................53
4-4-1 超音波發振功率與銲點強度之關係................53
4-4-2 實際接觸面積與銲點強度之關係..................54
4-4-3 界面溫度與銲點強度之關係......................54
4-4-4 界面能量與銲點強度之關係......................55
4-4-5 銲接負荷對銲點品質的影響......................55
4-4-6 銲接時間對銲點品質的影響......................56
4-5 界面能量理論模式..............................56
4-6 結果討論......................................57
第五章 結論與未來研究方向............................60
第六章 參考文獻.......................................65
表 目 錄
表3-1 金線材料合金成分表.............................29
表3-2 金線材料性質表.................................30
表3-3 超音波發振功率設定值與功率單位換算對照表.......31
表4-1 選用材料性質表.................................37
表4-2 具氧化膜銅晶片之迴路電阻值(Ω)..................52
表4-3 裸銅晶片與具氧化膜銅晶片之優缺點較.............53
圖 目 錄
圖1-1 不銅導線材料與介電材料在各世代下訊號延遲的趨勢.71
圖1-2 電子構裝各階層示意圖...........................71
圖1-3 非密封性塑膠封裝元件示意圖.....................72
圖1-4 球形-楔行銲點示意圖............................72
圖1-5 熱音波銲接原理示意圖............................73
圖1-6 熱音波線步驟示意圖..............................73
圖1-7 傳統導線結構製程示意圖.........................74
圖1-8 先蝕刻導線溝槽再蝕刻通孔.......................74
圖1-9 先進行通孔蝕刻再進行導線溝槽蝕刻...............75
圖1-10 熱音波銲線製程分析.............................75
圖1-11 研究流程.......................................76
圖2-1 視接觸面積與實際接觸面積示意圖.................77
圖2-2 接觸表面粗糙峰示意圖...........................77
圖2-3 單一粗糙峰變形示意圖...........................78
圖2-4 單一粗糙峰塑性變形體積不滅示意圖...............78
圖2-5 彈塑性接觸面積與干涉量間的關係圖...............79
圖2-6 具鍍層接觸表面與粗糙峰示意圖...................79
圖2-7 具鍍層接觸表面與粗糙峰接觸變形圖...............80
圖2-8 瞬閃溫度模式示意圖.............................80
圖3-1 銅製程晶片實體圖及局部放大圖...................81
圖3-2 晶片表面剝落之實體圖...........................81
圖3-3 導線架實體圖...................................81
圖3-4 Micro-Swiss 41484-0013-335-RED鋼嘴示意圖.......82
圖3-5 Toshiba HN-932-FAB型熱音波銲線機...............82
圖3-6 推力測試機.....................................83
圖3-7 推力測試示意圖.................................83
圖3-8 工具實體顯微鏡.................................84
圖3-9 視面積量測示意圖...............................84
圖3-10 精密探針平台...................................85
圖3-11 晶片迴路電阻量測示意圖.........................85
圖3-12 電源供應器.....................................86
圖4-1 銅晶片受氬氣保護前後之銲接功率對銲點剪力強度的關係87
圖4-2 銅晶片受氬氣保護前後之銲接功率對銲點尺寸的關係.87
圖4-3 超音波發振功率與銲點強度之關係(裸銅晶片, 150℃、170℃)88
圖4-4 超音波發振功率與銲點強度之關係(裸銅晶, 130℃、190℃)88
圖4-5 實際接觸面積與銲點強度之關係(裸銅晶片, 150℃、170℃)89
圖4-6 實際接觸面積與銲點強度之關係(裸銅晶片, 130℃、190℃)89
圖4-7 界面溫度與銲點強度之關係(裸銅晶片, 150℃、170℃)90
圖4-8 界面溫度與銲點強度之關係(裸銅晶片, 130℃、190℃)90
圖4-9 界面能量與銲點強度之關係(裸銅晶片, 150℃、170℃)91
圖4-10 界面能量與銲點強度之關係(裸銅晶片, 130℃、190℃)91
圖4-11 銲接負荷與銲點強度之關係(裸銅晶片, 150℃).......92
圖4-12 超音波發振時間與銲點強度之關係(裸銅晶片, 150℃).92
圖4-13 晶片表層銅膜SEM照片.............................93
圖4-14 晶片表層銅膜SEM照片.............................93
圖4-15 裸銅晶片不同加熱溫度下氧化銅之生成厚度..........94
圖4-16 加熱400℃不同退火時間下銅氧化物之生長厚度與時間.94
圖4-17 超音波發振時間與銲點強度之關係(氧化膜晶片)......95
圖4-18 實際接觸面積與銲點強度之關(氧化膜晶片, 225℃、250℃)95
圖4-19 實際接觸面積與銲點強度之關(氧化膜晶片, 275℃)...96
圖4-20 界面溫度與銲點強度之關係(氧化膜晶片, 225℃、250℃)96
圖4-21 界面溫度與銲點強度之關係(氧化膜晶片, 275℃).....97
圖4-22 界面能量與銲點強度之關係(氧化膜晶片, 225℃、250℃)97
圖4-23 界面能量與銲點強度之關係(氧化膜晶片, 275℃).....98
圖4-24 超音波功率與晶片迴路電阻的關係..................98
圖4-25 視接觸面積與晶片迴路電阻的關係..................99
圖4-26 視接觸面積與晶片迴路電阻的關係..................99
圖4-27 超音波功率與晶片迴路電阻的關係.................100
圖4-28 超音波發振功率與銲點強度之關係(鍍鈦晶片, 250℃)100
圖4-29 實際接觸面積與銲點強度之關係(鍍鈦晶片, 250℃)..101
圖4-30 界面溫度與銲點強度之關係(鍍鈦晶片, 250℃)......101
圖4-31 界面能量密度與銲點強度之關係(鍍鈦晶片, 250℃)..102
圖4-32 銲接負荷與銲點強度之關係(鍍鈦晶片, 250℃)......102
圖4-33 銲接負荷與實際接觸面積之關係(鍍鈦晶片, 250℃)..103
圖4-34 超音波發振時間與銲點強度之關係(鍍鈦晶片, 250℃)103
圖4-35 超音波發振時間與實際接觸面積之關係(鍍鈦晶片, 250℃)104

1.崔秉鉞,“多層導線製程發展趨勢”,銅晶片構裝月刊,第一期,
88.1.20, pp. 9-15
2.鄭友仁、敖仲寧、丁榮豐, ”銅晶片銲線製程技術分析”,機械工業
雜誌, Vol. 210,Sep 2000, pp.158-169
3.顧子琨, “極大型積體電路之銅導線連結線技術－世紀末的明星：
銅導線製程技術概論”, 電子月刊第五卷第六期, pp. 117- 133, 1999
4.P.C.Andrjcacos et. AL.”Damascene Copper Electroplating for chip Interconnections.”,IBM Journal Res. Develop. Vol. 42. No 5
5.K. K. H. Wong et Al. “Metallization by Plating for High
Performance Multichip Module.” IBM Journal Res. Develop. Vol. 42, No 5
6.C.-K. Hu and J. M. E Harper,”Copper Interconnections and Reliability”, Materials Chemistry and Physics Vol. 52, No 1, 1998
7.J. N. Antonevich, and R. E. Monroe, "Fundamental Study of Ultrasonic Welding," Welding Journal Research Supplement. Aug, 1960
8.J. M. Peterson, IRE Itern. Conv. Record, Vol. 10, 1962, p-3
9.J. L. Jellison, and J. A. Wagner, "The Role of Surface Contaminants in the Deformation Welding of Gold to Thick and Thin Film," Proc. 29th IEEE Electronic Component Conference, 1979, pp. 336-345.
10.E. A. Neppiras, "Ultrasonic Welding of Metals," Ultrasonic, No. 3, 1965, pp. 128-135.
11.B. Langenecker, ”Effects on Ultrasound on Deformation Characteristics of Metals", IEEE Transactions on Sonics And Ultrasonics, Vol. SU-13, 1966, pp. 1-8.
12.G. George, Harman and John Albers, "The Ultrasonic Bonding in Microelectronics", IEEE Transactions on Parts, Hybrids, and Packing, v 13, n 4, Sep. 1977, pp. 406-412
13.T. Hund, and P. Plunkett, "Improving Thermosonic Gold Ball Bond Reliability," IEEE Transactions on Components, Hybrids and Manufacturing Technology, Vol. CHMT-8, No. 4, 1985, pp. 446-456.
14.M. Sheaffer, and L. Levine, "How to Optimize and Control the Wire Bonding Process: Part II," Solid State Technology, 1991, pp.67-70
15.S. J. Hu, G. E. Lim, T. L. Lim, and K. P. Foong, "Study of Temperature Parameter on the Thermosonic Gold Wire Bonding of High-Speed CMOS", IEEE Transactions on Components, Hybrids, and Manufacturing Technology, Vol. 14, No. 4, 1991, pp. 855-858.
16.林政男, "由界面現象探討電子構裝之熱音波銲線製程", 國立中正大學碩士論文, 1999年。
17.Y. R. Jeng and J. N. Lin, “Study of Interfacial Phenomena Affecting Thermosonic Wire Bonding in Microelectronics,” ASME Journal of Tribology, 2001, under minor revision.
18.陳津佑, "電子構裝熱音波銲線製程之界面能量理論模式的建立及其應用", 國立中正大學碩士論文, 2000年。
19.Yeau-Ren Jeng, J. Y. Chen, 2001, “A Study on the Saturation of Interfacial Phenomena in Thermosonic Wire Bonding,” submitted to IEEE Transactions on Components and Packaging Technologies for publication.
20.Y. R. Jeng and J. H. Horng, "A Microcontact Approch for Ultrasonic Wire Bonding in Microelectronics", ASME Journal of Tribology, 2001, vol. 123, pp. 725-731
21.Ueno, Hiroshi, "Au wire bonding to Cu pad using Ti thin film", Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes v 31 n 5A May 1992 p 1547-1548
22.R. Kajiwara, T. Takahashi, K. Tsubosaki, H. Watanabe, "Influence of Surface Cleanness on Ultrasonic Ball Bondability of Au Wire onto Au, Cu and Al pads." Yosetsu Gakkai Ronbunshu/Quarterly Journal of the Japan Welding Society v 16 n 1 Feb 1998
23.Toyozawa, Kenji, Fujita, Kazuya, ”Development of Copper Wire Bonding Application Technology”, IEEE Transaction on Components, Hybrids and Manufacturing Technology v 13 n 4,Dec 1990 pp. 667-672
24.Kajiwara, Ryoichi, Takahashi, Toshiyuki, Tsubosaki, Kunihiro, Watanabe, Hiroshi, ”Influence of Ambient Gas on Ultrasonic Ball Boundablity of Au Wire onto Au, Cu and Al Pads — Study of Ultrasonic Bonding With Surface Cleaning by Ion Bombardment(Report), “Yosetsu Gakkai Ronbunshu/Quarterly Journal of the Japan Welding Society v16 n 1,Feb 1998
25.Y. R. Jeng, J. H. Aoh and C. M. Wang, “Thermosonic Wire Bonding of Gold Wire onto Copper Pad Using the Saturated Interfacial Phenomena”, J. Phys. D: Appl. Phys. 34, No. 24, 2001, pp. 3515-3521
26.J. A. Greenwood and J. B. P. Williamson, “Contact of Nominal Flat Surface.”, Proceeding of the Royal Society of London, A295, No. 1442,1996, pp. 300-319
27.Z. H. Powierza, T. Klimczak, A. Polijaniuk, “On the Experimen-
tal Verification of the Greenwood-Willianmson Model for the Contact of Rough Surface.”, WEAR, Vpl. 154, 1992, pp 115-124
28.J. Pullen and J. B. P. Williamson, ”On the Plastic Contact of Rough Surface.”, Proceedings of the Royal Society of London, A327, 1972, pp. 157-173
29.J. B. P. Williamson, J. Pullen and R. T. Hunt, “ The Shape of Solid Surfaces ”, Surface Mechanics, a symposium volume, ASME, 1970, pp.24-35.
30.W. R. Chang, I. Etsion, ang D. B. Bogy, “An Elastic-Plastic for Contact of Rough Surface”, ASME Journal of Tribology, Vol. 109, 1987, pp. 257-263
31.Y. Zhao, D. McCool and L. Chang, “An Asperity Microcontact Model Incroporating the Transition From Elastic Deformation to Fully Plastic Flow.” , ASME Journal of Tribology
32.E. J. Abbot and F. A. Firestone, “ Specifying Surface Quality-A Method Based on AccurateMeasurement and Comparison ”, Institution of Mechanical Engineers, Vol. 55, 1933, pp. 569
33.C. Hardy, C. N. Baronet, G. V. Tordion, ” Elastico-plastic indentation of a half-space by a rigid sphere. ”, Int. J. Numer. Methods Eng., 3(1971),451-462
34.K. L. Johnson, “Contact Mechanics”, Cambridge University Press, Cambridge
35.J. B. Pethica, R. Hutchings, and W.C. Oliver, (1983).Hardness measurements at penetration depths as small as 20 nm. Phil. Mag. (A) 48, 593-606
36.J. L. Louber, J. M. Georges, J. M. Murchesini, and G. J. Meille, Tribology 106, 43, 1984
37.M. F. Doerner, and W. D. Nix, (1986). “ A method for interpret-
ing the data from depthsensing indentation instruments. “ J. Mater Res. 4, 601-609
38.M. F. Doerner, D. S. Gardner and W. D. Nix, (1986). “Plasric
properties of thin films on substrates as measured by sub-
micron indentation hardness and substrate curvature techniques. “ J. Mater Res. 6, 845-851
39.A. K. Bhattacharya and W. D. Nix, (1988). “ Finite element simulation of indentation experiments.“ Int. J. Solids Structures Vol. 24, 881-891 (1988)
40.A. K. Bhattacharya and W. D. Nix, (1988). “Analysis of elastic and plastic deformation associated with indentation testing of thin films on substrates” Int. J. Solids Structures Vol.24,No. 12,1988,pp. 1287-1298
41.W. R. Chang, “An elastic-plastic contact model for a rough surface with an ion-plated soft metallic coating”, Wear, 1997, p229-237
42.J. Halling, ”Surface Coating”, Tribology International, 1979, pp. 203-208.
43.H. Blok, "Theoretical Study of Temperature Rise at Surface of Actual Contact Under Oilness Lubricating Conditions", Proc. General Discussion on Lubrication, Vol. 2, Institution of Mechanical Engineers, London, 1937, pp. 222-235.
44.J. C. Jaeger, "Moving Source of Heat and the Temperature at the Sliding Surfaces", Proc. Roy. Soc. NSW, 1942, Vol. 66, pp 203-224.
45.H. A. Francis, "Interfacial Temperature Distribution within a Sliding Hertzian Contact", ASME Transaction, Vol. 14, 1970, pp 41-54.
46.B. Gecim, W. O. Winer, "Transient Temperatures in the Vicinity of an Asperity Contact", ASME Journal of Tribology, 1985, Vol. 107, pp. 333-345.
47.D. Kuhlmann-Wilsdorf, "Temperature at Interfacial Contact Spots: Dependence on Velocity and on Role Reversal of Two Materials in Sliding Contact", ASME Journal of Tribology, 1987, Vol. 109, pp. 321-329.
48.J. L. McCool, "The Distribution of Microcontact Area, Load, Pressure and Flash Temperature under the Greenwood -
Williamson Model", ASME Journal of Tribology, 1987, Vol. 110, pp. 106-111.
49.Xuefeng Tian, Francis E. Kennedy, Jr., “Maximum and average flash temperatures in sliding contacts”, ASME Journal of Tribology, 1994, Vol. 116, pp.167-174.
50.丁榮豐, "銅晶片熱音波銲線製程參數與機裡研究", 國立中正大學碩士論文, 2001年。
51.J. N. Aoh, C. L. Chuang, R. F. Din, S. Torng, D. S. Lin, “On the Oxidation Behavior of Sputtered Copper Film on Si Wafer”, Journal of Materials Science and Engineering, 2002, Vol. 34, No. 1, pp. 1-7.
52.S. Y. Lee, S. H. Choi, C. O. Park, “Oxidation, Grain Growth and Reflow Characteristics of Copper Thin Films Prepared by Chemical Vapor Deposition”, Thin Solid Films, 2000, Vol. 359, pp. 261-267.