溫度與基板對脈衝電鍍製備銅膜微結構影響之研究

簡易檢索 / 詳目顯示

回結果列表

研究生：	曾麗倩 Tseng, Li-Chien
論文名稱：	溫度與基板對脈衝電鍍製備銅膜微結構影響之研究 The Effects of Temperature and Substrate on Microstructure of Copper Films Prepared by Pulsed Electrodeposition
指導教授：	廖建能 Liao, Chien-Neng
口試委員:	吳文偉徐文光
學位類別：	碩士 Master
系所名稱：	工學院 - 材料科學工程學系 Materials Science and Engineering
論文出版年：	2012
畢業學年度：	100
語文別：	英文
論文頁數：	79
中文關鍵詞：	銅膜、電鍍、奈米雙晶、低溫
外文關鍵詞：	copper film, electrodeposition, nanotwin, low temperature
相關次數：	點閱：3 下載：0
分享至:	分享至facebook 分享至twitter

查詢本校圖書館目錄查詢臺灣博碩士論文知識加值系統勘誤回報

電鍍製程擁有容易量產及低成本的經濟效益，因此被大量運用於製備積體電路中的銅金屬導線。因應微電子積體電路元件尺寸不斷的微縮，為了提升元件的可靠度，瞭解電鍍製程參數對銅金屬導線微結構的影響是一個重要的課題。銅的微結構與晶體成長的優選方向會受到電鍍時的過電位、電鍍液的成份、基板以及溫度的影響。在本研究中，主要是探討基板與電鍍液溫度對脈衝電鍍製程所製備銅金屬膜微結構之影響。本實驗所採用的基板，一為市售的鎳金屬箔，其具備很強的(200)晶體優選方向，另一基板為利用磁控濺鍍法在矽基板上沉積銅薄膜。電鍍液的溫度則控制在攝氏-1及20度。接著利用觀察不同條件下銅膜的表面形貌、優選方向及雙晶的間距作為探討。實驗結果發現，當溫度降低時，利用定電流模式下進行脈衝電鍍所鍍出的銅金屬膜其表面較為光滑，且在電鍍過程中整體的過電位也有所提升。推論降低溫度而造成的過電位上升使銅膜成核速率上升，進而使晶粒細化，而得到較為平整的表面。另外觀察到當電鍍液的溫度控制在攝氏20度時，初始電鍍的銅膜繼承了基板的優選方向，而當溫度下降時，初始電鍍的銅膜其基板效應較不明顯。導致此差異的主要原因在於溫度下降所造成的過電位提升使得各生長方向成核所需要的能量都大幅下降，導致晶粒各方向的成核速度沒有明顯差異而得到無特定優選方向的薄膜。最後也觀察到當溫度降低時，雙晶結構的間距大幅的下降。推論當溫度下降後，銅膜內的應力因在低溫電鍍下成核數量較多及晶界較多而有所提升，另外在低溫下，推測應力釋放將由差排滑移轉變成形成奈米雙晶的機制，使低溫下製備的銅膜內的雙晶結構更為緻密。

Electrochemical deposition is commonly employed in the fabrication of copper interconnects owing to its low cost advantage and ease of mass production. To further down scaling the microelectronic device, more in-deep knowledge and process control concerning interconnect microstructure are required to improve device reliability. Copper film microstructure is known to be tailored by various process parameters such as electrodeposition overpotential, electrolyte composition, substrate and temperature. In this study, nanocrystalline copper films were fabricated by galvanostatic pulsed electrodeposition using an addictive-free sulfate solution as an electrolyte. In comparison, two types of substrate have been used: one is a commercial nickel foil with strong (200) texture and the other is copper film prepared by sputtering which has no preferred orientation. The electroplated copper films were deposited at -1C and 20C. The surface topology, morphology, crystallographic texture and twin spacing distribution of the copper films electrodeposited under various conditions were examined. In this experiment, we observed that as the deposition temperature decreases, the copper film showed an increase in the deposition overpotential and a decrease in surface roughness. The inheritance of substrate texture in the electrodeposited copper film was found to be tailored by deposition temperature. As the deposition temperature decreases, the deposits show less dependent on the crystallographic orientation of the substrate. It was also found that twin spacing lamella reduces with decreasing deposition temperature. We proposed that the increase of overpotential has significant influence on the nucleation behavior. The increase of overpotential leads to higher nucleation rate and lower growth rate of existing nuclei, thus a smoother surface was obtained. At lower deposition temperature, the probabilities of nucleus formation on varies planes are generally the same, thus the electrodeposited copper films did not show any preferred orientation. Finally, the decrease of twin spacing was believed to be associated with the increasing stress caused by high nucleation rate under low deposition temperature.

摘要    I
Abstract    II
誌謝    IV
Contents    V
List of figures    VII
List of tables    XIII
Chapter 1 Introduction    1
1 Motivation    1
2 Organization of thesis    2
Chapter 2 Literature review    4
1 Galvanostatic pulsed deposition    4
1.1 Electrodeposition parameters    4
1.2 Model of duplex diffusion layer    6
1.3 The electrical double layer    10
2 The nucleation behavior    12
2.1 The effect of overpotential on the nucleation behavior    12
2.2 The effect of temperature on the nucleation behavior    16
3 The intrinsic stress in films during deposition process    19
4 Nanotwinned copper    21
4.1 Nanotwinned copper formation mechanism    23
4.2 Nanotwinned copper fabrication by pulsed electrodeposition    25
4.3 The effect of temperature on nanotwinned copper formation    29
Chapter 3 Experimental procedure    31
1 Specimen preparation    31
1.1 Substrates preparation    31
1.2 Electrodeposition process    33
1.3 Specimen preparation for transmission electron microscope    35
2 Morphology analysis    37
2.1 Alpha step    37
2.2 Atomic force microscopy    39
2.3 Scanning electron microscopy    39
3 Microstructure analysis    39
3.1 X-ray diffractometry    39
3.2 Transmission electron microscope    40
Chapter 4 Results and discussion    41
1 The evolution of copper film texture during deposition    44
2 The effect of substrates crystallographic orientation on electroplating copper films    46
2.1 Crystallographic texture    46
2.2 Morphology    49
2.3 Nanotwinned structure    52
3 The effect of temperature on electroplating copper films    56
3.1 Overpotential    56
3.2 Crystallographic texture    59
3.3 Morphology    61
3.4 Nanotwinned structure    66
Chapter 5 Conclusion and future works    72
1 Conclusion    72
2 Future works    73
References        75



                                

1. Lu, K., Lu, L., Shen, Y. F., Chen, X. H., & Qian, L. H. (2004). Ultrahigh strength and high electrical conductivity in copper. Science, 304(5669), 422-426.
2. Liao, C. N., Chen, K. C., Wu, W. W., Chen, L. J., & Tu, K. N. (2008). Observation of atomic diffusion at twin-modified grain boundaries in copper. Science, 321(5892), 1066-1069.
3. Chan, T. C., Chueh, Y. L., & Liao, C. N. (2011). Manipulating the crystallographic texture of nanotwinned cu films by electrodeposition. Crystal Growth & Design, 11(11), 4970-4974.
4. Nikolic, N. D., Brankovic, G., & Maksimovic, V. M. (2012). Morphology and internal structure of copper deposits electrodeposited by the pulsating current regime in the hydrogen co-deposition range. Journal of Solid State Electrochemistry, 16(1), 321-328.
5. Kozlov, V. M., & Bicelli, L. P. (2003). Texture formation of electrodeposited fcc metals. Materials Chemistry and Physics, 77(1), 289-293.
6. Rasmussen, A. A., Jensen, J. A. D., Horsewell, A., & Somers, M. A. J. (2001). Microstructure in electrodeposited copper layers; the role of the substrate. Electrochimica Acta, 47(1-2), 67-74.
7. Cui, B. Z., Han, K., Xin, Y., Waryoba, D. R., & Mbaruku, A. L. (2007). Highly textured and twinned Cu films fabricated by pulsed electrodeposition. Acta Materialia, 55(13), 4429-4438.
8. Chiu, Y. L., & Tjahyono, N. I. (2008). The effect of substrate on the microstructure and preferred orientation of nanocrystalline copper prepared by electrodeposition. Physica Status Solidi C - Current Topics in Solid State Physics, 5(11), 3522-3525.
9. Natter, H., & Hempelmann, R. (1996). Nanocrystalline copper by pulsed electrodeposition: The effects of organic additives, bath temperature, and pH. Journal of Physical Chemistry, 100(50), 19525-19532.
10. Mallik, A., & Ray, B. C. (2009). Morphological study of electrodeposited copper under the influence of ultrasound and low temperature. Thin Solid Films, 517(24), 6612-6616.
11. Xu, D., Kwan, W. L., Chen, K., Zhang, X., Ozolins, V., & Tu, K. N. (2007). Nanotwin formation in copper thin films by stress/strain relaxation in pulse electrodeposition. Applied Physics Letters, 91(25), 1-3.
12. Mavoori, H., Chin, J., Vaynman, S., Moran, B., Keer, L., & Fine, M. (1997). Creep, stress relaxation, and plastic deformation in Sn-Ag and Sn-Zn eutectic solders. Journal of Electronic Materials, 26(7), 783-790
13. Ibl, N. (1980). Some theoretical aspects of pulse electrolysis. Surface Technology, 10(2), 81-104.
14. Ibl, N., Puippe, J. C., & Angerer, H. (1978). Electrocrystallization in pulse electrolysis. Surface Technology, 6(4), 287-300.
15. Devaraj, G., Guruviah, S., & Seshadri, S. K. (1990). Pulse plating. Materials Chemistry and Physics, 25(5), 439-461.
16. Hodge, A. M., Wang, Y. M., & Barbee, T. W. (2006). Large-scale production of nano-twinned, ultrafine-grained copper. Materials Science and Engineering a-Structural Materials Properties Microstructure and Processing, 429(1-2), 272-276.
17. Moriyama, M., Matsunaga, K., Morita, T., Tsukimoto, S., & Murakami, M. (2004). The effect of strain distribution on abnormal grain growth in Cu thin films. Materials Transactions, 45(10), 3033-3038.
18. Xu, D., Sriram, V., Ozolins, V., Yang, J. M., Tu, K. N., Stafford, G. R., & Beauchamp, C. (2009). In situ measurements of stress evolution for nanotwin formation during pulse electrodeposition of copper. Journal of Applied Physics, 105(2), 1-3.
19. Chaudhar.P. (1972). Grain growth and stress relief in thin films. Journal of Vacuum Science & Technology, 9(1), 520-522.
20. Pangarov, N. A. (1965). Preferred orientations in electro-deposited metals. Journal of Electroanalytical Chemistry, 9(1), 70-85.
21. Zhang, X., & Misra, A. (2004). Residual stresses in sputter-deposited copper/330 stainless steel multilayers. Journal of Applied Physics, 96(12), 7173-7178.
22. Zhang, X., Misra, A., Wang, H., Shen, T. D., Nastasi, M., Mitchell, T. E., Hirth, J. P., Hoagland, R. G., & Embury, J. D. (2004). Enhanced hardening in Cu/330 stainless steel multilayers by nanoscale twinning. Acta Materialia, 52(4), 995-1002.
23. Heino, P., Perondi, L., Kaski, K., & Ristolainen, E. (1999). Stacking-fault energy of copper from molecular-dynamics simulations. Physical Review B, 60(21), 14625-14631.
24. Abermann, R. (1990). Measurements of the intrinsic stress in thin metal-films. Vacuum, 41(4-6), 1279-1282.
25. Hong, B., Jiang, C. H., & Wang, X. J. (2007). Influence of complexing agents on texture formation of electrodeposited copper. Surface & Coatings Technology, 201(16-17), 7449-7452.
26. Hertzberg, Richard W. (1989). Deformation and fracture mechanics of engineering materials (3rd ed.). New York: Wiley.
27. Field, D. P., & Park, N. J. (2006). Predicting thickness dependent twin boundary formation in sputtered cu films. Scripta Materialia, 54(6), 999-1003.
28. Grahame, D. C. (1947). The electrical double layer and the theory of electrocapillarity. Chemical Reviews, 41(3), 441-501.
29. Finch, G. I., Quarrell, A. G., & Wilman, H. (1935). Electron diffraction and surface structure. Transactions of the Faraday Society, 31(2), 1051-1080.
30. Finch, G. I., & Sun, C. H. (1936). An electron-diffraction study of the structure of electro-deposited metals. Transactions of the Faraday Society, 32(1), 0852-0863.
31. Finch, G. I., & Williams, A. L. (1937). The structure of electrodeposited nickel. Transactions of the Faraday Society, 33(1), 0564-0569.
32. Karlsson, R., & Isacsson, U. (2003). Laboratory studies of diffusion in bitumen using markers. Journal of Materials Science, 38(13), 2835-2844.
33. Chung, C. K., Chang, W. T., & Hung, S. T. (2010). Electroplating of nickel films at ultra low electrolytic temperature. Microsystem Technologies-Micro-and Nanosystems-Information Storage and Processing Systems, 16(8-9), 1353-1359.
34. Kremmer, K., Yezerska, O., Schreiber, G., Masimov, M., Klemm, V., Schneider, M., & Rafaja, D. (2007). Interplay between the deposition mode and microstructure in electrochemically deposited Cu thin films. Thin Solid Films, 515(17), 6698-6706
35. Meyers, M. A., Vohringer, O., & Lubarda, V. A. (2001). The onset of twinning in metals: A constitutive description. Acta Materialia, 49(19), 4025-4039.
36. Clemm, P. J., & Fisher, J. C. (1955). The influence of grain boundaries on the nucleation of secondary phases. Acta Metallurgica, 3(1), 70-73.
37. Grujicic, D., & Pesic, B. (2002). Electrodeposition of copper: The nucleation mechanisms. Electrochimica Acta, 47(18), 2901-2912.
38. Haiss, W., Nichols, R. J., & Sass, J. K. (1997). In situ monitoring of intrinsic stress changes during copper electrodeposition on Au(111). Surface Science, 388(1-3), 141-149.
39. Koch, R. (1994). The intrinsic stress of polycrystalline and epitaxial thin metal-films. Journal of Physics-Condensed Matter, 6(45), 9519-9550.
40. Hoffman, R. W. (1996). Physics of thin films: New York, Academic.
41.Kongstein, O. E., Bertocci, U., & Stafford, G. R. (2005). In situ stress measurements during copper electrodeposition on (111)-textured Au. Journal of the Electrochemical Society, 152(3), C116-C123.
42. Hinatsu, J. T., & Foulkes, F. R. (1989). Diffusion-coefficients for copper(II) in aqueous cupric sulfate-sulfuric acid-solutions. Journal of the Electrochemical Society, 136(1), 125-132.
43. Chene, O., & Landolt, D. (1989). The influence of mass-transport on the deposit morphology and the current efficiency in pulse plating of copper. Journal of Applied Electrochemistry, 19(2), 188-194.
44. J. B. Allen, R.F. Larry (2001). Electrochemical methods fundamentals and applications: New York, Wiley.

全文公開日期本全文未授權公開 (校內網路)
全文公開日期本全文未授權公開 (校外網路)

簡易檢索 / 詳目顯示

相關論文