由於奈米雙晶銅有許多優點，例如:跟塊材一樣的電阻率、比塊材更高的機械強度、熱穩定性與良好的抗電遷移性，所以奈米雙晶銅成為三維立體堆疊晶片封裝技術(3D IC)的一顆新星。為了理解3D IC的微凸塊銅銅直接接合技術的機制，奈米雙晶銅的熱穩定性與壓力影響需要被研究，本實驗著重於濺鍍的奈米雙晶銅的熱穩定性。我們首先用非平衡磁控濺鍍機(UBMS)濺鍍鈦或氮化鈦到矽基板作為黏著層，然後鍍附高強度(111)的奈米雙晶銅，鍍膜的工作壓力操作在2 mtorr。200℃與250℃的4.4 mtorr真空環境下退火實驗用來分析不同介層對銅的熱穩定性影響。微結構改變與晶向改變分別由聚焦電子束顯微鏡(FIB)與電子背向散射繞射(EBSD)檢測；然而殘留應力藉由X光繞射(XRD)的cos2αsin2Ψ方法計算。
本實驗發現兩種介層試片在不同溫度下退火均會有異向性晶粒成長，雙晶銅由(111)轉變為(200)的大晶粒；許多垂直的Σ3晶界出現在200℃退火實驗中；而具有氮化鈦介層的奈米雙晶銅對於有鈦介層的雙晶銅有較好的熱穩定性。異向性晶粒成長的能量主要來自於應變能、表面/界面能、晶界能最小化，而高角度的晶界能為主導因素。此外，高角度晶界為引發異向性晶粒成長的一個必要因素，異向性晶粒在成長過程中，其晶界多為高角度晶界；若成長完畢(與其他大晶粒碰撞)，則晶界會往低能量晶界發展，如低角度晶界、雙晶晶界。

　　Copper with nanotwinned structures exhibits many superior properties than bulk Cu, such as higher mechanical strength, good electrical conductivity and thermal stability, and better electromigration resistance. Therefore, nanotwinned copper has become a potential candidate used in three-dimensional integrated circuits (3D IC). To understand the behavior of nanotwinned copper-copper direct bonding used in 3D IC, we investigated the thermal stability and microstructure evolution of nanotwinned copper during the bonding temperature in this study. Firstly, the unbalanced magnetron sputtering (UBMS) was used to sputter Ti or TiN onto Si substrate as adhesion layer, and then the highly (111)-oriented nanotwinned copper was deposited on the adhesion layer under working pressure of 2×10-3 torr. Then samples were annealed under the vacuum environment of 4.4×10-3 torr at the temperature of 200℃ and 250℃ for 0, 10, 20, and 30 min, respectively. After the annealing test, semi insitu microstructural evolution and orientation change of nanotwinned Cu bumps were observed by focus ion beam (FIB) and electron backscattered scattering detection (EBSD), respertively. Residual stress was also calculated by using XRD cos2αsin2Ψ method.
　　Anisotropic grain growth was observed in all samples with TiN and Ti interlayer at different annealing temperatures of 200℃ and 250℃, and (111) nanotwinned copper transferred into (200) grains, and linear Σ3 twin boundary was observed in anisotropic grains. In addition, sputtered Cu bumps with TiN interlayer exhibit better thermal stability than that with Ti interlayer. We found that misorientation of grain boundary is the dominant factor for anisotropic grain growth because grains with high angle grain boundaries have higher mobility to trigger anisotropic grain growth. In addition, anisotropic grain growth occurs with misorienataion of grain boundary lager than 45∘ in this study. The anisotropic grain growth stops when it encounters with other anisotropic grains and the grain boundary changes into the low energy boundary, such as twin boundary and low angle grain boundary. Driving force of anisotropic grain growth is the competition between surface/ interface energy, strain energy, and grain boundary energy minimization, and high angle grain boundary is the dominant factor.

中文摘要 i
Abstract ii
致謝 iv
目錄 v
圖目錄 vii
表目錄 xi
第一章 簡介 1
第二章 文獻回顧 2
2.1 鍍膜方法 2
2.2 鈦性質 5
2.3 氮化鈦性質 5
2.4 雙晶 7
2.4.1共位晶界 7
2.4.2 變形雙晶、退火雙晶和成長雙晶 8
2.4.3 疊差能 8
2.5 奈米雙晶銅特性 13
2.5.1 超高機械強度與高導電性 13
2.5.2機械與熱穩定性 13
2.6 銅的異常晶粒成長 17
第三章 實驗步驟 20
3.1實驗設計 20
3.1.1第一道黃光微影製程 20
3.1.2深矽蝕刻製程 21
3.1.3濺鍍製程 21
3.1.4第二道黃光微影製程 22
3.1.5銅濕式蝕刻製程 23
3.1.6介層濕式蝕刻製程 23
3.1.7晶圓切割 23
3.2實驗分析 32
3.2.1退火實驗 32
3.2.2特性檢測 33
3.2.3性能量測 37
第四章 實驗結果 40
4.1微凸塊 40
4.2 退火實驗微結構與分析 42
4.2.1 介層 42
4.2.2 銅在鈦介層(Ti系列) 45
4.2.3 銅在氮化鈦介層(TiN系列) 64
4.2.4殘留應力 83
第五章 結果討論 85
5.1 退火實驗中的異向性晶粒成長現象 85
5.2 退火實驗中的異向性晶粒成長機制 87
5.3不同介層對退火的影響 93
5.4 不同溫度對退火的影響 95
5.5 TiN系列退火實驗對比 96
第六章 結論 100
第七章 未來工作 101
參考文獻 102

1. Liu, C.M., H.W. Lin, Y.S. Huang, Y.C. Chu, C. Chen, D.R. Lyu, K.N. Chen, and K.N. Tu, Low-temperature direct copper-to-copper bonding enabled by creep on (111) surfaces of nanotwinned Cu. Sci Rep, 2015. 5: p. 9734.
2. Lim, D.F., J. Wei, K.C. Leong, and C.S. Tan, Cu passivation for enhanced low temperature (⩽300°C) bonding in 3D integration. Microelectronic Engineering, 2013. 106: p. 144-148.
3. Zhang, X., O. Anderoglu, A. Misra, and H. Wang, Influence of deposition rate on the formation of growth twins in sputter-deposited 330 austenitic stainless steel films. Applied Physics Letters, 2007. 90(15): p. 153101.
4. Kelly, P.J. and R.D. Arnell, Magnetron sputtering a review of recent developments and applications. Vacuum, 2000. 56: p. 159-172.
5. Kelly, P.J. and R.D. Arnell, The influence of magnetron configuration on ion current density and deposition rate in a dual unbalanced magnetron sputtering system. Surface and Coating Technology, 1998. 108-109: p. 317-322.
6. Abbaschian, L.A.R. and R.E. Reed-hill, physical metallurgy principles.
7. Liu, C.-M., H.-W. Lin, C.-L. Lu, and C. Chen, Effect of grain orientations of Cu seed layers on the growth of <111>-oriented nanotwinned Cu. Scientific Reports, 2014. 4: p. 6123.
8. Zhang, X., H. Wang, X.H. Chen, L. Lu, K. Lu, R.G. Hoagland, and A. Misra, High-strength sputter-deposited Cu foils with preferred orientation of nanoscale growth twins. Applied Physics Letters, 2006. 88(17): p. 173116.
9. Chen, X.H., L. Lu, and K. Lu, Electrical resistivity of ultrafine-grained copper with nanoscale growth twins. Journal of Applied Physics, 2007. 102(8): p. 083708.
10. Beyerlein, I.J., X. Zhang, and A. Misra, Growth Twins and Deformation Twins in Metals. Annual Review of Materials Research, 2014. 44(1): p. 329-363.
11. Haasen, C.P., Physical Metallurgy. 1996.
12. Wu, X.L., S.G. Liao Xz Fau - Srinivasan, F. Srinivasan Sg Fau - Zhou, E.J. Zhou F Fau - Lavernia, R.Z. Lavernia Ej Fau - Valiev, Y.T. Valiev Rz Fau - Zhu, and Y.T. Zhu, New deformation twinning mechanism generates zero macroscopic strain in nanocrystalline metals. (0031-9007 (Print)).
13. Christian, J.W. and S. Mahajan, Deformation twinning. Progress in Materials Science, 1995. 39(1): p. 1-157.
14. Zhu, Y.T. and T.G. Langdon, Influence of grain size on deformation mechanisms: An extension to nanocrystalline materials. Materials Science and Engineering: A, 2005. 409(1): p. 234-242.
15. Suzuki, H. and C.S. Barrett, deformation twinning in silver-gold alloys. Acta Metallurgica, 1958. 6: p. 156-165.
16. Meyers, M.A., O. Vöhringer, and V.A. Lubarda, The onset of twinning in metals: a constitutive description. Acta Materialia, 2001. 49(19): p. 4025-4039.
17. Germain, V., J. Li, D. Ingert, Z.L. Wang, and M.-P. Pileni, Stacking Faults in Formation of Silver Nanodisks. The Journal of Physical Chemistry B, 2003. 107: p. 8717-8720.
18. Meng, G., Y. Shao, T. Zhang, Y. Zhang, and F. Wang, Synthesis and corrosion property of pure Ni with a high density of nanoscale twins. Electrochimica Acta, 2008. 53(20): p. 5923-5926.
19. Sun, F., G. Meng, T. Zhang, Y. Shao, F. Wang, C. Dong, and X. Li, Electrochemical corrosion behavior of nickel coating with high density nano-scale twins (NT) in solution with Cl−. Electrochimica Acta, 2009. 54(5): p. 1578-1583.
20. Chen, M., E. Ma, K.J. Hemker, H. Sheng, Y. Wang, and X. Cheng, Deformation Twinning in Nanocrystalline Aluminum. Science, 2003. 300: p. 1275-1277.
21. Meng, G., L. Wei, Y. Shao, T. Zhang, F. wang, C. Domg, and X. Li, high pitting corrosion resistance of pure aluminum with Nanoscale twins. Journal of The Electrochenmical Society, 2009. 156: p. C240-C245.
22. Zhang, X., O. Anderoglu, R.G. Hoagland, and A. Misra, Nanoscale growth twins in sputtered metal films. JOM, 2008. 60(9): p. 75-78.
23. Yan, F.K., G.Z. Liu, N.R. Tao, and K. Lu, Strength and ductility of 316L austenitic stainless steel strengthened by nano-scale twin bundles. Acta Materialia, 2012. 60(3): p. 1059-1071.
24. Dahlgren, S.D., W.L. Nicholson, M.D. Merz, W. Bollmann, J.F. Devlin, and R. Wang, Microstructural analysis and tensile properties of thick copper and nickel sputter deposits. Thin Solid Films, 1977. 40: p. 345-353.
25. Aifantis, K.E., Interfaces in crystalline materials. Procedia Engineering, 2009. 1(1): p. 167-170.
26. Lu, L., Y. Shen, X. Chen, L. Qian, and K. Lu, Ultrahigh Strength and High Electrical Conductivity in Copper. science, 2004: p. 422.
27. Zhao, Y., T.A. Furnish, M.E. Kassner, and A.M. Hodge, Thermal stability of highly nanotwinned copper: The role of grain boundaries and texture. Journal of Materials Research, 2012. 27(24): p. 3049-3057.
28. Anderoglu, O., A. Misra, H. Wang, and X. Zhang, Thermal stability of sputtered Cu films with nanoscale growth twins. Journal of Applied Physics, 2008. 103(9): p. 094322.
29. Xu, D., V. Sriram, V. Ozolins, J.-M. Yang, K.N. Tu, G.R. Stafford, C. Beauchamp, I. Zienert, H. Geisler, P. Hofmann, and E. Zschech, Nanotwin formation and its physical properties and effect on reliability of copper interconnects. Microelectronic Engineering, 2008. 85(10): p. 2155-2158.
30. Saldana, C., T.G. Murthy, M.R. Shankar, E.A. Stach, and S. Chandrasekar, Stabilizing nanostructured materials by coherent nanotwins and their grain boundary triple junction drag. Applied Physics Letters, 2009. 94(2): p. 021910.
31. Chen, H.-Y., The effect of interlayer on abnormal grain growth of Nanotwinned copper thin film during annealing process. 2015.
32. Huang, Y.-S., C.-M. Liu, W.-L. Chiu, and C. Chen, Grain growth in electroplated (111)-oriented nanotwinned Cu. Scripta Materialia, 2014. 89: p. 5-8.
33. Keller, R.M., S.P. Baker, and E. Arzt, Quantitative analysis of strengthening mechanisms in thin Cu films: Effects of film thickness, grain size, and passivation. Journal of Materials Research, 2011. 13(5): p. 1307-1317.
34. Vaidya, S. and A.K. Sinha, Effect of texture and grain structure on electromigration in Al-0.5%Cu thin films. Thin Solid Films, 1981. 75(3): p. 253-259.
35. Hommel, M. and O. Kraft, Deformation behavior of thin copper films on deformable substrates. Acta Materialia, 2001. 49(19): p. 3935-3947.
36. Vinci, R.P., E.M. Zielinski, and J.C. Bravman, Thermal strain and stress in copper thin films. Thin Solid Films, 1995. 262(1): p. 142-153.
37. Herbstein, F.H. and B.L. Averbach, The structure of lithium-magnesium solid solutions—II: Measurements of diffuse X-ray scattering. Acta Metallurgica, 1956. 4(4): p. 414-420.
38. Frost, H.J., C.V. Thompson, and D.T. Walton, Simulation of thin film grain structures—I. Grain growth stagnation. Acta Metallurgica et Materialia, 1990. 38(8): p. 1455-1462.
39. Frost, H.J., C.V. Thompson, and D.T. Walton, Simulation of thin film grain structures—II. Abnormal grain growth. Acta Metallurgica et Materialia, 1992. 40(4): p. 779-793.
40. Takewaki, T., H. Yamada, T. Shibata, T. Ohmi, and T. Nitta, Formation of giant-grain copper interconnects by a low-energy ion bombardment process for high-speed ULSIs. Materials Chemistry and Physics, 1995. 41(3): p. 182-191.
41. Greiser, J., P. Müllner, and E. Arzt, Abnormal growth of “giant” grains in silver thin films. Acta Materialia, 2001. 49(6): p. 1041-1050.
42. Lu, C.-L., H.-W. Lin, C.-M. Liu, Y.-S. Huang, T.-L. Lu, T.-C. Liu, H.-Y. Hsiao, C. Chen, J.-C. Kuo, and K.-N. Tu, Extremely anisotropic single-crystal growth in nanotwinned copper. NPG Asia Materials, 2014. 6(10): p. e135-e135.
43. Wang, S., E.A. Holm, J. Suni, M.H. Alvi, P.N. Kalu, and A.D. Rollett, Modeling the recrystallized grain size in single phase materials. Acta Materialia, 2011. 59(10): p. 3872-3882.
44. Holm, E.A., M.A. Miodownik, and A.D. Rollett, On abnormal subgrain growth and the origin of recrystallization nuclei. Acta Materialia, 2003. 51(9): p. 2701-2716.
45. Holm, E.A., T.D. Hoffmann, A.D. Rollett, and C.G. Roberts, Particle-assisted abnormal grain growth. IOP Conference Series: Materials Science and Engineering, 2015. 89(1): p. 012005.
46. Park, N.J., D.P. Field, M.M. Nowell, and P.R. Besser, Effect of film thickness on the evolution of annealing texture in sputtered copper films. Journal of Electronic Materials, 2005. 34(12): p. 1500-1508.
47. Sonnweber-Ribic, P., P. Gruber, G. Dehm, and E. Arzt, Texture transition in Cu thin films: Electron backscatter diffraction vs. X-ray diffraction. Acta Materialia, 2006. 54(15): p. 3863-3870.
48. Zielinski, E.M., R.P. Vinci, and J.C. Bravman, Effects of barrier layer and annealing on abnormal grain growth in copper thin films. Journal of Applied Physics, 1994. 76(8): p. 4516-4523.
49. Mechanics of Materials. 1996. p. 314.
50. Riege, S.P. and C.V. Thompson, modeling of texture evolution in copper interconnects annealed in trenches. Scripta Materialia, 1999. 41: p. 403-408.
51. Thompson, C.V. and R. Carel, Stress and grain growth in thin films. Journal of the Mechanics and Physics of Solids, 1996. 44(5): p. 657-673.
52. Sundquist, B.E., A direct determination of the anisotropy of the surface free energy of solid gold, silver, copper, nickel, and alpha and gamma iron. Acta Metallurgica, 1964. 12(1): p. 67-86.