本研究製備金屬內連線釕透過臨場TEM加熱觀察其熱擴散反應，並分別與不同擴散阻礙層做成元件，研究其失去阻擋能力的反應溫度。以下將分為兩個部分探討：有無自身氧化層SiO2和TaTiN與不同MoS2厚度的阻擋差異。
在第一部份的研究中，發現無自身氧化層的試片在低至250 ℃便開始有Ru2Si3生成，反應至450 ℃後有明顯生成物跨越至Si層中，且Ru2Si3與Si會有磊晶成長關係，推測Si會不受阻礙地快速擴散進Ru層反應，使整層Ru反應為矽化物。反之，有自身氧化層的試片會在500~550 ℃開始擴散進Ru層，使部分Ru反應成Ru2Si3，但始終無生成物跨過介面，推測SiO2能夠阻擋Ru的擴散，防止Ru2Si3生成於Si層中，得知自身氧化層能提升擴散阻礙能力。
第二部分先加入過往所使用的TaTiN觀察擴散阻礙能力，並與不同厚度MoS2的阻礙效能進行比較，結果可得TaTiN能阻擋擴散至700 ℃，而無論多層、雙層及單層MoS2皆能阻擋Si的擴散至750 ℃。分析得知多層MoS2結構可允許Ru2Si3的穿越，而雙層及單層MoS2會在加熱至800 ℃後部分受不再完整，推測反應達MoS2的臨界損壞溫度允許Si原子擴散。最後為了解缺陷對MoS2作為擴散阻礙層的影響，因此利用氧電漿轟擊使單層MoS2產生缺陷，結果顯示其阻擋Si擴散的溫度降低至700 ℃，且反應後無MoS2殘存，證實富有缺陷的MoS2熱穩定性較低且易被破壞殆盡。
兩部分的結果證實沒有任何阻礙層的試片能夠生成Ru2Si3並與Si磊晶成長，相互比較後可得知自身氧化層搭配上TaTiN與MoS2有提升的作用，而兩種擴散阻礙層的熱穩定性皆有高於400 ℃的效能，有利於半導體金屬內連線的應用。此外，本實驗在每個溫度僅停留15分鐘，接著用較高溫度以加速性實驗概念進行探討。

In this study, ruthenium was prepared with different diffusion barriers for in-situ TEM heating experiments to observe its thermal diffusion reaction. The following studies will be separated into two parts: one is the effect of native oxide layer, and the other is the comparison between TaTiN and different thickness of MoS2.
In the first part, Ru/Si is found that Ru2Si3 began forming as low as 250 ℃, and then penetrates Si layer forming epitaxial growth between Ru2Si3 and Si after reacting to 450 ℃. It’s speculated that Si will rapidly diffuse into Ru layer and react with the entire layer, then Ru will interdiffuse towards Si layer. On the contrary, the sample with native oxide (Ru/SiO2/Si) will start Si diffusion at 500~550 ℃, so some grains have reacted into Ru2Si3, but no product will cross the interface. Thus, we conclude that SiO2 can block the diffusion of Ru and prevent Ru2Si3 from penetrating Si, confirming that native oxide can improve the diffusion barrier ability.
Second part of the study will compare the barrier ability of 5 nm TaTiN with different thickness of MoS2. The results show that TaTiN can block the diffusion up to 700 ℃, and regardless of MoS2 thickness, Si can be blocked up till 750 ℃. The analysis shows that layered structure of MoS2 can allow the inclusion of Ru2Si3, while 2L- and 1L-MoS2 will become partially incomplete to allow Si diffusing, indicating the critical temperature of MoS2 is the critical factor despite their thickness. Finally, to confirm the MoS2 failure reason, we used O2-plasma treatment on 1L-MoS2 to generate defects. Results show that the reaction temperature will lower to 700 ℃, and no p-1L-MoS2 remains, confirming the defect-rich MoS2 has lower thermal stability.
This experiment acts as accelerated results due to holding 15 min. at each temperature, and understanding barrier properties beneficial for semiconductor process.

摘要 I
Abstract II
致謝 III
目錄 IV
圖目錄 VII
表目錄 XII
第一章 緒論與文獻探討 1
1.1. 金屬內連線（Interconnect） 1
1.1.1. 銅金屬內連線之瓶頸 2
1.1.2. 銅與矽之擴散行為 5
1.1.3. 釕取代銅作為金屬內連線 7
1.1.4. 釕與矽之擴散行為 9
1.2. 擴散阻礙層 11
1.2.1. 高分子自組裝單分子膜（SAMs） 12
1.2.2. 氮化鈦（TiN）/氮化鉭（TaN） 14
1.2.3. 二維材料：石墨烯（Graphene） 15
1.2.4. 二維材料：過渡金屬二硫族化物－二硫化鉬（MoS2） 16
1.3. 二維材料 17
1.3.1. 二硫化鉬之基本性質 18
1.3.2. 二硫化鉬之合成 19
1.3.3. 二硫化鉬之層數檢測 21
1.3.4. 二硫化鉬進行電漿處理 22
1.4. 臨場電子顯微鏡觀測技術 (in-situ TEM observation) 23
1.4.1. 臨場加熱觀測技術 24
1.5. 研究動機 25
第二章 實驗方法與儀器 26
2.1. 實驗架構與步驟 26
2.1.1. 實驗架構 26
2.1.2. 化學氣相沉積法製備二硫化鉬 27
2.1.3. PMMA濕式轉移製程 28
2.1.4. 物理氣相沈積法 29
2.1.5. TEM臨場觀測試片製備 30
2.1.6. TEM臨場加熱步驟 32
2.2. 實驗儀器介紹 33
2.2.1. 單區加熱爐管 (Single Zone Furnace) 33
2.2.2. 光學顯微鏡 (Optical Microscope, OM) 34
2.2.3. 掃描式電子顯微鏡 (Scanning Electron Microscope, SEM) 35
2.2.4. X光繞射分析儀 (X-Ray Diffractometer, XRD) 36
2.2.5. 顯微拉曼光譜儀 (Micro-Raman Spectrometer) 37
2.2.6. 光激螢光光譜(Photoluminescence, PL) 38
2.2.7. 電漿表面改質系統(Plasma Treatment) 39
2.2.8. 原子力顯微鏡 (Atomic Force Microscope, AFM) 40
2.2.9. 旋轉塗佈機 (Spin coater) 41
2.2.10. 物理氣相沈積系統 (Physical Vapor Deposition) 42
2.2.11. 聚焦離子束顯微鏡 (Focused Ion Beam, FIB) 43
2.2.12. 穿透式電子顯微鏡 (Transmission Electron Microscope, TEM) 44
2.2.13. 電子顯微鏡臨場加熱系統 46
第三章 結果與討論 47
3.1. 單晶二硫化鉬之特徵分析 47
3.1.1. 合成之MoS2層數與結構檢測 47
3.1.2. 轉移後的MoS2層數與結構分析 49
3.1.3. 進行氧電漿處理後的單層MoS2結構分析 51
3.2. Ru/Si樣品 53
3.2.1. Ru/Si之TEM臨場加熱觀察擴散反應 54
3.2.2. Ru/SiO2/Si之TEM臨場加熱觀察擴散反應 58
3.2.3. 有無氧化層對擴散阻礙能力之影響 61
3.3. Ru/TaTiN/SiO2/Si樣品 62
3.3.1. TaTiN之TEM臨場加熱觀察擴散反應 (Ru/TaTiN/SiO2/Si) 62
3.4. Ru/MoS2/SiO2/Si元件 66
3.4.1. 多層MoS2之TEM臨場加熱觀察擴散反應 (Ru/multi-MoS2/SiO2/Si) 66
3.4.2. 雙層MoS2之TEM臨場加熱觀察擴散反應 (Ru/2L-MoS2/SiO2/Si) 71
3.4.3. 單層MoS2之TEM臨場加熱觀察擴散反應 (Ru/1L-MoS2/SiO2/Si) 74
3.4.4. MoS2厚度對擴散阻礙能力之影響 78
3.4.5. 進行氧電漿處理的單層MoS2之TEM臨場加熱觀察擴散反應 (Ru/p-1L-MoS2/SiO2/Si) 79
3.5. 所有參數之臨場加熱結果探討 83
第四章 結論 85
第五章 未來展望 86
參考文獻 87

1. Bernasconi R, et al. Review—Ruthenium as Diffusion Barrier Layer in Electronic Interconnects: Current Literature with a Focus on Electrochemical Deposition Methods. J Electrochem Soc 166, D3219-D3225 (2018).

2. Gupta T. Copper interconnect technology. Springer Science & Business Media (2010).

3. Gall D. The search for the most conductive metal for narrow interconnect lines. Journal of Applied Physics 127, 050901 (2020).

4. Haynes WM. CRC handbook of chemistry and physics, 95th Edition, 95th edn. CRC Press (2014).

5. Davis JA, et al. Interconnect limits on gigascale integration (GSI) in the 21st century. Proceedings of the IEEE 89, 305-324 (2001).

6. Tran T. Synthesis of Germanium-Tin Alloys by Ion Implantation and Pulsed Laser Melting: Towards a Group IV Direct Band Gap Semiconductor.) (2017).

7. Andricacos PC, et al. Damascene copper electroplating for chip interconnections. IBM Journal of Research and Development 42, 567-574 (1998).

8. Gladkikh A, et al. Activation Energy of Electromigration in Copper Thin Film Conductor Lines. MRS Proceedings 427, (2011).

9. Corn SH, et al. The copper–silicon interface: Composition and interdiffusion. Journal of Vacuum Science & Technology A 6, 1012-1016 (1988).

10. Gao X-X, et al. The interdiffusion and solid-state reaction of low-energy copper ions implanted in silicon. Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms 266, 2572-2575 (2008).

11. Weber ER. Transition metals in silicon. Applied Physics A 30, 1-22 (1983).

12. Chromik RR, et al. Thermodynamic and kinetic study of solid state reactions in the Cu-Si system. Journal of Applied Physics 86, 4273-4281 (1999).

13. Damayanti M, et al. Study of Ru barrier failure in the Cu/Ru/Si system. Journal of Materials Research 22, 2505-2511 (2007).

14. Adelmann C, et al. Alternative metals for advanced interconnects (2014).

15. Abe M, et al. Highly-oriented PVD Ruthenium Liner for Low-resistance Direct-plated Cu Interconnects. In: 2007 IEEE International Interconnect Technology Conferencee) (2007).

16. Dey S, et al. Atomic layer deposited ultrathin metal nitride barrier layers for ruthenium interconnect applications. Journal of Vacuum Science & Technology A 35, 03E109 (2017).

17. Kotsugi Y, et al. Atomic Layer Deposition of Ru for Replacing Cu-Interconnects. Chemistry of Materials 33, 5639-5651 (2021).

18. Choi D. Potential of Ruthenium and Cobalt as Next-generation Semiconductor Interconnects. Korean J Met Mater 56, 605-610 (2018).

19. Xunyuan Z, et al. Ruthenium interconnect resistivity and reliability at 48 nm pitch. In: 2016 IEEE International Interconnect Technology Conference / Advanced Metallization Conference (IITC/AMC)) (2016).

20. Varela Pedreira O, et al. Metal reliability mechanisms in Ruthenium interconnects (2020).

21. Petersson CS, et al. Silicides of ruthenium and osmium: Thin film reactions, diffusion, nucleation, and stability. Journal of Applied Physics 53, 4866-4883 (1982).

22. Matsui Y, et al. An oxidation barrier layer for metal–insulator–metal capacitors: ruthenium silicide. Thin Solid Films 437, 51-56 (2003).

23. Okamoto H. Ru-Si (ruthenium-silicon). Journal of Phase Equilibria and Diffusion 23, 388 (2002).

24. Li Z, et al. Recent Advances in Barrier Layer of Cu Interconnects. Materials (Basel) 13, 5049 (2020).

25. Lo C-L, et al. Studies of two-dimensional h-BN and MoS2 for potential diffusion barrier application in copper interconnect technology. npj 2D Materials and Applications 1, 1-7 (2017).

26. Singh M, et al. The role of self-assembled monolayers in electronic devices. Journal of Materials Chemistry C 8, 3938-3955 (2020).

27. Caro AM, et al. Bottom-Up Engineering of Subnanometer Copper Diffusion Barriers Using NH2-Derived Self-Assembled Monolayers. Advanced Functional Materials 20, 1125-1131 (2010).

28. Sun SC. CVD and PVD transition metal nitrides as diffusion barriers for Cu metallization. In: 1998 5th International Conference on Solid-State and Integrated Circuit Technology. Proceedings (Cat. No.98EX105)) (1998).

29. Wen LG, et al. Atomic Layer Deposition of Ruthenium with TiN Interface for Sub-10 nm Advanced Interconnects beyond Copper. ACS Applied Materials & Interfaces 8, 26119-26125 (2016).

30. and AEK, et al. Ultrathin Diffusion Barriers/Liners for Gigascale Copper Metallization. Annual Review of Materials Science 30, 363-385 (2000).

31. Ikeda S, et al. Film texture evolution in plasma treated TiN thin films. Journal of Applied Physics 86, 2300-2306 (1999).

32. Uhm J, et al. TiN Diffusion Barrier Grown by Atomic Layer Deposition Method for Cu Metallization. Japanese Journal of Applied Physics 40, 4657-4660 (2001).

33. Lee C, et al. The evolution of diffusion barriers in copper metallization. JOM 59, 44-49 (2007).

34. Novoselov KS, et al. Electric Field Effect in Atomically Thin Carbon Films. Science 306, 666-669 (2004).

35. Lee C, et al. Measurement of the Elastic Properties and Intrinsic Strength of Monolayer Graphene. Science 321, 385-388 (2008).

36. Balandin AA, et al. Superior Thermal Conductivity of Single-Layer Graphene. Nano Letters 8, 902-907 (2008).

37. Zhang Y, et al. Experimental observation of the quantum Hall effect and Berry's phase in graphene. Nature 438, 201-204 (2005).

38. Nguyen B-S, et al. 1-nm-thick graphene tri-layer as the ultimate copper diffusion barrier. Applied Physics Letters 104, 082105 (2014).

39. Hong J, et al. Graphene as an atomically thin barrier to Cu diffusion into Si. Nanoscale 6, 7503-7511 (2014).

40. Watson AJ, et al. Transfer of large-scale two-dimensional semiconductors: challenges and developments. 2D Materials 8, 032001 (2021).

41. Lo C, et al. Large-Area, Single-Layer Molybdenum Disulfide Synthesized at BEOL Compatible Temperature as Cu Diffusion Barrier. IEEE Electron Device Letters 39, 873-876 (2018).

42. Lattuada M, et al. Synthesis, properties and applications of Janus nanoparticles. Nano Today 6, 286-308 (2011).

43. Pumera M, et al. Layered transition-metal dichalcogenides (MoS2 and WS2) for sensing and biosensing. TrAC Trends in Analytical Chemistry 61, 49-53 (2014).

44. Radisavljevic B, et al. Single-layer MoS2 transistors. Nature Nanotechnology 6, 147-150 (2011).

45. Xiang Q, et al. Synergetic effect of MoS2 and graphene as cocatalysts for enhanced photocatalytic H2 production activity of TiO2 nanoparticles. Journal of the American Chemical Society 134, 6575-6578 (2012).

46. Jeon J, et al. Layer-controlled CVD growth of large-area two-dimensional MoS2 films. Nanoscale 7, 1688-1695 (2015).

47. Yin H, et al. Substrate effects on the CVD growth of MoS2 and WS2. Journal of Materials Science 55, 990-996 (2020).

48. Luo L, et al. Hydrothermal synthesis of MoS2 with controllable morphologies and its adsorption properties for bisphenol A. Journal of Saudi Chemical Society 23, 762-773 (2019).

49. Duraisamy S, et al. One-Step Hydrothermal Synthesis of Phase-Engineered MoS2/MoO3 Electrocatalysts for Hydrogen Evolution Reaction. ACS Applied Nano Materials 4, 2642-2656 (2021).

50. Chaudhary N, et al. Hydrothermal synthesis of MoS2 nanosheets for multiple wavelength optical sensing applications. Sensors and Actuators A: Physical 277, 190-198 (2018).

51. Li H, et al. Novel dual-petal nanostructured WS2@MoS2 with enhanced photocatalytic performance and a comprehensive first-principles investigation. Journal of Materials Chemistry A 3, 20225-20235 (2015).

52. Cho D-H, et al. Enhanced sulfurization reaction of molybdenum using a thermal cracker for forming two-dimensional MoS2 layers. Physical Chemistry Chemical Physics 20, 16193-16201 (2018).

53. Kim S, et al. Effects of plasma treatment on surface properties of ultrathin layered MoS2. 2D Materials 3, 035002 (2016).

54. Liu Y, et al. Layer-by-Layer Thinning of MoS2 by Plasma. ACS Nano 7, 4202-4209 (2013).

55. Islam M, et al. Electrical property tuning via defect engineering of single layer MoS2 by oxygen plasma. Nanoscale 6, (2014).

56. Peng Q, et al. Defect engineering of 2D monatomic-layer materials. Mod Phys Lett B 27, 1330017 (2013).

57. Chen Y, et al. Tuning Electronic Structure of Single Layer MoS2 through Defect and Interface Engineering. ACS Nano 12, 2569-2579 (2018).

58. Zhang Y, et al. The evolution of MoS2 properties under oxygen plasma treatment and its application in MoS2 based devices. Journal of Materials Science: Materials in Electronics 30, 18185-18190 (2019).

59. Chen Y, et al. Kinetic Competition Model and Size-Dependent Phase Selection in 1-D Nanostructures. Nano Letters 12, 3115-3120 (2012).

60. Hsueh Y-H, et al. In situ TEM observations of void movement in Ag nanowires affecting the electrical properties under biasing. Chemical Communications 57, 11221-11224 (2021).

61. Jacobsson D, et al. Interface dynamics and crystal phase switching in GaAs nanowires. Nature 531, 317-322 (2016).

62. Sutter E, et al. In situ liquid-cell electron microscopy of silver–palladium galvanic replacement reactions on silver nanoparticles. Nature Communications 5, 4946 (2014).

63. Huang Y, et al. In situ mechanical properties of individual ZnO nanowires and the mass measurement of nanoparticles. Journal of Physics: Condensed Matter 18, L179-L184 (2006).

64. Ferreira P, et al. In situ transmission electron microscopy. Mrs Bulletin 33, 83-90 (2008).

65. Hou A-Y, et al. Atomic-scale silicidation of low resistivity Ni-Si system through in-situ TEM investigation. Applied Surface Science 538, 148129 (2021).

66. Li L, et al. BEOL compatible graphene/Cu with improved electromigration lifetime for future interconnects. In: 2016 IEEE International Electron Devices Meeting (IEDM)) (2016).

67. Sasaki H, et al. Specimen preparation for high-resolution transmission electron microscopy using focused ion beam and Ar ion milling. J Electron Microsc (Tokyo) 53, 497-500 (2004).

68. Wolf SG, et al. STEM Tomography in Biology. In: Cellular Imaging: Electron Tomography and Related Techniques (ed Hanssen E). Springer International Publishing (2018).

69. Yue J, et al. Growth of Single-Layer MoS2 by Chemical Vapor Deposition on sapphire substrate. IOP Conference Series: Materials Science and Engineering 592, 012044 (2019).

70. Wen YY, et al. Synthesis of Monolayer MoS2 by CVD Approach. In: Proceedings of the 2nd Annual International Conference on Advanced Material Engineering (AME 2016)). Atlantis Press (2016).

71. Plechinger G, et al. Raman spectroscopy of the interlayer shear mode in few-layer MoS2 flakes. Applied Physics Letters 101, 101906 (2012).

72. Lee YH, et al. Synthesis of large-area MoS2 atomic layers with chemical vapor deposition. Adv Mater 24, 2320-2325 (2012).

73. Rice C, et al. Raman-scattering measurements and first-principles calculations of strain-induced phonon shifts in monolayer MoS2. Phys Rev B 87, 081307 (2013).

74. Michele B, et al. The effect of the substrate on the Raman and photoluminescence emission of single-layer MoS2. Nano Research 7, 561-571 (2014).

75. Smithe KKH, et al. Investigation of monolayer MX2 as sub-nanometer copper diffusion barriers. In: 2018 IEEE International Reliability Physics Symposium (IRPS)) (2018).

76. Le L, et al. Thermal stability of MoS2 encapsulated by graphene. Acta Physica Sinica 67, 226501 (2018).

77. Chen P, et al. Thermal Degradation of Monolayer MoS2 on SrTiO3 Supports. The Journal of Physical Chemistry C 123, 3876-3885 (2019).