在功率半導體的發展上，第三代半導體具有寬能隙、耐高溫等特性，故為目前發展半導體材料焦點之一。其中第三代半導體的氮化鋁具有直接能隙，且耐高溫等特性，除了可以發展深紫外光光學元件，氮化鋁亦適合最為其他氮化物之磊晶緩衝層；然而，氮化鋁磊晶薄膜多以異質磊晶成長，主要是因為氮化鋁基板難以大面積成長，因此本研究將以異質磊晶成長氮化鋁。

本研究中主要研究以電漿輔助分子束磊晶系統(Plasma-Assisted Molecular Beam Epitaxy，PA-MBE)將氮化鋁磊晶於碳化矽上，以此方法成長氮化鋁薄膜可獲得較高品質的磊晶薄膜。由於碳化矽表面粗糙度影響其之後磊晶薄膜晶體品質，故研究中首先會先探討碳化矽平坦化之研究，除了比較以氫蝕刻前後之碳化矽表面形貌差異，也比較經良好化學機械拋光之碳化矽表面粗糙度。

接著，研究成長之氮化鋁薄膜結構、表面形貌及晶體品質。從成長結果分析可知氮化鋁薄膜有成功磊晶於碳化矽基板上，由於氮化鋁成長參數並未控制在氮鋁比為一，故在表面形貌上有凸起小顆粒，之後再分析晶體之差排密度，從巨觀XRC及微觀TEM之結果來看，我們自己成長的氮化鋁薄膜有較多水平缺陷；而商用氮化鋁薄膜表面形貌有許多凹洞，以SEM分析其凹洞大小平均 ~ 300 nm2，並可在TEM之剖面圖可以看見凹洞深度佔薄膜約三分之一，接著分析商用氮化鋁薄膜之差排密度，從巨觀XRC及微觀TEM之結果來看，商用氮化鋁薄膜存在較多垂直方向之缺陷。

The third-generation semiconductors have the characteristics of wide energy gap and high-temperature resistance, which are the development for high-power and high-frequency device applications. The aluminum nitride can develop deep ultraviolet optical components due to its direct bandgap. Besides, aluminum nitride is suitable as the epitaxial buffer layer of other nitrides. However, aluminum nitride epitaxial thin films are grown by heteroepitaxy due to the difficulty of large area. Therefore, heteroepitaxial aluminum nitride has a huge capability to solve this problem.

In this study, the high-quality epitaxial aluminum nitride was grown on two-inch silicon carbide by plasma-assisted molecular beam epitaxy (PA-MBE). We discuss the planarization of silicon carbide since the surface morphology of silicon carbide affects the quality of the epitaxial thin film. First, we analyze the surface morphology of silicon carbide without hydrogen etching and silicon carbide with hydrogen etching at high temperature. Second, we investigate the surface morphology of silicon carbide via good chemical mechanical polishing (CMP), and CMP with hydrogen etching.

After that, we study the crystal structure, surface morphology, and crystal quality of the aluminum nitride thin film. From the results, the aluminum nitride film was successfully grown on the silicon carbide substrate. However, the growth parameters of aluminum nitride are not well controlled. The ratio of aluminum and nitrides is not equal to 1, so there are small hills on the thin film surface. Then, we analyze the dislocation density of the thin film. The results of macro XRC and micro TEM show that the aluminum nitride film grown by ourselves has many horizontal defects. We analyze the commercial aluminum nitride on silicon carbide to know that the thin film quality we grew is better or not. The results show that commercial film has many holes which have an average size of ~ 300 nm2 by SEM. It can be seen in the TEM cross-section images that the depth of holes occupy about one-third of the film. Finally, we analyze the dislocation density of commercial aluminum nitride films from XRC and TEM; we find that commercial aluminum nitride films have more defects in the vertical direction. Hence, these aluminum nitride films have different defects due to different growth parameters and environments.

摘要 ..............................................................I
Abstract.............................................................II
致謝 ............................................................III
目錄 .............................................................IV
圖目錄 .............................................................V
表目錄 ..........................................................VIII
第一章 簡介.........................................................1
1.1 簡介及原理......................................................1
1.1.1 碳化矽材料簡介................................................1
1.1.2 氮化鋁材料簡介................................................6
1.1.3 碳化矽表面平坦化..............................................12
1.1.4 晶體缺陷密度分析..............................................13
1.1.5 碳化矽上成長氮化鋁之研究理論與文獻回顧..........................15
1.2 論文結構簡介...................................................16
第二章 儀器介紹....................................................17
2.1 氫蝕刻加熱系統.................................................17
2.2 電漿輔助分子束磊晶系統(Plasma-assisted molecular beam epitaxy，PA-MBE).................................................................18
2.3 晶格結構及表面分析系統..........................................20
2.3.1 反射式高能電子繞射儀(Reflection high-energy electron diffraction，RHEED)..................................................20
2.3.2 高解析X光繞射儀(High resolution X-ray diffractometer，HRXRD).22
2.3.3 原子力顯微鏡(Atomic force microscope，AFM)...................24
2.3.4 掃描式電子顯微鏡 (Scanning electron microscope，SEM)..........26
2.3.5 穿透式電子顯微鏡 (Transmission electron microscope，TEM)......28
第三章 碳化矽上成長氮化鋁之研究及討論................................30
3.1 碳化矽經氫蝕刻之表面形貌分析.....................................30
3.2 碳化矽上成長氮化鋁之步驟........................................37
3.3 碳化矽上成長氮化鋁之高能量電子繞射分析............................39
3.4 碳化矽上成長氮化鋁之X光繞射分析..................................40
3.5 碳化矽上成長氮化鋁之表面形貌分析.................................47
3.6 碳化矽上成長氮化鋁之TEM分析.....................................51
第四章 結論及未來展望...............................................68
參考文獻 ..........................................................69

(1) Wu, J. The Development and Application of Semiconductor Materials. In 2020 7th International Forum on Electrical Engineering and Automation (IFEEA); IEEE, 2020; pp 153–156. https://doi.org/10.1109/IFEEA51475.2020.00039.
(2) Chang, W.-H.; Huang, Y.-C.; Lin, R.-J. 單晶碳化矽在微電子及微感測元件之 應用 Applications of Single Crystal SiC in Microelectronic Devices and Microsensors. 科儀新知 2003, 第二十四卷 (第四期), 4–14.
(3) Yazdi, G.; Iakimov, T.; Yakimova, R. Epitaxial Graphene on SiC: A Review of Growth and Characterization. Crystals (Basel) 2016, 6 (5), 53. https://doi.org/10.3390/cryst6050053.
(4) Philip J. Guichelaar. ACHESON PROCESS. In Carbide, nitride, and boride materials synthesis and processing; Weimer, A. W., Ed.; Chapman & Hall, 1997; pp 115–129.
(5) Katoh, Y.; Snead, L. L. Silicon Carbide and Its Composites for Nuclear Applications – Historical Overview. Journal of Nuclear Materials 2019, 526, 151849. https://doi.org/10.1016/j.jnucmat.2019.151849.
(6) Brezeanu, G. Silicon Carbide (SiC): A Short History. An Analytical Aproach for SiC Power Device Design. In Proceedings of the International Semiconductor Conference, CAS; Institute of Electrical and Electronics Engineers Inc., 2005; Vol. 2, pp 345–348. https://doi.org/10.1109/SMICND.2005.1558796.
(7) Borysiuk, J.; Sołtys, J.; Boek, R.; Piechota, J.; Krukowski, S.; Strupiński, W.; Baranowski, J. M.; Stȩpniewski, R. Role of Structure of C-Terminated 4H-SiC(0001̄) Surface in Growth of Graphene Layers: Transmission Electron Microscopy and Density Functional Theory Studies. Phys Rev B Condens Matter Mater Phys 2012, 85 (4). https://doi.org/10.1103/PhysRevB.85.045426.
(8) Abderrazak, H.; Hadj Hmi, E. S. B. Silicon Carbide: Synthesis and Properties. In Properties and Applications of Silicon Carbide; InTech, 2011. https://doi.org/10.5772/15736.
(9) Tairov, Y. M.; Tsvetkov, V. F. INVESTIGATION OF GROWTH PROCESSES OF INGOTS OF SILICON CARBIDE SINGLE CRYSTALS. J Cryst Growth 1978, 43, 209–212.
(10) Kuroda, N.; Shibahara, K.; YOO, W.; Nishino, S.; Matsunami, H. Step-Controlled VPE Growth 0f SiC Single Crystals at Low Temperatures. 1987, 227–230.
(11) Matsunami, H.; Kimoto, T. Step-Controlled Epitaxial Growth of SiC: High Quality Homoepitaxy. Materials Science and Engineering: R: Reports 1997, 20 (3), 125–166. https://doi.org/10.1016/S0927-796X(97)00005-3.
(12) Stephan Mueller, A. P. V. F. T. SEED AND SEEDHOLDER COMBINATIONS FOR HIGH QUALITY GROWTH OF LARGE SILICON CARBIDE SINGLE CRYSTALS; 2007.
(13) Fraga, M. A.; Bosi, M.; Negri, M. Silicon Carbide in Microsystem Technology — Thin Film Versus Bulk Material. In Advanced Silicon Carbide Devices and Processing; InTech, 2015. https://doi.org/10.5772/60970.
(14) Elasser, A.; Chow, T. P. Silicon Carbide Benefits and Advantages for Power Electronics Circuits and Systems. Proceedings of the IEEE 2002, 90 (6), 969–986. https://doi.org/10.1109/JPROC.2002.1021562.
(15) Sergey Lazarev aus Petropavlovsk, von. X-RAY INVESTIGATION OF DEFECTS IN III-NITRIDES AND THEIR ALLOYS; 2013.
(16) Choudhary, R. K.; Mishra, P.; Biswas, A.; Bidaye, A. C. Structural and Optical Properties of Aluminum Nitride Thin Films Deposited by Pulsed DC Magnetron Sputtering. ISRN Materials Science 2013, 2013, 1–5. https://doi.org/10.1155/2013/759462.
(17) Chaurasia, H.; Tripathi, S. K.; Bilgaiyan, K.; Pandey, A.; Mukhopadhyay, K.; Agarwal, K.; Prasad, N. E. Preparation and Properties of AlN (Aluminum Nitride) Powder/Thin Films by Single Source Precursor. New Journal of Chemistry 2019, 43 (4), 1900–1909. https://doi.org/10.1039/C8NJ04594A.
(18) L.A. Cunha, C.; C. Pimenta, T.; A. Fraga, M. Development and Applications of Aluminum Nitride Thin Film Technology. In Thin Film Deposition - Fundamentals, Processes, and Applications [Working Title]; IntechOpen, 2022. https://doi.org/10.5772/intechopen.106288.
(19) Ballestín-Fuertes, J.; Muñoz-Cruzado-Alba, J.; Sanz-Osorio, J. F.; Laporta-Puyal, E. Role of Wide Bandgap Materials in Power Electronics for Smart Grids Applications. Electronics (Basel) 2021, 10 (6), 677. https://doi.org/10.3390/electronics10060677.
(20) Liu, A.-C.; Tu, P.-T.; Langpoklakpam, C.; Huang, Y.-W.; Chang, Y.-T.; Tzou, A.-J.; Hsu, L.-H.; Lin, C.-H.; Kuo, H.-C.; Chang, E. Y. The Evolution of Manufacturing Technology for GaN Electronic Devices. Micromachines (Basel) 2021, 12 (7), 737. https://doi.org/10.3390/mi12070737.
(21) Ebling, D. G.; Rattunde, M.; Steinke, L.; Benz, K. W.; Winnacker, A. MBE of AlN on SiC and Influence of Structural Substrate Defects on Epitaxial Growth. J Cryst Growth 1999, 201–202, 411–414. https://doi.org/10.1016/S0022-0248(98)01364-5.
(22) Yu, R.; Liu, G.; Wang, G.; Chen, C.; Xu, M.; Zhou, H.; Wang, T.; Yu, J.; Zhao, G.; Zhang, L. Ultrawide-Bandgap Semiconductor AlN Crystals: Growth and Applications. J Mater Chem C Mater 2021, 9 (6), 1852–1873. https://doi.org/10.1039/D0TC04182C.
(23) Deng, H.; Endo, K.; Yamamura, K. Competition between Surface Modification and Abrasive Polishing: A Method of Controlling the Surface Atomic Structure of 4H-SiC (0001). Sci Rep 2015, 5 (1), 8947. https://doi.org/10.1038/srep08947.
(24) Shi, X.; Pan, G.; Zhou, Y.; Zou, C.; Gong, H. Extended Study of the Atomic Step-Terrace Structure on Hexagonal SiC (0001) by Chemical-Mechanical Planarization. Appl Surf Sci 2013, 284, 195–206. https://doi.org/10.1016/j.apsusc.2013.07.080.
(25) Ramachandran, V.; Brady, M. F.; Smith, A. R.; Feenstra, R. M.; Greve, D. W. Preparation of Atomically Flat Surfaces on Silicon Carbide Using Hydrogen Etching. J Electron Mater 1998, 27 (4), 308–312. https://doi.org/10.1007/s11664-998-0406-7.
(26) Kimoto, T.; Itoh, A.; Matsunami, H. Step Bunching in Chemical Vapor Deposition of 6H– and 4H–SiC on Vicinal SiC(0001) Faces. Appl Phys Lett 1995, 66 (26), 3645–3647. https://doi.org/10.1063/1.114127.
(27) Kawasuso, A.; Kojima, K.; Yoshikawa, M.; Itoh, H.; Narumi, K. Effect of Hydrogen Etching on 6H SiC Surface Morphology Studied by Reflection High-Energy Positron Diffraction and Atomic Force Microscopy. Appl Phys Lett 2000, 76 (9), 1119–1121. https://doi.org/10.1063/1.125957.
(28) Kumagawa, M.; Kuwabara, H.; Yamada, S. Hydrogen Etching of Silicon Carbide. Jpn J Appl Phys 1969, 8 (4), 421. https://doi.org/10.1143/JJAP.8.421.
(29) Bao, J.; Yasui, O.; Norimatsu, W.; Matsuda, K.; Kusunoki, M. Sequential Control of Step-Bunching during Graphene Growth on SiC (0001). Appl Phys Lett 2016, 109 (8), 081602. https://doi.org/10.1063/1.4961630.
(30) Chang, C. W.; Wadekar, P. V.; Guo, S. S.; Cheng, Y. J.; Chou, M.; Huang, H. C.; Hsieh, W. C.; Lai, W. C.; Chen, Q. Y.; Tu, L. W. Controlling Surface Morphology and Circumventing Secondary Phase Formation in Non-Polar m-GaN by Tuning Nitrogen Activity. J Electron Mater 2018, 47 (1), 359–367. https://doi.org/10.1007/s11664-017-5773-5.
(31) Wu, W.; Schaeublin, R. TEM Diffraction Contrast Images Simulation of Dislocations. J Microsc 2019, 275 (1), 11–23. https://doi.org/10.1111/jmi.12797.
(32) Yu, R.; Liu, G.; Wang, G.; Chen, C.; Xu, M.; Zhou, H.; Wang, T.; Yu, J.; Zhao, G.; Zhang, L. Ultrawide-Bandgap Semiconductor AlN Crystals: Growth and Applications. J Mater Chem C Mater 2021, 9 (6), 1852–1873. https://doi.org/10.1039/D0TC04182C.
(33) Tanaka, S.; Kern, R. S.; Davis, R. F. Initial Stage of Aluminum Nitride Film Growth on 6H‐silicon Carbide by Plasma‐assisted, Gas‐source Molecular Beam Epitaxy. Appl Phys Lett 1995, 66 (1), 37–39. https://doi.org/10.1063/1.114173.
(34) Ferro, G.; Okumura, H.; Yoshida, S. Growth Mode of AlN Epitaxial Layers on 6H-SiC by Plasma Assisted Molecular Beam Epitaxy. J Cryst Growth 2000, 209 (2–3), 415–418. https://doi.org/10.1016/S0022-0248(99)00582-5.
(35) Harada, M.; Ishikawa, Y.; Saito, T.; Shibata, N. Substrate-Polarity Dependence of AlN Single-Crystal Films Grown on 6H–SiC(0001) and (000-1) by Molecular Beam Epitaxy. Jpn J Appl Phys 2003, 42 (Part 1, No. 5A), 2829–2833. https://doi.org/10.1143/JJAP.42.2829.
(36) Le, D. D.; Kim, D. Y.; Hong, S.-K. Effect of First-Stage Growth Manipulation and Polarity of SiC Substrates on AlN Epilayers Grown Using Plasma-Assisted Molecular Beam Epitaxy. Korean Journal of Materials Research 2014, 24 (5), 266–270. https://doi.org/10.3740/MRSK.2014.24.5.266.
(37) Onojima, N.; Suda, J.; Matsunami, H. Lattice Relaxation Process of AlN Growth on Atomically Flat 6H-SiC Substrate in Molecular Beam Epitaxy. J Cryst Growth 2002, 237–239, 1012–1016. https://doi.org/10.1016/S0022-0248(01)02118-2.
(38) Fan, Z. Y.; Rong, G.; Newman, N.; Smith, D. J. Defect Annihilation in AlN Thin Films by Ultrahigh Temperature Processing. Appl Phys Lett 2000, 76 (14), 1839–1841. https://doi.org/10.1063/1.126185.
(39) 倪澤恩、李清庭. 分子束磊晶成長系統簡介. 真空科技 1994, 七卷三、四期, 38–42.
(40) 黃榮俊. 分子束磊晶技術之發展與磁性薄膜之製備應用. 科儀新知 2002, 第二十三卷第六期, 74–79.
(41) Pang, W.-Y.; Lo, I.; Hsieh, C.-H.; Hsu, Y.-C.; Chou, M.-C. Plasma-Assisted Molecular Beam Epitaxy for GaN Growth. Instruments Today 2010, 31, 65–72.
(42) N. Hattori, A.; Hattori, K. Creation and Evaluation of Atomically Ordered Side- and Facet-Surface Structures of Three-Dimensional Silicon Nano-Architectures. In 21st Century Surface Science - a Handbook; IntechOpen, 2020. https://doi.org/10.5772/intechopen.92860.
(43) 魏賢華. RHEED的構造與原理. In 反射高能電子衍射在薄膜生長中的表面分析; 科學出版社, 2012.
(44) Banerjee, D. X-Ray Diffraction (XRD).
(45) Akhtar, K.; Khan, S. A.; Khan, S. B.; Asiri, A. M. Scanning Electron Microscopy: Principle and Applications in Nanomaterials Characterization. In Handbook of Materials Characterization; Springer International Publishing: Cham, 2018; pp 113–145. https://doi.org/10.1007/978-3-319-92955-2_4.
(46) Franken, L. E.; Grünewald, K.; Boekema, E. J.; Stuart, M. C. A. A Technical Introduction to Transmission Electron Microscopy for Soft-Matter: Imaging, Possibilities, Choices, and Technical Developments. Small 2020, 16 (14), e1906198. https://doi.org/10.1002/smll.201906198.
(47) Bow, J.-S. 淺談TEM分析上常見的主要困惑A Short Summary of Some Typical Puzzles in TEM Analyses. 科儀新知 2022, 232, 71–86.
(48) Amelinckx, S.; Van Landuyt, J. Transmission Electron Microscopy. In Electron Microscopy: Principles and Fundamentals; John Wiley & Sons, 2001.