臺灣博碩士論文加值系統

本實驗是以分子束磊晶(Molecular beam epitaxy, MBE)系統成長磁性拓樸絕緣體Cry(Sb1-xBix)2-yTe3/(Sb1-xBix)2-yTe3/Cry(Sb1-xBix)2-yTe3三層(Trilayer)異質結構，希望利用本實驗室先前最好的參數來得到晶向與結構良好的樣品，並進行磁電性的分析。
在晶體結構的部分，首先利用反射式高能電子繞射儀(Reflection high-energy electron diffraction, RHEED)初步確認樣品各層的晶向為單晶薄膜，再利用X光繞射儀(X-ray diffraction, XRD)確定樣品各層皆以C軸方向成長且並無其他雜向。接著透過原子力顯微鏡(Atomic force microscope, AFM)確認樣品各層的平整度均相當平坦。藉由穿透式電子顯微鏡(Transmission electron microscope, TEM)觀察樣品，確認是以層狀排列的方式成長。元素組成的部分，利用X射線光電子能譜儀(X-ray photoelectron spectroscopy, XPS)與能量色散光譜儀(Energy dispersive spectrometer, EDS)分析樣品的元素組成無誤。經由以上的實驗，確定樣品的品質與結構良好。
磁性的部分，利用X光磁圓偏振二項性(X-ray magnetic circular dichroism, XMCD)與超導量子干涉儀(Super conducting quantum interference device, SQUID)進行量測，得知三層中磁性層的耦合會提升整體樣品的磁化強度，並藉由不同溫度的磁滯曲線來推算出樣品的居禮溫度。
電性的部分，利用物理性質量測系統(Physical properties measurement systems, PPMS)在低溫高磁場的環境量測中間層不同厚度的樣品，觀察到樣品具有量子異常霍爾效應及軸子絕緣體效應，且軸子絕緣體效應會隨中間層厚度增加而增強。

In this experiment, we grow the MTI/TI/MTI trilayer heterostructure thin film on the sapphire substrate by the molecular beam epitaxy (MBE) system, where MTI is Cry(BixSb1-x)2-yTe3, and TI is (BixSb1-x)2Te3. We change the growth time to adjust the thickness of the middle layer. The first experiment part is to confirm the quality and structure of each layer in the thin film is fine. We first use in-situ reflective high-energy electron diffraction (RHEED) and X-ray diffraction (XRD) to measure that the crystal structure of each layer is single crystal and grows along the c-axis direction. Then we use atomic force microscope (AFM) to observe the surface morphology and roughness. And we use transmission electron microscope (TEM) to show the layered structure in the thin film. In element analysist part, we use X-ray photoelectron spectroscopy (XPS) and energy dispersive spectrometer (EDS) to confirm the element component and ratio. In magnetic properties part, we use X-ray magnetic circular dichroism (XMCD) and super conducting quantum interference device (SQUID) to measure that the coupling of magnetic layers in trilayer will enhance the magnetization of the thin film and estimate the Curie temperature by the hysteresis curve of different temperature. Finally in electric properties part, we use physical properties measurement systems (PPMS) to measure the sample with different thickness of middle layer in low temperature, find the quantum anomalous Hall effect and axion insulator effect. The axion insulator effect will enhance with the thickening of middle layer, and is most effective when the thickness is 30nm.

摘要 i
Extended Abstract ii
誌謝 v
目錄 vi
圖目錄 ix
表目錄 xii
第一章 緒論 1
1-1 拓樸絕緣體的特性與發展 1
1-2 文獻回顧 4
1-2-1 文獻（一） 4
1-2-2 文獻（二） 7
1-3 研究動機 10
第二章 實驗相關原理 11
2-1 薄膜成長理論 11
2-1-1 薄膜沉積原理 11
2-1-2 薄膜成長模式 11
2-2 霍爾效應 14
2-2-1 霍爾效應(Hall Effect) 14
2-2-2 異常霍爾效應(Anomalous Hall Effect) 15
2-2-3 量子霍爾效應(Quantum Hall Effect) 15
2-2-4 自旋霍爾效應(Spin Hall Effect) 16
2-2-5 量子自旋霍爾效應(Quantum Spin Hall Efect) 16
2-2-6 量子異常霍爾效應(Quantum Anomalous Hall Effect) 17
第三章 實驗儀器介紹與製備流程 18
3-1 製程儀器與製備流程 18
3-1-1 分子束磊晶系統 18
3-1-2 MBE製備流程 25
3-1-3 黃光微影蝕刻製程儀器 27
3-1-4 黃光微影蝕刻製備流程 30
3-2 量測儀器 32
3-2-1 X光繞射儀(X-ray Diffractometer, XRD) 32
3-2-2 原子力顯微鏡(Atomic Force Microscopy, AFM) 34
3-2-3 X射線光電子能譜儀(X-ray Photoelectron Spectroscopy, XPS) 37
3-2-4 霍爾量測系統 38
3-2-5 物理性質量測系統(Physical Properties Measurement System, PPMS) 41
3-2-6 超導量子干涉儀(Superconducting Quantum Interference Device Vibrating Sample Magnetometer, SQUID VSM) 42
3-2-7 X光磁圓偏振二項性(X-ray Magnetic Circular Dichroism, XMCD) 43
3-2-8 穿透式電子顯微鏡(Transmission Electron Microscope, TEM) 44
第四章 實驗結果與討論 45
4-1 實驗大綱 45
4-2 SBTCr/SBT/SBTCr/Sapphire 異質結構 46
4-2-1 晶體結構 47
4-2-1-1 RHEED 47
4-2-1-2 XRD 48
4-2-1-3 TEM 49
4-2-2 表面形貌 52
4-2-2-1 AFM 52
4-2-3 元素組成 54
4-2-3-1 XPS 54
4-2-3-2 EDS 56
4-2-4 磁性分析 58
4-2-4-1 XMCD 58
4-2-4-2 SQUID 63
4-2-5 電性分析 70
4-2-5-1 PPMS 70
第五章 結論 79
第六章 參考文獻 80

C. L. Kane and E. J. Mele, "Quantum spin Hall effect in graphene," Phys Rev Lett, vol. 95, no. 22, p. 226801, Nov 25 2005, doi: 10.1103/PhysRevLett.95.226801.
C. L. Kane and E. J. Mele, "Z2 topological order and the quantum spin Hall effect," Phys Rev Lett, vol. 95, no. 14, p. 146802, Sep 30 2005, doi: 10.1103/PhysRevLett.95.146802.
B. A. Bernevig, L. Hughes Taylor, and S.-C. Zhang, "Quantum Spin Hall Effect and Topological Phase Transition in HgTe Quantum Wells," Science, vol. 314, no. 5806, pp. 1757-1761, 2006/12/15 2006, doi: 10.1126/science.1133734.
M. König et al., "Quantum Spin Hall Insulator State in HgTe Quantum Wells," Science, vol. 318, no. 5851, pp. 766-770, 2007/11/02 2007, doi: 10.1126/science.1148047.
X.-L. Qi and S.-C. Zhang, "The quantum spin Hall effect and topological insulators," Physics Today, vol. 63, no. 1, pp. 33-38, 2010, doi: 10.1063/1.3293411.
L. Fu and C. L. Kane, "Topological insulators with inversion symmetry," Physical Review B, vol. 76, no. 4, 2007, doi: 10.1103/PhysRevB.76.045302.
D. Hsieh et al., "A topological Dirac insulator in a quantum spin Hall phase," Nature, vol. 452, no. 7190, pp. 970-4, Apr 24 2008, doi: 10.1038/nature06843.
H. Zhang, C.-X. Liu, X.-L. Qi, X. Dai, Z. Fang, and S.-C. Zhang, "Topological insulators in Bi2Se3, Bi2Te3 and Sb2Te3 with a single Dirac cone on the surface," Nature Physics, vol. 5, no. 6, pp. 438-442, 2009, doi: 10.1038/nphys1270.
Y. Xia et al., "Observation of a large-gap topological-insulator class with a single Dirac cone on the surface," Nature Physics, vol. 5, no. 6, pp. 398-402, 2009, doi: 10.1038/nphys1274.
D. Hsieh et al., "Observation of Time-Reversal-Protected Single-Dirac-Cone Topological-Insulator States in Bi2Te3 and Sb2Te3," Physical Review Letters, vol. 103, no. 14, p. 146401, 09/28/ 2009, doi: 10.1103/PhysRevLett.103.146401.
J. Wang, B. Lian, X.-L. Qi, and S.-C. Zhang, "Quantized topological magnetoelectric effect of the zero-plateau quantum anomalous Hall state," Physical Review B, vol. 92, no. 8, 2015, doi: 10.1103/PhysRevB.92.081107.
J. Wang, B. Lian, and S.-C. Zhang, "Universal scaling of the quantum anomalous Hall plateau transition," Physical Review B, vol. 89, no. 8, 2014, doi: 10.1103/PhysRevB.89.085106.
Y. Feng et al., "Observation of the Zero Hall Plateau in a Quantum Anomalous Hall Insulator," Phys Rev Lett, vol. 115, no. 12, p. 126801, Sep 18 2015, doi: 10.1103/PhysRevLett.115.126801.
X. Kou et al., "Metal-to-insulator switching in quantum anomalous Hall states," Nat Commun, vol. 6, p. 8474, Oct 7 2015, doi: 10.1038/ncomms9474.
M. Mogi et al., "A magnetic heterostructure of topological insulators as a candidate for an axion insulator," Nat Mater, vol. 16, no. 5, pp. 516-521, May 2017, doi: 10.1038/nmat4855.
J. C. A. Huang, "pH. D Thesis," University of Illinois, 1992.
C. Z. Chang and M. Li, "Quantum anomalous Hall effect in time-reversal-symmetry breaking topological insulators," J Phys Condens Matter, vol. 28, no. 12, p. 123002, Mar 31 2016, doi: 10.1088/0953-8984/28/12/123002.
E. H. Hall, "On a New Action of the Magnet on Electric Currents," American Journal of Mathematics, vol. 2, no. 3, pp. 287-292, 1879, doi: 10.2307/2369245.
E. H. Hall, "XVIII. On the “Rotational Coefficient” in nickel and cobalt," The London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science, vol. 12, no. 74, pp. 157-172, 1881/09/01 1881, doi: 10.1080/14786448108627086.
K. v. Klitzing, G. Dorda, and M. Pepper, "New Method for High-Accuracy Determination of the Fine-Structure Constant Based on Quantized Hall Resistance," Physical Review Letters, vol. 45, no. 6, pp. 494-497, 08/11/ 1980, doi: 10.1103/PhysRevLett.45.494.
M. I. D'Yakonov and V. I. Perel', "Possibility of Orienting Electron Spins with Current," Soviet Journal of Experimental and Theoretical Physics Letters, vol. 13, p. 467, June 01, 1971 1971. [Online]. Available: https://ui.adsabs.harvard.edu/abs/1971JETPL..13..467D.
M. I. Dyakonov and V. I. Perel, "Current-induced spin orientation of electrons in semiconductors," Physics Letters A, vol. 35, no. 6, pp. 459-460, 1971/07/12/ 1971, doi: https://doi.org/10.1016/0375-9601(71)90196-4.
Y. K. Kato, R. C. Myers, A. C. Gossard, and D. D. Awschalom, "Observation of the Spin Hall Effect in Semiconductors," Science, vol. 306, no. 5703, pp. 1910-1913, 2004/12/10 2004, doi: 10.1126/science.1105514.
C.-X. Liu, X.-L. Qi, X. Dai, Z. Fang, and S.-C. Zhang, "Quantum Anomalous Hall Effect in Hg1-yMnyTe Quantum Wells," Physical Review Letters, vol. 101, no. 14, p. 146802, 10/01/ 2008, doi: 10.1103/PhysRevLett.101.146802.
C.-Z. Chang et al., "Experimental Observation of the Quantum Anomalous Hall Effect in a Magnetic Topological Insulator," Science, vol. 340, no. 6129, pp. 167-170, 2013/04/12 2013, doi: 10.1126/science.1234414.
A. Y. Cho and J. R. Arthur, "Molecular beam epitaxy," Progress in Solid State Chemistry, vol. 10, pp. 157-191, 1975/01/01/ 1975, doi: https://doi.org/10.1016/0079-6786(75)90005-9.
R. Gutzler, W. M. Heckl, and M. Lackinger, "Combination of a Knudsen effusion cell with a quartz crystal microbalance: in situ measurement of molecular evaporation rates with a fully functional deposition source," Rev Sci Instrum, vol. 81, no. 1, p. 015108, Jan 2010, doi: 10.1063/1.3292510.
劉昱宏, "利用分子束磊晶成長拓樸絕緣體鉍化硒參雜銻薄膜之特性分析與場效之研究應用," Ph.D., Physics, National Cheng Kung University, 2017.
董弈, "調控多元鉍化硒合金拓樸絕緣體其電子結構、傳輸及磁性研究," Ph.D., Physics, National Cheng Kung University, 2017.
張哲華, "厚度對於鉻及銻共摻硒化鉍拓樸絕緣體其磁電性影響之研究," Master, Physics, National Cheng Kung University, 2017.
許家傑, "磊晶拓樸絕緣體Cry(Sb1-xBix)2-yTe3之物理特性研究," Master, Physics, National Cheng Kung University, 2020.
彭鈺瑋, "利用分子束磊晶系統成長反鐵磁拓撲絕緣體MnBi2Te4單晶薄膜及其物理特性研究," Master, Physics, National Cheng Kung University, 2020.
楊鴻昌, "最敏感的感測元件SQUID及其前瞻性應用," 物理雙月刊, vol. 24:5, pp. 652-666, 2002.
A. Tcakaev et al., "Comparing magnetic ground-state properties of the V- and Cr-doped topological insulator (Bi,Sb)2Te3," Physical Review B, vol. 101, no. 4, 2020, doi: 10.1103/PhysRevB.101.045127.
M. Ye et al., "Carrier-mediated ferromagnetism in the magnetic topological insulator Cr-doped (Sb,Bi)2Te3," Nat Commun, vol. 6, p. 8913, Nov 19 2015, doi: 10.1038/ncomms9913.
Z. Zhou, Y.-J. Chien, and C. Uher, "Thin film dilute ferromagnetic semiconductorsSb2−xCrxTe3with a Curie temperature up to190K," Physical Review B, vol. 74, no. 22, 2006, doi: 10.1103/PhysRevB.74.224418.
Y. Feng et al., "Tunable chiral and helical edge state transport in a magnetic topological insulator bilayer," Physical Review B, vol. 100, no. 16, 2019, doi: 10.1103/PhysRevB.100.165403.