臺灣博碩士論文加值系統

本研究的目標為磊晶成長鉍銅硒氧(BiCuSeO)薄膜及鐵酸鉍(BiFeO3)薄膜，並期望鉍銅硒氧薄膜及鐵酸鉍薄膜能依序以磊晶的方式成長至(001)及(110)鈦酸鍶單晶基板上。
實驗室曾嘗試以射頻磁控濺鍍法於(001)鈦酸鍶基板沉積鉍銅硒氧薄膜，但由於鍍率過快無法以磊晶方式成長，因此分別以兩種方式來達到降低鍍率之方法(1)於基板上方架設不鏽鋼網目來增加粒子散射(2)利用擋板開關秒數設置給粒子充份的時間擴散排列。使用不鏽鋼網目降低鍍率限制較多，依網目的開口面積比例達到不同速率的鍍率，使用120mesh於基板溫度400oC可以沉積出具有(001)優選方向的鉍銅硒氧薄膜，但仍然存在(110)方向，且使用不鏽鋼網目增加粒子散射之方式會造成薄膜表面平整度變差；使用擋板秒數設置，可以準確的控制不同速率的鍍率，於基板溫度400oC下擋板開1秒關30秒，即可磊晶出(001)鉍銅硒氧薄膜，膜厚約為40nm，鍍率約1.33nm/min，導電率約49.5 S×cm-1，透過精密的XRD分析晶格常數a、b軸拉長，c軸輕微壓縮，顯示未受基板晶格箝制，而是氧空缺存在使整體晶包體積變大，特別於a、b平面缺少氧原子束縛，使其拉長效果特別明顯，使用擋板秒數設置可以於不同基板溫度下成長(001)方向之鉍銅硒氧薄膜，但溫度高於500oC後，鉍銅硒氧相會出現高溫分解相。
本實驗中也嘗試於(110)鈦酸鍶基板上磊晶成長鉍銅硒氧，其唯有在基板溫度500oC能成長(001)之鉍銅硒氧薄膜，且不需透過其他方式降低鍍率；基板溫度低於500oC形成多晶的鉍銅硒氧相；基板溫度600oC可形成(001)鉍銅硒氧相，但伴隨高溫分解相。基板溫度500oC於(110)鈦酸鍶基板上磊晶的鉍銅硒氧薄膜，鍍率約為15nm/min、導電率為105 S×cm-1，其晶格常數a、b也是受到拉長與(001)鈦酸鍶沉積的鉍銅硒氧薄膜相同，以微氧條件退火證明氧空缺確實存在。
於(001)鉍銅硒氧薄膜沉積鐵酸鉍薄膜，鐵酸鉍於基板溫度600oC下才能得較佳的結晶度，而鉍銅硒氧相因鉍元素大量揮發無法於基板溫度600oC下成長，因此以一多鉍靶材濺鍍成長鉍銅硒氧薄膜，其確實可於基板溫度600oC下成長(001)鉍銅硒氧薄膜但伴隨些微雜相，此外鉍銅硒氧薄膜與鐵酸鉍薄膜交界處，部分的鉍銅硒氧會分解出現另一結構，由XRD與TEM元素分析結果為CuSeO5、Cu1.8Se及Bi2O3，其中CuSeO5與Cu1.8Se為鉍銅硒氧於高溫下常出現之雜相，而Bi2O3相應為鉍銅硒氧接觸鐵酸鉍薄膜中較高濃度的鉍與氧後，擴散入鉍銅硒氧薄膜表層所形成之雜相，當基板溫度越高分解相越嚴重，此分解相會造成鐵酸鉍無法磊晶至鉍銅硒氧薄膜上，因此改善及增加鉍銅硒氧的穩定性將成鉍銅硒氧材料應用的關鍵所在。

In this study, we attempted to grow epitaxial BiCuSeO (BCSO) films on (110) and (001) SrTiO3 (STO) substrates as the bottom electrode for the growth of multiferroic BiFeO3 (BFO) films. In our previous attempts, BCSO films of two in-plane orientations were obtained owing to the rapid deposition rate. So, in this work, we used two methods to reduce the rate. One was placing a stainless steel mesh above the substrate in order to scatter the sputtered atoms. Another one was controlling shutter opening time to adjust deposition rate. The films grown with the mesh were mainly (001) orientated but contained some (110) orientation and yet the film surface was rough. The films grown with the shutter had a unique (001) texture when the substrate temperature was 400 C and the shutter opening and closing times were 1 and 30 seconds, respectively. High-resolution X-ray diffraction (HRXRD) confirmed that the (001) oriented films were in-plane aligned as well, i.e. the grown BCSO films were epitaxial. Although bulk BCSO had larger a/b axes than STO, HRXRD showed that the a/b axes of BCSO films were stretched rather than compressed. Similarly, the c-axis of films was slightly shortened instead of being elongated. This was probably related to oxygen deficiency in the films. Cross-sectional transmission electron microscopy confirmed the epitaxial relationship between BCSO film and STO substrate. The resistivity of films measured at room temperature was 2.02×10-2 Ohmcm, which was good enough as the electrode. It was found that (001) BCSO epitaxial films could also be grown on the (110) oriented STO substrates. The BCSO films on (110) STO could be grown at very high rate, but only at the substrate temperature of 500 C. The resistivity of the BCSO epitaxial films on (110) STO was higher (9.55×10-3 Ohmcm). Preliminary attempts were made to grow epitaxial BFO films on BCSO. Polycrystalline BFO films of a pure phase were obtained, but the epitaxial growth has yet to be achieved.

摘要 I
Extended Abstract III
致謝 IX
目錄 X
表目錄 XII
圖目錄 XIII
第一章 緒論 1
1-1 前言 1
1-2 研究動機與目的 2
第二章 文獻回顧 3
2-1 鉍銅硒氧BiCuSeO 3
2-1-1 鉍銅硒氧晶體結構及電導特性 3
2-1-2 鉍銅硒氧之穩定性 4
2-1-3鉍銅硒氧薄膜製程 5
2-2 鐵酸鉍BiFeO3 6
2-3薄膜磊晶成長[27] 8
2-4射頻磁控濺鍍沉積簡介 9
第三章 實驗方法與分析儀器 14
3-1 實驗方法 14
3-1-1 固相反應法製作氧化物靶材 15
3-1-1-1鉍銅硒氧靶材製作 15
3-1-1-2鐵酸鉍靶材製作 17
3-1-2 基板準備 18
3-1-3 射頻磁控濺鍍沉積薄膜 18
3-2 使用藥品 19
3-3分析儀器及原理 20
3-3-1 X光繞射儀(X-ray Diffraction, XRD)[28] 20
3-3-2高解析掃描式電子顯微鏡(High Resolution Scanning Electron Microscope, HRSEM) 22
3-3-3穿透式電子顯微鏡(Transmission Electron Microscopy, TEM) 23
3-3-4原子力顯微鏡(Atomic Force Microscopy, AFM) 25
3-3-5霍爾量測系統(Hall measurement system) 26
第四章 結果與討論 28
4-1於(001)STO成長BiCuSeO 28
4-1-1 以不鏽鋼網目(Mesh)增加散射 28
4-1-1-1以不同mesh數實驗觀察降低鍍率的效果 29
4-1-1-2針對120mesh改變基板溫度 32
4-1-2 以設置sputter擋板開關秒數來達到降低鍍率之目的 35
4-1-2-1於120 mesh基板溫度400oC下改變擋板開關秒數沉積BiCuSeO薄膜 35
4-1-2-2基板溫度400oC下改變擋板開關秒數沉積BiCuSeO薄膜 37
4-1-2-3基板溫度400oC擋板開1秒關30秒沉積1小時BiCuSeO薄膜之結構與形貌分析 41
4-1-2-4提升基板溫度於(001)鈦酸鍶上成長鉍銅硒氧薄膜 50
4-2於(110)STO成長BiCuSeO 53
4-2-1改變基板溫度於(110)STO成長BiCuSeO 53
4-2-2於(110)SrTiO3基板溫度500oC上成長 BiCuSeO薄膜之結構與形貌分析 57
4-2-3以微量氧氣作背景進行退火處理藉以證明氧空缺的存在 63
4-2-4利用擋板改變基板溫度400 oC、500 oC之鍍率於(110)STO成長BiCuSeO 65
4-3於(001) BiCuSeO成長BiFeO3 67
4-3-1改變瓦數於(001)BiCuSeO成長鐵酸鉍薄膜 67
4-3-2改變氧分壓於(001)BiCuSeO成長鐵酸鉍薄膜 71
4-3-3改變基板溫度於(001)BiCuSeO成長鐵酸鉍薄膜 76
4-3-4多鉍靶材於600oC鍍製(001)BiCuSeO接續成長鐵酸鉍薄膜 78
4-3-5試圖利用退火改善鉍銅硒氧穩定性 80
第五章 結論 82
第六章 參考文獻 84

Nicola A. Spaldin, Manfred Fiebig, 'The Renaissance of Magnetoelectric Multiferroics', Science, 309(2005)391-392.
P. Fischer,M. Polomska,,I. Sosnowska,M. Szymanski, 'Temperature dependence of the crystal and magnetic structures of BiFeO3 ', Journal of Physics C:Solid State Physics ,13(1980)1931-1940.
Popov,Yu.F.,Kadomtseva,A.M.,Vorobev,G.P. and Zvezdin,A.K., 'Discovery of the linear magnetoelectric effect in magnetic ferroelectric BiFeO3 in a strong magnetic field', Ferroelectric,162(1994)135-140.
J. R. Teague, R. Gerson, and W. J. James, 'Dielectric Hysteresis in Single Crystal BiFeO3', Solid State Communications, 8 (1970), 1073.
W. J. Lin, W. C. Chang, and X. D. Qi, 'Exchange Bias and Magneto-Resistance in an All-Oxide Spin Valve with Multi-Ferroic BiFeO3 as the Pinning Layer', Acta Materialia, 61 (2013), 7444-7453.
林蔚叡, 博士論文, '以鐵酸鉍複鐵式材料為釘札層製作全氧化物自旋閥之研究', 成功大學材料科學及工程學系 (2014).
羅易平, 碩士論文, '鉍銅硒氧薄膜製備及結構分析', 成功大學材料科學及工程學系 (2017).
A. M. Kusainova, P. S. Berdonosov, L. G. Akselrud, L. N. Kholodkovskaya, V. A. Dolgikh, and B. A. Popovkin, 'New Layered Compounds with the General Composition (Mo) (Cuse), Where M=Bi, Nd, Gd, Dy, and BiOCuS - Syntheses and Crystal-Structure', Journal of Solid State Chemistry, 112 (1994), 189-191.
J. Suia, J. Lia, J. He, Y. L. Peic, D. Berardand, H. Wue, N. Dragoed, W. Caia and L. D. Zhao, 'Texturation Boosts the Thermoelectric Performance of BiCuSeO Oxyselenides', Energy ＆ Environmental Science, 6 (2013), 2916-2920.
A. P. Richard, J. A. Russell, A. Zakutayev, L. N. Zakharov, D. A. Keszler, and J. Tate, 'Synthesis, Structure, and Optical Properties of BiCuOCh (Ch=S, Se, and Te)', Journal of Solid State Chemistry, 187 (2012), 15-19.
L. D. Zhao, J. Q. He, D. Berardan, Y. H. Lin, J. F. Li, C. W. Nan, and N. Dragoe, 'BiCuSeO Oxyselenides: New Promising Thermoelectric Materials', Energy ＆ Environmental Science, 7 (2014), 2900-2924.
Hsiao,C.L. and X.Qi, 'The oxidation states of elements in pure and Ca-doped BiCuSeO thermoelectric oxides',Acta Materialia,102 (2016),88-96.
Celine Barreteau,David Berardan,David Berardan and Nita Dragoe, 'Studies on the thermal stability of BiCuSeO',Journal of Solid State Chemistry,222 (2015),53-59
A. Zakutayev, P. F. Newhouse, R. Kykyneshi, P. A. Hersh, D. A. Keszler, and J. Tate, 'Pulsed Laser Deposition of BiCuOSe Thin Films', Applied Physics a-Materials Science ＆ Processing, 102 (2011), 485-92.
X. L. Wu, J. L. Wang, H. R. Zhang, S. F. Wang, S. J. Zhai, Y. G. Li, D. Elhadj, and G. S. Fu, 'Epitaxial Growth and Thermoelectric Properties of c-axis Oriented Bi1-xPbxCuSeO Single Crystalline Thin Films', Crystengcomm, 17 (2015), 8697-8702.
G. Y. Yan, L. Wang, S. Qiao, X. L. Wu, S. F. Wang, and G. S. Fu, 'Light-Induced Transverse Voltage Effect in c-axis Inclined BiCuSeO Single Crystalline Thin Films', Optical Materials Express, 6 (2016), 558-565.
X. L. Wu, L. J. Gao, P. Roussel, E. Dogheche, J. L. Wang, G. S. Fu, and S. F. Wang, 'Growth of c-axis-Oriented BiCuSeO Thin Films Directly on Si Wafers', Journal of the American Ceramic Society, 99 (2016), 3367-3370.
Lingyun Wang, Guoying Yan, Shuaihang Hou, Shuang Guo, Jianglong Wang, Nian Fu, and Shufang Wang, 'Temperature-dependent LITT effect in c axis inclined BiCuSeO thin films', Optical Materials Express,57 (2018), 3061-3064.
Jung-Hoon Lee, Min-Ae Oak, Hyoung Joon Choi, Jong Yeog Sonc and Hyun Myung Jang, 'Rhombohedral–orthorhombic morphotropic phase boundary in BiFeO3-based multiferroics: first-principles prediction', Journal of Materials Chemistry, 22 (2012), 1667–1672.
M. Mahesh Kumar,V. R. Pallar,K. Srinivas and S. V. Suryanarayana, 'Ferroelectricity in a pure BiFeO3 ceramic', Applied Physics Letters, 76 (2000),2764.
T. Kimura,T. Goto,H. Shintani,K. Ishizaka,T. Arima and Y. Tokura, 'Magnetic control of ferroelectric polarization',Nature,55 (2003),426.
M. Fiebig,Th. Lottermoser,D. Fro ̈hlich,A. V. Goltsev and R. V. Pisarev, 'Observation of coupled magnetic and electric domains',Nature,818 (2002),419
M. I. Morozov,N. A. Lomanova,V. V. Gusarov, 'Specific features of BiFeO3 formation in a mixture of bismuth(Ⅲ) and iron(Ⅲ) oxides',Russian Journal of General Chemistry,73 (2003),1676-1680.
A. Mai ̂tre,M. Franc and J. C. Gachon, 'Experimental Study of the Bi2O3-Fe2O3 Pseudo-Binary System',Journal of Phase Equilibria and Diffusion,25 (2004),59-67.
Y. P. Wang,L. Zhou,M. F. Zhang,X. Y. Chen,J. M. Liu,Z. G. Liu, 'Roomtemperature saturated ferroelectric polarization in BiFeO3 ceramics synthesized by rapid liquid phase sintering',Applied Physics Letters,84 (2004),1730-1733.
J. G. Wu,J. Wang,' BiFeO3 thin films of (111)-orientation deposited on SrRuO3 buffered Pt/TiO2/SiO2/Si(100) substrates',Acta Materialia,58 (2010),1688-1697.
田民波, '薄膜技術與薄膜材料',五南(2007),339-445.
汪建民, '材料分析',中國材料科學學會(1998),47-53,353-359.