臺灣博碩士論文加值系統

稀磁性半導體薄膜能夠被應用在自旋電子學的領域，讓我們在很低的功率下有較快的操作速率。由於氧化鋅的寬能隙特性和鈷在氧化鋅中能展現良好磁矩等原因，氧化鋅摻雜鈷的材料很適合用來製作稀磁性的半導體。
本實驗所製備的薄膜有很大的電阻，因此薄膜的磁性應當是由氧空缺和束縛電子所形成的束縛磁極化子來產生的。實驗所製備的樣品要儘可能避免在薄膜中出現磁性離子的團簇與二次相位析出，因為當這些磁性析出物產生後會產生蕭基位障，而形成傳導電子散射中心，所以要對薄膜作XRD的晶格結構分析，希望薄膜能以C軸為優先成長的方向，再來是用電子顯微鏡觀察薄膜的表面形貌，希望能夠看到微小晶粒的出現，以期望薄膜中有較多的氧空缺來形成束縛磁極化子。最後再透過超導量子干涉儀進行磁滯曲線的測量，希望能展現室溫的鐵磁性。
本實驗觀察到薄膜的表面若是有較微小的晶粒，可以有比較明顯的磁滯現象，而透過在45 mtorr的500℃低壓退火製程30分鐘後，晶格結構會從原本的C軸改為以(103)為主要的成長方向。從文獻上的結果推論以此方向生長有助於介電常數的增加，且因為有縮短的晶格面距離故應有較大機會讓束縛磁極化子半徑重疊，進而提升了對齊磁離子磁矩的可能。增大膜厚，則是減少雜訊干擾的辦法。

Diluted magnetic semiconductors can utilize charge and spin degrees of freedom of a single device and could be applied to the spintronics. By virtue of the wide-bandgap characteristic of ZnO and the large magnetic moment of Co in ZnO, Co-doped ZnO material is ideal for fabricating the diluted magnetic semiconductor.
By using the instruments like XRD, SEM, and SQUID, we can examine the crystal structure, the surface morphology, and the magnetic behaviors of the deposited thin film respectively. We observed that as the grain size decreases, the measured hysteresis loop has more obvious remanance and coercivity. The phenomenon may be due to the richer oxygen vacancies of the sample with smaller grain size and can be illustrated by the bound magnetic polaron model.
If we annealed the as-deposited ZnCoO thin film under the pressure of 45 mtorr, the resulted sample would display higher remanence and larger saturated magnetization. We infer that the improvement is due to the higher dielectric constant and lower d-spacing of the (103) crystal plane when compared with the (002) one.

中文摘要...................................................i
英文摘要................................................. ii
誌謝 ................................................... iii
目錄 .................................................... iv
表目錄.................................................. vii
圖目錄................................................. viii
第一章 緒論............................................... 1
1.1 前言................................................ 1
1.2 研究動機與目的...................................... 4
第二章 理論基礎與文獻回顧................................ 10
2.1 磁學理論............................................10
2.1.1 磁矩來源........................................10
2.1.2 磁性分類........................................12
2.1.3 磁振子..........................................13
2.1.4 鐵磁疇..........................................14
2.1.5 布洛赫牆........................................15
2.1.6 矯頑力與磁滯現象................................15
2.1.7 單一磁疇粒子的應用..............................16
2.2 稀磁性半導體簡介....................................17
2.3 稀磁性半導體歷史發展................................21
2.3.1 2000年以前文獻回顧..............................22
2.3.2 Ueda團隊研究成果................................22
2.3.3 金重勳團隊研究成果..............................24
2.3.4 C. H. Patterson的研究成果.......................25
2.3.5 黃榮俊研究團隊之研究............................25
2.3.6 劉軍雄研究團隊的研究成果........................27
2.3.7 許小紅教授等人的研究成果........................29
2.3.8 文獻探討........................................30
2.4 描述物質鐵磁特性的理論模型..........................31
2.4.1 分子場理論......................................31
2.4.2 平均場理論......................................32
2.5 磁性來源............................................34
2.5.1 交換交互作用理論................................35
2.5.2 雙交換交互作用模型..............................36
2.5.3 超交換交互作用模型..............................37
2.5.4 交互巡迴式理論..................................39
2.5.5 RKKY交互作用....................................40
2.5.6 束縛載子交互作用模型............................41
2.5.7 束縛磁極化子模型................................42
2.5.8 探討圍觀的磁性來源..............................43
2.6 ZnO結構與特性.......................................44
2.6.1 ZnO晶格結構與特性...............................45
2.6.2 過渡金屬元素在ZnO的溶解度.......................47
2.6.3 製程條件對ZnO薄膜的影響.........................48
2.7 製備氧化鋅薄膜之方法................................49
2.8 濺鍍原理............................................50
2.8.1 電漿原理........................................51
2.8.2 平均自由路徑....................................53
2.8.3 磁控濺鍍原理....................................54
2.8.4 射頻濺鍍原理....................................55
2.9 薄膜沉積原理........................................56
第三章 實驗流程與架構.....................................59
3.1 實驗流程............................................59
3.1.1 基板材切與清洗..................................59
3.1.2 實驗材料與靶材壓製..............................61
3.2 濺鍍系統............................................62
3.2.1 濺鍍流程........................................63
3.3 量測儀器............................................64
3.3.1 X-Ray繞射分析系統...............................64
3.3.2 EDS能量色散光譜儀...............................66
3.3.3 SEM掃描式電子顯微鏡.............................67
3.3.4 SQUID超導量子干涉儀.............................68
第四章 實驗結果與討論.....................................70
4.1 氧化鋅不同成長製程之探討............................70
4.1.1 不同RF電漿功率..................................74
4.1.2 不同成長時間....................................75
4.1.3 不同製程溫度....................................76
4.1.4 不同腔體壓力....................................78
4.1.5 不同氣體流量....................................78
4.1.6 通入氮氣時的比較................................80
4.1.7 不同退火製程的比較..............................81
4.1.8 不同溫度的繞射峰值角度偏移......................82
4.2 ZnO摻雜Co薄膜的晶格結構分析.........................82
4.3 量測ZnCoO薄膜的能量色散光譜.........................86
4.4 掃描式電子顯微鏡分析................................88
4.4.1 膜厚的量測..................................... 88
4.4.2 表面形貌的拍攝..................................90
4.5 超導量子干涉儀量測結果..............................94
4.5.1 不同摻雜濃度與製程參數的薄膜量測結果............94
4.5.2 增加薄膜中的載子濃度後的磁滯曲線量測結果........99
4.5.3 退火處理對磁性的影響...........................100
4.5.4 磁偶極矩的穩定性量測...........................104
第五章 結論..............................................105
參考文獻.................................................106
附錄
A 電子內部的磁荷分不理論.............................. 114
A.1 理論基礎........................................ 114
A.2 由電子內部的磁荷理論解釋物理現象................ 118

[1] 宋秉純，p-type ZnO薄膜摻雜Mn之研究，碩士論文，國立台北科技大學光電工程研究所，台北，2009。
[2] S. J. Pearton, C. R. Abernathy, D. P. Norton, A. F. Hebard, Y. D. Park, L. A. Boatner, J. D. Budai, “Advances in wide bandgap materials for semiconductor spintronics,”Material Science and Engineering R, Vol. 40, 2003, pp. 137-168.
[3] C. Liu, F. Yun, H. Morkoç, “Ferromagnetism of ZnO and GaN: A Review,” Journal of Materials Science: Materials in Electronics, Vol. 16, No. 9, 2005, pp. 555.
[4] H. Ohno, “Making Nonmagnetic Semiconductors Ferromagnetic,” Science, Vol. 281, 1998, pp. 951.
[5] T. Fukumura, Zhengwu Jin, M. Kawasaki, T. Shono, T. Hasegawa, S. Koshihara, and H. Koinuma, “Magnetic properties of Mn-doped ZnO,” Applied Physics Letters, Vol. 78, 2001, pp. 958-960.
[6] S. J. Pearton, D. P. Norton, K. Ip, Y. W. Heo, T. Steiner, “Recent progress in precessing and properties of ZnO,” Superlattices and Microstructures, Vol. 34, 2003, pp. 3-32.
[7] Gen-Hua Ji, Zheng-Bin Gu, Ming-Hui Lu, Di Wu, “Ferromagnetism in Mn and Sb co-doped ZnO films,” J. Phys.: Condens. Matter, Vol. 20, 2008, pp. 425207.
[8] T. Dietl, H. Ohno, F. Matsukura, J. Cibert, D. Ferrand, “Zener Model Description of Ferromagnetism in Zinc-Blende Magnetic Semiconductors,” Science, Vol. 287, 2000, pp. 1019-1021.
[9] G. D. Mahan, “Intrinsic defects in ZnO varistors,” J. Appl. Phys., Vol. 54, 1983, pp. 3825.
[10] Fumiyasu Oba, Shigeto R. Nishitani, Seiji Isotani, and Hirohiko Adachi, “Energetics of native defects in ZnO,” J. Appl. Phys., Vol. 90, 2001, pp. 824.
[11] S. B. Zhang, S. H. Wei, and A. Zunger, “A phenomenological model for systematization and prediction of doping limits in II–VI and I–III–VI2 compounds,” J. Appl. Phys., Vol. 83, 1998, pp. 3192.
[12] K. Sato and H. Katayama-Yoshida, “Material Design for Transparent Ferromagnets with ZnO-Based Magnetic Semiconductors,” Jpn. J. Appl. Phys., Part 2, Vol. 39, No. 6B, 2000, L555-L558.
[13] Ü. Özgür, Ya. I. Alivov, C. Liu, A. Teke, M. A. Reshchikov, S. Doğan, V. Avrutin, S. –J. Cho, and H. Morkoç, “A comprehensive review of ZnO materials and devices,” Journal of applied physics, Vol. 98, 2005, pp. 041301.
[14] Kenji Ueda, Hitoshi Tabata, and Tomoji Kawai, “Magnetic and electric properties of transition-metal-doped ZnO films,” Applied Physics Letters, Vol. 79, 2001, pp. 988.
[15] J. M. D. Coey, M. Venkatesan and C. B. Fitzgerald, “Donor impurity band exchange in dilute ferromagnetic oxides,” Nature Materials, Vol. 4, 2005, pp. 173.
[16] A. S. Risbud, N. A. Spaldin, Z. Q. Chen, S. Stemmer, and Ram Sechadri, “Magnetism in polycrystalline cobalt-substituted zinc oxide,” Phys. Rev. B, Vol. 68, 2003, pp. 205202.
[17] X. C. Liu, E. W. Shi, Z. Z. Chen, H. W. Zhang, B. Xiao, and L. X. Song, “High-temperature ferromagnetism in (Co, Al)-codoped ZnO powers,” Applied Physics Letters, Vol. 88, 2006, pp. 252503.
[18] V. K. Sharma and G. D. Varma, “Effect of Al and Sb doping on the magnetic properties of ZnMnO and ZnCoO,” Journal of Applied Physics, Vol. 105, 2009, pp. 07C510.
[19] Y. Belghazi, D. Stoeffler, S. Colis, G. Schmerber, C. Ulhaq-Bouillet, J. L. Rehspringer, A. Berrada, H. Aubriet, J. Petersen, C. Becker, D. Ruch, and A. Dina, “Magnetic properties of Al-doped Zn0.95Co0.05O films: Experiment and theory,” Journal of Applied Physics, Vol. 105, 2009, pp. 113904.
[20] Charles Kittel, Introduction to Solid State Physics, 8th Ed. USA: John Wiley & Sons, Inc., 2005, pp. 297-357.
[21] Gengyun Li, What is the electron spin?, Sunnyvale: Spin Publishing, 2003, pp. 26.
[22] Michael E. Flatté, “Spintronics,” IEEE TRANSACTIONS ON ELECTRON DEVICES, Vol. 54, No. 5, 2007, pp. 907-920.
[23] 李名揚，「2007年諾貝爾物理獎得主費赫的巨磁阻世界」，科學人，第87期，2007，第82-87頁。
[24] J. Kossut and W. Dobrowolski, Edited by K. H. J. Buschow, Handbook of magnetic Material, Vol. 7, Amsterdam: Elsevier, 1993, pp. 231-305.
[25] T. Dietl, Edited by T.S. Moss, Handbook on Semiconductors, Vol. 3b, Amsterdam: North-Holland, 1994, pp. 1251.
[26] T. Baron, S. Tatarenko, K. Saminadayar, N. Magnea, and J. Fontenille, “Plasma nitrogen doping of ZnTe, Cd1−xZnxTe, and CdTe by molecular beam epitaxy,” Appl. Phys. Lett., Vol. 65, 1994, pp. 1284-1286.
[27] A. Haury, A. Wasiela, A. Arnoult, J. Cibert, S. Tatarenko, T. Dietl, and Y. Merle d''Aubigné, “Observation of a Ferromagnetic Transition Induced by Two-Dimensional Hole Gas in Modulation-Doped CdMnTe Quantum Wells,” Phys. Rev. Lett., Vol. 79, 1997, pp. 511-514.
[28] D. Ferrand, J. Cibert, C. Bourgognon, S. Tatarenko, A. Wasiela, G. Fishman, A. Bonanni, H. Sitter, S. Kolenik, J. Jaroszyski, A. Barcz, T. Dietl, “Carrier-induced ferromagnetic interactions in p-doped Zn(1−x)MnxTe epilayers,” J. Cryst. Growth, Vol. 214-215, 2000, pp. 387-390.
[29] Hung-Ta Lin, Tsung-Shune Chin, Jhy-Chau Shih, Show-Hua Lin, Tzay-Ming Hong, Rong-Tan Huang, Fu-Rong Chen, and Ji-Jung Kai, “Enhancement of ferromagnetic properties in Zn1-xCoxO by additional Cu doping,” Appl. Phys. Lett., Vol. 85, No. 4, 2004, pp. 621-623.
[30] C. H. Patterson, “Role of defects in ferromagnetism in Zn1-xCoxO: Ahybrid density-functional study,” Physical Review B, Vol. 74, 2006, pp. 144432.
[31] H. S. Hsu and J. C. A. Huang, S. F. Chen, and C. P. Liu, “Role of grain boundary and grain defects on ferromagnetism in Co:ZnO films,” APPLIED PHYSICS LETTERS, Vol. 90, 2007, pp. 102506.
[32] X. J. Liu, C. Song, F. Zeng and F. Pan, “Enhancement of electrical and ferromagnetic properties by additional Al doping in Co:ZnO thin films,” J. Phys.: Condens. Matter, Vol. 19, 2007, pp. 296208-296217.
[33] Xiao-Hong Xu, Xiu-Fang Qin, Feng-Xing Jiang, Xiao-Li Li, Ya Chen, G. A. Gehring, “The dopant concentration and annealing temperature dependence of ferromagnetism in Co-doped ZnO thin films,” Applied Surface Science, Vol. 254, 2008, pp. 4956-4960.
[34] 李國棟，當代磁學，北京：中國科學技術大學出版社，1999，第55-57頁。
[35] C. Zener, “Interaction between the d-Shells in the Transition Metals. II. Ferromagnetic Compounds of Manganese with Perovskite Structure,” Phys. Rev., Vol. 82, 1951, pp. 403.
[36] 邱淑琳，磊晶單雙晶氧化鋅摻雜鈷稀磁性半導體磁性來源之研究，碩士論文，國立成功大學物理研究所，台南，2007。
[37] Wikipedia article, “Double Exchange Mechanism” (Wikipedia, 2010). http://en.wikipedia.org/wiki/Double-exchange_mechanism.
[38] P. W. Anderson, “Antiferromagnetism. Theory of Superexchange Interaction,” Physical Review, Vol. 79, No. 2, 1950, pp. 350-356.
[39] M. A. Ruderman and C. Kittel, “Indirect Exchange Coupling of Nuclear Magnetic Moments by Conduction Electrons,” Physical Review, Vol. 96, No. 1, 1954, pp. 99-102.
[40] Yu P, Tang ZK, Wong GKL, Kawaski M, Ohtomo A, Koinuma H., In: Scheffler M, Zimmermann R, editors. “Room temperature luminescence and stimulated UV emission from ZnO,” Proceedings of the 23rd international conference on the physics of semiconductors, Singapore, 1996.
[41] T. Sekiguchi, N. Ohashi, Y. Terada, “Effect of Hydrogenation on ZnO Luminescence,” Jpn. J. Phys., Vol. 36, 1997, pp. L289-L291.
[42] Dongping Zhang, Ping Fan, Xingmin Cai, Jianjun Huang, Lili Ru, Zhuanghao Zheng, Guangxing Liang and Yukun Huang, “Properties of ZnO thin films deposited by DC reactive magnetron sputtering under different plasma power,” Applied Physics A, Vol. 97, No. 2, 2009, pp. 437-441.
[43] Zhengwu Jin, T. Fukumura, and M. Kawasaki, Appl. Phys. Lett. Vol. 78, No. 24, 2001, pp. 11.
[44] F.C.M. VAN DE POL, F.R. BLOM and Th. J.A. POPMA, “R.f. planar magnetron sputtered ZnO films I: Structural properties,” Thin Solid Films, Vol. 204, 1991, pp. 349-364.
[45] B. T. Khuri-Yakub, G. S. Kino and P. Galle, “Studies of the optimum conditions for growth of rf‐sputtered ZnO films,” J. Appl. Phys., Vol. 46, 1975, pp. 3266-3272.
[46] Sandeep Srivastav, C. V. R. Vasant Kumar and A Mansingh, “Effect of oxygen on the physical parameters of RF sputtered ZnO thin film,” J. Phys. D: Appl. Phys.,
Vol. 22, No. 11, 1989, pp. 1768-1772.
[47] F. S. Hickernell, “dc triode sputtered zinc oxide surface elastic wave transducers” J. Appl. Phys., Vol. 44, 1973, pp. 1061-1071.
[48] Ki Hyun Yoon, Ji-Won Choi, Dong-Heon Lee, “Characteristics of ZnO thin films deposited onto Al / Si substrates by rf magnetron sputtering” Thin Solid Films, Vol. 302, 1997, pp. 116-121.
[49] M.F. Ogawa, Y. Natsume, T. Hirayama, “Preparation and electrical properties of undoped zinc oxide films by CVD,” Journal of Material Science Letters, Vol. 9, No. 11, 1990, pp. 1351-1353.
[50] S. Major, A. Banerjee and K. L. Chopra, “Highly transparent and conducting indium-doped zinc oxide films by spray pyrolysis,” Thin Solid Films, Vol. 108, 1983, pp. 333-340.
[51] N. J. Ianno, L. McConville, N. Shaikh, S. Pittal and P. G. Snyder, “Characterization of pulsed laser deposited zinc oxide,” Thin Solid Films, Vol. 220, 1992, pp. 92-99.
[52] J. S. Kim, H. A. Marzouk and P. J. Rrucroft, “Characterization of high quality c axis oriented ZnO thin films grown by metal organic chemical vapor deposition using zinc acetate as source material,” Thin Solid Films, Vol. 217, 1992, pp. 133-137.
[53] T. Okamura, Y. Seki, S. Nagakari, and H. Okushi, “Preparation of n-ZnO/p-Si Heterojunction by Sol-Gel Process,” Jpn. J. Appl. Phys., Vol. 31, 1992, pp. L762-L764.
[54] W. S. Law and S.J. Fonash, “Highly transparent and conducting zinc oxide films deposited by activated reactive evaporation,” J. Electron Mater., Vol. 16, No. 3, 1987, pp. 141-149.
[55] S.M. Rossnagel et al., Handbook of Plasma Processing Technology, Park Ridge, New Jersey: Noyes Publications, 1982.
[56] Brain Campman, Plasma, Glow Discharge Process, New York: John Wiley & Sons, 1980, Chap. 3.
[57] 吳俊明，以RF磁控濺鍍法在塑膠基材上沉積銅膜之性質研究，碩士論文，國立成功大學材料科學及工程學系，台南，2003。
[58] Hong Xiao著，羅正忠 張鼎張 譯，半導體製造技術導論，台北：台灣培生教育出版股份有限公司，2004。
[59] 陳靜怡，氧化鋅中介層對ITO透明導電膜性質之影響，碩士論文，國立成功大學材料科學及工程學系，台南，2002。
[60] “PVD - physical vapor deposition” (Wikimedia) http://www.umms.sav.sk/index.php?ID=415.
[61] ETA FILM Technology Inc. General Introduction, “Physical Vapor Deposition - Sputtering” (ETA FILM Technology Inc. Coating Introduction) http://www.etafilm.com.tw/PVD_Sputtering_Deposition.html.
[62] 汪吉祥，ZnO/MgZnO發光二極體的光電特性，碩士論文，中華技術學院電子工程研究所，2005。
[63] 林瑞樺，以濺鍍法成長摻銻氧化鋅薄膜，碩士論文，國立台北科技大學光電工程研究所，台北，2009。
[64] 奈米線上辭典，「掃描式電子顯微鏡」(奈米科技K-12教育發展計畫，2007)。http://pesto.lib.nthu.edu.tw/k12/one_character_detail.asp?auto_vocabulary_id=462&from_url=/k12/one_character.asp?word=S。
[65] C. Periasamy, Rajiv Prakash, P. Chakrabarti, “Effect of post annealing on structural and optical properties of ZnO thin films deposited by vacuum coating technique,” J. Mater. Sci.: Mater. Electron., Vol. 21, No. 3, 2010, pp. 309-315.
[66] Hao-Long Chen, Yang-Ming Lu, Weng-Sing Hwang, “Characterization of sputtered NiO thin films,” Surface & Coatings Technology, Vol. 198, 2005, pp. 138-142.
[67] Jae-Hyeong Lee, “Effects of sputtering pressure and thickness on properties of ZnO:Al films deposited on polymer substrates,” J. Electroceram., Vol. 23, 2009, pp. 512–518.
[68] A. Sivasankar Reddy, Hyung-Ho Park, V. Sahadeva Reddy, K.V.S. Reddy, N.S. Sarma, S. Kaleemulla, S. Uthanna, P. Sreedhara Reddy, “Effect of sputtering power on the physical properties of dc magnetron sputtered copper oxide thin films,” Materials Chemistry and Physics, Vol. 110, 2008, pp. 397–401.
[69] Jing Li, SuntaoWu and Junyong Kang, “ZnO Films Deposited by RF Magnetron Sputtering,” 13th International Conference on Semiconducting and Insulating Materials. SIMC-XIII-2004, Beijing, China, 2004, pp. 77-80.
[70] Kazuhiro YAMADA, Yoshiaki OKU, Nobuhiro HATA, Syozo TAKADA and Takamaro KIKKAWA, “Effects of Surfactants on the Properties of Ordered Periodic Porous Silica Films,” Jpn. J. Appl. Phys., Part 1, Vol. 42, No. 4B, 2003, pp. 1840-1842.