MgO基片上的YBCO高温超导薄膜生长研究
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摘要
大面积双面YBCO高温超导薄膜具有优异的电学性能和微波性能,能够进一步提高微波无源器件的特性,因此受到了科学与工业界的广泛重视。MgO基片具有各向同性的介电常数,而且介质损耗很低,非常适用于微波器件的制作。但是MgO与YBCO晶格失配度较大,并且MgO在空气中容易潮解,这为YBCO薄膜的外延生长带来了困难。本论文针对这些难点,对MgO基片上YBCO薄膜的生长展开了研究,具体工作内容如下:
1.研究MgO基片上YBCO薄膜的溅射沉积工艺参数(如基片温度,沉积气氛等)对薄膜结构、形貌和性能的影响。通过对YBCO薄膜微观结构、表面形貌分析和性能分析得到生长YBCO薄膜所需的最优工艺参数为:基片温度为650℃,溅射电流为0.5A×2,溅射气氛为30Pa,氧氩比为1:2。
2.试验和改进了多种制备方法,采用YBCO自外延生长和在基片表面增加MgO同质外延层提高了YBCO薄膜的电性能。与常规的沉积方法相比,上述方法制得的YBCO薄膜临界电流密度有一定提高。
3、研究基片的高温退火处理工艺对生长的YBCO薄膜的面内外取向和Jc大小的影响。在经过预退火处理的基片上制备的YBCO薄膜性能有显著提高,临界电流密度Jc达2.3MA/cm2,微波表面电阻Rs降低到0.16m?,满足高性能高温超导微波器件对薄膜材料的要求。
4、初步探讨了潮湿和干燥空气,以及外加磁场等不同环境中YBCO薄膜的稳定性问题,为微波超导器件的存放环境提供了参考。
Large-area double-sided YBCO high temperature superconductor (HTS) thin films with excellent electrical and microwave properties, which can improve the performance of the microwave passive devices, have been paid intensive attention. MgO substrate with isotropic dielectric constant and very low dielectric loss is very suitable for the application of the microwave devices. It is difficult to prepare YBCO film on MgO substrate because of the large lattice mismatch between MgO and YBCO, and the deliquescency of MgO in the air. The growth of YBCO thin film on MgO substrate aiming at these difficult issues was studied in this thesis. The content in detail is as follows:
1. The influence of the substrate temperature, and sputtering pressure, etc. on the film structure, surface state and performance has been studied. By analyzing the microstructure, orientation and surface state, optimum process parameters were obtained: substrate temperature being 650℃, sputtering power being 0.5(×2)A, sputtering pressure being 30Pa, and PO2:PAr being 1:2.
2. YBCO self-epitaxy method and MgO homogenous epitaxy method were adopted to improve its properties. The critical current density (Jc) of YBCO film was relatively higher than that of YBCO thin film prepared by common sputtering method.
3. The improvement of Jc and in-plain and out-of-plain grain orientation of YBCO film had been realised by pre-annealing of MgO substrates. The properties of YBCO films deposited on the annealed substrates were greatly improved, with Jc=2.3MA/cm2, and Rs(microwave resistance)≈0.16m?, which met the requirement of high performance microwave device.
4. The stability of YBCO film in different environments was discussed and further suggestion has been given for preserving the films.
1.研究MgO基片上YBCO薄膜的溅射沉积工艺参数(如基片温度,沉积气氛等)对薄膜结构、形貌和性能的影响。通过对YBCO薄膜微观结构、表面形貌分析和性能分析得到生长YBCO薄膜所需的最优工艺参数为:基片温度为650℃,溅射电流为0.5A×2,溅射气氛为30Pa,氧氩比为1:2。
2.试验和改进了多种制备方法,采用YBCO自外延生长和在基片表面增加MgO同质外延层提高了YBCO薄膜的电性能。与常规的沉积方法相比,上述方法制得的YBCO薄膜临界电流密度有一定提高。
3、研究基片的高温退火处理工艺对生长的YBCO薄膜的面内外取向和Jc大小的影响。在经过预退火处理的基片上制备的YBCO薄膜性能有显著提高,临界电流密度Jc达2.3MA/cm2,微波表面电阻Rs降低到0.16m?,满足高性能高温超导微波器件对薄膜材料的要求。
4、初步探讨了潮湿和干燥空气,以及外加磁场等不同环境中YBCO薄膜的稳定性问题,为微波超导器件的存放环境提供了参考。
Large-area double-sided YBCO high temperature superconductor (HTS) thin films with excellent electrical and microwave properties, which can improve the performance of the microwave passive devices, have been paid intensive attention. MgO substrate with isotropic dielectric constant and very low dielectric loss is very suitable for the application of the microwave devices. It is difficult to prepare YBCO film on MgO substrate because of the large lattice mismatch between MgO and YBCO, and the deliquescency of MgO in the air. The growth of YBCO thin film on MgO substrate aiming at these difficult issues was studied in this thesis. The content in detail is as follows:
1. The influence of the substrate temperature, and sputtering pressure, etc. on the film structure, surface state and performance has been studied. By analyzing the microstructure, orientation and surface state, optimum process parameters were obtained: substrate temperature being 650℃, sputtering power being 0.5(×2)A, sputtering pressure being 30Pa, and PO2:PAr being 1:2.
2. YBCO self-epitaxy method and MgO homogenous epitaxy method were adopted to improve its properties. The critical current density (Jc) of YBCO film was relatively higher than that of YBCO thin film prepared by common sputtering method.
3. The improvement of Jc and in-plain and out-of-plain grain orientation of YBCO film had been realised by pre-annealing of MgO substrates. The properties of YBCO films deposited on the annealed substrates were greatly improved, with Jc=2.3MA/cm2, and Rs(microwave resistance)≈0.16m?, which met the requirement of high performance microwave device.
4. The stability of YBCO film in different environments was discussed and further suggestion has been given for preserving the films.
引文
[1] 任清褒, 朱维婷. 超导电性及其应用的研究现状和前景. 丽水师范专科学校学报, 2002, 24: 31-37
[2] 曲喜新, 杨邦朝. 电子薄膜材料. 北京: 科学出版社, 1996
[3] D.R.Harshman, A.P.Mills. Concerning the nature of high-Tc superconductivity: Survey of experimental properties and implications for interlayer coupling. Phys. Rev.B, 1992, 45: 10684-10712
[4] C. N. R. Rao, R. Nagarajan, R. Vijayaraghavan. Synthesis of cuprate superconductors. Supercond. Sci. Technol., 1993, 6: 1–22
[5] Aranda, M. A. Garcia. Crystal structures of copper-based high-Tc superconductors. Adv. Mater., 1994, 6(12): 905–921
[6] F. M. Granozio, U. Scotti di Uccio, M. Valentino, et al. Morphology and surface properties of YBCO and TBCCO thin films: influence of etching processes. Physica C, 1996, 271(1-2): 83-93
[7] B. A. Davidson, R. D. Redwing, T. Nguyen, et al. Magnetic field sensitivity of variable thickness microbridges in TBCCO, BSCCO, and YBCO. IEEE Trans. Appl. Supercond., 1994, 4(4): 228-235
[8] 科兴华. 超导研究的进展. 科技大视野, 2004, 2: 61-62
[9] Tsukamoto, O., Enomoto, Y. Superconductivity and its Applications. Physics C, 2003, 392-396: 778p
[10] B. Avenhaus, A. Porch, M.J. Lancaster, et. al. Microwave properties of YBCO thin films. IEEE Trans. Appl. Supercond., 1995, 5(2): 1737-1740
[11] W. Prusseit, S. Furtner, R. Nemetschek. Series production of large area YBa2Cu3O7 films for microwave and electrical power applications. Supercond. Sci. Technol., 2000, 13(5): 519-521
[12] K. Gotoh, N. Fujimaki, T. Imamura, et al. 8-Channel array of single-chip SQUIDs connection to Josephson multiplexer. IEEE Trans. Appl. Supercond., 1993, 3(1): pt 4: 2601-260
[13] L. H. Lee, S. M. Ali, W. G. Lyons, et al. Analysis of superconducting transmission-line structures for passive microwave device applications. IEEE Trans. Appl. Supercond., 1993, 3(1): pt 4: 2782-2787
[14] E. Husse, D. Chauvel, C. Thivet, et al. Microwave HTSC resonators and filters. Physica C, 1994, 235-240(5): 3379-3380
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[21] J. Geerk, A. Zaitsev, G. Linker, et al. A 3-chamber deposition system for the simultaneous double-sided coating of 5-inch wafers. IEEE Trans. Appl. Supercond. 2001, 11: 3856-3858
[22] R.H. Hammond, R. Bormann. Correlation between the in situ growth conditions of YBCO thin films and the thermodynamic stability criteria. J. Physica C, 1989, 162-164: 703-704
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[27] J. Geerk, P. Ratzel, H. Rietschel, et al. Simultaneous double-sided deposition of HTS films on 3-inch wafers by ICM-sputtering. IEEE Trans. Appl. Supercond. 1999, 9: 1543-1546
[28] Xiong J., Tao B.W., Xie T M, et al. Growth of epitaxial CeO2 films on sapphire by radio-frequency sputtering. Journal of the Chinese Ceramic society, 2005,33(2): 149
[29] J. Chrosch, E. K. H. Senkel. Thin domain walls in YBa2Cu3O7-σ and their rocking curves: An X-ray diffraction study. Physica C, 1994, 225: 111-116
[30] X. Castel, M. Guilloux-Viry, J. Padiou, et al. Effects of in-plane high angle grain boundaries in YBa2Cu3O7 thin films epitaxially grown on (100) MgO on their physical properties. J. Alloy. Comp. , 1997, 251: 74-77
[31] 刘小虹, 颜肖慈, 罗明道, 等. 原子力显微镜及其应用. 自然杂志, 2002, 24(1): 36-40.
[32] Yang Sen, Li Shangdong, Liu Xiansong, et al. Exchange coupled Nd2Fe14B/а-Fe nanocomposite magnets with fine Grains Obtained by low wheel speeds pinning [J]. .J.Alland Comp. , 2002, 1: 1-6
[33] Chen Z M, Zhang Y, Hadjipanayis DC, et al. Studies on magnetic properties and microstructure of melt spun nano composite R8(Fe,Co,Nb)86B6(R=Nd,Pr) magnets[J]. J.Magn. Magn. Mater. , 1999, 195: 420
[34] 李言荣, 恽正中, 曲喜新. 电子材料导论. 清华大学出版社, 2001
[35] J.M.MARIOT, M.Mcelfresh C.F. Hague. Electronic structure of YBCO as a function of oxygen content: An x-ray emission approach. Physica C, 1994, 235-240: 1055-1056
[36] Z. X. Luo, K. Yang, J. Lu, et al. Sapphire resonator probe for accurate characterization of microwave surface resistance of high Tc superconductive thin films. Chinese Journal of Low Temperature Physics, 1998, 20(4): 311-315
[37] T. Siegrist, S. Sunshine, D. W. Murphy, et al. Crystal structure of the high-TC superconductor YBa2Cu3O9-delta. Phys. Rev. B, 1987, 35(13): 7137-7139
[38] J.D.Jorgensen, M.A.Beno, D.G.Hinks, et al. Oxygen ordering and the orthorhombic to tetragonalphase transition in YBa2Cu3O7-x. Phys. Rev. B, 1987, 36(7): 3608-3616
[39] 陶伯万. 3 英寸 YBCO 双面超导薄膜的外延生长和均匀性研究: [博士学位论文]. 成都: 电子科技大学, 2003
[40] 熊杰, 邱旸, 陈寅, 等. YBCO 超导厚膜的制备及表征. 低温与超导增刊, 2004, 27-31
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[2] 曲喜新, 杨邦朝. 电子薄膜材料. 北京: 科学出版社, 1996
[3] D.R.Harshman, A.P.Mills. Concerning the nature of high-Tc superconductivity: Survey of experimental properties and implications for interlayer coupling. Phys. Rev.B, 1992, 45: 10684-10712
[4] C. N. R. Rao, R. Nagarajan, R. Vijayaraghavan. Synthesis of cuprate superconductors. Supercond. Sci. Technol., 1993, 6: 1–22
[5] Aranda, M. A. Garcia. Crystal structures of copper-based high-Tc superconductors. Adv. Mater., 1994, 6(12): 905–921
[6] F. M. Granozio, U. Scotti di Uccio, M. Valentino, et al. Morphology and surface properties of YBCO and TBCCO thin films: influence of etching processes. Physica C, 1996, 271(1-2): 83-93
[7] B. A. Davidson, R. D. Redwing, T. Nguyen, et al. Magnetic field sensitivity of variable thickness microbridges in TBCCO, BSCCO, and YBCO. IEEE Trans. Appl. Supercond., 1994, 4(4): 228-235
[8] 科兴华. 超导研究的进展. 科技大视野, 2004, 2: 61-62
[9] Tsukamoto, O., Enomoto, Y. Superconductivity and its Applications. Physics C, 2003, 392-396: 778p
[10] B. Avenhaus, A. Porch, M.J. Lancaster, et. al. Microwave properties of YBCO thin films. IEEE Trans. Appl. Supercond., 1995, 5(2): 1737-1740
[11] W. Prusseit, S. Furtner, R. Nemetschek. Series production of large area YBa2Cu3O7 films for microwave and electrical power applications. Supercond. Sci. Technol., 2000, 13(5): 519-521
[12] K. Gotoh, N. Fujimaki, T. Imamura, et al. 8-Channel array of single-chip SQUIDs connection to Josephson multiplexer. IEEE Trans. Appl. Supercond., 1993, 3(1): pt 4: 2601-260
[13] L. H. Lee, S. M. Ali, W. G. Lyons, et al. Analysis of superconducting transmission-line structures for passive microwave device applications. IEEE Trans. Appl. Supercond., 1993, 3(1): pt 4: 2782-2787
[14] E. Husse, D. Chauvel, C. Thivet, et al. Microwave HTSC resonators and filters. Physica C, 1994, 235-240(5): 3379-3380
[15] B. K. Sarkar, P. Usha, R. Pinto, et al. High temperature superconducting thin film microwave filters. IEEE Journal of Research, 1999, 45(3-4): 265-269
[16] 张其瑞. 高温超导电性. 浙江大学出版社, 1992
[17] Fukutomi. M, Komori.K, Kawagishi.K, et al. A new laser plume scanning technique for uniform large area YBa2Cu3O7?x deposition. Physica C, 2001, 357-360: 1342-1345
[18] S.Liang, C.S.Chenrn, Z.Q.Shi, et al. Control of CeO2 growth by metalorganic chemical vapor deposition with a special source evaporator. Journal of Crystal Growth, 1995, 151: 359-364
[19] M.Lorenz, H.Hochmuth, D. Natusch, et al. Large-area and double-sided pulsed laser deposition of Y-Ba-Cu-O thin films applied to HTSC microwave devices. Appl.Phys.A, 1999, 69: 905-911
[20] Yamada, Yutaka, Muroga. T, et al., Progress of PLD and IBAD processes for YBCO wire in the SRL-Nagoya coated conductor centre-New method for a coated conductor using a self-epitaxial PLD-CeO2 buffer. Superconductor Science and Technology, 2004, 17: 70-73
[21] J. Geerk, A. Zaitsev, G. Linker, et al. A 3-chamber deposition system for the simultaneous double-sided coating of 5-inch wafers. IEEE Trans. Appl. Supercond. 2001, 11: 3856-3858
[22] R.H. Hammond, R. Bormann. Correlation between the in situ growth conditions of YBCO thin films and the thermodynamic stability criteria. J. Physica C, 1989, 162-164: 703-704
[23] 熊杰. 蓝宝石上生长大面积 YBCO 薄膜中的 CeO2 缓冲层研究: [硕士学位论文]. 成都: 电子科技大学, 2004
[24] 杨邦朝, 王文生. 薄膜物理与技术. 电子科技大学出版社, 1994
[25] 田民波, 刘德令. 薄膜科学与技术手册(上). 北京: 机械工业出版社, 1991, 421-425
[26] R.A.Rao, C.B.Eom, M.Santer, et al. Deposition of YBCO thin films over large areas by a 90° off-axis sputtering technique, IEEE Trans. Appl. Supercond., 1997, 7: 1278-1282
[27] J. Geerk, P. Ratzel, H. Rietschel, et al. Simultaneous double-sided deposition of HTS films on 3-inch wafers by ICM-sputtering. IEEE Trans. Appl. Supercond. 1999, 9: 1543-1546
[28] Xiong J., Tao B.W., Xie T M, et al. Growth of epitaxial CeO2 films on sapphire by radio-frequency sputtering. Journal of the Chinese Ceramic society, 2005,33(2): 149
[29] J. Chrosch, E. K. H. Senkel. Thin domain walls in YBa2Cu3O7-σ and their rocking curves: An X-ray diffraction study. Physica C, 1994, 225: 111-116
[30] X. Castel, M. Guilloux-Viry, J. Padiou, et al. Effects of in-plane high angle grain boundaries in YBa2Cu3O7 thin films epitaxially grown on (100) MgO on their physical properties. J. Alloy. Comp. , 1997, 251: 74-77
[31] 刘小虹, 颜肖慈, 罗明道, 等. 原子力显微镜及其应用. 自然杂志, 2002, 24(1): 36-40.
[32] Yang Sen, Li Shangdong, Liu Xiansong, et al. Exchange coupled Nd2Fe14B/а-Fe nanocomposite magnets with fine Grains Obtained by low wheel speeds pinning [J]. .J.Alland Comp. , 2002, 1: 1-6
[33] Chen Z M, Zhang Y, Hadjipanayis DC, et al. Studies on magnetic properties and microstructure of melt spun nano composite R8(Fe,Co,Nb)86B6(R=Nd,Pr) magnets[J]. J.Magn. Magn. Mater. , 1999, 195: 420
[34] 李言荣, 恽正中, 曲喜新. 电子材料导论. 清华大学出版社, 2001
[35] J.M.MARIOT, M.Mcelfresh C.F. Hague. Electronic structure of YBCO as a function of oxygen content: An x-ray emission approach. Physica C, 1994, 235-240: 1055-1056
[36] Z. X. Luo, K. Yang, J. Lu, et al. Sapphire resonator probe for accurate characterization of microwave surface resistance of high Tc superconductive thin films. Chinese Journal of Low Temperature Physics, 1998, 20(4): 311-315
[37] T. Siegrist, S. Sunshine, D. W. Murphy, et al. Crystal structure of the high-TC superconductor YBa2Cu3O9-delta. Phys. Rev. B, 1987, 35(13): 7137-7139
[38] J.D.Jorgensen, M.A.Beno, D.G.Hinks, et al. Oxygen ordering and the orthorhombic to tetragonalphase transition in YBa2Cu3O7-x. Phys. Rev. B, 1987, 36(7): 3608-3616
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