全反射相关的X射线荧光分析技术及其应用
摘要
基于X射线全反射现象,在常规X射线荧光分析的基础上成功研制了用于薄膜多层膜元素深度分布研究和微结构表征的掠入射X射线荧光(GI-XRF)分析系统及掠出射X射线荧光(GE-XRF)分析系统。两套分析系统均为国内首台。建立了GI-XRF和GE-XRF分析系统的评测方法,并应用两种分析系统对多种类型薄膜进行了微结构分析。
用GaAs晶片作标准样品对GI-XRF分析零度角测量方法进行了评测,结果显示,用远距离狭缝确定的零度角是准确的。用Ge晶片对GI-XRF分析系统进行了评测,结果显示,系统设计合理,稳定性高,重复性好,能够满足GI-XRF分析的要求。分析平台拆装简单,可以多维调节,既适用于常规光源也适用于同步辐射光源。标称结构为[Si(substrate)/Ru(50A)/NiFe(40A)/IrMn(120A)/CoFe(40A)/Ru(21A)/CoFeB(40A)/Ru(50A)]磁性隧道结多层膜的GI-XRF分析结果显示GI-XRF分析系统具有较高的深度分辨能力。
用GI-XRF分析方法研究了三种典型厚度Ta缓冲层的和两种厚度Bi插入层的、不同热处理状态的FePt系列薄膜的元素深度分布及微结构特征,结合磁性能的测试分析,揭示了磁性能变化的微结构原因。并结合XRR分析方法对三种典型厚度Ta缓冲层的FePt系列薄膜500℃退火后的GI-XRF曲线进行了定量拟合计算。在Ta层或Bi层上溅射制备FePt层时部分非晶的Ta或Bi原子向FePt中发生了扩散,并在靠近FePt层上表面的区域形成了一个Ta或Bi原子含量相对较高的层。较薄的Ta层退火过程中Ta原子向FePt层中发生了明显的扩散。Bi层在退火过程中甚至发生了从FePt下层到FePt上表面区的翻转。退火过程中Ta或Bi原子在FePt层中的扩散过程以及FePt层中引入一定量的Ta或Bi杂质原子对于FePt薄膜磁性能的优化及有序化转变都大有好处。
用GaAs晶片作标准样品对GE-XRF分析系统进行了评测,结果显示,系统
Grazing Incidence X-Ray Fluorescence (GI-XRF) analysis system and Grazing Exit X-Ray Fluorescence (GE-XRF) analysis system, which are based upon the conventional X-Ray Fluorescence (XRF) and related to the X-Ray Total Reflection phenomenons, have been designed and constructed. Currently, both systems are the first setup in domestic. Furthermore, performance evaluation methods of the two analysis systems have been developed. GI-XRF and GE-XRF are very valuable techniques for elemental depth profile analysis and microstructure characterization of thin films and multilayers.The zero-angle measurement of GI-XRF analysis has been evaluated using GaAs wafer as the standard reference material. The result showed that determination of zero-angle is fully exact. Moreover, GI-XRF analysis was examined for several times using Ge wafer. The experimental results indicated its advantages of good repeatability and stability. The experimental design is reasonable. Together, these results demonstrate that this system can be suitable for the requirement of GI-XRP analysis. In addition, GI-XRF analysis stage is easily able to be installed and to be performed multidimensional adjustment. Thus, GI-XRF analysis can also be used for Synchrotron Radiation (SR) X-Ray. The analytical results of Magnetic Tunnel Junctions (MTJs) with a nominal structure [Si(substrate)/Ru(50A)/NiFe(40A)ArMn (120A)/CoFe(40A)/Ru(2lA)/CoFeB(40A)/Ru(50A)] using GI-XRP showed that this analysis system has a relative high depth resolving power.On the basis of magnetic properties analysis, elemental depth profile and microstructure characterization of FePt thin films with different annealing state and different thickness of Ta buffer layers and Bi insert layers were investigated by GI-XRF analysis method. The result showed that the cause of magnetic properties
change was relative to films microstructure. Combined with the XRR analysis, GI-XRF curves of FePt thin films annealed at 500°C with three typical thickness of Ta buffer layers have been calculated. When the FePt films were deposited on the Ta or Bi layers, the diffusion of Ta or Bi polycrystalline atoms into FePt films has been observed. We also found that a relatively higher concentration region of Ta or Bi atoms has generated near the upper surface of FePt layer. During the subsequence annealing process, Ta atoms diffuse continuously into FePt layers from the films with thinner Ta buffer layer. Bi layers even overturn to the upper surface region of FePt layers. The diffusion process of Ta or Bi atoms into FePt layers will promote the formation of the ordering phase and improve the magnetic properties, but the quantity of the impurity atoms in FePt layers should be appropriate.GaAs wafer, as the standard reference material, has been also used for the evaluation of GE-XRF analysis system. The result indicates that a reasonable design with good repeatability and stability can satisfy the requirement of GE-XRF analysis. Synchrotron Radiation (SR) analysis of GE-XRF was carried out. Thus, GE-XRF analysis can also be used for Synchrotron Radiation (SR) X-Ray. The GE-XRF analysis result of GaAs wafer showed that this analysis system has a high angle resolving power.Si\Ni monolayer and Si\Ni\Ti bilayer were studied by GE-XRF. Combined with the XRR analysis, the results of Ni monolayer's density, thickness and roughness were obtained. Meanwhile, the microstructures of both films have been analyzed.
用GaAs晶片作标准样品对GI-XRF分析零度角测量方法进行了评测,结果显示,用远距离狭缝确定的零度角是准确的。用Ge晶片对GI-XRF分析系统进行了评测,结果显示,系统设计合理,稳定性高,重复性好,能够满足GI-XRF分析的要求。分析平台拆装简单,可以多维调节,既适用于常规光源也适用于同步辐射光源。标称结构为[Si(substrate)/Ru(50A)/NiFe(40A)/IrMn(120A)/CoFe(40A)/Ru(21A)/CoFeB(40A)/Ru(50A)]磁性隧道结多层膜的GI-XRF分析结果显示GI-XRF分析系统具有较高的深度分辨能力。
用GI-XRF分析方法研究了三种典型厚度Ta缓冲层的和两种厚度Bi插入层的、不同热处理状态的FePt系列薄膜的元素深度分布及微结构特征,结合磁性能的测试分析,揭示了磁性能变化的微结构原因。并结合XRR分析方法对三种典型厚度Ta缓冲层的FePt系列薄膜500℃退火后的GI-XRF曲线进行了定量拟合计算。在Ta层或Bi层上溅射制备FePt层时部分非晶的Ta或Bi原子向FePt中发生了扩散,并在靠近FePt层上表面的区域形成了一个Ta或Bi原子含量相对较高的层。较薄的Ta层退火过程中Ta原子向FePt层中发生了明显的扩散。Bi层在退火过程中甚至发生了从FePt下层到FePt上表面区的翻转。退火过程中Ta或Bi原子在FePt层中的扩散过程以及FePt层中引入一定量的Ta或Bi杂质原子对于FePt薄膜磁性能的优化及有序化转变都大有好处。
用GaAs晶片作标准样品对GE-XRF分析系统进行了评测,结果显示,系统
Grazing Incidence X-Ray Fluorescence (GI-XRF) analysis system and Grazing Exit X-Ray Fluorescence (GE-XRF) analysis system, which are based upon the conventional X-Ray Fluorescence (XRF) and related to the X-Ray Total Reflection phenomenons, have been designed and constructed. Currently, both systems are the first setup in domestic. Furthermore, performance evaluation methods of the two analysis systems have been developed. GI-XRF and GE-XRF are very valuable techniques for elemental depth profile analysis and microstructure characterization of thin films and multilayers.The zero-angle measurement of GI-XRF analysis has been evaluated using GaAs wafer as the standard reference material. The result showed that determination of zero-angle is fully exact. Moreover, GI-XRF analysis was examined for several times using Ge wafer. The experimental results indicated its advantages of good repeatability and stability. The experimental design is reasonable. Together, these results demonstrate that this system can be suitable for the requirement of GI-XRP analysis. In addition, GI-XRF analysis stage is easily able to be installed and to be performed multidimensional adjustment. Thus, GI-XRF analysis can also be used for Synchrotron Radiation (SR) X-Ray. The analytical results of Magnetic Tunnel Junctions (MTJs) with a nominal structure [Si(substrate)/Ru(50A)/NiFe(40A)ArMn (120A)/CoFe(40A)/Ru(2lA)/CoFeB(40A)/Ru(50A)] using GI-XRP showed that this analysis system has a relative high depth resolving power.On the basis of magnetic properties analysis, elemental depth profile and microstructure characterization of FePt thin films with different annealing state and different thickness of Ta buffer layers and Bi insert layers were investigated by GI-XRF analysis method. The result showed that the cause of magnetic properties
change was relative to films microstructure. Combined with the XRR analysis, GI-XRF curves of FePt thin films annealed at 500°C with three typical thickness of Ta buffer layers have been calculated. When the FePt films were deposited on the Ta or Bi layers, the diffusion of Ta or Bi polycrystalline atoms into FePt films has been observed. We also found that a relatively higher concentration region of Ta or Bi atoms has generated near the upper surface of FePt layer. During the subsequence annealing process, Ta atoms diffuse continuously into FePt layers from the films with thinner Ta buffer layer. Bi layers even overturn to the upper surface region of FePt layers. The diffusion process of Ta or Bi atoms into FePt layers will promote the formation of the ordering phase and improve the magnetic properties, but the quantity of the impurity atoms in FePt layers should be appropriate.GaAs wafer, as the standard reference material, has been also used for the evaluation of GE-XRF analysis system. The result indicates that a reasonable design with good repeatability and stability can satisfy the requirement of GE-XRF analysis. Synchrotron Radiation (SR) analysis of GE-XRF was carried out. Thus, GE-XRF analysis can also be used for Synchrotron Radiation (SR) X-Ray. The GE-XRF analysis result of GaAs wafer showed that this analysis system has a high angle resolving power.Si\Ni monolayer and Si\Ni\Ti bilayer were studied by GE-XRF. Combined with the XRR analysis, the results of Ni monolayer's density, thickness and roughness were obtained. Meanwhile, the microstructures of both films have been analyzed.
引文
【1】H. G. J. Moseley, Philos. Mag. 26(1913), I024;27(1914), 703.
【2】A. H. Compton, The total reflexion of X-rays. Phil. Mag. 45(1923), 1121.
【3】Y. Yoneda and T. Horiuchi, Rev. Sci. Instrum. 42(1971), 1069.
【4】International Union of Pure and Applied Chemistry(1976). "Nomenclature, Symbols, Units and Their Usage in Spectrochemical Analysis. Ⅱ. Data Interpretation, " Pure Appl. Chem. 45, 99.
【5】P. Pianetta, K. Baur, A. singh et al., Application of Synchrotron Radiation to TXRF Analysis of Metal Contamination on Silicon Wafer Surfaces, Thin Solid Films, 373(2000), 222.
【6】Born, M. and Wolf, E., Principles of Optics, Pergamon, Oxford, 1980.
【7】M. J. Bedzyk, G. M. Bommarito, and J. S. Schildkraut, X-ray standing wave and reflectometric characterization of multilayer structures, Phys. Rev. Lett. 62(1989), 1376.
【2】A. H. Compton, The total reflexion of X-rays. Phil. Mag. 45(1923), 1121.
【3】Y. Yoneda and T. Horiuchi, Rev. Sci. Instrum. 42(1971), 1069.
【4】International Union of Pure and Applied Chemistry(1976). "Nomenclature, Symbols, Units and Their Usage in Spectrochemical Analysis. Ⅱ. Data Interpretation, " Pure Appl. Chem. 45, 99.
【5】P. Pianetta, K. Baur, A. singh et al., Application of Synchrotron Radiation to TXRF Analysis of Metal Contamination on Silicon Wafer Surfaces, Thin Solid Films, 373(2000), 222.
【6】Born, M. and Wolf, E., Principles of Optics, Pergamon, Oxford, 1980.
【7】M. J. Bedzyk, G. M. Bommarito, and J. S. Schildkraut, X-ray standing wave and reflectometric characterization of multilayer structures, Phys. Rev. Lett. 62(1989), 1376.