CrAlN/TiAlN纳米多层膜界面结构的中子与X射线反射研究

采用反应磁控溅射技术在单晶硅基片上制备了CrN纳米单层膜和CrAlN/TiAlN纳米周期膜,利用非极化中子和X射线反射对膜层厚度、膜层界面粗糙度、界面扩散等表面、界面结构和性质进行了系统研究。中子反射测得的CrN纳米单层膜和CrAlN/TiAlN纳米周期膜的厚度与设计厚度的差别为3.8%～4.2%。散射长度密度（SLD）分析结果表明,膜层间和膜层与基底间界面较为清晰,扩散较少。X射线反射测得的膜层厚度较中子反射测得的膜层厚度偏高,对于较小调制周期的多层膜,界面弥散会对X射线反射结果产生较大误差。     

中子应力谱仪双聚焦Si单色器设计、模拟与测试

本文对中国先进研究堆中子应力谱仪使用的双聚焦Si单色器进行了设计、模拟和测试。采用SIMRES模拟程序确定了单色器垂直曲率及Si片厚度的最优值,并得到品质因数与散射角、单色器水平曲率和波长的依赖关系。实际测试结果表明,与平板Cu单色器相比,使用双聚焦Si单色器样品处中子强度提高了15倍。     

中子反射数据分析技术

从中子反射基本原理出发,介绍了Fresnel反射、单层膜和多层膜中子反射理论以及膜层描述及反射率计算方法。讨论了中子反射实验数据分析基本方法,介绍了目前常用的数据分析软件Parratt32和NOD及其特点。针对CoFeV单层膜中子反射实验数据分析,给出了数据分析计算实例,结果表明:材料散射势直接影响反射率曲线全反射临界点位置,界面粗糙度则直接影响反射率随散射矢量的变化速度,而膜层厚度则决定振荡峰的疏密关系。     

Neutron Reflectivities of Ni-Mn and Ni-Ti Multilayers for Monochromators and Supermirrors

Multilayer films for neutron mirror were made by vacuum depositing thin films of Ni and Mn or Ni and Ti on a glass plate alternately. Their neutron reflectivities were measured as a function of neutron wavelength by the time-of-flight technique. For Ni-Mn multilayer monochromators, the numbers of layers necessary to give a nearly perfect reflection (≥90%) at the main Bragg peak, were found to be 7, 11 and 21 for layer thicknesses of 163, 112 and 83 Å, respectively. The reflectivities obtained experimentally were compared with those calculated with the method applying the conventional optics, and their agreements were quantitatively reasonable. Moreover, for supermirrors, the numbers of layers and the distributions of layer thicknesses were examined in order to get a reflectivity of near unity down to the wavelength much shorter than the critical wavelength of a totally reflecting mirror of Ni. The reflectivity of a supermirror consisting of 160 layers of Ni and Ti was observed to behave like that of a totally reflecting mirror with the critical wavelength of 1/2.5 time as long as that of the conventional Ni mirror. Such a supermirror can be used to improve much the characteristics of the neutron guide tube.     

超高真空脉冲激光沉积Au、U单层膜及Au/U/Au复合膜研究

采用超高真空脉冲激光沉积（PLD）方法,在单晶Si基底表面制备了单层Au、单层U薄膜和Au/U/Au复合薄膜,应用SEM、白光干涉轮廓分析和AES分析,研究了靶基距、基片温度和激光能量对薄膜形貌、成分的影响。目前的实验结果显示,PLD所制备的Au、U薄膜表面有μm级以下粒径的液滴产生,在液滴较少位置,薄膜表面粗糙度R_a小于1 nm,在包含大液滴位置,R_a不超过15 nm。在相同沉积条件下,U薄膜表面液滴数量大于Au薄膜。优化单层薄膜沉积工艺后制备的Au/U/Au复合膜厚度约为195 nm,均方根粗糙度R_q在0.3～1.5 nm之间。AES分析显示,Au/U/Au复合膜中强化学活性的铀呈金属状态,复合膜中的氧含量低于5%（原子百分数）,表层Au薄膜对U薄膜起到了良好的防氧化作用。在沉积工艺中,通过减小激光功率、增大靶基距并适当升高基片温度,可减少液滴的数量及粒径。     

CoFeV/TiZr复合薄膜材料的极化中子反射实验研究

CoFeV/TiZr多层膜界面结构在其极化超镜产品中起着重要的作用。针对膜层需求设计、制备了不同结构的CoFeV/TiZr膜层样品,应用极化中子镜反射技术研究了CoFeV/TiZr复合薄膜材料的膜层结构,获得了薄膜材料的膜层厚度、界面粗糙度、界面扩散层等结构参数。结果表明,多层膜膜层界面粗糙度变化可采用粗糙度递增律进行描述,界面扩散约0.5 nm,膜层制备工艺基本达到预期目标。     

CR-39测量中子能谱响应函数的计算

在一定的化学和电化学蚀刻条件下，计算了由聚乙烯、铅（金）和CR－39组成的叠层探测器的响应函数（1－20MeV）。计算结果表明，叠层探测器的响应函数分布近似为高斯分布，由铅组成的探测器的响应函数的半高宽比由金组成的探测器的响应函数的半高宽窄，由前者组成的探讨器测量中子能谱分辨率高于后者。     

CR-39测量中子能谱响应函数的计算

计算了在一定的化学和电化学蚀刻条件下,由聚乙稀、铅(金)和CR-39组成的叠层探测器的响应函数(1～20 MeV)。计算结果表明,叠层探测器的响应函数分布近似为高斯分布,由铅组成的探测器的响应函数的半高宽比由金组成的探测器的响应函数的半高宽窄,由前者组成的探测器测量中子能谱分辨率高于后者。     

Studies of multilayer structure in depth direction by soft X-ray spectroscopy

1 Introduction Over the recent several decades, artificial layered structures have been extensively developed as useful functional structures for semiconductor devices [1], magnetic devices [2], X-ray high-reflectance mirrors [3], and so on. They are initially designed as multilayers consisting of uniform layers with the same properties as those of bulk materials and having clear-cut inter- faces (boundaries). However, in real cases, some lay- ers have structures different from those of bulk m…     

不同材料中子反射与屏蔽效应研究

利用Monte Carlo粒子输运计算程序Super MC对厚度1-5 cm的多种材料进行中子反射和屏蔽性能分析计算。这些材料包括金属材料铍、铅、铜、含硼钢以及~(238)U和非金属材料聚乙烯、氢化锂、混凝土,中子能段选取10~(-5) e V-20 MeV。结果显示,中子反射能力和屏蔽性能都会随着材料厚度而增加,但增加的幅度逐渐减小。铍和聚乙烯在中子反射和屏蔽方面性能优越,而常用来屏蔽γ射线的铅在这两方面性能都是8种材料中最差的。~(238)U只在材料厚度很小时性能卓著,随着材料厚度增加,其性能便远不如大部分材料。考虑到聚乙烯的力学性能较差,在屏蔽材料的选择上有很大的限制,所以在8种材料中,铍的综合性能相对较好。     

Effects of gamma ray strong irradiation in single crystal LiF

1IntroductionThelithiurnfluoridesing1ecrystaJisawidelyusedmateria1.ItpossessessomeexcellentopticalandluIninescenceproperties,andisanionicconductance.ItscharactershavebeenresearchedforalongtAne.ItstandsapaItfromtheotherairallhalidecrystaJsbecauseofitsgoodpropertiesandtheexcellenttheImalstabilityofthecolor...t..,[1].AlkallhalldecrystalswithcolorcentershavebeenatthefOcusofattentionofthesolid-statecoInmwhtysincethebegin-ningofthiscentury.And,besidesadirectinterestintheirpecallaropticalproperti…     

Characterization of Tantalum Oxide Thin Films Prepared by Cylindrical Magnetron Sputtering: Influence of O2% in the Gas Mixture

The amorphous tantalum oxide thin films were prepared by DC reactive magnetron cylindrical sputtering onto p-type silicon (100) substrate. We report the composition and optical properties of thin films under O₂ amount variation. The sample’s reflectance was measured with a UV-Vis-NIR spectrophotometer (320–850?nm). The optical characterization of thin layers was analyzed by ellipsometry in spectral region for wavelength from 250 to 850?nm to obtain the refractive index and film’s thickness. The RMS roughness and grain size were investigated by atomic force microscope (AFM). Simulations to Rutherford backscattering spectroscopy (RBS) data revealed film’s stoichiometry. The reflectance, refractive index, thickness, RMS roughness and grain size were found to be affected by increasing oxygen amount. We calculated the porosity of grown layers using measured refractive index at the wavelength of 633?nm.     

Formation of Si/SiC multilayers by low-energy ion implantation and thermal annealing

Si/SiC multilayer systems for XUV reflection optics with a periodicity of 10-20 nm were produced by sequential deposition of Si and implantation of 1 keV ions. Only about 3% of the implanted carbon was transferred into the SiC, with a thin, 0.5-1 nm, buried SiC layer being formed. We investigated the effect of thermal annealing on further completion of the carbide layer. For the annealing we used a vacuum furnace, a rapid thermal annealing system in argon atmosphere, and a scanning e-beam, for different temperatures, heating rates, and annealing durations. Annealing to a temperature as low as 600 °C resulted in the formation of a 4.5 nm smooth, amorphous carbide layer in the carbon-implanted region. However, annealing at a higher temperature, 1000 °C, lead to the formation of a rough poly-crystalline carbide layer. The multilayers were characterized by grazing incidence X-ray reflectometry and cross section TEM.     

8.0nm X射线激光反射镜Mo/B4C多层膜制备及其特性

用磁控溅射法制备工作波长约８０ ｎｍ 的 Ｍｏ／ Ｂ４ Ｃ多层膜作为正入射短波长（λ＜ １０．０ ｎｍ ）软 Ｘ 射线激光反射腔的反射镜。经 Ｘ 射线衍射仪和 Ｔ Ｅ Ｍ 检测,多层膜周期结构准确,热稳定性高。     

北京同步辐射软X射线偏振测量装置及其应用

在北京同步辐射装置(BSRF)设计建造了-套基于多层膜偏振元件的软X射线偏振测量分析装置,可工作在双反、双透、前反后透和前透后反四种工作模式,既可作为偏振测量装置,用于同步辐射光束线和多层膜偏振元件偏振特性测量,也可作为通用反射率计,用于多层膜和薄膜的反射或透射率测量,又可用于磁性材料的磁光效应研究等.利用自行研制的装置和光学元件对BSRF的3W1B光束线的偏振特性进行了系统的测量.测量结果指出,在206 eV时,输出光的线偏振度从起偏前的O.585上升到起偏后的0.995,同步光的线偏振度得到极大改善.利用非周期宽带Mo/Si多层膜开展了铁磁性材料的磁光法拉第效应测量,获得了Ni薄膜3p边附近(60-70 eV)的法拉第旋转角度,最大偏转角度在65.5 eV和68 eV分别为1.85±0.19°和-0.75±0.09°.     

8.0 nm X射线激光反射镜Mo/B4C多层膜制备及其特性

The Mo/B₄C multilayer at wavelength of 8.0 nm is fabricated by magnetron sputtering. The microstructure of multilayer are tested using X-ray diffraction and TEM,and the results show that Mo/B₄C multilayer have high structural quality and thermal stability.     

多层介质/金属紫外滤光膜系的辐照损伤特性

利用电子束蒸发方法制备用于BaF₂晶体慢成分滤光的多层介质/金属紫外滤光膜系。在γ射线、中子和激光辐照环境中研究薄膜的损伤特性。结果表明：薄膜对γ射线和中子具有优良的耐辐照特性；在激光辐照环境中，薄膜的激光损伤阈值受多层薄膜中金属层的影响，激光入射时，最先辐照到的金属层的厚度决定了多层薄膜的耐激光辐照损伤特性。     

基于脉冲激光单粒子效应的二次光斑研究

脉冲激光可有效模拟重离子触发芯片的单粒子效应。本工作在应用背部激光试验方法辐照芯片时观察到了二次光斑现象,通过Si衬底和Si晶圆片研究了芯片单粒子效应实验中二次光斑的成因。实验结果表明,二次光斑主要是由于激光在芯片有源区附近的金属布线层反射形成的。通过测量芯片的Si衬底厚度以及激光触发芯片单粒子效应时的聚焦深度,实验验证了二次光斑是在金属布线层区域形成的。     

Structural analysis of DC magnetron sputtered and spin coated thin films using RBS, TEM and X-ray reflectivity methods

Metallic thin films such as Au, Cr, Ag, etc., on silicon substrate have many technologically important applications as contact layers in microelectronic industry, as reflecting mirrors in synchrotron radiation research, etc. The native oxide layer on crystalline silicon surface inhibits wetting of few nm thick Au or Ag on native oxide/silicon systems. To obtain continuous thin metallic films (a few nm thick), a Cr layer was first deposited as a adhesion layer on the Si substrate. In this paper, Rutherford backscattering analysis (RBS) of Si/Cr/SiO₂/Si, Si/Au/SiO₂/Si, Si/Au/Cr/SiO₂/Si and Polystyrene (PS) polymer coated on some of these bi- or tri-layer structures has been reported. The X-ray reflectometry and transmission electron microscopy studies were carried out to complement the RBS measurements. The thickness, surface and interface roughness, and crystalline quality have been determined.     

Measurement of Cold Neutron Spectrum with Liquid Mirror Reflection

Making use of the wavelength dependency of the critical angle for the total reflection of neutrons, the possibility of determining the energy spectrum of cold neutrons by means of a liquid mirror is examined. A carbon tetrachloride mirror, combined with a pair of fine slits, are used for the measurement of the angular distribution of the reflection intensity of beryllium filtered neutrons. For determining the correction required to account for non-reflected neutrons detected by the counter, the direct beam component is measured by disturbing the liquid mirror surface with small ripples generated by an ultrasonic vibrator submerged in the liquid, and the value obtained with this clouded mirror is subtracted from that determined with the clear undisturbed liquid mirror. The experimental results qualitatively show good agreement with those obtained with a helical-slot neutron velocity selector, and further reveal even better resolution than possible with the latter method, in the cold neutron energy region.