不同B/C摩尔比碳化硼薄膜的光学性能

多层膜反射镜是X射线波段和极紫外波段的重要光学部件.碳化硼作为常见的反射膜材料,其薄膜成分及光学常数计算的准确性对反射镜的反射性能具有明显影响.本研究使用直流磁控溅射技术制备碳化硼薄膜,利用X射线光电子能谱(XPS)、X射线全反射(XRR)、原子力显微镜(AFM)和同步辐射光源等对试样进行了表征,利用改进的拟合函数拟合了基底和薄膜的反射率曲线.结果表明,非晶碳化硼薄膜的元素化学状态相同,其基本成分包含碳化硼和含氧碳化硼;在5～45 nm波段,薄膜B/C摩尔比为4.23时,反射性能最好,同时其基底与薄膜的电子密度差值最大,试样反射性能变化与试样电子密度差值变化基本一致;与原始拟合函数相比,改进的拟合函数提高了薄膜光学常数计算的准确性.     

X射线反射(XRR)对薄膜样品厚度的研究

X射线的反射(XRR)测量法可精确地确定平行层及其薄膜结构,如测定光滑基体上聚合物膜的特性,包括层的厚度、密度和界面粗糙度.使用X'Pert X射线粉晶衍射仪对单晶硅片上的有机薄膜镀层进行了其厚度的精确测定,测定结果为该单晶硅片上的有机薄膜有3层,其厚度分别为5.0、60.2和245.3nm.并用倒易向量方法计算和验证了测量结果的正确性.还讨论了用X射线反射测定薄膜结构的一些影响因素.     

SiGe上NbAlO栅介质薄膜微结构和电学性能分析

本文针对SiGe上Al2O3/NbAlO/Al2O3三明治结构介质栈的热稳定性和电学性能进行了研究.高分辨透射电镜(HRTEM)测试表明退火后薄膜是结晶的,同步辐射X射线反射率(XRR)和X射线衍射(XRD)分析表明在薄膜中存在超晶格结构,有0.5nm的界面层存在,X射线光电子谱(XPS)表明界面层主要成分是SiOx,...     

X射线反射法分析ZnO基薄膜的厚度、密度和表面粗糙度

采用X射线反射法(XRR)测试了在SiO_2玻璃衬底上磁控溅射沉积的单层ZnO基薄膜的反射强度,得到了反射强度随掠入射角变化的曲线;讨论了薄膜厚度、密度和表面粗糙度与反射曲线的关系,最后通过拟合XRR曲线获得了所制备薄膜的厚度、密度和表面粗糙度分别为55.8 nm,5.5 g·cm~(-3)和1.7 nm,与利用XRR数据直接计算出的薄膜厚度56.2 nm仅相差0.4 nm,表面粗糙度也与AFM测试的结果基本相符。可见XRR能无损伤、精确且快速地测试薄膜试样的厚度、密度和表面粗糙度等参数。     

纳米晶结构NiOx薄膜Li+致色性能研究

采用中频孪生非半衡磁控溅射方法制备了纳米晶结构NiOx电致变色薄膜.原子力显微镜(AFM)、掠入射X射线衍射(GID)、X射线反射(XRR)分析薄膜结构、形貌及薄膜厚度;利用电化学设备、紫外分光光度计等手段测试薄膜循环伏安及光谱特性.结果表明:沉积获得NiOx薄膜质地均匀,晶粒尺寸约为4.5 nm,薄膜表面粗糙度Ra=1.659 nm;以Li 离子为致色粒子,厚度60nm的NiOx薄膜在±3 V的高驱动电压下薄膜对可见光透过率凋制范围达30%以七,电致变色性能较好.     

近空间升华法制备CdZnTe外延厚膜及其性能研究

采用近空间升华法在GaAs(100)衬底上外延生长CdZnTe单晶厚膜,用化学腐蚀的方法去除掉GaAs(100)衬底后,对CdZnTe外延膜上、下表面的形貌、成分、结构以及电学性能进行了表征分析。SEM和EDS的结果表明,CdZnTe外延膜表面平滑致密且膜中成分分布较均匀;红外透过成像分析的结果表明,CdZnTe厚膜中无明显的Te夹杂相;X射线摇摆曲线、PL谱的结果表明,随着薄膜厚度的增加,CdZnTe外延膜中的晶体缺陷减少,应变弛豫,结晶质量提高,通过增加膜厚可以获得高质量的CdZnTe外延膜;电学测试表明,CZT外延膜的电阻率在1010Ω·cm数量级,且具有较好的光电响应特性,可用于高能射线探测。     

SiGe薄膜的RPCVD负载影响及特性研究

利用RPCVD系统,在150mm(100)硅片衬底上了制备出高质量锗硅合金薄膜,研究了温度和锗烷流量对薄膜生长速率与合金中锗浓度的影响,并对薄膜进行了掺杂处理。分别利用高分辨透射电子显微镜、高分辨X射线衍射、原子力显微镜、二次离子质谱表征了薄膜特性。结果表明,通过克服RPCVD系统中外延层高缺陷密度、掺杂控制困难等缺点,制备出高质量的SiGe薄膜。     

新型硅基双异质外延SOI材料Si/γ-Al2O3/Si制备

异质外延法是目前制备新型SOI材料的技术途径之一。采用低压化学气相沉积技术(LPCVD)在硅衬底上先外延γ-Al2O3绝缘单晶薄膜，制备出硅衬底上外延氧化物外延结构γ-Al2O3/Si(EOS)，然后采用类似SOS薄膜生长的常压CVD(APCVD)方法在EOS上外延硅单晶薄膜，形成新型硅基双异质SOI材料Si／γ-Al2O3／Si。利用反射高能电子衍射(RHEED)、X射线衍射(XRD)、俄歇电子能谱(AES)及MOS电学测量等技术表征分析了Si(100)／γ-Al2O3(100)／Si(100)SOI异质结构的晶体结构、组分和电学性能。测试结果表明，已成功实现了高质量的新型双异质外延SOI结构材料Si(100)／γ-Al2O3(100)／Si(100)，γ-Al2O3与Si外延薄膜均为单晶，γ-Al2O3薄膜具有良好绝缘性能，SOI结构界面清晰陡峭，该SOI材料可应用于CMOS电路的研制。     

同步辐射原位X射线散射技术在纳米与能源材料中的应用

同步辐射原位X射线散射技术可以实现对材料结构进行多尺度的、无损的、高时间空间分辨率的表征,动态地揭示材料微观结构在不同外界环境下的演变过程。X射线散射基础理论已经相对成熟。第三代同步辐射光源大幅提高了X射线散射技术的时空分辨率,进一步拓宽X射线散射技术的应用场景。当前同步辐射原位X射线散射技术的难点主要集中于实验装置设计和大数据处理。概述了X射线散射技术的主要分类和基本的实验方法,主要介绍了不同分类的同步辐射原位X射线散射技术在纳米材料(纳米颗粒生长和纳米颗粒自组装)与能源材料(以钙钛矿薄膜材料为代表)研究中的应用。最后结合当前国内外先进同步辐射光源的发展现状,展望了同步辐射原位X射线散射技术未来发展的方向和应用前景。     

调制比对GDC/YSZ多层氧离子导体薄膜结构与电学性能的影响

采用反应射频磁控溅射技术在(0001)蓝宝石基片上制备了不同调制结构的(GDC/YSZ)12多层氧离子导体电解质薄膜。利用电子探针微区分析技术测得薄膜的摩尔质量比为m(Zr):m(Y)=5.73:1、m(Ce):m(Gd)=4.12:1;X射线衍射(XRD)与小角X射线反射(XRR)结果表明,GDC/YSZ调制比为5:1、2:1和1:2的样品(A1～A3)具有好的超晶格结构,而A4样品未形成超晶格结构;原子力显微镜形貌分析结果表明多层膜呈密集岛状生长形貌,与GDC、YSZ单层膜比较,多层膜生长岛尺寸减小,密度增大,表面粗糙度明显减小;电学性能测试与理论分析结果表明,界面缺陷使多层膜电导率提高,而GDC成分增多,则超晶格多层膜电导率增大。     

In-line monitoring of advanced microelectronic processes using combined X-ray techniques

Accurate and reliable in-line monitoring of the different films thickness that occur throughout the integrated circuit manufacturing process is mandatory to develop and produce advanced microelectronic devices. X-ray reflectivity (XRR) is a fundamental and suitable metrology technique to precisely determine the thickness of both transparent and metallic thin films. Furthermore, XRR is very sensitive to surface and interface roughness, and also provides information about the film density. X-ray fluorescence (XRF) is currently used as a metrology technique to control the thickness and the elemental composition of relatively thick films. The performance of a new in-line metrology tool, which gathers XRR and XRF data to monitor film thickness, has been assessed. Results on the monitoring of high κ thin films, low κ materials, copper barrier and copper seed layers are presented.     

X-ray reflectometry analyses of chromium thin films

A series of thin (less than 100 nm) chromium films on Si and SiO₂/Si substrates has been examined using X-ray reflectometry (XRR) and cross-section scanning electron microscopy. Comparisons of the measured film thicknesses from the two disparate methods were in good agreement. Because of this accord, it was possible to use these chromium thin films as model systems in order to probe the impact of both random and systematic errors on quantitative XRR measurements. In general, the errors associated with common XRR operations such as sample placement, system alignment, and choice of an instrumental broadening characteristic were much smaller than the statistical error obtained from a genetic algorithm fitting process to the experimental XRR curve.     

Characterization of vapor-deposited l-leucine nanofilm

X-ray reflective measurements (XRR), atomic force microscopy and single wavelength ellipsometry were used to investigate the optical properties of thin l-leucine films deposited onto silicon substrates. The ellipsometry data (Ψ,Δ) were fitted with a four-layer-model, and the optical refractive index of the l-leucine film measured with ellipsometry was determined to be 1.37. With the conventional effective medium approximation theory and the ellipsometry results, the density of the l-leucine nanofilm was determined to be 70% (0.81 g/cm³) of crystalline l-leucine. This value was in good agreement with the density of 69% (0.80 g/cm³) obtained with XRR measurement. The ellipsometry measurements also enabled us to estimate the surface roughness or absorption layer of the film. This procedure of combined XRR and ellipsometry measurements could be a powerful tool for the determination of the (otherwise hard-to-determine) refractive index in thin organic material films with a rough surface layer.     

Combined ellipsometry and X-ray related techniques for studies of ultrathin organic nanocomposite films

Ultrathin nanocomposite films of nitrobenzene on silicon were analyzed by Infrared Spectroscopic Ellipsometry (IRSE), X-ray reflectivity (XRR) and X-ray standing waves (XSW) before and after evaporation of gold. Infrared Spectroscopic Ellipsometry measurements were performed for identification of adsorbates and for investigation of the molecular orientation. Results for film thickness were correlated with XRR measurements. Further, XSW measurements of elements incorporated in nitrobenzene (C, N, and O) were performed with soft X-rays. The combination of the different methods allowed to confirm a model for the electrochemically deposited nitrobenzene films before and after gold evaporation. The characterization by XRR and XSW scans using hard X-rays showed that gold had penetrated into the nitrobenzene film and thus changed density and optical properties of this layer significantly. A depth profile correlated to the electron density is deduced from the XRR measurements. This profile allows to localize—in vertical direction—gold islands within the composite film.     

Structural and optical properties of amorphous oxygenated iron boron nitride thin films produced by reactive co-sputtering

Amorphous oxygenated iron boron nitride (a-FeBN:O) thin films were prepared by reactive radio-frequency (RF) sputtering, from hexagonal boron nitride chips placed on iron target, under a total pressure of a gas mixture of argon and oxygen maintained at 1 Pa. The films were deposited onto silicon and glass substrates, at room temperature. The power of the generator RF was varied from 150 to 350 W. The chemical and structural analyses were investigated using X-ray photoelectron spectroscopy (XPS), energy dispersive of X-ray and X-ray reflectometry (XRR). The optical properties of the films were obtained from the optical transmittance and reflectance measurements in the ultraviolet-visible-near infrared wavelengths range. XPS reveals the presence of boron, nitrogen, iron and oxygen atoms and also the formation of different chemical bonds such as Fe-O, B-N, B-O and the ternary BNO phase. This latter phase is predominant in the deposited films as observed in the B 1s and N 1s core level spectra. As the RF power increases, the contribution of N-B bonds in the as-deposited films decreases. The XRR results show that the mass density of a-FeBN:O thin films increases from 2.6 to 4.12 g/cm³ with increasing the RF power from 150 to 350 W. This behavior is more important for films deposited at RF power higher than 150 W, and has been associated with the enhancement of iron atoms in the film structure. The optical band gap decreases from 3.74 to 3.12 eV with increasing the RF power from 150 to 350 W.     

Transformation of X-ray Server from a set of WWW-accessed programs into WWW-based library for remote calls from X-ray data analysis software

X-ray Server [x-server.gmca.aps.anl.gov] is a public project providing a collection of online software tools for modeling data in the fields of surface X-ray scattering and grazing-incidence X-ray diffraction from thin solid films and multilayers with account for the effects of crystal lattice strains, magnetization and interface roughness. This paper reports on recent developments that are addressing numerous requests to expand the Server access beyond plain web browser sessions and facilitate batch processing, remote fitting and integration of Server programs into users’ data analysis software.     

Polyelectrolyte-mediated assembly of copper-phthalocyanine tetrasulfonate multilayers and the subsequent production of nanoparticulate copper oxide thin films

An approach to producing films of nanometer-sized copper oxide particulates, based on polyelectrolyte-mediated assembly of the precursor, copper(II)phthalocyanine tetrasulfonate (CPTS), is described. Multilayered CPTS and polydiallyldimethylammonium chloride (PDADMAC) were alternately assembled on different planar substrates via the layer-by-layer (LbL) procedure. The growth of CPTS multilayers was monitored by UV-visible spectrometry and quartz crystal microbalance (QCM) measurements. Both the UV-visible spectra and the QCM data showed that a fixed amount of CPTS could be attached to the substrate surface for a given adsorption cycle. Cyclic voltammograms at the CPTS/PDADMAC-covered gold electrode exhibited a decrease in peak currents with the layer number, indicating that the permeability of CPTS multilayers on the electrodes had diminished. When these CPTS multilayered films were calcined at elevated temperatures, uniform thin films composed of nanoparticulate copper oxide could be produced. Ellipsometry showed that the thickness of copper oxide nanoparticulate films could be precisely tailored by varying the thickness of CPTS multilayer films. The morphology and roughness of CPTS multilayer and copper oxide thin films were characterized by atomic force microscopy. X-ray diffraction (XRD) measurements indicated that these thin films contained both CuO and Cu2O nanoparticles. The preparation of such copper oxide thin films with the use of metal complex precursors represents a new route for the synthesis of inorganic oxide films with a controlled thickness.     

Effect of thermal annealing on properties of zinc selenide thin films deposited by chemical bath deposition

Zinc selenide films have been deposited on glass substrate by chemical bath deposition method. The resultant films were annealed up to 473 K temperature. The structural properties of zinc selenide thin films have been investigated by X-ray diffraction techniques. The X-ray diffraction spectra showed that zinc selenide thin films are polycrystalline and have a cubic structure. The most preferential orientation is along the (111) direction for all films. The lattice parameter, grain size, and microstrain were calculated and correlated with annealing temperature. The optical properties showed direct band gap values were found to be in the region of 2.69–2.81 eV. The electrical studies shows conductivity increases with increase in annealing temperature. The optoelectric and structural data are discussed from the point of applications based on achieving high performance devices.     

X-ray and transmission electron microscopy structural characterization of multifunctional Perovskite thin films

Different multifunctional (PbTiO₃, Sm_0.6Nd_0.4NiO₃, NdMnO₃) thin films were grown by metalorganic chemical vapor deposition (MOCVD) technique on SrTiO₃ and LaAlO₃ substrates. Transmission electron microscopy (TEM) and X-ray diffraction measurements reveal that almost single crystalline thin films can be epitaxially grown on the top of substrates. The relationship between the crystallographic orientation of the films and those of the substrates were determined by reciprocal space mapping and TEM analyses. PbTi03 thin films appear to be under tensile or compressive strain according to the different mismatch of their cell parameter with those of the substrate. Relaxation mechanism as a function of the film thickness arises from coexistence of different type of domains and size and strain effect are analyzed. SmNiO₃ thin films present diffuse scattering strikes and are less well organized when compared to PbTi0₃ thin films. Different domains are observed as well as an additional parasitic phase close to NiO. Its regular distribution can be associated to reduced transport properties. Preliminary observations on NdMnO₃ thin films shows that an amorphous phase is obtained during MOCVD that can be transformed in a single crystalline film by annealing. The films are under tensile or compressive strain according to the different mismatch of their cell parameter with those of the substrate. Magnetic properties are investigated.     

RBS,XRR and optical reflectivity measurements of Ti–TiO2 thin films deposited by magnetron sputtering

Single-, bi- and tri-layered films of Ti–TiO₂ system were deposited by d.c. pulsed magnetron sputtering from metallic Ti target in an inert Ar or reactive Ar + O₂ atmosphere. The nominal thickness of each layer was 50 nm. The chemical composition and its depth profile were determined by Rutherford backscattering spectroscopy (RBS). Crystallographic structure was analysed by means of X-ray diffraction (XRD) at glancing incidence. X-ray reflectometry (XRR) was used as a complementary method for the film thickness and density evaluation. Modelling of the optical reflectivity spectra of Ti–TiO₂ thin films deposited onto Si(1 1 1) substrates provided an independent estimate of the layer thickness. The combined analysis of RBS, XRR and reflectivity spectra indicated the real thickness of each layer less than 50 nm with TiO₂ film density slightly lower than the corresponding bulk value. Scanning Electron Microscopy (SEM) cross-sectional images revealed the columnar growth of TiO₂ layers. Thickness estimated directly from SEM studies was found to be in a good agreement with the results of RBS, XRR and reflectivity spectra.