圆柱表面微结构超精密车削加工技术研究

辊筒模具是加工微结构阵列光学薄膜的关键零件,辊筒表面由大量微结构构成,其表面的微结构通过UV固化技术复制到光学薄膜上,可以实现许多新型光学功能。在该技术中,辊筒模具表面数量庞大的微结构超精密加工质量是保证压印加工质量的关键和难点。为此,利用自主研发的光鼓车加工微V槽型辊筒,分析并解决了刀具、程序、加工表面等方面的关键技术难点,得到了预期的微结构效果。     

聚焦离子束再沉积修正方法的元胞自动机验证

利用聚焦离子束技术加工微结构时,由于溅射过程的再沉积效应,难以获得较为陡直的侧壁,对于高深宽比微结构尤甚。为优化聚焦离子束的加工工艺,提出一种单像素线辅助溅射刻蚀方法,对非陡直侧壁进行局部刻蚀修正,以期改善再沉积现象,提高侧壁陡直度。采用元胞自动机算法,对该方法应用于溅射过程时各参数对刻蚀结果的影响进行了数值模拟,获得了V型截面侧壁的修正效果,指出实际加工中局部刻蚀修正的位置选择存在着侧壁再沉积改善和离子束斑扩展之间的矛盾。聚焦离子束刻蚀实验验证了该方法的有效性,确定了局部刻蚀修正的最佳位置,在刻蚀宽度100 nm的圆环微结构时,沟道侧壁的校正效果较好,获得了深宽比为3∶1的沟槽结构。该方法可为相似微结构再沉积现象削弱提供技术支持。     

面向微结构阵列的超精密切削加工与测量关键技术研究

正微结构阵列是指具有规则阵列分布的微观几何拓扑形状及特定功能的一类微结构表面。微结构阵列的微观和宏观几何形貌决定了器件的功能,如光学功能、摩擦功能、润滑功能、信息存储功能等。微结构阵列以其无法比拟的优越性能,已经成为光电子、信息通讯以及精密工程等领域的关键零部件。如用于平板显示的微透镜阵列光学薄膜、用于空间光学回射的微金字塔阵列、用于太阳能电池的微槽阵列结构光栅、用于先进动态随机存储器的具有高深-宽比特征的深沟槽微结构阵列等。随着科技产品向高性能化、高精度化、高集成化方向发展,微结构阵列在航空航天、电子制造、生物医疗等高端产业得到了     

时间监控离子束溅射沉积光学薄膜的厚度修正

通过单层和多层膜的实验模拟,研究了离子束溅射沉积速率和沉积时间的关系。在溅射镀膜的初始阶段,对于Ta2O5,沉积速率随时间增加而增大;对于SiO2,沉积速率随时间先显著地增加,随后逐渐地减小。结果表明,通过对高、低折射率各层的监控时间进行补偿,即可实现光学薄膜厚度的精确监控。     

激光器使用的光学薄膜

介绍了近年来研制的激光器用光学薄膜元器件,内容涉及二极管泵浦激光器使用的光学薄膜、光参量振荡激光器使用的光学薄膜以及激光美容仪使用的光学薄膜。     

光学薄膜数据库

本文详细论述了一个建立在VAX/11小型计算机上的光学薄膜数据库系统。整个数据库由ORACLE构成,包括光学薄膜材料数据库;光学薄膜基底材料数据库和典型膜系数据库。这个数据库内容丰富、功能完善、全部使用中文提示,菜单操作,使用方便,维护灵活。为广大的光学工作者从事光学薄膜研究和生产提供了一个有力的辅助工具。     

反应性离化团束制备光学薄膜新技术

本文叙述了离化团束淀积光学薄膜的基本概念及特性,研制了离化团束淀积光学薄膜装置,开展了光学薄膜晶体结构与性能关系的研究。所研制的光学薄膜的牢固性相当好。基底不加温就可以得到ZnS、MgF₂的硬膜。反应性离化团束淀积的ZnO光学薄膜具有优良的织构,SiO₂光学薄膜呈现多晶结构。     

光学薄膜表面微细缺陷在线检测方法研究

为了对光学薄膜进行精密光学检测,需要采用数个具有高解析度的线阵CCD相机进行光学薄膜缺陷图像的同步采集。基于计算机视觉的理论,提出了一种有效的自动质量监测方案,实现对光学薄膜表面微细缺陷项目的检测,并根据检测结果驱动打标机对光学薄膜缺陷进行自动标识和定位,该方法具有高精度、实时、在线和非接触的显著优势。探索性实验结果表明,采用该方法可获得光学薄膜表面缺陷的清晰图像,缺陷的细节能够得到很好的展现,并且能够完成缺陷特征的提取与识别。     

无温漂滤光片的制备方法

随着光学薄膜技术的不断发展,光学薄膜器件应用的日益广泛,光学薄膜器件的温度稳定性也被提取了极重要的地位。针对这一问题进行了研究,并给出了相应的解决办法。     

无温漂滤光片的制备方法

随着光学薄膜技术的不断发展,光学薄膜器件应用的日益广泛,光学薄膜器件的温度稳定性研究也被提到了极重要的地位。针对这一问题进行了研究,并给出了相应的解决办法。     

Combining Ar ion milling with FIB lift-out techniques to prepare high quality site-specific TEM samples

Focused ion beam (FIB) techniques can prepare site‐specific transmission electron microscopy (TEM) cross‐section samples very quickly but they suffer from beam damage by the high energy Ga⁺ ion beam. An amorphous layer about 20–30 nm thick on each side of the TEM lamella and the supporting carbon film makes FIB‐prepared samples inferior to the traditional Ar⁺ thinned samples for some investigations such as high resolution transmission electron microscopy (HRTEM) and electron energy loss spectroscopy (EELS). We have developed techniques to combine broad argon ion milling with focused ion beam lift‐out methods to prepare high‐quality site‐specific TEM cross‐section samples. Site‐specific TEM cross‐sections were prepared by FIB and lifted out using a Narishige micromanipulator onto a half copper‐grid coated with carbon film. Pt deposition by FIB was used to bond the lamellae to the Cu grid, then the coating carbon film was removed and the sample on the bare Cu grid was polished by the usual broad beam Ar⁺ milling. By doing so, the thickness of the surface amorphous layers is reduced substantially and the sample quality for TEM observation is as good as the traditional Ar⁺ milled samples.     

Structure analysis of sputter-coated and ion-beam sputter-coated films: a comparative study

Gold, platinum and tungsten films were deposited by low energy input (7 mA, 450 V), or high deposition rate (80 mA, 1500 V), diode sputter coating and by ion beam sputter coating. Film structures on Formvar coated grids and on the surface of coated erythrocytes, resin embedded, sectioned, and recorded at high magnification in a TEM were compared using computer-assisted measurements and analysis of film thickness and grain size. The average grain size of the thinnest gold and platinum films was relatively independent of the mode or rate of deposition but as the film thickness increased, significant differences in grain size and film structure were observed. Thick platinum or gold films deposited by low energy input sputter coating contained large grain size and electron transparent cracks; however, more even films with narrower cracks but larger grain size were produced at high deposition rates. Ion beam sputter coated gold had relatively large grain size in 10 nm thick films, but beyond this thickness the grains coalesced to form a continuous film. Platinum films deposited by ion beam sputter coating were even and free of electron transparent cracks and had a very small grain size (1–2 nm), which was relatively independent of the film thickness. Tungsten deposition either by low energy input or ion beam sputter coating resulted in fine grained even films which were free of electron transparent cracks. Such films remained granular in substructure and had a grain size of about 1 nm which was relatively independent of film thickness. Tungsten films produced at high deposition rates were of poorer quality. We conclude that thick diode sputter coated platinum and gold films are best deposited at high deposition rates provided the specimens are not heat sensitive, the improvement in film structure being more significant than the slight increase in grain size. Thick diode or ion beam sputter coated gold films should be suitable for low resolution SEM, and thin discontinuous gold films for medium resolution SEM. Diode sputter coated platinum should be suitable for medium resolution SEM and ion beam sputter coated platinum for medium and some high resolution SEM. 1–5 nm thick tungsten films, deposited by low energy input or ion beam sputter coating should be suitable for high resolution SEM, particularly where contrast is of less importance than resolution.     

高能离子束辅助沉积制备钛纳米膜

用离子束溅射沉积和高能离子束辅助沉积方法制备了具有择尤性的钛纳米薄膜,并采用原子力显微镜、X射线衍射仪和俄歇电子谱仪研究了试样表面预处理、离子束流和温度等离子束工艺参数对钛薄膜结构的影响。结果表明：离子束溅射沉积的钛膜在[002]和[102]晶向上呈现出明显的择尤生长现象,并分别在该两个晶向上表现出纳米晶型和非纳米晶型结构;当用高能离子束辅助沉积时,[102]晶向择尤生长现象消失,且钛膜的结构对束流变化较为敏感,束流较低时,钛膜为纳米结构且择尤生长现象减弱,而束流增加时晶粒长大,择尤生长现象叉增强。另外钛膜容易受到氧的污染,并随辅助离子强度增加而增强。     

Helium ion microscopy and its application to nanotechnology and nanometrology

Helium ion microscopy (HeIM) presents a new approach to nanotechnology and nanometrology, which has several potential advantages over the traditional scanning electron microscope (SEM) currently in use in research laboratories and manufacturing facilities across the world. Owing to the very high source brightness, and the shorter wavelength of the helium (He) ions, it is theoretically possible to focus the ion beam into a smaller probe size relative to that of the electron beam of an SEM. Hence, resolution 2 × – 4 × better than that of comparable SEMs is theoretically possible. In an SEM, an electron beam interacts with the sample and an array of signals are generated, collected and imaged. This interaction zone may be quite large depending upon the accelerating voltage and materials involved. Conversely, the helium ion beam interacts with the sample, but it does not have as large an excitation volume and, thus, the image collected is more surface sensitive and can potentially provide sharp images on a wide range of materials. Compared with an SEM, the secondary electron yield is quite high—allowing for imaging at extremely low beam currents and the relatively low mass of the helium ion, in contrast to other ion sources such as gallium, potentially results in minimal damage to the sample. This article reports on some of the preliminary work being done on the HeIM as a research and measurement tool for nanotechnology and nanometrology being done at NIST. SCANNING 30: 457–462, 2008. Published 2008 by Wiley Periodicals, Inc.     

离子束辅助真空电弧沉积Zr-Ni-N薄膜的研究

采用多弧离子镀技术在高速钢和单晶硅基体上制备Zr-Ni-N复合薄膜,研究了低能氮离子束对Zr-Ni-N涂层结构、表面形貌和硬度的影响。研究表明:用低能氮离子束辅助真空电弧沉积Zr-Ni-N膜,ZrN结构在(111)晶面出现一定的择优取向,并对Zr-Ni-N膜层有一定的强化作用,膜层表现出较高的显微硬度。     

Tribological properties of nickel-base nanocrystalline coatings sputter-deposited on austenitic stainless steel

500 nm-thick films are deposited on austenitic stainless steel by neutral (Ar⁺) or reactive (N⁺) ion beam sputtering of Ni or NiTi targets, with (or without) high energy 160 keV-Ar⁺ ion beam assistance. Most of the time the coatings are nanocrystalline and induce a large (excellent in some conditions) increase of the wear resistance. Only Ar⁺ ion beam sputtering of a NiTi target gives an amorphous deposit which does not improve the substrate tribological properties. The hardness and wear resistance of ion beam assisted films are larger than those obtained with non-ion beam assisted coatings. The presence of a hard TiN phase inside a ductile Ni phase, of grains with preferential orientation beneficial to slip, as well as film densification are the main factors which increase the wear resistance. The best results are obtained when the structure is composed of two phases, Ni and TiN. The TiN phase strengthens the already good tribological Ni properties and the Ni ductility induces mechanical accommodation during the friction process.     

16厘米低能强流宽束离子源

介绍了一个新型16厘米束径多会切磁场低能强流宽束离子源(MCLB-16)。由于采用新型多会切磁场和优化的低能引出系统,所以该源在薄膜辅助沉积的能量(200eV～800eV)范围内,具有较好的低能特性。源的最大引出束流可达650mA。可用反应气体或惰性气体工作。源在使用氧气时,可连续工作数十小时。该源可用于各种高性能薄膜制备的辅助沉积,也可用于制备大面积类金钢石膜(DLC)。叙述了该源的结构及性能。     

用脉冲多弧离子源研制镍铬铁合金膜

介绍了采用脉冲多弧离子源镀制镍铬铁合金膜的新技术,研究了采用这一新技术镀制镍铬铁合金膜的镀制工艺,对采用这一新技术所镀制的镍铬铁合金膜进行了性能测试。结果表明：选用合适的工艺参数,采用这一新技术镀制的镍铬铁合金膜膜层均匀,牢固度好,膜层成分与脉冲多弧离子源阴极靶材成分含量误差小于±３％ ,符合实际应用要求     

Low-energy beam transport studies supporting the spallation neutron source 1-MW beam operation

The H(-) injector consisting of a cesium enhanced RF-driven ion source and a 2-lens electrostatic low-energy beam transport (LEBT) system supports the spallation neutron source 1 MW beam operation with ～38 mA beam current in the linac at 60 Hz with a pulse length of up to ～1.0 ms. In this work, two important issues associated with the low-energy beam transport are discussed: (1) inconsistent dependence of the post-radio frequency quadrupole accelerator beam current on the ion source tilt angle and (2) high power beam losses on the LEBT electrodes under some off-nominal conditions compromising their reliability.     

Contouring algorithm for ion figuring

Ion beam figuring provides a highly deterministic method for the final precision figuring of optical components with advantages over conventional methods. The ion-figuring process involves bombarding a component with a stable beam of accelerated particles, which selectively removes material from the surface. The specific figure corrections are achieved by rastering the fixed-current beam across the workpiece at varying velocities. Unlike conventional methods, ion figuring is a noncontract technique that avoids such problems inherent in traditional fabrication processes as edge roll-off effects, tool wear, and force loading of the work piece. Other researchers have demonstrated that ion beam figuring is effective for correcting of large optical components. This work is directed toward the development of the precision ion-machining system (PIMS) at NASA's Marshall Space Flight Center (MSFC). This system is designed for processing small ( 10 cm diameter) optical components. The ion-figuring process involves obtaining an interferometric error map of the surface, choosing a raster pattern for the beam, and determining the velocities along that path. Because the material removed is the convolution of the fixed ion beam removal and the rastering velocity as a function of position, determining the appropriate velocities from the desired removal map and the known ion beam profile is a deconvolution process. A unique method of performing this deconvolution was developed for the project, which is also applicable to other mathematically similar processes, including computer-controlled polishing. This paper presents the deconvolution algorithm, a comparison of this technique with other methods, and a simulation analysis. Future research will implement this procedure at MSFC.