制作工艺误差对X射线组合折射透镜聚焦性能影响研究

本文主要介绍对X射线组合折射透镜的制作工艺误差对其聚焦性能影响的研究结果. 首先给出采用深度X射线光刻技术制作的PMMA材料圆柱面型X组合折射透镜的工艺测试结果,得出制作工艺误差值,定性分析制作工艺误差对X射线组合折射透镜聚焦性能的影响. 然后根据实际的制作工艺误差建模,给出详尽的理论分析和定量的理论模拟结果. 最后在北京同步辐射装置(BSRF)上,构建基于PMMA材料的圆柱面型X射线组合折射透镜的微束聚焦实验系统,实际测试了有明显工艺误差和尽量消除工艺误差的两种X射线组合折射透镜的聚焦性能,给出实测结果 关键词： X射线组合折射透镜 制作工艺误差 X射线聚焦性能 同步辐射     

2000 1/mm X射线镂空透射光栅的制备研究

在满足工艺要求的前提下,通过模拟光栅衍射,设计出镂空透射光栅模型,在此基础上将电子束和X射线光刻技术相结合,研究了制造2000 1/mm X射线镂空透射光栅的新工艺技术.首先利用电子束光刻和微电镀技术在镂空聚酰亚胺薄膜底衬上制备X射线母光栅掩模.然后利用X射线光刻和微电镀技术实现了光栅图形的复制,之后采用紫外光刻和微电镀技术制作加强筋结构,最后通过腐蚀体硅和等离子体刻蚀聚酰亚胺完成镂空透射光栅的制作.从此新的制造工艺结果上来看.制备的光栅栅线平滑,占空比合理,侧壁陡直,不同光栅之间一致性好,完全可以满足应用需求,充分表明了该制造技术是透射式X射线衍射光学元件制造的良好选择.     

2000 l/mm X射线镂空透射光栅的制备研究

在满足工艺要求的前提下,通过模拟光栅衍射,设计出镂空透射光栅模型,在此基础上将电子束和X射线光刻技术相结合,研究了制造2000 l/mm X射线镂空透射光栅的新工艺技术.首先利用电子束光刻和微电镀技术在镂空聚酰亚胺薄膜底衬上制备X射线母光栅掩模.然后利用X射线光刻和微电镀技术实现了光栅图形的复制,之后采用紫外光刻和微电镀技术制作加强筋结构,最后通过腐蚀体硅和等离子体刻蚀聚酰亚胺完成镂空透射光栅的制作.从此新的制造工艺结果上来看.制备的光栅栅线平滑,占空比合理,侧壁陡直,不同光栅之间一致性好,完全可以满足应用需求,充分表明了该制造技术是透射式X射线衍射光学元件制造的良好选择.     

合肥国家同步辐射实验同就辐射光刻研究

同步辐射光刻技术是Ｘ射线光刻技术的重要发展，适用于深亚微米乃至纳米图形的超微细加工，特别是ＬＩＧＡ的出现大大拓展了同步辐射光刻的应用领域，使它不仅适合于超大规模集成电路等平面微结构的加工，也适合于具有复杂构造的三维立体结构和器件的制作，文章简要介绍了ＮＳＲＬ光刻光束线和实验站概况及研究工作进展。     

合肥国家同步辐射实验室同步辐射光刻研究

同步辐射光刻技术是Ｘ射线光刻技术的重要发展，适用于深亚微米乃至纳米级图形的 超微细加工，特别是ＬＩＧＡ技术的出现大大拓展了同步辐射光刻的应用领域．使它不仅适合于超大规模 集成电路等平面微结构的加工，也适合于具有复杂构造的三维立体结构和器件的制作．文章简要介绍了 ＮＳＲＬ光刻光束线和实验站概况及研究工作进展．     

利用喷气式Z箍缩等离子装置进行X射线光刻

喷气式Ｚ箍等离子体装置可以产生较强的软Ｘ射线，能量大约在２－６ｋｅＶ之间，利用此装置产生的软Ｘ射线，用ＣＳＭ作光刻胶，进行了Ｘ射线光刻的初步研究，得到了较为的光刻图形，曝光深度估计在１０μｍ左右。     

利用喷气式Z箍缩等离子体装置进行X射线光刻

喷气式Ｚ箍缩等离子体装置可以产生较强的软Ｘ射线，能量大约在２—６ｋｅＶ之间。利用此装置产生的软Ｘ射线，用ＣＳＭ作光刻胶，进行了Ｘ射线光刻的初步研究，得到了较为清晰的光刻图形，曝光深度估计在１０μｍ左右     

微结构X射线源中电子与阳极作用的蒙特卡罗模拟

根据电子多重散射理论,基于蒙特卡罗方法研究不同能量电子垂直入射不同材料的阳极靶后,电子在阳极靶内的沉积能量分布,及X射线发射位置的能量分布.结果表明：电子在靶内的轨迹扩展和入射电子能量、靶材料有关,99%电子能量沉积在近似圆柱形区域内.且电子在入射方向上的沉积能量分布不是直接递减,而是先递增到一定深度后再递减,符合电子背散射理论.说明X射线产生区域是在距表面一定深度区域内.另外,通过对比分析发现金刚石膜作为电子吸收光栅是不可行的,但作为热沉材料有很大的潜力.这些结论可为微结构X射线源研究及高亮度高相干X射线源设计提供参考.     

中国的X射线晶体学与结构生物学

<正>X射线晶体学是一门利用X射线来研究物质结构的学科。利用电子对X射线的散射作用,X射线晶体学可以获得晶体中电子密度的分布情况,再从中分析获得晶体内部分子的结构信息。近几十年来,X射线晶体学与生命科学充分融合,并且充分吸收包括核磁共振(NMR)、电镜技术等在内的各种研究生物结构的技术方法,形成了以X射线晶体学为核心的结构生物学,为认识生物分子的三维结构和功能机制,提供     

扩展X射线吸收精细结构的实验方法研究

一、引 言 扩展X射线吸收精细结构(EXAFS)是一种新的结构分析方法[1].测定EXAFS要求的实验条件较高,数据处理与分析也较复杂[2,3].我们利用12kw转靶X射线源在衍射仪样品台上放置平晶作分光晶体,开展了EXAFS实验方法的研究.对有关的实验技术和数据处理等问题初步作了一些工作. 二、实验方法 EXAFS的测定来用透射法,测量经吸收体吸收前、后射线强度I0与I随能量的变化.应用Rigaku RU-200 12kW转靶X射线源及D/max-rA型X射线衍射仪.实验条件一般为:银靶20 kV,70—150mA,入射和散射狭缝取1/2—2 ,接收狭缝为 0.15mm,分光晶体为LiF(…     

LIGA technology for the synthesis of diffractive refractive intraocular lenses

The manufacturing of test diffractive refractive intraocular lenses is illustrated by means of LIGA (deep X-ray LIthography and GAlvanoplastics and polymer forming). Dynamic X-ray lithography used while rotating the substrate versus an X-ray mask fixed in a beam of synchrotron radiation (SR) yields smooth optical 3D surfaces with roughnesses of 10–30 nm rms in polymethylmethacrylate (PMMA) layers. The axisymmetric diffractive refractive profile of a lens is predetermined by the radial angular function of the X-ray mask topology. The quality of the optical surface is reproduced for the nickel master form, which is electroplated onto a gold layer atop the PMMA relief. The optical quality also remains high for replicated lenses synthesized in this manner during silicon polymerization.     

Polymer saturable absorber materials in the 1.5 microm band using poly-methyl-methacrylate and polystyrene with single-wall carbon nanotubes and their application to a femtosecond laser

We report saturable absorber materials in the 1.5 microm band that consist of poly-methyl-methacrylate (PMMA) and polystyrene (PS) polymers with single-wall carbon nanotubes (SWNTs). A very uniform dispersion of SWNT in PMMA and PS polymers has been realized by using chlorobenzene or tetrahydrofuran as a dispersion solvent. These materials, which are as thick as 1 mm, are easily optically polished on both surfaces. This was difficult to achieve with previous thin-film materials. By incorporating PMMA/SWNT as a saturable absorber, a 171 fs pulse is successfully generated in a passively mode-locked fiber laser.     

3333lp/mm X射线透射光栅的研制

针对X射线透射光栅摄谱仪中的高线密度光栅,研究了采用电子束曝光和X射线曝光技术结合制作高线密度X射线透射光栅的工艺技术.首先利用电子束曝光和微电镀技术在镂空的薄膜上制备母光栅X射线掩模版,然后利用X射线曝光和微电镀技术小批量复制光栅.在国内首次完成了3333lp/mm X射线透射光栅的研制,栅线宽度为150nm,周期为300nm,金吸收体厚度为500nm.衍射效率标定的结果表明,该光栅的占空比合理、侧壁陡直,具有良好的色散特性,能够满足空间探测、同步辐射和变等离子诊断等多个领域的应用.     

极紫外投影光刻接触孔掩模的快速仿真计算

采用一个极紫外投影光刻掩模衍射简化模型实现了三维接触孔掩模衍射场的快速仿真计算。基于该模型,得到了接触孔掩模衍射场分布的解析表达式,并对光刻成像时的图形位置偏移现象进行了解释和分析。简化模型中,掩模包括吸收层和多层膜两部分结构,吸收层的透射利用薄掩模修正模型进行计算,多层膜的反射近似为镜面反射。以周期44 nm、特征尺寸分别为16 nm和22 nm的方形接触孔为例,入射光方向发生变化时,该简化模型与严格仿真相比,图形特征尺寸误差小于0.4 nm,计算速度提高了近100倍。此外,考虑到多层膜镜面位置对图形位置偏移量的影响,得到了图形位置偏移量的计算公式,其计算结果也与严格仿真相一致。     

Fabrication of TiO2 μ-donuts by sol-gel spin coating using a polymer mask

TiO₂ μ-donuts have been fabricated on glass and silicon substrates using polymer masks in combination with a sol-gel technique. Cylindrical poly(methyl methacrylate) (PMMA) nanopillars have been created using a composite polymer of polystyrene (PS) and PMMA followed by careful removal of the PS. Atomic force microscopy (AFM) analyses show that the height and diameter of the PMMA cylinders used as the mask are 440 ± 5 nm and 2.1 ± 0.2 μm, respectively. The cylindrical PMMA nanopillars have been coated with the sol of the TiO₂ precursor by a spin coating technique and annealed in air at elevated temperature to remove the PMMA mask. Removal of the PMMA mask has resulted in the formation of well ordered μ-donuts of TiO₂ on silicon surfaces. The interior and exterior heights of the TiO₂ μ-donuts are found to be 373 ± 152 nm and 457 ± 136 nm, respectively; and the interior and exterior diameters of the TiO₂ μ-donuts are found to be 1.33 ± 0.63 μm and 2.82 ± 0.50 μm, respectively. X-ray photoelectron spectroscopy (XPS) spectra of the TiO₂ μ-donuts as well as the smooth TiO₂ thin film showed signals from Ti and O confirming the presence of TiO₂ with Ti 2p_3/2 and O 1s peaks at 458.8 eV and 530.4 eV, respectively. The O 1s peak of the TiO₂ μ-donuts shows another peak at binding energy 532.0 eV due to SiO₂, as during annealing, the PMMA evaporates and the Si substrate is exposed. The X-ray diffractometer (XRD) pattern of the smooth TiO₂ thin film indicates that the anatase phase is present, with the characteristic peaks observed at 2θ values of 25.4°, 37.4°, and 48° corresponding to (1 0 1), (0 0 4), and (2 0 0) planes, respectively. UV-vis absorption spectra of TiO₂ μ-donuts on glass showed an unusual absorption of light in the visible region at ∼524 nm in addition to the usual UV absorption at ∼337 nm.     

Lithographic processing of polymers using plasma-generated electronbeams

Pattern definition in polymer films is achieved using electron beams generated in soft vacuum (0.05-0.50 torr) glow discharges either on a continuous or a pulsed (20-100 ns) basis. With the continuous-mode electron beam, 7-μm transmission mask features are replicated in both polymethyl methacrylate (PMMA) and polyimide resists. Using a pulsed electron-beam submicron (~0.5 μm) features are transferred from an electron-transmitting stencil mask into the PMMA. The soft-vacuum pulsed electron beam is also eminently suited for polymer stabilization. Pulsed electron-beam hardening of 0.05-3.5 μ-thick AZ-type and MacDermid resist patterns is also demonstrated with hardened resist patterns stable to temperatures between 200° and 350°C. The demonstrated replication and pattern stabilization technique may be applicable in microelectronics packaging lithography where the resist thickness is substantial, linewidths are 1-10 μm, and registration requirements are less stringent     

Fabrication of an integrated optical Mach-Zehnder interferometer based on refractive index modification of polymethylmethacrylate by krypton fluoride excimer laser radiation

It is known that deep ultraviolet (UV) radiation induces a refractive index increase in the surface layer of polymethylmethacrylate (PMMA) samples. This effect can be used for the fabrication of integrated optical waveguides. PMMA is of considerable interest for bio and chemical sensing applications because it is biocompatible and can be micromachined by several methods, e.g. structuring by photolithography, ablation and hot embossing. In the presented work direct UV irradiation of a common PMMA substrate by a krypton fluoride excimer laser beam through a contact mask has been used to write integrated optical Mach-Zehnder interferometers (MZI). MZI are used as sensitive bio and chemical sensors. The aim was to determine contact mask design and laser irradiation parameters for fabricating single-mode MZI for the infrared region from 1.30 μm to 1.62 μm. Straight and curved waveguides have been generated and characterized to determine the optical losses. The generation of channel waveguide structures has been optimized by a two step irradiation process to minimize the lithographic writing time and optical loss. By flood exposure to UV laser radiation in the first step the optical absorption of PMMA can be increased in the irradiated region. The required refractive index profile is then achieved with a second lithographic irradiation. The spectral behaviour of an unbalanced, integrated optical MZI fabricated by this excimer laser based contact mask method is shown for the first time. Further the optical intensity at the output port of a MZI has been measured while the optical path length difference was tuned by creating a temperature difference between the two arms of the MZI.     

Atomic force microscopy investigation of surface roughness generated between SiO2 micro-pits in CHF3/Ar plasma

The present paper investigates the surface roughness generated by reactive ion etching (RIE) on the location between silicon dioxide (SiO₂) micro-pits structures. The micro-pit pattern on polymethyl methacrylate (PMMA) mask was created by an electron beam lithography tool. By using PMMA as a polymer resist mask layer for pattern transfer in RIE process, the carbon (C) content in etching process is increased, which leads to decrease of F/C ratio and causes domination of polymerization reactions. This leads to high surface roughness via self-organized nanostructure features generated on SiO₂ surface which was analyzed using atomic force microscopy (AFM) technique. The etching chemistry of CHF₃ plasma on PMMA masking layer and SiO₂ is analyzed to explain the polymerization. The surface root-mean-square (RMS) roughness below 1 nm was achieved by decreasing the RF power to 150 W and process pressure lower than 10 mTorr.     

Time-resolved experiments on the photoablation of polystyrene and PMMA by ArF-laser radiation

The photoablation of polystyrene (PS) and polymethylmethacrylate (PMMA) was studied in real-time during the uv laser pulse at 193 nm. The transmission and total reflection of thin polymer layers on quartz glass substrates was measured time-resolved. From the results for the strongly absorbing PS it can be concluded that the emission of material starts within the first few nanoseconds of the laser pulse. Photoablation of PMMA, which is a relatively weak absorber at 193 nm, is accompanied by strong modifications of the transmission by the first several ten laser pulses.