双掺杂LiNbO3:Fe:Mn晶体局域光折变体全息光栅形成及衍射特性

将带输运模型与二维耦合波理论相结合,研究了双掺杂LiNbO3∶Fe∶Mn晶体中由两束有限宽度平面波干涉产生的局域光折变体全息的动力学机制及其衍射特性。采用三步法联立求解了双中心带输运物质波方程和二维耦合波方程。数值计算结果表明,局域光折变体全息光栅的空间电荷场在空间上呈不均匀分布。当光栅区域较小时空间电荷场较强,随着光栅区域的增大,空间电荷场急剧下降,并降低一个数量级。此外,在接近光束入射边界的区域,空间电荷场时空变化规律与一维无限大光折变体全息光栅的结果相似,随着光栅区域的扩大,边界效应对空间电荷场的影响越显著。研究还发现,局域光折变体全息光栅的衍射效率随光栅厚度的增加而增加。理论结果对于由局域光折变体全息光栅形成的光学器件与系统的设计和应用具有重要的参考意义。     

介质膜光栅槽形无损检测方法的研究

为了从理论上探究介质膜基底光刻胶光栅掩模槽形的检测方法,对此种光栅掩模建立了以C方法为理论基础的衍射效率理论计算的数学模型,并将从实际光栅掩模的SEM照片得出的光栅槽形参数带入到该模型中,得到了一系列-1级衍射光的光谱分布曲线,这些曲线的变化趋势与一定光栅槽形相对应,提出了通过测量衍射光的光谱分布曲线判断光栅槽形的无损检测方法。分析表明,该方法在光栅槽形的检测过程中,可以较为有效地判断光刻胶是否到底,而这一点在掩模的制作工艺中至关重要。     

一种基于因果分析的光纤Bragg光栅设计方法

从光栅矩阵分析法出发，介绍了一种基于因果分析的光纤Bragg光栅设计方法，并采用该方法设计了用于滤波的均匀光纤Bragg光栅和用于色散补偿的啁啾光纤光栅的结构参数。结果表明，所设计的光栅的分析曲线与目标曲线吻合性很好。     

用透射光谱法测光栅参数的数值模拟

本文基于光栅的严格理论,提出结合透射光谱和优化算法来测量光栅参数的新方法,首先,利用傅立叶模式理论和反射透射系数递推算法(RTCM) ,计算出在2 0 0 -90 0nm波段内的理论透射光谱图,通过在上面叠加不同偏差的高斯噪声来模拟光栅的实际测量曲线,接着在模拟曲线上任取若干个点作为实验测量值,最后利用优化算法进行反演搜索,找到待测光栅的结构参数。文中我们选择了三种类型的光栅对该法进行数值上的模拟,其结果是成功的。该法可能会给光栅参数的测量指明一条新的途径。     

光学自增强效应与衍射效率的提高

利用含时光折交双光耦合方程数字模拟计算了掺铁铌酸锂晶体中双光耦合的动态过程,分析了空间电荷场及其位相、光折交光栅位相等光折交参量的变化过程,解释了光折变自增强效应,提出了提高光折交光栅衍射效率的有效方法．     

消除温度对应变测量的影响

提出了用光纤布喇格光栅( FBG)传感器测量光纤有效弹光系数的方法。利用光纤布 喇格光栅的性质,建立了一个可以有效地解决温度与应变对光栅存在交叉敏感的问题实验系统。实验结果表明,该系统能有效地测出了光纤的有效弹光系数,而且测量误差小于1. 3%。     

MEMS交叉梳齿光栅设计和优化

采用MEMS技术设计和制造了一种由梳齿驱动器驱动的新型交叉梳齿光栅,同时优化了该光栅的驱动器结构,着重分析了优化驱动器结构对光栅机械特性和光学传感特性的影响,优化后的光栅相对于未优化时具有更大的位移、更好的光学传感特性。基于PolyMUMPs工艺制作了梳齿驱动器驱动交叉梳齿光栅,并逐步分析了该光栅的加工步骤。结合有限元分析软件,对该MEMS光栅的机械特性进行了分析。分析结果表明,在85V下,该光栅驱动器的位移为2.7μm,而实际测量的位移为2.1μm。通过对该光栅驱动器结构进行优化,得到在同等电压下优化后的光栅驱动器位移较未优化时有显著提高,在85V时,优化后的MEMS光栅驱动器的位移为4.3μm。根据傅里叶光学理论计算得到,该光栅的传感灵敏度与驱动器位移成正比,经过计算得到优化后MEMS光栅的光学传感曲线更加陡峭,具有更好的传感特性。     

向列液晶中的光控永久光栅

液晶中的光折变光栅在数据存储、实时全息术、干涉测量、光放大、相位共轭、光学图像处理和光束操控等领域具有潜在的应用价值。通过二波耦合的方法在掺C60的向列液晶中记录了永久光栅，该光栅的衍射特性能够被外加直流电场或以任意角度入射的、与记录光强度相当的一束平面光波控制。为了进一步了解光栅建立的机制，研究了在恒定外加直流电场下的电流动态过程，从而证明该光栅源于表面电荷的光调制。     

镀铬基片全息光栅光刻胶掩模槽形参量光谱检测方法

为了检测全息光栅掩模槽形,运用严格耦合波理论(RCWT)分析镀铬基片光栅光刻胶掩模反射0级衍射效率光谱曲线与槽形参量的关系。测量了400~700 nm波长范围内60°入射角条件下的镀铬基片全息光栅光刻胶掩模反射0级衍射效率光谱曲线。将实验曲线与不同槽形参数对应理论曲线相减、求标准差进行匹配,标准差最小者为匹配结果,从而找到被测掩模的槽深和占宽比(光栅齿宽占光栅周期的百分比)。结果表明,该方法图形匹配速度快,误差容限大,匹配结果与电镜结果相符。对于要求同时检测矩形或接近矩形槽形的全息光刻胶光栅掩模的槽深和占宽比,该方法完全适用。     

激光全息防伪标识质量检测方法的研究

提出一种对光源输出功率稳定度要求相对较低的激光全息防伪产品光学特性参数检测方法.使用一块透反比一定的玻璃基片,将相对不稳定度3%的He-Ne激光器输出光束分为两柬:反射光和透射光.两束光光强度比例恒定,测量反射光强计算出透射光强度.透射光作为再现光照明激光全息防伪标识,其衍射光构成物体再现像.实时探测标识光栅处以及无光栅处的衍射光强与反射光强,进而得到光栅处衍射光强与再现光强的比值及其与无光栅处衍射光强的比值,即全息防伪标识的衍射效率和信噪比.实验结果表明:透射光强测量值相对误差不超过0.2%;衍射效率及信噪比的测量值相对误差分别不超过0.8%和1.9%.     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.     

Curved crystal spectrometer for the measurement of X-ray lines from laser-produced plasmas

In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal （200） （2d = 0.4027 nm） is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line（w）, the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line（x）, the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines（y）, the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line（z） in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line（q） in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution（λ/△ 2） is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

Electronic Structure of Semiconductor Nanocrystals

This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors.     

Critical Stage Rule-Based Real Time Dispatch（RTD）System in Highly-Mixed-Products （HMP） FAB

An improving utilization and efficiency of critical equipments in semiconductor wafer fabrication facilities are concerned. Semiconductor manufacturing FAB is one of the most complicated and cost sensitive environments. A good dispatching tool will make big difference in equipment utilization and FAB output as a whole. The equipment in this paper is In-Line DUV Scanner. There are many factors impacting utilization and output on this equipment group. In HMP environment one of the issues is changing of reticule in this area and idle counts due to load unbalance between equipments. Here we'll introduce a rule-based RTD system which aiming at decreasing the number of recipe change and idle counts among a group of scanner equipment in a high-mixed-products FAB.