电子束曝光系统中精密工件台的测量系统

介绍了电子束曝光技术的原理。根据精密工件台对测量系统的需要,设计了三轴工件台测量系统布局方式,并简单介绍了激光干涉测量系统所需元器件数量的计算方法。重点讨论了双频激光干涉测量原理、双频光束与运动方向敏感性的关系以及读出装置信号处理方法。在此基础上,对研制的电子束曝光系统精密工件台进行了直线性和垂直性实验测试,其测量分辨率达到0.6nm,测量重复性精度达到±0.06μm,测量绝对误差达到0.011μm。结果表明,采用双频激光测量系统可确保工件台系统测量和定位准确性。     

以微细加工设备为例评述精密定位工件台系统的发展趋势

<正> 半导体硅片的微细加工,对母掩模版的制造精度提出了很高的要求。一组掩模的套刻精度,主要取决于分步重复相机坐标工件台的精度。套刻误差不得大于最小线宽的约10—20%,即±0.1—0.2μm。工件台的精度又取决于两个坐标的重复定位精度和定向精度。这也就是说,要有一个精密的制造掩模平行导向运动     

基于电流变效应的超精密工件台研究与展望

通过分析超精密工件台系统的研究现状和存在问题及电流变液ERF的机理和应用现状,提出"基于ERF半主动阻尼的直线电机驱动-气浮/磁浮导轨"纳米级超精密工件台系统.介绍了国内外相关研究,分析了此工件台系统具有的特性及尚待解决的问题.     

掩模移动曝光系统精密定位工件台研制

为满足掩模移动曝光技术制作微光学元件的要求,研制了接近式曝光系统中使用的x-y二维精密移动工件台.该工件台由x-y二维整体手动工作台子系统、x-y二维掩模精密移动台子系统和承片台子系统组成.利用一个方导轨和两对V形导轨组成的滚动导轨副实现了x向和y向精密移动的导向功能;利用驱动器、电机、光栅、细分卡、单片机构成的闭环控制系统保证了x和y向的运动精度;在气浮的作用下,利用掩模版靠平基片实现了调平功能;利用差动螺旋机构和1∶2杠杆缩小机构实现了间隙的调整功能.经检测,工件台在8 mm的工作行程范围内,沿x,y方向移动的直线性分别达到了4"和3",两个方向的正交性达到了10",运动定位精度达到了1.2 μm.     

基于FPGA的电子束曝光机工件台控制器设计

基于激光干涉仪的精密工件台是电子束曝光机的关键设备。为了改进工件台控制器的运算速度．设计了一种基于FPGA的电子束曝光机工件台控制器。本控制器由上位机接口、激光干涉仪测量系统接口、电机控制接口、手动面板接口和主处理器组成,以美国Xilinx公司Spantan3系列的FPGA芯片XC3s400为核心。实现控制器与上位机、激光干涉仪测量系统、伺服驱动系统、手动控制面板之间的数据交换和指令传递。完成工件台的精确移动。满足电子束曝光的定位精度和拼接精度的要求。     

基于FPGA的电子束曝光村工件台控制器设计

基于激光干涉仪的精密工件台是电子束曝光机的关键设备。为了改进工件台控制器的运算速度．设计了一种基于FPGA的电子束曝光机工件台控制器。本控制器由上位机接口、激光干涉仪测量系统接口、电机控制接口、手动面板接口和主处理器组成,以美国Xilinx公司Spantan3系列的FPGA芯片XC3s400为核心。实现控制器与上位机、激光干涉仪测量系统、伺服驱动系统、手动控制面板之间的数据交换和指令传递。完成工件台的精确移动。满足电子束曝光的定位精度和拼接精度的要求。     

光刻机超精密工件台研究

针对步进扫描投影型光刻机超精密工件台开展研究熏所搭建的超精密气浮运动试验台采用气浮直线导轨支撑、直线电机驱动、直线光栅尺反馈组成大行程直线运动系统,其上叠加洛仑兹电机驱动的气浮微动台,提供对直线电机运动的精度补偿,由双频激光干涉仪提供粗、精动运动系统的超精密位置检测和反馈,两套直线运动系统可研究同步扫描运动,并可灵活地组成多种x-y超精密运动系统。介绍了基于该试验台进行的超精密运动控制试验研究,运动定位精度已经达到12nm     

共光路多自由度运动误差测量及补偿技术研究

工件台是TFT阵列基板长寸测量设备中最为核心的技术单元之一,其定位精度将直接决定最终长寸测量设备的测量精度.在运动过程中由于运动导轨加工和装配误差会使工件台产生运动误差,而这些运动误差会影响TFT阵列基板长寸测量精度.为解决上述工件台运动误差对长寸测量精度的影响,文中基于桥式结构的长寸测量设备研究分析了工件台运动误差对...     

六维磁悬浮纳米级精密工件台的研究

设计了“H”型六维x-y工件台，利用磁悬浮技术将工件台悬浮在x、y导轨上，消除了导轨的摩擦和磨损；直线电机无接触驱动实现了工件台的粗定位；控制不同磁悬浮电磁铁的电流大小，可以实现工件台的微定位以及逐场调平调焦。计算了工件台由于重力弯曲、热膨胀等原因引起结构变形而带来的精度误差，理论上分析证明工件台在x、y方向能满足0.02μm的定位精度要求以及达到0．1μm调焦精度和3．0μrad调平精度的要求。将应用于特征尺寸0．18μm线宽激光光刻机上。     

电子束曝光机激光工件台测量系统研究

由于电子束曝光机采用的修正技术,工件台的测量系统显得十分重要。介绍了电子束曝光机激光定位精密工件台的工作原理,其测量系统首次采用国际先进的HP5527双频激光干涉仪。对测量系统进行了详细的误差分析,在此基础上提出了系统误差的补偿方法。     

Simulation tool design for the two-axis nano stage of lithography systems

For advanced electron beam lithography systems, a simulation tool for a two-axis nano stage is developed in this paper. The stage is equipped with piezo-actuators and flexure guides. Even if piezo-actuators are believed to be feasible for realizing nano scale motions, it is difficult to predict their characteristics due to their nonlinearities such as hysteresis and creep. In this paper, the nonlinear properties are modeled considering the input conditions. In detail, the hysteresis is described as a first order differential equation with 24 sets of the hysteresis parameters and the creep is modeled as a time-dependent logarithmic function with two sets of creep parameters. The characteristics of the flexure guides are analyzed using the finite element method and are embodied into a multi-body-dynamics simulation tool. The dynamic behavior of the simulation tool is compared with the experimental data.     

电子束曝光机激光工件台系统研制

介绍了nm级电子束曝光机激光定位精密工件台系统的结构组成、各部分技术措施及总体性能指标。该工件台采用HP5527激光干涉测量系统,测量分辨率达0.6nm,结构上成功将导向与承载分离,对承片台、机械手等进行重大创新。无论是整机性能还是关键技术单元均处于国内领先水平,是一台性能优良、高精度的电子束曝光机工件台。     

Experimental Attenuation of Rectangular Waveguides at Millimeter Wavelengths

The experimental values of attenuation of commercially available rectangular waveguides were determined at frequencies between 25 and 200 GHz with emphasis on high accuracy. They were compared with the theoretical values computed from the dc conductivities, taking into consideration temperature effects, work hardening, size effects, surface roughness, and a room-temperature anomaly of the skin effect. A new way to express the excess attenuation due to these effects was fomulated. Excess ratios of attenuation of coin-silver waveguides were found to be well below the values used in engineering in the past. They can satisfactorily be explained by surface roughness. The normalized excess attenuations of copper guides are higher than those of guides made of silver but lower than cited in the literature.     

Accurate modeling of line-defect photonic crystal waveguides

An accurate three-dimensional method to calculate the Bloch modes of photonic crystal (PhC) waveguides is proposed. Good agreement with available experimental and numerical data is obtained. The originality of the method lies in the fact that the Bloch modes are seen as the electromagnetic fields associated to the complex poles of an in-plane transversal scattering matrix. In comparison with previous approaches, the computational domain discretized is smaller and a higher accuracy for the losses of PhC waveguides is achieved.     

极坐标系中的B样条有限元法解波导本征值问题

本文提出了用极坐标系中的Ｂ样条有限元法解波导本征值问题，该方法有两个突出优点：（１）避免某些含曲线边界的波导截面的剖分误差；（２）改善尖角波导的计算精度，本文首先建立了极坐标系中Ｂ样条有限元方程，然后通过对圆形，扇形，双脊加圆形和心形波导本征值问题的实际计算，表明方法的有效性和实有价值。     

基于嫁接遗传算法的微波电路优化技术

嫁接种群向进化种群添加个体的多样信息，避免了基本遗传算法的过早收敛。同时嫁接种群指导进化方向，加快了收敛速度。另一方面交叉矩阵使适值高的个体以低概率交叉，在一定程度上改善了算法的收敛性。最后用四种优化方法设计宽带阶梯阻抗变换器，结果表明基于嫁接遗传算法的微波电路优化设计具有高效性和精确性。     

无源多站时差定位技术研究及在频谱监测中的应用

研究了无源定位中时差定位的方法及其应用。通过此方法来确定在频谱监测系统中检测到的发射异常信号的信源位置。仿真实验证明本定位方法切实可行,并且在实践中有很好的指导意义。     

Transmission Modes of Closed Elliptic-Groove Waveguides for Millimeter Waves

In this paper, a new type of horizontal-flat and vertical-flat closed elliptic-groove guides is firstly presented. The field components and characteristic equations for some main transmission modes of the closed elliptic-groove guides are derived by with the help of the mode-matching method and Mathieu function. The variations of the cut-off wavelengths along with eccentricities, widths and lengths of the parallel plates for a number of lower order transmission modes of the closed elliptic-groove guides are also analysed in detail. The calculated results in good agreement with ones in the relevant references are of very important values in theoretical researches and actual applications of closed elliptic-groove guides for millimeter and submillimeter waves.     

Scattering and mode conversion by a screen-like inhomogeneityinside a dielectric slab waveguide

In this paper, the interaction of surface guided waves with a perfectly conducting scatterer shaped as a part of a circular screen and placed into a dielectric slab waveguide is investigated in mathematically correct manner. Due to the geometry of screen the original boundary value problem is reduced to dual series equations treated further by means of the Riemann-Hilbert Problem technique. Based on this approach, the numerical solution can be obtained, theoretically, with any desired accuracy. The reflection, transmission, and radiated-field quantities are computed for both single-mode and multimode slab guides containing cavity-shaped and strip-shaped scatterers     

Finite-element solution of planar arbitrarily anisotropic diffused optical waveguides

The finite-element method for propagation in planar anisotropic diffused optical waveguides with arbitrary permittivity tensor is presented. A Galerkin procedure has been introduced to the finite-element formulation, to study both the nonleaky and leaky surface waves. The complex propagation constants are determined as a function of frequency for possible modes of propagation. The accuracy of the method has been checked by calculating the nonleaky and leaky surface waves of Ti-diffused LiNbO3waveguides with Gaussian index profiles. The numerical results of Ti-diffused LiNbO3waveguides with dielectric overlays are also presented and the effects of dielectric overlays on the propagation characteristics for the nonleaky and leaky surface waves are examined.