步进扫描光刻机硅片台连续扫描时间优化算法

为减少步进扫描光刻机连续曝光扫描运动的扫描过渡时间(扫描时间和步进时间),将硅片台扫描方向曝光扫描运动分解为逻辑步进运动和逻辑扫描运动,提出扫描和步进运动时间重叠的轨迹规划算法(时间重叠算法)处理连续曝光扫描运动。在不破坏运动约束条件下(恒速运动要求以及速度、加速度边界限制),根据时间重叠算法重新计算并推导不同扫描运动路径下连续扫描运动过程的步进和扫描运动转折点。经理论分析和硅片曝光场连续曝光实例计算表明：基于时间重叠算法的轨迹规划可获得时间优化的硅片台连续曝光扫描,比传统扫描方法减少曝光扫描运动过程中的无效率时间,提高步进扫描光刻机生产率,为步进扫描光刻机工程实践提供理论基础。     

光刻机工作台超精密运动与同步控制

以同步扫描的运动性能为目标,研究针对步进扫描投影光刻机工作台的超精密运动与同步控制策略.结合工作台的结构特点,提出一种粗、微复合运动控制方法,即:微动台纳米级微动,粗动台微米级跟随运动;以硅片台、掩模台的三阶轨迹规划与轨迹重叠为基础,进行扫描过程中的同步状态规划;为实现纳米级的同步运动精度,进行硅片台与掩模台的动态特性比较,在此基础上提出工作台交叉反馈的同步控制策略,使掩模台实时跟踪硅片台的运动趋势,并设计同步误差模型进行运动性能评估.该方法已在100nm步进扫描投影光刻机中得到实际应用,并取得良好效果.     

光刻机步进扫描运动轨迹重叠规划算法

研究一种步进扫描投影光刻机的步进运动与扫描运动的轨迹重叠规划算法。根据给定的系统动力学约束,以保证最大加速度与最大速度不超限为目标,建立步进运动与扫描运动轨迹重叠规划的约束基准。依据该基准,分析步进运动与扫描运动轨迹重叠规划的各种可能情形,推导在最大程度上缩短运动执行时间的轨迹拐点调整计算公式。以此为基础,提出步进运动与扫描运动的轨迹重叠规划算法。通过仿真计算验证算法的正确性与有效性。实际应用证明该算法能在保证运动精度基础上,极大地提高生产率。该算法已被100 nm步进扫描投影光刻机工作台超精密运动控制系统所采用。     

光刻机模拟工件台掩模台同步运动误差分析

步进扫描光刻机是半导体制造行业的关键设备，在这种光刻机系统中，硅片台和掩模台要按照1：4的速度比进行同步扫描运动，同步运动性能指标以移动平均差（MA）和移动标准差（MSD）来度量。扫描过程中的同步性能对光刻机最终能生产出的芯片特征尺寸有着很大的影响。文章对模拟硅片一掩模台同步运动的同步误差进行了分析，给出在一定的扫描速度下，不同频率范围的误差成分对MA和MSD的影响的规律。分析结果对于有针对性地提高同步性能指标具有一定的指导意义。     

高精密运动平台的重复控制

为给步进扫描光刻机的设计研究提供理论指导,解决光刻机工作台宏动平台的控制问题,建立了步进扫描光刻机模拟减振试验平台宏动定位系统工作台伺服系统的数学模型,并根据该系统重复运动的特点,提出一种基于重复控制补偿的PID控制方式.运用MATLAB软件进行仿真试验,仿真结果表明与普通PID控制相比,基于重复控制补偿的PID控制器可以有效地减小跟踪误差,因而可以使系统有更好的控制效果.     

步进扫描光刻机扫描运动轨迹规划及误差控制

研究一种步进扫描投影光刻机工作台扫描运动超精密轨迹规划算法及误差控制策略。在分析三阶扫描运动与步进运动轨迹规划异同点的基础上,提出三阶扫描运动轨迹规划算法。针对扫描运动精确性与严格同步性要求,分析扫描运动轨迹规划误差补偿的几个关键问题。根据扫描运动轨迹算法离散实现存在的误差,结合内部整数积分策略,提出扫描运动轨迹规划加减速段与扫描速度稳定段运动距离的离散积分策略误差控制方法。此外,为克服切换时间圆整引起的扫描曝光匀速段位置误差,提出一种基于常速扫描运动段位置修正因子的误差补偿方法。以上方法共同实现光刻机工作台扫描运动轨迹规划精度控制。实例证明提出算法是有效和精确的。该算法成功应用于100nm步进扫描投影光刻机工作台的超精密运动控制系统中。     

光刻机工作台运动控制中的若干关键问题

100 nm步进扫描投影光刻机是我国攻关研究的主流机型,工作台是实现其超精密性能的核心子系统。光刻机工作台采用粗、微复合的运动结构,其同步最大运动平均误差(5 nm)和同步最大运动标准偏差(12 nm)等性能指标对运动控制系统提出严苛要求。分析硅片台与掩模台的结构特点,提出了运动控制系统中保证精度实现的组成单元,分别论述轨迹规划、测量系统、控制策略单元等的工作机理与实现特点;为进一步提高运动控制精度,分析工作台可能受到的扰动因素,提出相应的补偿控制策略,探讨运动控制中各环节的参数校准策略。综合论述步进扫描投影型光刻机工作台运动控制中的关键问题,并提出相应的实现与解决方法,可为实际光刻设备超高精度的实现提供指导。     

六自由度摇摆台动力学建模与分析

根据六自由度摇摆台的机构学原理,采用牛顿欧拉法建立了摇摆台的系统动力学模型,完成了动力学的建模与分析,然后运用Matlab软件对上述动力学模型进行编程计算,最后运用所建立的动力学模型对实际摇摆台各液压缸的出力进行了仿真,得到了运动平台以不同姿态运动时各液压缸的受力情况,为摇摆台的结构参数优化及动态分析提供了基础。     

冷压印光刻工艺精密定位工作台的研制

冷压印光刻工艺是一种将模板图形翻制到硅片上的技术。为了获得高分辨率压印图形，为压印光刻机设计了一个精密定位工作台。精密定位工作台是压印光刻机的关键部件，它既能够保证模板-抗蚀剂-硅片结构间的接触均匀一致，并实现模板与承片台间的三个运动自由度，即沿z轴的直线运动和绕x、y轴的旋转运动(α和β)，又可以实现步进对准所需要的沿x、y轴的直线运动和绕z轴的旋转运动(θ)。设计中采用了柔性机械结构，消除了使用铰链连接所引起的间隙与摩擦等问题。压印实验结果显示定位系统在200mm的行程中，精密定位工作台定位精度达到8nm以内。实现了压印光刻工艺在集成电路制造中的高精度定位要求。     

步进电机驱动六自由度并联运动平台设计

为了能够在实验室内进行小型仪器元件的六自由度运动模拟和演示,设计了以步进电机驱动滚珠丝杠传动的小型六自由度并联运动平台。通过运动学反解建立了算法公式,应用Matlab仿真,得出了平台运动时各支路长度的变化曲线,验证了求解算法的正确性;运用Kutzbach-Grubler公式分析了电驱动UPU结构形式并联运动平台自由度的计算方法。根据给定参数建立了平台的三维模型,进行了结构协调性检测,并完成了步进电机驱动的六自由度平台的实体结构研制。将Lab VIEW组态软件与Matlab脚本解算程序结合,用于对平台的运动控制。测试结果表明:平台完全可以按照预定轨迹进行空间6个自由度的运动,实现对小型仪器元件的运动模拟。     

Vibro-acoustic analysis of free piston engine structure using finite element and boundary element methods

This paper presents the results of vibro-acoustic modeling and simulation using the finite element and the boundary element methods for the free piston engine structure. A model of the engine was constructed through the use of finite element software to perform a normal mode analysis of the engine structure. The objective was to determine the mode shapes and the natural frequency that contribute to engine structure vibration. Theoretical development of the engine balance motion and frequency response was also conducted. From the simulation and finite element analysis, the force response pattern of the engine vibration was determined and then compared with its natural frequency. The vibration data were used as the input data for noise analysis using the boundary element method. The integration of the finite element and the boundary element determined the noise-frequency data of the engine structure toward the occurrence of engine noise. The information can be used by designers to analyze engine specifications and structure, especially at the preliminary design stage.     

Comparative analysis of internal friction and natural frequency measured by free decay and forced vibration

Relations between various values of the internal friction (tgdelta, Q(-1), Q(-1*), and Lambda/pi) measured by free decay and forced vibration are analyzed systemically based on a fundamental mechanical model in this paper. Additionally, relations between various natural frequencies, such as vibration frequency of free decay omega(FD), displacement-resonant frequency of forced vibration omega(d), and velocity-resonant frequency of forced vibration omega(0) are calculated. Moreover, measurement of natural frequencies of a copper specimen of 99.9% purity has been made to demonstrate the relation between the measured natural frequencies of the system by forced vibration and free decay. These results are of importance for not only more accurate measurement of the elastic modulus of materials but also the data conversion between different internal friction measurements.     

杆状弯曲行波超声电机定子和转子的优化设计

采用有限元模态分析和谐响应分析方法，分析了杆状弯曲行波型超声电机定了上开槽尺寸与其一介弯曲固有频率的关系以及开槽尺寸与定子上与转子接触部位振幅的关系。对电机转子的两种设计方案进行运动分析和有限元接触分析，并得出两者结论是一致的。     

Vibration analysis of cantilever plates undergoing translationally accelerated motion

This paper presents a modeling method for the vibration analysis of translationally accelerated cantilever plates. An accurate dynamic modeling method, which was introduced in the previous study, is employed to obtain the equations of motion for the vibration analysis. Dimensionless parameters are identified to generalize the conclusions from numerical results. The effects of the dimensionless parameters on the natural frequencies and mode shapes are investigated. Particularly, the magnitude of critical acceleration which causes the dynamic buckling of the structure is calculated. Incidentally, the natural frequency loci veering phenomena are observed and discussed.     

钻井液与钻柱的耦合纵向振动分析

考虑钻井液与钻柱的泊松耦合,基于管内外钻井液与钻柱间的耦合纵向波动方程组,应用特征矢量法,研究地层切变模量和钻柱泊松比边界对钻柱内纵向应力波和钻井液纵向压力波传输的影响。在此基础上推导钻柱纵向振动的频率方程,引入等效质量分析管内外液动压力下的钻柱固有频率。理论求解表明,钻柱的泊松效应造成应力波与压力波耦合,且管内外不同介质间的波速耦合对压力波的影响明显,而对应力波的影响较弱,故耦合对泥浆脉冲传输的影响远大于钻柱声遥测。钻井液的液动压力增加纵振的惯性质量,导致固有频率与不考虑钻井液相比有较大下降。综合等效粘惯性质量、粘性阻尼系数和钻井液惯性力,建立多因素影响下的钻柱纵向耦合振动模型。     

Correction and evaluation of the effect due to parasitic motion on primary accelerometer calibration

Primary accelerometer calibration is carried out under the assumption that a vibration exciter gives a rectilinear motion to an accelerometer to be calibrated. However practical vibration given by the vibration exciter includes parasitic motion such as transverse, rocking, and bending motion. Such parasitic motion would give two serious effects on primary calibration results, transverse motion effect and vibration distribution effect. Transverse motion effect is caused by an inner product of the vectors of both transverse motion and transverse sensitivity. On the other hand, the vibration distribution effect is caused by relative motion between a sensing point of accelerometer and a spot sensed by the interferometer. As these effects have close interaction between parasitic motion and measuring instruments, it would be very difficult to evaluate them by measuring independently each component.     

圆盘型非接触压电微马达定子的振动分析

提出一种圆盘型非接触压电微马达,采用有限元方法分析了马达定子的振动模态和固有频率,对定子的振幅与施加电压的关系进行了数值分析。最后,采用激光多谱勒测振仪对定子的振型和振幅进行了测试,实验结果与有限元分析吻合较好,为马达定子的设计和优化提供了理论依据。     

Semi-analytical approach for free vibration analysis of cracked beams resting on two-parameter elastic foundation with elastically restrained ends

In present study, free vibration of cracked beams resting on two-parameter elastic foundation with elastically restrained ends is considered. Euler-Bernoulli beam hypothesis has been applied and translational and rotational elastic springs in each end considered as support. The crack is modeled as a mass-less rotational spring which divides beam into two segments. After governing the equations of motion, the differential transform method (DTM) has been served to determine dimensionless frequencies and normalized mode shapes. DTM is a semi-analytical approach based on Taylor expansion series that converts differential equations to recursive algebraic equations. The DTM results for the natural frequencies in special cases are in very good agreement with results reported by well-known references. Also, the DTM procedure yields rapid convergence beside high accuracy without any frequency missing. Comprehensive studies to analyze the effects of crack location, crack severity, parameters of elastic foundation and boundary conditions on dimensionless frequencies as well as effects of elastic boundary conditions on cracked beams mode shapes are carried out and some problems handled for first time in this paper. Since this paper deals with general problem, the derived formulation has capability for analyzing free vibration of cracked beam with every boundary condition.     

基于模态综合方法的叉车门架系统振动特性研究

采用Yee和Tsuei提出的直接部件模态综合法,将自由界面模态综合法与频响函数法相结合,在试验得到内、外门架振动模型基础上,建立内、外门架组装后门架整体系统振动特性的分析方法,编制MatLab程序计算门架整体的振动特性,分析门架系统各阶振型特点,并把数值仿真结果与试验结果做比较,误差最大达到2．5％。证实该方法在工程机械的整机或部件的振动特性研究中有实用价值。     

基于灵敏度分析的汽车动力传动系扭振特性优化

利用偏导数法分析得出汽车动力传动系无阻尼自由扭振固有频率和振型对转动惯量和扭转刚度的灵敏度。以某车型动力传动系扭振特性为例,通过分析固有频率和振型对转动惯量和扭转刚度的灵敏度,找出对固有频率和振型影响最灵敏的结构参数,对其进行动力学修改,实现传动系固有频率和振型的优化,从而减轻扭振的程度。研究成果可为汽车传动系的动态特性优化提供依据。