基于并联柔顺机构共面平衡的晶圆交接关键技术研究

发布时间：2018-01-16 22:01

本文关键词：基于并联柔顺机构共面平衡的晶圆交接关键技术研究　出处：《哈尔滨工业大学》2017年博士论文　论文类型：学位论文

【摘要】：晶圆交接是晶圆在输送机构与工件台间的传输与转移,是光刻流程的开始和结束,其平稳性、准确性和快速性是光刻过程安全、稳定、高效的前提和保证。平稳性可以减小碰撞和应力集中,避免晶圆破损;准确性可以保证晶圆交接位姿满足对准测量的要求;快速性与最终产率息息相关。作为晶圆交接中的核心部件,并联柔顺机构结构轻量紧凑,运动平滑连续,在平稳快速方面具有优势。但柔性单元的多自由度带来了复杂的运动行为,同时柔性结构加工装配困难使交接面位姿存在差异,这些都给并联柔顺机构的结构设计、位姿分析以及运动控制增加了难度,影响晶圆交接的平稳性、准确性和快速性,成为制约并联柔顺机构在光刻机晶圆交接中应用的关键技术瓶颈。本文旨在解决光刻机中晶圆交接平稳性、准确性和快速性的实现问题。本文在建立并联柔顺机构整体柔度模型的基础上,针对晶圆吸附过程分析了交接面柔性支撑晶圆达到共面平衡的作用机理,从而提出基于并联柔顺机构共面平衡的晶圆位姿解算方法,并利用最小区域平面拟合方法准确提供位姿解算必须的交接面信息,达到了晶圆平稳、准确交接的目的。同时针对柔性臂运动过程提出限幅下时间最优的高精度运动定位方法,实现了快速、高精度的晶圆交接。论文的主要研究内容如下:针对现有简单柔性单元模型无法完整、准确的描述并联柔顺机构整体柔度特性和交接中晶圆位姿变化的问题,建立了并联柔顺机构整体柔度模型,并基于特征旋量的方法对整体柔度矩阵进行柔度分析,优化结构参数使工作方向特征柔度满足平稳性要求。在整体柔度模型与交接面准确位姿研究的基础上,提出基于并联柔顺机构共面平衡的晶圆位姿解算方法。该方法中,柔性臂末端的交接面与晶圆发生相互作用达到共面平衡,交接面产生了小角度旋转与小范围平移,通过坐标变换得到柔性结构的相应变形,建立平衡方程和几何约束方程,实现晶圆交接位姿的准确解算,然后分析了交接面位姿对晶圆交接位姿的影响。分析结果表明,并联柔顺机构可极大地减小交接面高度差异产生的晶圆倾斜,可以自行调整交接面初始倾斜实现交接共面,同时消除点接触引起的应力集中问题,使晶圆交接更加平稳。最后对晶圆交接位姿解算方法进行了实验验证,结果表明,晶圆交接共面平衡位姿的实验结果与理论分析结果偏差小于0.2mrad,验证了晶圆交接位姿解算方法的正确性和有效性。针对交接面位姿平面拟合中存在求取最小区域精确解与高效可靠处理大量离散点数据之间难以兼顾的问题,提出一种逐步缩小约束区域的凸壳投影最小区域平面拟合方法。该方法通过缩小平面法向量的约束区域减小搜索范围,在处理大量凸壳点时可以快速定位到目标区域,结合基于凸壳棱边投影的计算几何方法计算得到最小区域精确解。分别对多种典型数据集和交接面的实测数据集进行平面拟合,结果表明,该方法可以得到与现有多种典型算法相等或更优的最小区域解,同时可以高效可靠处理大量离散点数据,实现了交接面最小区域平面拟合的精确求解,保证了晶圆交接的准确性。针对并联柔顺机构晶圆交接中时间最优与高精度跟踪指令运动以及控制幅值限制间难以兼顾的问题,建立了并联柔顺机构晶圆交接运动模型,并提出了一种零相位误差跟踪和限幅的最小拍方法。该方法在原有最小拍方法基础上,通过调整控制拍数满足幅值限制,利用无振荡和时间最优建立非齐次线性方程组来求解每拍的控制量,同时结合零相位误差跟踪环节,实现限幅下最优运动时间与高精度跟踪定位。仿真结果表明,在满足输入电压幅值小于等于6伏的要求下,系统经过4个采样周期8ms完成100μm的定位运动,阶跃响应准确、稳定,同时有良好的快速跟踪性能。最后,搭建了实验平台,对并联柔顺机构的性能以及晶圆交接技术进行了实验研究。结果表明,并联柔顺机构在交接位附近可以实现1μm的分辨力,100μm阶跃响应调节时间为8ms,相比传统交接方法时间缩短了59.4%,定位误差为2μm。晶圆交接实验采用零相位误差跟踪和限幅最小拍方法完成时间为0.454s,相比传统交接方法缩短9.9%,验证了新方法的正确性和有效性,实现了快速高精度的晶圆交接。
[Abstract]:The transfer of wafer in wafer conveying transmission and transfer mechanism and the workpiece table between the start and end of the lithography process, stability, accuracy and rapidity of the lithography process is safe, stable and efficient. The premise and guarantee of stability can reduce the collision and the stress concentration, avoid wafer breakage; can ensure the accuracy of wafer transfer to meet the requirements of pose alignment measurement; fast and is closely related to the final yield. As a core component of wafer handover in parallel, compliant mechanism structure lightweight and compact, smooth and continuous movement, has advantages in fast and steady. But the flexible element of multi degree of freedom movement brought the complex behavior of a flexible structure and difficult processing and assembling the handover face pose differences, which gave the parallel compliant mechanism design, displacement analysis and motion control to increase the difficulty, influence the stability of wafer transfer, accuracy and Fast, has become key technology bottlenecks in the application of parallel compliant mechanism of lithography wafer transfer. This paper aims to solve the smooth circular handover lithography machine MICROTEK, realize the speed and accuracy. Based on the establishment of this parallel compliant mechanism general flexibility model, according to the analysis of the adsorption process wafer interface flexible support to wafer the mechanism of coplanar balance, thus put forward the wafer position based on coplanar parallel balancing of compliant mechanism solution method, and using the minimum zone plane fitting method provides accurate pose calculation interface information must be reached, wafer is stable, accurate transfer. At the same time put forward high precision motion positioning method under the optimal time limit for the flexible arm movement process, to achieve a rapid, high precision wafer transfer. The main contents of this thesis are as follows: according to the existing simple flexible single element model Able to complete, accurate description of the parallel compliant mechanism overall flexibility characteristic and transfer MICROTEK circular posture change, established a parallel compliant mechanism overall flexibility model, and the overall flexibility matrix method for feature torsors based on flexibility analysis, optimization of structure parameters of the work to meet the stability requirement of directional features flexibility in the overall flexibility. The interface model and the exact position on the basis of the research, put forward the wafer pose based on coplanar parallel balance compliant mechanism calculation method. In this method, the interface with the end of the flexible arm wafer interact to produce coplanar balance, the interface of small angle rotation and small range of translation, the corresponding deformation of flexible structures by coordinate transformation, the establishment of equations and geometric constraint equations of equilibrium, achieve accurate pose wafer handover solution, and then analyzes the interface position of the wafer transfer position . analysis results show that the parallel mechanism can greatly reduce the production of soft handover surface height difference of wafer tilt, can adjust the interface to achieve the initial tilt transfer of coplanar, while eliminating stress caused by the contact problem, make the transition more smoothly. At the end of the wafer wafer transfer pose calculation method is verified by experiments. The results show that the experimental results of wafer transfer balance pose coplanar with the theoretical analysis results deviation is less than 0.2mrad, to verify the correctness and effectiveness of the wafer transfer pose calculation method. The minimum area accurate and efficient and reliable treatment is difficult to balance between a large number of discrete data problems in the interface plane pose this presents a narrow convex hull projection plane fitting method of minimum area constraint. The method by reducing the constraint plane normal vector to reduce the search The scope of the handling of large quantity of convex hull points can quickly locate the target region, combined with the exact solution of minimum convex hull edge projection area calculation method based on computational geometry. On several typical data sets and the interface between measured data set plane fitting, results show that the method can be obtained with various existing typical algorithms or equal the better the minimum zone solution, at the same time can be efficient and reliable processing of discrete data, the exact solution of the interface of minimum zone plane fitting, to ensure the accuracy of wafer handover. The parallel mechanism of wafer transfer smooth time optimal and high precision tracking motion and control amplitude constraints difficult to balance, set up parallel transfer wafer motion model of compliant mechanism, and proposes a method of minimum zero phase error tracking and limiting the beat. The original method in the small shoot Based on the method, by adjusting the number of beats to meet the amplitude limit, the oscillation and time optimal control quantity to establish non homogeneous linear equations for each shot, with zero phase error tracking links, to achieve optimal motion amplitude and time limit of high precision tracking. The simulation results show that while the input voltage amplitude less than or equal to 6 volts at the request of the system after the 4 sampling period 8ms completed 100 m positioning movement, the step response is accurate, stable, fast and good tracking performance. Finally, the experimental platform is set up on the performance of parallel compliant mechanism and wafer transfer technology were studied. The results show that the parallel compliant mechanism can achieve 1 m resolution in the transfer of a near 100 m step response settling time is 8ms, compared to the traditional handover method can shorten the time of 59.4%, the positioning error of 2 M. wafer transfer experiments. The zero phase error tracking and limiting minimum beat method is completed at 0.454s, which is shortened by 9.9% compared with the traditional handover method. The correctness and effectiveness of the new method is verified, and the wafer transfer with fast and high accuracy is achieved.

【学位授予单位】：哈尔滨工业大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TN405

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