Development of Friction Drive System and Intelligent Linear Guide for Nanometer Positioning

为了实现下一代大规模集成电路(LSI)的高精度和高生产率，必须实现纳米量级的高精度和高速定位。本研究的目的是建立一种基于超声波电机的纳米定位摩擦驱动系统，以满足这些要求。建立了一种新的监测方法来预测和控制超声电机的磨损模式。采用新技术控制影响精密定位工作台定位精度劣化的磨粒。主要研究结论如下：1.提出了以工作电压Ef的波动量作为驱动尖端与被动轨接触严重程度的监测参数。2.从实验和理论上阐明了静电力是摩擦磨损颗粒在接触界面的粘附力的主要组成部分。在Al_2O_3针尖的情况下，施加在1μm量级磨粒上的静电作用力是范德华力的505倍。3.采用Al_2O_3基复合材料作为超声电机的尖端材料，并在摩擦界面进行带电吹风，保证了定位精度。与未去除磨粒和使用Al_2O_3刀尖时的寿命相比，寿命提高了530倍。

A high precise of the order of nanometer and high speed positioning must be necessary in order to achieve a high accuracy and high throughput productivity for the next generation of LSI (large scale integrated circuit). The purpose of this research was establishment of a friction drive system with ultrasonic motor for nanometer positioning to reply these requirements. As a result of this investigation, new monitoring method was established to predict and to control wear mode of the ultrasonic motor. Further new technology was introduced to control wear particles which affect position accuracy degradation of the precise positioning stage. The conclusions obtained in this investigation are described as follows ;1.The amount of fluctuation of operating voltage Ef was proposed as a monitoring parameter of severity of contact between drive tip and driven rail. It was clarified that the transition between mild wear and severe wear could be predicted by using Ef values.2.It was clarified both experimentally and theoretically that electrostatic force accounts for most part of the total adhesive force of wear particles at the contact interface. In the case of Al_2O_3 tip, electrostatic force applied to wear particles of the order of 1 μm is 505 times larger than van der Waals force.3.Position accuracy was kept stable and by using Al_2O_3 base composite as tip material of the ultrasonic motor and air blow with electric discharge in to the friction interface. The life of the stage was increases as much as 530 times, compared with the stage life without wear particle removal and by using Al_2O_3 tip.