基于瞳面干涉的自参考干涉仪的研制

发布时间：2019-05-19 11:04

【摘要】：为了用更简单的光学器件使对准标记产生的衍射光实现重叠干涉,同时能够降低对准系统的加工和装调难度,设计了基于瞳面干涉的自参考干涉仪系统。首先,对当前光刻机所使用的对准技术展开研究,以光栅衍射原理和偏振光学为理论基础,提出了用Koster棱镜作为合光器件的自参考干涉仪,最后使用线阵CCD收集信号并将数据用计算机做后续的位置信息处理。由于自参考干涉仪测量系统是以光栅的栅距作为测量基准,而不是使用激光波长,故测量系统受环境因素造成的测量误差影响较小。实验结果表明:系统分辨率为0.2 nm,使得该系统可以达到纳米级分辨率。证明了所设计的干涉仪可用于目前前道光刻机的对准系统,实现纳米级精度的对准测量,从而使光刻设备的套刻精度满足最新工艺节点的要求。
[Abstract]:In order to achieve overlapping interference of diffracted light produced by alignment mark with simpler optical devices, and to reduce the difficulty of processing and adjusting the alignment system, a self-reference interferometer system based on pupil interference is designed. Firstly, the alignment technology used in lithography machine is studied. Based on the principle of grating diffraction and polarization optics, a self-reference interferometer using Koster prism as optical device is proposed. Finally, linear CCD is used to collect the signal and the data is processed by computer. Because the measuring system of self-reference interferometer takes the grating distance as the measuring reference, instead of using laser wavelength, the measurement error caused by environmental factors is less affected by the measuring system. The experimental results show that the resolution of the system is 0.2 nm, which makes the system achieve nanometer resolution. It is proved that the designed interferometer can be used in the alignment system of the front lithography machine at present, and the alignment measurement of nanometer precision can be realized, so that the engraving accuracy of the lithography equipment can meet the requirements of the latest process nodes.
【作者单位】：上海理工大学光电信息与计算机工程学院;
【基金】：沪江基金(C14002)项目资助
【分类号】：TH744.3

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