摘要
随着光刻机分辨力节点的提高,纳米级的高精度检焦技术变得愈发重要。针对投影光刻的特点,介绍了一种基于叠栅条纹相位解析的纳米检焦方法。此方法基于三角法测量原理,通过光弹调制器和横向剪切板的光学调制、平行平板的相位调整,硅片位移的变化会引起调制光强发生正余弦变化。根据光强的正余弦变化,求出焦面位移量。经实验与数据分析,该方法具有纳米级的检焦精度,且具有实时性强、非接触等特点,能满足100 nm投影光刻中焦面检测的需要。
With the improvement of lithography resolution node, high precision focus detection method becomes more and more important. The focus detection method which is based on moire fringe phase analysis and the triangulation principle is introduced. By analyzing optical modulation of photoelastic modulator and Savart plate, adjusting the parallel plate, the light intensity modulation which is caused by focal plane displacement changes in sine or cosine form. By analyzing the experimental data, focusing accuracy of this method is at nanoscale, hard real-time, and non-contact. It can meet the need of projection lithography with the line width of less than 100 nm.
出处
《光学学报》
EI
CAS
CSCD
北大核心
2015年第2期194-199,共6页
Acta Optica Sinica
基金
国家自然科学基金(61376110)
关键词
测量
纳米检焦
相位解析
光弹调制
横向剪切板
measurement
nano focusing
phase analysis
photoelastic modulation
Savart plate
