摘要
扫描狭缝是步进扫描光刻机用于控制曝光剂量的重要单元。随着光刻工艺节点减小到90 nm及以下,光刻照明分系统对刀口半影宽度的测量精度和重复性提出了更高要求。基于此,提出一种基于光瞳像的光刻机扫描狭缝刀口半影宽度测量技术。分析了共面扫描狭缝刀片成像光路,推导得到掩模面半影区与光瞳像的对应关系。搭建了扫描狭缝刀口半影检测系统,并对90 nm光刻机照明分系统的扫描狭缝刀口半影宽度进行测量。实验结果表明,所提测量技术可有效改善光强波动对刀口半影宽度测量的影响,扫描狭缝刀口半影宽度的测量重复性达到0.026 mm,提高了3.46倍(与传统扫描法相比)。该技术可用于高数值孔径浸没式光刻机照明分系统光学半影参数的测量。
Scanning slit is one of the most important elements in step-and-scan lithographic tools for controlling exposure doses.As the technology of lithography extends to 90-nm(and lower)process nodes,the lithographic-tool illumination subsystem has presented significant requirements for the precision and repeatability of the penumbra measurement.Based on this,a blade edge′s penumbra measurement technique for scanning slits of lithographic tools based on the pupil image is proposed.The corresponding relationship between the penumbra of the mask surface and pupil image is deduced by analyzing the imaging optical path of the coplanar scanning slit.A penumbra measurement system is developed,and the scanning slit edges′penumbra of a 90-nm lithographic-tool illumination system is measured.The experimental result shows that the proposed measurement method can effectively reduce the impact of light-intensity fluctuation on the penumbra measurement.The repeatability of the penumbra measurement is 0.026 mm,which is 3.46-times higher than that of the conventional scanning method.This technique can be used to measure the optical penumbra parameters of high-numerical-aperture immersion-lithographic-tool illumination subsystems.
作者
刘志帆
陈明
步扬
徐静浩
范李立
张建华
王向朝
Liu Zhifan;Chen Ming;Bu Yang;Xu Jinghao;Fan Lili;Zhang Jianhua;Wang Xiangzhao(School of Mechatronic Engineering and Automation,Shanghai University,Shanghai 200444,China;Laboratory of Information Optics and Opto-Electronic Technology,Shanghai Institute of Optics and Fine Mechanics,Chinese Academy of Sciences,Shanghai 201800,China)
出处
《中国激光》
EI
CAS
CSCD
北大核心
2019年第10期252-259,共8页
Chinese Journal of Lasers
基金
国家科技重大专项课题(2009ZX02205-001)
广西高校光电信息处理重点实验室开放基金(KFJJ2016-03)
关键词
测量
光刻机
扫描狭缝
半影宽度
成像测量
光瞳
measurement
lithographic tools
scanning slit
penumbra width
imaging measurement
pupil
作者简介
步扬,E-mail:buyang@siom.ac.cn。
