浸没式光刻机浸液系统污染控制研究现状及进展

Research Status and Progress of Contamination Control in Immersion Liquid System of Immersion Lithography Machine

浸没式光刻是实现5 nm以上线宽高性能超大规模集成电路产品制造的关键技术。相比传统干式光刻,浸没式光刻需在末端物镜和硅片之间填充浸没液体。浸没液体的高折射率可以提高光刻机的数值孔径和曝光分辨率,但也对浸没式光刻的污染控制提出了挑战。为了减少曝光缺陷,提升曝光良率,需要对浸液系统中的各类污染物进行高精度检测与精准控制,以达到超洁净流控。从浸没式光刻技术的原理出发对比分析了干式光刻与浸没式光刻,概述了浸没式光刻机的发展历程,着重介绍了浸没式光刻浸液系统中几种污染物的产生机理、检测方法和控制手段,为进一步提高浸没式光刻芯片的曝光良品率提供了理论基础。

Immersion lithography is a crucial technology for the exposure process in the production of highperformance very large-scale integrated circuits with line widths greater than 5 nm.Compared to the traditional dry lithography,the immersion liquid fills the space between the last projective objective and the wafer of immersion lithography.The immersion liquid could improve the numerical aperture and exposure resolution due to its high refractive index;however,it poses a challenge to immersion lithography contamination control.To reduce the exposure defects and increase the manufacturing yield,high-precision detection and the control of various contaminants in the immersion system,i.e.,achieving the ultra-clean flow control,must be implemented.This paper discusses the development of immersion lithographic equipment by introducing the principles of immersion lithographic technology and comparing dry and immersion lithography.The focus is on the review of the contaminants for the immersion system of immersion lithography,including their generation mechanism,detection methods,and control techniques.It will serve as a theoretical basis for further improving the chip yield after exposure.