摘要
随着半导体产业的高速发展,集成电路制造中光刻工艺特征尺寸极限化微缩,套刻精度的要求也愈来愈极端严苛。本文基于影响套刻精度的核心技术,即对准技术,对该技术中精密测量传感系统的设计和微纳测量对象对准标记的设计两个方面进行了归纳分析,就业内国际顶尖科技公司的技术发展进行了整理,并详细介绍了他们在对准测量技术路径演化进程中所起到的推动作用。同时,还对当前国内各相关技术团队在该方向的最新研究成果进行了总结。以此为基础,进一步讨论了面向更为先进的工艺节点,光刻对准技术的改进方向和优化思路,从而为获得更高精度的套刻性能提供重要的技术参考。
Significance Lithography technology is crucial for manufacturing all kinds of semiconductor integrated circuits.Overlay,a major performance indicator,is critical to monitor the lithography quality.Together with the increasing density of integrated circuit(IC)chips and continuously shrinking critical dimension,alignment accuracy for lithographic overlay is required to be extreme.Overlay usually refers to the process where each layer of the pattern needs to be accurately transferred to the correct position on the silicon wafer so that its position error relative to the previous layer of the pattern is within the tolerance range.The position error among different layers mainly depends on the alignment system situated inside the lithographic equipment.Thus,the measurement capability of an alignment system is very important,since the budget of the overlay budget is set to be just one-third to one-fifth of the resolution of a node,and the budget of alignment is only allowed to be within one-third of the overlay.For each lithography step,the alignment system measures special marks at certain targeted locations.By calculating the mark positions,microscopic aligning errors can be captured dynamically and compensated when necessary.Moreover,considering the wafer deformation during the process,such as the warpage caused by thin film deposition,the partition is needed with 20-40 marks placed in each region of the wafer.By these means,every exposure field is measured and controlled precisely.With the continuous development of lithography,alignment systems have achieved measurement accuracy from a submicrometer level in the 1980s to a nanometer level in 2002 and then reached a sub-nanometer level in 2016.Advanced lithography companies,such as ASML,Nikon,and Canon,evolve distinctly with their alignment technologies.At the same time,the designs of the alignment marks vary significantly based on the characteristics of specific alignment systems.Consequently,it is crucial to categorize and analyze the measurement principles and te
作者
邱俊
杨光华
李璟
卢增雄
丁敏侠
Qiu Jun;Yang Guanghua;Li Jing;Lu Zengxiong;Ding Minxia(Institute of Microelectronics of the Chinese Academy of Sciences,Beijing 100029,China;University of Chinese Academy of Sciences,Beijing 100049,China)
出处
《光学学报》
EI
CAS
CSCD
北大核心
2023年第19期1-23,共23页
Acta Optica Sinica
关键词
集成光学
对准
标记
套刻
光刻
集成电路
integrated optics
alignment
mark
overlay
lithography
integrated circuit
