极紫外光刻的随机性问题及其研究进展  

Stochastics in EUV Lithography and Recent Research Status

作　　者：王翔 何建君 魏佳亮 朱慧娥 Wang Xiang;He Jianjun;Wei Jialiang;Zhu Huie(Zhangjiang Laboratory,Shanghai 201210,China)

机构地区：[1]张江实验室,上海201210

出　　处：《中国激光》2024年第7期85-104,共20页Chinese Journal of Lasers

摘　　要：极紫外光刻技术是支撑最先端半导体芯片制造工艺的关键核心技术,有力推动了3 nm工艺节点的量产以及2 nm工艺节点的研发进程。极紫外光刻中的随机缺陷是限制其良率提升的关键难题。一方面,急剧减小的光刻图形特征尺寸对光刻胶各组分化学结构的规整性要求越来越高,而光刻胶中存在的组分不均一、后烘过程中光酸迁移距离以及位置的不确定性等因素都会导致缺陷,这些统称为化学随机性问题。另一方面,极紫外光源的波长(13.5 nm)较短,致使其光子密度很低,仅为上一代ArF光刻工艺中所使用光源(193 nm)的1/14,因此光子的散粒噪声大幅增加,导致了不可避免的光子随机性问题。这些问题的存在,使得EUV光刻胶中的材料体系在分子尺寸、分布均一性等方面较上一代光刻材料有着更严格的要求。本文系统性综述了近年来针对极紫外光刻胶中上述随机性问题的研究,并从化学随机性、光子随机性以及计算模拟三个方向对研究现状进行了追踪。Significance Extreme ultraviolet(EUV)lithography is the most advanced photolithography technology used in semiconductor device fabrication to fabricate integrated circuits(ICs),providing a guarantee for a 3 nm node that is currently in mass production.Random defect in EUV lithography is a key problem that limits yield improvement.The extremely reduced feature size places much higher requirements on the regularity of the chemical structure of the photoresist components.However,chemical stochastics,such as unavoidable chemical inhomogeneity in the photoresist components and uneven photoacid diffusion distance during the postexposure baking process,always cause printing defects,which present severe challenges for the development of next-generation photoresist materials.Meanwhile,the EUV light source has a shorter wavelength(13.5 nm),resulting in a very low photon density,which is only 1/14 of that of the light source(193 nm)used in ArF lithography.Therefore,the photon-shot noise increases by several times,leading to the inevitable problem of photon stochastics.Owing to these problems,higher requirements have been proposed for the molecular size and system uniformity of the EUV photoresist material system compared to the previous generation of photolithography materials.This article presents a systematic review of the research development on the above-mentioned stochastic issues in EUV photoresists in recent years by focusing on the current research status in three aspects:chemical stochastics,photon stochastics,and computational simulation methods used to clarify the stochastic issues in EUV lithography.Progress As the minimum feature sizes continue to shrink in EUV lithography,stochastic defects have become the“black swans”of yield loss as stochastic phenomena scales as one over the feature size cubed.Ultimately,stochastic effects originate from the fact that both light(EUV photons)and matter(resist materials)are discrete particles with finite numbers that interact with each other in discrete volumes.Thus,the t

关 键 词：极紫外 化学随机性 光子随机性 光刻胶 光酸迁移距离 

分 类 号：O436[机械工程—光学工程]