摘要
极紫外(EUV)光刻是7 nm及以下技术节点芯片大规模量产的关键技术。随着技术节点的减小、工艺复杂性的增加,芯片的良率面临着巨大挑战。边缘放置误差(EPE)是量化多重曝光技术过程中制造图案保真度的最重要指标。EPE控制已成为多重曝光和EUV融合光刻时代最大的挑战之一。EPE是关键尺寸(CD)误差和套刻误差的结合。在EUV光刻中,光学邻近效应和随机效应是引起光刻误差的重要因素。光学邻近效应校正(OPC)可以使EPE最小化。对于最先进的技术节点,EPE通常由随机效应主导,因此需要对EPE进行建模,尤其是需要对随机效应进行严格的建模,以分析影响EPE的关键参数。选择不同的测量手段对关键参数进行测量并优化EPE是提高芯片良率的重要途径。本文首先综述了EPE在EUV光刻中的重要作用,然后讨论了OPC和随机效应、EPE模型及涉及的关键参数,并介绍了关键参数的测量方法,最后总结和展望了与EPE相关的技术。
Significance Extreme ultraviolet(EUV)lithography is considered to be the most promising technology for fabricating technology nodes of 7 nm and below in high volume manufacturing(HVM).Due to the shrinkage of semiconductor device features and the increase in process complexity,achieving an acceptable yield is challenging.Edge placement error(EPE)quantifies the pattern fidelity of a device structure created in a multi-patterning scheme.It is urgent to reduce EPE to guarantee the proper functioning of semiconductor devices.Therefore,controlling EPE is one of the most serious challenges in the field of multi-patterning and EUV lithography.EPE is a complex metric,involving error components from various process steps(e.g.,lithography and etching steps).It is the combination of critical dimension(CD)errors and overlay errors(see Fig.1(a)).The ratio of each component to the EPE budget changes with the iteration of the logic node(see Fig.1(b)).Stochastic contributions to the EPE budget are increasing rapidly(>50%).Hence,the accurate estimation and measurement of each component of EPE,particularly the stochastic components,are critical to enabling a holistic approach to EPE control and thereby improving the yield.A holistic approach is adopted to optimize the EPE budget(see Fig.2).This review is organized in five parts.First,we take a broad view of EPE in EUV lithography.Second,we highlight the characteristics peculiar to EUV lithography,considering the optical proximity correction(OPC)and stochastics.Third,we discuss two EPE models,including the optimization flow and the calculation process of EPE from metrology inputs(e.g.,CD and overlay).Fourth,we present the metrologies of CD and overlay errors,summarizing the advantages and disadvantages of each method.Finally,we discuss the techniques for EPE.Progress The typical deep ultraviolet(DUV)immersion lithography works with a transmissive mask,while EUV works with a reflective one(see Fig.4).In addition,the EUV mask is exposed under oblique incidence.Some characteristics suc
作者
曹晶
杨文河
刘泽旭
陈韫懿
魏鑫
林楠
Cao Jing;Yang Wenhe;Liu Zexu;Chen Yunyi;Wei Xin;Lin Nan(State Key Laboratory of High Field Laser Physics,Shanghai Institute of Optics and Fine Mechanics,Chinese Academy of Sciences,Shanghai 201800,China;Key Laboratory of Ultra-Intense Laser Science and Technology(CAS),Shanghai 201800,China)
出处
《中国激光》
EI
CAS
CSCD
北大核心
2024年第7期64-84,共21页
Chinese Journal of Lasers
关键词
测量
极紫外光刻光源
套刻
光学邻近效应校正
对准
measurement
extreme ultra violet lithography light source
overlay
optical proximity correction
alignment
