摘要
目前极紫外(EUV)光刻技术已成为突破芯片性能和集成度瓶颈的核心手段,然而极紫外光与绝大多数物质的强烈相互作用对作为极紫外光刻窗口材料的自支撑薄膜提出了极高的要求。综述了国内外相关研究成果,首先回顾了极紫外光刻技术的发展历程及其对窗口材料的要求。在材料体系上,重点聚焦传统硅基、金属基材料和低维材料体系。传统材料(如硅基和金属基薄膜)已实现工程化应用,但存在力学强度受限、热稳定性不足等问题,难以满足先进EUV光刻中不断提升的功率需求。在低维材料中,石墨烯和碳纳米管具有较高的力学强度,同时凭借其原子级厚度展现出超高透射和热管理等优势,但它们也面临着氢等离子体蚀刻的挑战。进一步讨论了复合材料体系在提高氢等离子体耐受性、耐热性能和力学性能方面的研究成果。最后,分别总结了传统材料和低维材料在极紫外环境下的局限性和优势,期望为新型极紫外光刻窗口材料的原子级制造提供有价值的参考,推动半导体工艺的进一步发展与应用。
With the semiconductor industry rapidly advancing toward sub-5-nanometer technology nodes,extreme ultraviolet lithography(EUVL),operating at a wavelength of 13.5 nm,has become a cornerstone technology to sustain Moore's Law and address the increasingly stringent demands for resolution and integration.However,the unique high-energy nature of EUV(92 eV)leads to strong interactions with matters,posing significant challenges for the design and durability of key optical components.Window materials made of freestanding thin films play a critical role.These films include pellicles for mask protection and filters for spectral purity.They must combine four key qualities.First,they need high EUV transmittance.Second,they must span large areas without sagging or tearing.Third,they must resist pressure differences and mechanical stress.Fourth,they must remain stable under high heat loads and in hydrogen plasma.This review provides a summary of the current research and technological development in freestanding EUV window materials.First,it outlines the fundamental role of such materials in EUVL systems,emphasizing their dual functionality:contamination control and filtering.It elaborates on the specific demands placed on freestanding EUV window materials,including high EUV transmittance,atomic-scale thickness,large-area freestanding structures,and mechanical robustness under pressure differentials.Furthermore,it highlights the need for high thermal conductivity and emissivity to manage heat loads in vacuum environments,as well as chemical resistance against hydrogen plasma used in EUV light sources.Conventional window materials,such as silicon nitride and metal-based thin films,are adopted in EUVL systems due to their process maturity.However,these materials increasingly fall short in terms of EUV transmittance,heat tolerance,and mechanical strength at ultrathin dimensions.To overcome these limitations,emerging low-dimensional materials,including graphene and carbon nanotubes(CNTs),garner considerable attention.Their intrinsic properties,including atomic-scale thickness,high strength and excellent thermal conductivity,render them promising candidates for next-generation EUV window materials.The review further explores hybrid architectures combining low-dimensional and traditional materials to synergize their advantages.Graphene pellicles with EUV transmittance exceeding 90%and CNT membranes with superior mechanical strength and thermal emissivity are demonstrated.Composite designs,such as ZrSi2/SiNx or TiN-coated graphene,exhibit improved resistance to hydrogen plasma while maintaining optical performance.Nevertheless,challenges remain in terms of large-area uniformity,defect control,and long-term environmental stability.In addition to surveying fabrication techniques,it discusses characterization methods for evaluating optical,mechanical,thermal,and chemical properties under EUV exposure conditions.It also summarizes industry standards and performance metrics necessary for commercial adoption.Looking forward,the development of scalable,high-throughput processes for low-dimensional and composite EUV window materials will be essential to meet the demands of future high-power lithographic tools.The development roadmap for EUV window materials emphasizes three phases:refinement of silicon-based films via advanced deposition techniques;optimization of metal-silicide composites for high-power applications;and integration of low-dimensional composites to achieve atomic-scale manufacturing.By integrating optical,mechanical,thermal,and chemical perspectives,this review delivers a comprehensive guide.It offers a clear path for designing and deploying next-generation freestanding thin films.These window materials will propel future extreme ultraviolet lithography and sustain semiconductor scaling for generations to come.
作者
赵灌中
赵翀
刘科海
刘畅
刘开辉
ZHAO Guanzhong;ZHAO Chong;LIU Kehai;LIU Chang;LIU Kaihui(School of Physics,Peking University,Beijing 100871,China;Songshan Lake Materials Laboratory,Guangdong Dongguan 523830,China;Tsientang Institute for Advanced Study,Hangzhou 310024,China)
出处
《表面技术》
北大核心
2025年第23期34-46,共13页
Surface Technology
基金
广东省基础与应用基础研究重大项目(2021B0301030002)
国家自然科学基金(52025023,12427806,12304204)
国家重点研发计划(2022YFA1403500,2022YFA1403504)。
关键词
极紫外光刻
自支撑薄膜
窗口材料
低维材料
原子级制造
extreme ultraviolet lithography
freestanding thin films
window materials
low-dimensional materials
atomic-scale manufacturing
