极紫外光刻机多层膜反射镜表面碳污染的清洗
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摘要
针对极紫外(EUV)光刻机工作过程中,多层膜反射镜表面沉积碳污染造成的反射率下降问题展开研究,讨论了多层膜反射镜表面碳污染清洗方法。首先描述了在EUV曝光过程中多层膜表面的碳污染形成过程,简单阐述了碳污染对多层膜反射镜的危害。然后从清洗机理、速率以及效果等方面详细描述了多种EUV多层膜表面碳污染清洗方法,分析对比了各清洗技术在清洗速率和效果等方面的优缺点。分析表明:离子体氧和活化氧清洗速率相差不多,可达到2nm/min,但清洗过程中容易造成表面氧化;等离子体氢和原子氢的清洗速率相对较慢,一般在0.37nm/min左右,但清洗过程中不易产生氧化。最后针对不同方法应用于在线清洗EUV多层膜反射镜过程中将遇到的问题和难点进行了讨论。
This paper focuses on the reflectivity decrease of reflective elements caused by the carbon contamination deposited on multilayers during EUV(Extreme Ultraviolet)lithography working and emphasizes the clear method of carbon contamination deposited on multilayers.The process of carbon contamination deposited on multilayers was elucidated and the damage of carbon contamination on the multilayers was introduced briefly.Several kinds of cleaning methods for carbon contamination deposited on multilayers were described in detail from cleaning mechanism,removing rate and cleaning effect,and their advantages and disadvantages were analyzed.The result indicates that the cleaning rates of plasma oxygen and activated oxygen reach 2 nm/min,but the multilayer surface is easy to be oxidized in cleaning process;and the plasma hydrogen and atomic hydrogen have relatively slow cleaning rates,they are only about 0.37 nm/min,but the multilayer surface is hardly to be oxidized.Moreover,the difficulties of different cleaning methods for X-ray multilayer mirrors in-situ are discussed.
This paper focuses on the reflectivity decrease of reflective elements caused by the carbon contamination deposited on multilayers during EUV(Extreme Ultraviolet)lithography working and emphasizes the clear method of carbon contamination deposited on multilayers.The process of carbon contamination deposited on multilayers was elucidated and the damage of carbon contamination on the multilayers was introduced briefly.Several kinds of cleaning methods for carbon contamination deposited on multilayers were described in detail from cleaning mechanism,removing rate and cleaning effect,and their advantages and disadvantages were analyzed.The result indicates that the cleaning rates of plasma oxygen and activated oxygen reach 2 nm/min,but the multilayer surface is easy to be oxidized in cleaning process;and the plasma hydrogen and atomic hydrogen have relatively slow cleaning rates,they are only about 0.37 nm/min,but the multilayer surface is hardly to be oxidized.Moreover,the difficulties of different cleaning methods for X-ray multilayer mirrors in-situ are discussed.
引文
[1]WOOD O,KOAY C S,PETRILLO K,et al..EUV lithography at the 22 nm technology node[J].SPIE,2010,7636:76361M.
[2]占平平,刘卫国.EUV光刻技术进展[J].科技信息,2011(21):44,418.ZHAN P P,LIU W G.Progress of EUVL technology[J].Science&Technology Information,2011(21):44,418.(in Chinese)
[3]WU B Q.Next-generation lithography for 22and 16nm technology nodes and beyond[J].Science China Information Sciences,2011,54(5):959-979.
[4]WANG L H,WANG X K,CHEN B.Study for dual-function EUV multilayer mirror[J].Optics&Laser Technology,2008,40(3):571-574.
[5]杜宇禅,李海亮,史丽娜,等.32nm节点极紫外光刻掩模的集成研制[J].光学学报,2013,33(10):1034002.DU Y CH,LI H L,SHI L N,et al..Integrated development of extreme ultraviolet lithography mask at 32nm node[J].Acta Optica Sinica,2013,33(10):1034002.(in Chinese)
[6]王珣,金春水,李春,等.极紫外反射镜氧化物保护层的制备与表征[J].光学学报,2015,35(3):0331001.WANG X,JIN CH SH,LI CH,et al..Preparation and characteristic of oxide capping-layer on extreme ultraviolet reflective mirrors[J].Acta Optica Sinica,2015,35(3):0331001.(in Chinese)
[7]祝文秀,金春水,匡尚奇,等.提高极紫外光谱纯度的多层膜设计及制备[J].光学学报,2012,32(10):1031002.ZHUW X,JIN CH SH,KUANG SH Q,et al..Design and fabrication of the multilayer film of enhancing spectral-purity in extreme ultraviolet[J].Acta Optica Sinica,2012,32(10):1031002.(in Chinese)
[8]GONG X P,LU Q P,LU G Q.Establishment of theoretical model and experimental equipment for researching on carbon contamination of EUV multilayer mirror[J].SPIE,2015,9446:94460W.
[9]STREIN E,ALLRED D.Eliminating carbon contamination on oxidized Si surfaces using a VUV excimer lamp[J].Thin Solid Films,2008,517(3):1011-1015.
[10]LIN B J.Making lithography work for the 7-nm node and beyond in overlay accuracy,resolution,defect,and cost[J].Microelectronic Engineering,2015,143:91-101.
[11]朱京涛,黄秋实,白亮,等.不同本底真空度下SiC/Mg极紫外多层膜的制备和测试[J].光学精密工程,2009,17(12):2946-2951.ZHU J T,HUANG Q SH,BAI L,et al..Manufacture and measurement of Sic/Mg EUV multilayer mirrors in different base pressures[J].Opt.Precision Eng.,2009,17(12):2946-2951.(in Chinese)
[12]尉伟,张波,洪远志,等.同步辐射光源光束线光学元件碳污染原位清洗研究[J].真空科学与技术学报,2013,33(6):552-555.WEI W,ZHANG B,HONG Y ZH,et al..In-Situ cleaning of carbon-contaminated optical components in beam-line of synchrotron radiation light source[J].Chinese Journal of Vacuum Science and Technology,2013,33(6):552-555.(in Chinese)
[13]周洪军,钟鹏飞,霍同林,等.同步辐射活化氧清洗碳污染的研究[J].光学学报,2010,30(3):907-910.ZHOU H J,ZHONG P F,HUO T L,et al..Cleaning of carbon contamination on Si wafer with activated oxygen by synchrotron radiation[J].Acta Optica Sinica,2010,30(3):907-910.(in Chinese)
[14]尉伟,王秋平,王勇,等.等离子体清洗同步辐射光学元件[J].真空科学与技术学报,2009,29(6):704-706.WEI W,WANG Q P,WANG Y,et al..Plasma cleaning of contaminated optical components of synchrotron radiation beam-line[J].Chinese Journal of Vacuum Science and Technology,2009,29(6):704-706.(in Chinese)
[15]徐向东,周洪军,洪义麟,等.同步辐射光学元件辐照污染及其清洁处理[J].真空科学与技术学报,2000,20(2):114-119.XU X D,ZHOU H J,HONG Y L,et al..Cleaning of contaminated optics devices by synchrotron radiation[J].Vacuum Science and Technology(China),2000,20(2):114-119.(in Chinese)
[16]钟鹏飞,周洪军,霍同林,等.光学元件清洗过程中同步辐射活化氧的研究[J].光学精密工程,2007,15(12):1921-1925.ZHONG P F,ZHOU H J,HUO T L,et al..Research of oxygen activation by synchrotron radiation in optical component cleaning process[J].Opt.Precision Eng.,2007,15(12):1921-1925.(in Chinese)
[17]鹿国庆.极紫外多层膜光学元件表面污染研究[D].长春:中国科学院研究生院(长春光学精密机械与物理研究所),2014.LU G Q.Study on Surface Contamination of EUV Multilayer Optics[D].Changchun:Graduate University of Chinese Academy of Sciences,Changchun Institute of Optics,Fine Mechanics and Physics,2014.(in Chinese)
[18]CHEN J Q,LOUIS E,WORMEESTER H,et al..Carbon-induced extreme ultraviolet reflectance loss characterized using visible-light ellipsometry[J].Measurement Science and Technology,2011,22(10):105705.
[19]CHEN J Q,LEE C J,LOUIS E,et al..Characterization of EUV induced carbon films using lasergenerated surface acoustic waves[J].Diamond and Related Materials,2009,18(5-8):768-771.
[20]BOLLER K,HAELBICHR P,HOGREFE H,et al..Investigation of carbon contamination of mirror surfaces exposed to synchrotron radiation[J].Nuclear Instruments and Methods in Physics Research,1983,208(1-3):273-279.
[21]ROSENBERGR A,MANCINI D C.Deposition of carbon on gold using synchrotron radiation[J].Nuclear Instruments and Methods in Physics Research Section A:Accelerators,Spectrometers,Detectors and Associated Equipment,1990,291(1-2):101-106.
[22]KURTR,VAN BEEK M,CROMBEEN C,et al..Radiation-induced carbon contamination of optics[J].SPIE,2002,4688:702-709.
[23]SHIRAISHIM,YAMAGUCHI T,YAMAZAKI A,et al..A simple modeling of carbon contamination on EUV exposure tools based on contamination experiments with synchrotron source[J].SPIE,2011,7969:79690N.
[24]KYRIAKOU G,DAVIS D J,GRANT R B,et al..Electron impact-assisted carbon film growth on Ru(0001):implications for next-generation EUV lithography[J].The Journal of Physical Chemistry C,2007,111(12):4491-4494.
[25]HOLLENSHEADJ,KLEBANOFF L.Modeling radiation-induced carbon contamination of extreme ultraviolet optics[J].Journal of Vacuum Science&Technology B,2006,24(1):64-82.
[26]王珣,金春水,匡尚奇,等.极紫外光辐照下表面碳沉积污染的计算模型[J].光学学报,2014,34(5):531001.WANG X,JIN CH SH,KUANG SH Q,et al..Simulation model of surface carbon deposition contamination under extreme ultraviolet radiation[J].Acta Optica Sinica,2014,34(5):531001.(in Chinese)
[27]鹿国庆,卢启鹏,彭忠琦,等.极紫外光学元件表面碳污染模型的建立[J].光学学报,2013,33(12):1234001.LU G Q,LU Q P,PENG ZH Q,et al..Carbon contamination modeling on extreme ultraviolet optic surfaces[J].Acta Optica Sinica,2013,33(12):1234001.(in Chinese)
[28]OESTREICHS,KLEIN R,SCHOLZE F,et al..Multilayer reflectance during exposure to EUV radiation[J].SPIE,2000,4146:64-71.
[29]KOSTERN,MERTENS B,JANSEN R,et al..Molecular contamination mitigation in EUVL by environmental control[J].Microelectronic Engineering,2002,61-62:65-76.
[30]MALYKHIN E M,LOPAEV D V,RAKHIMOV A T,et al..Plasma cleaning of multilayer mirrors in EUV lithography from amorphous carbon contaminations[J].Moscow University Physics Bulletin,2011,66(2):184-189.
[31]DOLGOV A,LOPAEV D,RACHIMOVA T,et al..Comparison of H2 and He carbon cleaning mechanisms in extreme ultraviolet induced and surface wave discharge plasmas[J].Journal of Physics D:Applied Physics,2014,47(6):065205.
[32]MORGAN C G,NAULLEAU P P,REKAWA S B,et al..Removal of surface contamination from EUV mirrors using low-power downstream plasma cleaning[J].SPIE,2010,7636:76361Q.
[33]PELLEGRIN E,ICS I,REYES-HERRERA J,et al..Characterization,optimization and surface physics aspects of in situ plasma mirror cleaning[J].Journal of Synchrotron Radiation,2014,21(2):300-314.
[34]GONZLEZCUXART M,REYES-HERRERA J,ICS I,et al..RF plasma cleaning of optical surfaces:a study of cleaning rates on different carbon allotropes as a function of RF powers and distances[J].Applied Surface Science,2015,81(7):533-536.
[35]HAMAMOTO K,TANAKA Y,WATANABE T,et al..Cleaning of extreme ultraviolet lithography optics and masks using 13.5nm and 172nm radiation[J].Journal of Vacuum Science&Technology B,Nanotechnology and Microelectronics:Materials,Processing,Measurement,and Phenomena,2005,23(1):247-251.
[36]TAKAGI N,ANAZAWA T,NISHIYAMA I,et al..Evaluation of the contamination removal capability and multilayer degradation in various cleaning methods[J].SPIE,2010,7823:782327.
[37]GRAHAM S JR,STEINHAUS C A,CLIFT W M,et al..Atomic hydrogen cleaning of EUV multilayer optics[J].SPIE,2003,5037:460-469.
[38]CHEN J Q,LOUIS E,HARMSEN R,et al..In situellipsometry study of atomic hydrogen etching of extreme ultraviolet induced carbon layers[J].Applied Surface Science,2011,258(1):7-12.
[39]NISHIYAMA Y,ANAZAWA T,OIZUMI H,et al..Carbon contamination of EUV mask:film characterization,impact on lithographic performance,and cleaning[J].SPIE,2008,6921:692116.
[40]OIZUMI H,YAMANASHI H,NISHIYAMA I,et al..Contamination removal from EUV multilayer using atomic hydrogen generated by heated catalyzer[J].SPIE,2005,5751:1147-1154.
[41]MOTAI K,OIZUMI H,MIYAGAKI S,et al..Atomic hydrogen cleaning of Ru-capped EUV multilayer mirror[J].SPIE,2007,6517:65170F.
[42]MOTAI K,OIZUMI H,MIYAGAKI S,et al..Cleaning technology for EUV multilayer mirror using atomic hydrogen generated with hot wire[J].Thin Solid Films,2008,516(5):839-843.
[2]占平平,刘卫国.EUV光刻技术进展[J].科技信息,2011(21):44,418.ZHAN P P,LIU W G.Progress of EUVL technology[J].Science&Technology Information,2011(21):44,418.(in Chinese)
[3]WU B Q.Next-generation lithography for 22and 16nm technology nodes and beyond[J].Science China Information Sciences,2011,54(5):959-979.
[4]WANG L H,WANG X K,CHEN B.Study for dual-function EUV multilayer mirror[J].Optics&Laser Technology,2008,40(3):571-574.
[5]杜宇禅,李海亮,史丽娜,等.32nm节点极紫外光刻掩模的集成研制[J].光学学报,2013,33(10):1034002.DU Y CH,LI H L,SHI L N,et al..Integrated development of extreme ultraviolet lithography mask at 32nm node[J].Acta Optica Sinica,2013,33(10):1034002.(in Chinese)
[6]王珣,金春水,李春,等.极紫外反射镜氧化物保护层的制备与表征[J].光学学报,2015,35(3):0331001.WANG X,JIN CH SH,LI CH,et al..Preparation and characteristic of oxide capping-layer on extreme ultraviolet reflective mirrors[J].Acta Optica Sinica,2015,35(3):0331001.(in Chinese)
[7]祝文秀,金春水,匡尚奇,等.提高极紫外光谱纯度的多层膜设计及制备[J].光学学报,2012,32(10):1031002.ZHUW X,JIN CH SH,KUANG SH Q,et al..Design and fabrication of the multilayer film of enhancing spectral-purity in extreme ultraviolet[J].Acta Optica Sinica,2012,32(10):1031002.(in Chinese)
[8]GONG X P,LU Q P,LU G Q.Establishment of theoretical model and experimental equipment for researching on carbon contamination of EUV multilayer mirror[J].SPIE,2015,9446:94460W.
[9]STREIN E,ALLRED D.Eliminating carbon contamination on oxidized Si surfaces using a VUV excimer lamp[J].Thin Solid Films,2008,517(3):1011-1015.
[10]LIN B J.Making lithography work for the 7-nm node and beyond in overlay accuracy,resolution,defect,and cost[J].Microelectronic Engineering,2015,143:91-101.
[11]朱京涛,黄秋实,白亮,等.不同本底真空度下SiC/Mg极紫外多层膜的制备和测试[J].光学精密工程,2009,17(12):2946-2951.ZHU J T,HUANG Q SH,BAI L,et al..Manufacture and measurement of Sic/Mg EUV multilayer mirrors in different base pressures[J].Opt.Precision Eng.,2009,17(12):2946-2951.(in Chinese)
[12]尉伟,张波,洪远志,等.同步辐射光源光束线光学元件碳污染原位清洗研究[J].真空科学与技术学报,2013,33(6):552-555.WEI W,ZHANG B,HONG Y ZH,et al..In-Situ cleaning of carbon-contaminated optical components in beam-line of synchrotron radiation light source[J].Chinese Journal of Vacuum Science and Technology,2013,33(6):552-555.(in Chinese)
[13]周洪军,钟鹏飞,霍同林,等.同步辐射活化氧清洗碳污染的研究[J].光学学报,2010,30(3):907-910.ZHOU H J,ZHONG P F,HUO T L,et al..Cleaning of carbon contamination on Si wafer with activated oxygen by synchrotron radiation[J].Acta Optica Sinica,2010,30(3):907-910.(in Chinese)
[14]尉伟,王秋平,王勇,等.等离子体清洗同步辐射光学元件[J].真空科学与技术学报,2009,29(6):704-706.WEI W,WANG Q P,WANG Y,et al..Plasma cleaning of contaminated optical components of synchrotron radiation beam-line[J].Chinese Journal of Vacuum Science and Technology,2009,29(6):704-706.(in Chinese)
[15]徐向东,周洪军,洪义麟,等.同步辐射光学元件辐照污染及其清洁处理[J].真空科学与技术学报,2000,20(2):114-119.XU X D,ZHOU H J,HONG Y L,et al..Cleaning of contaminated optics devices by synchrotron radiation[J].Vacuum Science and Technology(China),2000,20(2):114-119.(in Chinese)
[16]钟鹏飞,周洪军,霍同林,等.光学元件清洗过程中同步辐射活化氧的研究[J].光学精密工程,2007,15(12):1921-1925.ZHONG P F,ZHOU H J,HUO T L,et al..Research of oxygen activation by synchrotron radiation in optical component cleaning process[J].Opt.Precision Eng.,2007,15(12):1921-1925.(in Chinese)
[17]鹿国庆.极紫外多层膜光学元件表面污染研究[D].长春:中国科学院研究生院(长春光学精密机械与物理研究所),2014.LU G Q.Study on Surface Contamination of EUV Multilayer Optics[D].Changchun:Graduate University of Chinese Academy of Sciences,Changchun Institute of Optics,Fine Mechanics and Physics,2014.(in Chinese)
[18]CHEN J Q,LOUIS E,WORMEESTER H,et al..Carbon-induced extreme ultraviolet reflectance loss characterized using visible-light ellipsometry[J].Measurement Science and Technology,2011,22(10):105705.
[19]CHEN J Q,LEE C J,LOUIS E,et al..Characterization of EUV induced carbon films using lasergenerated surface acoustic waves[J].Diamond and Related Materials,2009,18(5-8):768-771.
[20]BOLLER K,HAELBICHR P,HOGREFE H,et al..Investigation of carbon contamination of mirror surfaces exposed to synchrotron radiation[J].Nuclear Instruments and Methods in Physics Research,1983,208(1-3):273-279.
[21]ROSENBERGR A,MANCINI D C.Deposition of carbon on gold using synchrotron radiation[J].Nuclear Instruments and Methods in Physics Research Section A:Accelerators,Spectrometers,Detectors and Associated Equipment,1990,291(1-2):101-106.
[22]KURTR,VAN BEEK M,CROMBEEN C,et al..Radiation-induced carbon contamination of optics[J].SPIE,2002,4688:702-709.
[23]SHIRAISHIM,YAMAGUCHI T,YAMAZAKI A,et al..A simple modeling of carbon contamination on EUV exposure tools based on contamination experiments with synchrotron source[J].SPIE,2011,7969:79690N.
[24]KYRIAKOU G,DAVIS D J,GRANT R B,et al..Electron impact-assisted carbon film growth on Ru(0001):implications for next-generation EUV lithography[J].The Journal of Physical Chemistry C,2007,111(12):4491-4494.
[25]HOLLENSHEADJ,KLEBANOFF L.Modeling radiation-induced carbon contamination of extreme ultraviolet optics[J].Journal of Vacuum Science&Technology B,2006,24(1):64-82.
[26]王珣,金春水,匡尚奇,等.极紫外光辐照下表面碳沉积污染的计算模型[J].光学学报,2014,34(5):531001.WANG X,JIN CH SH,KUANG SH Q,et al..Simulation model of surface carbon deposition contamination under extreme ultraviolet radiation[J].Acta Optica Sinica,2014,34(5):531001.(in Chinese)
[27]鹿国庆,卢启鹏,彭忠琦,等.极紫外光学元件表面碳污染模型的建立[J].光学学报,2013,33(12):1234001.LU G Q,LU Q P,PENG ZH Q,et al..Carbon contamination modeling on extreme ultraviolet optic surfaces[J].Acta Optica Sinica,2013,33(12):1234001.(in Chinese)
[28]OESTREICHS,KLEIN R,SCHOLZE F,et al..Multilayer reflectance during exposure to EUV radiation[J].SPIE,2000,4146:64-71.
[29]KOSTERN,MERTENS B,JANSEN R,et al..Molecular contamination mitigation in EUVL by environmental control[J].Microelectronic Engineering,2002,61-62:65-76.
[30]MALYKHIN E M,LOPAEV D V,RAKHIMOV A T,et al..Plasma cleaning of multilayer mirrors in EUV lithography from amorphous carbon contaminations[J].Moscow University Physics Bulletin,2011,66(2):184-189.
[31]DOLGOV A,LOPAEV D,RACHIMOVA T,et al..Comparison of H2 and He carbon cleaning mechanisms in extreme ultraviolet induced and surface wave discharge plasmas[J].Journal of Physics D:Applied Physics,2014,47(6):065205.
[32]MORGAN C G,NAULLEAU P P,REKAWA S B,et al..Removal of surface contamination from EUV mirrors using low-power downstream plasma cleaning[J].SPIE,2010,7636:76361Q.
[33]PELLEGRIN E,ICS I,REYES-HERRERA J,et al..Characterization,optimization and surface physics aspects of in situ plasma mirror cleaning[J].Journal of Synchrotron Radiation,2014,21(2):300-314.
[34]GONZLEZCUXART M,REYES-HERRERA J,ICS I,et al..RF plasma cleaning of optical surfaces:a study of cleaning rates on different carbon allotropes as a function of RF powers and distances[J].Applied Surface Science,2015,81(7):533-536.
[35]HAMAMOTO K,TANAKA Y,WATANABE T,et al..Cleaning of extreme ultraviolet lithography optics and masks using 13.5nm and 172nm radiation[J].Journal of Vacuum Science&Technology B,Nanotechnology and Microelectronics:Materials,Processing,Measurement,and Phenomena,2005,23(1):247-251.
[36]TAKAGI N,ANAZAWA T,NISHIYAMA I,et al..Evaluation of the contamination removal capability and multilayer degradation in various cleaning methods[J].SPIE,2010,7823:782327.
[37]GRAHAM S JR,STEINHAUS C A,CLIFT W M,et al..Atomic hydrogen cleaning of EUV multilayer optics[J].SPIE,2003,5037:460-469.
[38]CHEN J Q,LOUIS E,HARMSEN R,et al..In situellipsometry study of atomic hydrogen etching of extreme ultraviolet induced carbon layers[J].Applied Surface Science,2011,258(1):7-12.
[39]NISHIYAMA Y,ANAZAWA T,OIZUMI H,et al..Carbon contamination of EUV mask:film characterization,impact on lithographic performance,and cleaning[J].SPIE,2008,6921:692116.
[40]OIZUMI H,YAMANASHI H,NISHIYAMA I,et al..Contamination removal from EUV multilayer using atomic hydrogen generated by heated catalyzer[J].SPIE,2005,5751:1147-1154.
[41]MOTAI K,OIZUMI H,MIYAGAKI S,et al..Atomic hydrogen cleaning of Ru-capped EUV multilayer mirror[J].SPIE,2007,6517:65170F.
[42]MOTAI K,OIZUMI H,MIYAGAKI S,et al..Cleaning technology for EUV multilayer mirror using atomic hydrogen generated with hot wire[J].Thin Solid Films,2008,516(5):839-843.