T. Namioka, Masaki Yamamoto, M. Yanagihara, M. Koike
Soft-x-ray (SXR) multilayers havé been successfully applied to various optical elements and systems, and their technology seems to have been nearly perfected. However, many problems fundamental to multilayers have to be solved for further development. This paper presents results of our studies on some of these problems.
{"title":"Multilayers for Soft-X-Ray Optics","authors":"T. Namioka, Masaki Yamamoto, M. Yanagihara, M. Koike","doi":"10.1364/sxray.1991.thb1","DOIUrl":"https://doi.org/10.1364/sxray.1991.thb1","url":null,"abstract":"Soft-x-ray (SXR) multilayers havé been successfully applied to various optical elements and systems, and their technology seems to have been nearly perfected. However, many problems fundamental to multilayers have to be solved for further development. This paper presents results of our studies on some of these problems.","PeriodicalId":409291,"journal":{"name":"Soft-X-Ray Projection Lithography","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1992-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131322864","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
W. Waskiewicz, D. Windt, J. Bjorkholm, L. Eichner, R. Freeman
Spatial uniformity of the multilayer coatings deposited onto figured optics for soft x-ray projection lithography optical systems must be accurately controlled in order to maintain high throughput, and to preserve the imaging quality of the substrate. Controlling the uniformity with the desired accuracy can be quite challenging however, due to the nature of the deposition process.
{"title":"Achieving Uniform Multilayer Coatings on Figured Optics","authors":"W. Waskiewicz, D. Windt, J. Bjorkholm, L. Eichner, R. Freeman","doi":"10.1364/sxray.1991.thb3","DOIUrl":"https://doi.org/10.1364/sxray.1991.thb3","url":null,"abstract":"Spatial uniformity of the multilayer coatings deposited onto figured optics for soft x-ray projection lithography optical systems must be accurately controlled in order to maintain high throughput, and to preserve the imaging quality of the substrate. Controlling the uniformity with the desired accuracy can be quite challenging however, due to the nature of the deposition process.","PeriodicalId":409291,"journal":{"name":"Soft-X-Ray Projection Lithography","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1992-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115837404","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Laser-produced sources for soft x-ray projection lithography require high brightness in a narrow x-ray band in the region of high reflectivity for multilayer optics. Lasers will also probably be of only modest power matching near term laser technology development for high efficiency, high repetition rate lasers. Little experimental work has been done on characterizing x-ray emission below 300 eV at laser irradiations of a Joule or less. Experimental data will be needed over a large range of laser parameters including wavelength, intensity, and pulse width in order to assess the relative merits of any laser system proposed as a source for soft x-ray projection lithography.
{"title":"X-ray Production Efficiency at 130 Å from Laser-Produced Plasmas","authors":"R. Kauffman, D. Phillion","doi":"10.1364/sxray.1991.thc1","DOIUrl":"https://doi.org/10.1364/sxray.1991.thc1","url":null,"abstract":"Laser-produced sources for soft x-ray projection lithography require high brightness in a narrow x-ray band in the region of high reflectivity for multilayer optics. Lasers will also probably be of only modest power matching near term laser technology development for high efficiency, high repetition rate lasers. Little experimental work has been done on characterizing x-ray emission below 300 eV at laser irradiations of a Joule or less. Experimental data will be needed over a large range of laser parameters including wavelength, intensity, and pulse width in order to assess the relative merits of any laser system proposed as a source for soft x-ray projection lithography.","PeriodicalId":409291,"journal":{"name":"Soft-X-Ray Projection Lithography","volume":"157 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1992-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120849296","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Recent developments in x-ray laser research resulted in the experimental observation of laser amplification at many wavelengths in soft x-ray domain [1] ranging from λ=280 Å to λ = 42 Å. There is no doubts that within next few years powerful sources of coherent x-ray laser radiation at those wavelengths will also be available. This sets a stage for the research on the interaction of intense coherent x-ray radiation with a matter, in particular on x-ray nonlinear optics. The first obvious choice of the environment and frequency for the nonlinear effects to occur and to be experimentally observed, is the same plasma of ionized atoms that gives rise to the laser action itself, with the nonlinear interaction occurring at the frequency of lasing transition. The nonlinear effects in such a situation are essentially expected to be the same as in any other resonantly-enhanced nonlinear interaction of light with matter in a visible optical domain and could approximately be evaluated using basically two (or three) level model. In order to demonstrate the feasibility of this kind of nonlinear effects both in active and passive x-ray laser medium, we present here evaluations of the characteristic parameters pertinent to the resonant nonlinearity: the saturation driving intensity and nonlinear change of refractive index. We use simple and yet realistic model based on the neonlike Mo XXXIII plasma; observation of soft X-ray amplification in such a system has recently been reported [2].
{"title":"On the feasibility of X-ray nonlinear resonant effects in plasma","authors":"P. Shkolnikov, A. Kaplan","doi":"10.1364/sxray.1991.wa7","DOIUrl":"https://doi.org/10.1364/sxray.1991.wa7","url":null,"abstract":"Recent developments in x-ray laser research resulted in the experimental observation of laser amplification at many wavelengths in soft x-ray domain [1] ranging from λ=280 Å to λ = 42 Å. There is no doubts that within next few years powerful sources of coherent x-ray laser radiation at those wavelengths will also be available. This sets a stage for the research on the interaction of intense coherent x-ray radiation with a matter, in particular on x-ray nonlinear optics. The first obvious choice of the environment and frequency for the nonlinear effects to occur and to be experimentally observed, is the same plasma of ionized atoms that gives rise to the laser action itself, with the nonlinear interaction occurring at the frequency of lasing transition. The nonlinear effects in such a situation are essentially expected to be the same as in any other resonantly-enhanced nonlinear interaction of light with matter in a visible optical domain and could approximately be evaluated using basically two (or three) level model. In order to demonstrate the feasibility of this kind of nonlinear effects both in active and passive x-ray laser medium, we present here evaluations of the characteristic parameters pertinent to the resonant nonlinearity: the saturation driving intensity and nonlinear change of refractive index. We use simple and yet realistic model based on the neonlike Mo XXXIII plasma; observation of soft X-ray amplification in such a system has recently been reported [2].","PeriodicalId":409291,"journal":{"name":"Soft-X-Ray Projection Lithography","volume":"250 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1992-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123584383","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
G. Kubiak, E. Kneedler, K. Berger, R. Stulen, J. Bjorkholm
The characterization of resist materials for soft X-ray projection lithography (SXPL) in the 75-350 Å spectral region is an important issue, although it has received little attention to date. With the recent demonstration of diffraction-limited SXPL at 140 Å[1], the need to optimize resists at specific exposure wavelengths for future SXPL commercialization has become acute. Near 300 Å resist absorbance is so large that a single-layer resist strategy does not appear feasible, whereas near 80 Å it does. At intermediate wavelengths, for example where Mo/Si multilayer reflective coatings are efficient, it is not yet possible to determine whether a surface imaging or single-layer method is optimum. To estimate the maximum developed resist depth attainable at a given wavelength, the appropriate mass absorption coefficients may be used to calculate film absorbance. The accuracy of these estimates is questionable, however, especially at longer wavelengths where solid state effects can be pronounced. We have undertaken a study of single-layer resists in the spectral region relevant to SXPL and have characterized the sensitivity, contrast, and absolute absorbance of poly methylmethacrylate (PMMA), polysilane, and diazonapthoquinone/novolak resists. In addition, we have evaluated the lithographic performance of these materials at an exposure wavelength of 140 Å using an SXPL instrument illuminated by a laser plasma source (LPS) of high average power.
{"title":"Resist Characterization at Soft X-Ray Wavelengths","authors":"G. Kubiak, E. Kneedler, K. Berger, R. Stulen, J. Bjorkholm","doi":"10.1364/sxray.1991.thd3","DOIUrl":"https://doi.org/10.1364/sxray.1991.thd3","url":null,"abstract":"The characterization of resist materials for soft X-ray projection lithography (SXPL) in the 75-350 Å spectral region is an important issue, although it has received little attention to date. With the recent demonstration of diffraction-limited SXPL at 140 Å[1], the need to optimize resists at specific exposure wavelengths for future SXPL commercialization has become acute. Near 300 Å resist absorbance is so large that a single-layer resist strategy does not appear feasible, whereas near 80 Å it does. At intermediate wavelengths, for example where Mo/Si multilayer reflective coatings are efficient, it is not yet possible to determine whether a surface imaging or single-layer method is optimum. To estimate the maximum developed resist depth attainable at a given wavelength, the appropriate mass absorption coefficients may be used to calculate film absorbance. The accuracy of these estimates is questionable, however, especially at longer wavelengths where solid state effects can be pronounced. We have undertaken a study of single-layer resists in the spectral region relevant to SXPL and have characterized the sensitivity, contrast, and absolute absorbance of poly methylmethacrylate (PMMA), polysilane, and diazonapthoquinone/novolak resists. In addition, we have evaluated the lithographic performance of these materials at an exposure wavelength of 140 Å using an SXPL instrument illuminated by a laser plasma source (LPS) of high average power.","PeriodicalId":409291,"journal":{"name":"Soft-X-Ray Projection Lithography","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1992-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126252840","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Laser irradiation of cylindrical cavities has attracted considerable interest in the context of soft x-ray laser experiments because the confined plasma may act as an x-ray waveguide.1) Waveguiding requires a concave, radially symmetric density profile and thus uniform plasma ablation inside the cavity. In the case of transverse irradiation presented in this work, the uniformity of plasma ablation is primarily determined by the mechanisms which redistribute the energy from the initial location of plasma generation by the incident laser. Among the mechanisms to be considered are x-radiation, hot electrons, and laser light reflected at the primary spot. Experimentally, evidence was found that for short-pulse, long-wavelength, high-irradiance conditions, the redistribution of energy is dominated by reflected laser light.
{"title":"Characteristics of Sub-100-ps Laser Irradiation of Cylindrical Cavities","authors":"J. Balmer, B. Soom, U. Ellenberger, R. Weber","doi":"10.1364/sxray.1991.wa14","DOIUrl":"https://doi.org/10.1364/sxray.1991.wa14","url":null,"abstract":"Laser irradiation of cylindrical cavities has attracted considerable interest in the context of soft x-ray laser experiments because the confined plasma may act as an x-ray waveguide.1) Waveguiding requires a concave, radially symmetric density profile and thus uniform plasma ablation inside the cavity. In the case of transverse irradiation presented in this work, the uniformity of plasma ablation is primarily determined by the mechanisms which redistribute the energy from the initial location of plasma generation by the incident laser. Among the mechanisms to be considered are x-radiation, hot electrons, and laser light reflected at the primary spot. Experimentally, evidence was found that for short-pulse, long-wavelength, high-irradiance conditions, the redistribution of energy is dominated by reflected laser light.","PeriodicalId":409291,"journal":{"name":"Soft-X-Ray Projection Lithography","volume":"2012 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1992-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128160194","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
K. Murakami, Hiroshi Nakamura, T. Oshino, H. Nikaido
W/C multilayers, well known as good X-ray reflecting mirrors, were prepared by ion beam sputtering. The properties of the multilayers were investigated by low-angle X-ray diffraction, transmission electron microscopy (TEM) observation of the cross section and Auger electron spectroscopy.
{"title":"Tungsten/Carbon Multilayers Prepared By Ion Beam Sputtering","authors":"K. Murakami, Hiroshi Nakamura, T. Oshino, H. Nikaido","doi":"10.1364/sxray.1991.thb4","DOIUrl":"https://doi.org/10.1364/sxray.1991.thb4","url":null,"abstract":"W/C multilayers, well known as good X-ray reflecting mirrors, were prepared by ion beam sputtering. The properties of the multilayers were investigated by low-angle X-ray diffraction, transmission electron microscopy (TEM) observation of the cross section and Auger electron spectroscopy.","PeriodicalId":409291,"journal":{"name":"Soft-X-Ray Projection Lithography","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1992-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126988018","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The development of lens systems for projection x-ray lithography presents significant challenges associated with the fabrication and testing of ultra precise optical surfaces. Once assembled, these projection lenses must further be dimensionally stable to tolerances determined by the wavelength of the soft x-rays used for illumination, typically between 100Å and 300Å. Lens systems capable of printing over large areas will contain a number of mirrors with reflectivities in the range of 60±10%. For these systems, the first element will be subjected to a significant incident x-ray flux, of which ~40% will be absorbed. This absorbed power causes heating which in turn will cause a distortion of the optical surface. The intent of this study has been to examine the magnitude of these distortions under a variety of conditions.
{"title":"Analysis of Thermally Induced Distortion of Optics for Soft X-ray Projection Lithography","authors":"R. Watson, R. Stulen","doi":"10.1364/sxray.1991.fb4","DOIUrl":"https://doi.org/10.1364/sxray.1991.fb4","url":null,"abstract":"The development of lens systems for projection x-ray lithography presents significant challenges associated with the fabrication and testing of ultra precise optical surfaces. Once assembled, these projection lenses must further be dimensionally stable to tolerances determined by the wavelength of the soft x-rays used for illumination, typically between 100Å and 300Å. Lens systems capable of printing over large areas will contain a number of mirrors with reflectivities in the range of 60±10%. For these systems, the first element will be subjected to a significant incident x-ray flux, of which ~40% will be absorbed. This absorbed power causes heating which in turn will cause a distortion of the optical surface. The intent of this study has been to examine the magnitude of these distortions under a variety of conditions.","PeriodicalId":409291,"journal":{"name":"Soft-X-Ray Projection Lithography","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1992-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131622121","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In the scanning transmission x-ray microscope (STXM) the specimen is scanned in a raster by an x-ray probe formed with a Fresnel zone plate. To achieve near diffraction limited resolution it is necessary to have a coherent source, even when forming an incoherent brightfield image by measuring the x-ray intensity transmitted by the object. This has so far been the only imaging mode used in the STXM and for hydrated biological specimens is well suited to soft x-ray wavelengths within the “water window” (2‧33 to 4‧36 nm) where carbon absorbs much more strongly than water. However, by the use of phase contrast rather than amplitude contrast, it is possible to form images at wavelengths where the absorption is low, resulting in lower radiation dose for the same level of contrast. Calculations made by Howells [1] and Rudolph and Schmahl [2] have demonstrated very clearly the advantages of phase contrast imaging at wavelengths outside the water window.
{"title":"Differential Phase Contrast Imaging in the Scanning Transmission X-ray Microscope","authors":"J. R. Palmer, G. Morrison","doi":"10.1364/sxray.1991.wa15","DOIUrl":"https://doi.org/10.1364/sxray.1991.wa15","url":null,"abstract":"In the scanning transmission x-ray microscope (STXM) the specimen is scanned in a raster by an x-ray probe formed with a Fresnel zone plate. To achieve near diffraction limited resolution it is necessary to have a coherent source, even when forming an incoherent brightfield image by measuring the x-ray intensity transmitted by the object. This has so far been the only imaging mode used in the STXM and for hydrated biological specimens is well suited to soft x-ray wavelengths within the “water window” (2‧33 to 4‧36 nm) where carbon absorbs much more strongly than water. However, by the use of phase contrast rather than amplitude contrast, it is possible to form images at wavelengths where the absorption is low, resulting in lower radiation dose for the same level of contrast. Calculations made by Howells [1] and Rudolph and Schmahl [2] have demonstrated very clearly the advantages of phase contrast imaging at wavelengths outside the water window.","PeriodicalId":409291,"journal":{"name":"Soft-X-Ray Projection Lithography","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1992-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115846584","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
H. Kinoshita, K. Kurihara, T. Mizota, T. Haga, Y. Torii
We have conducted the research work on X-ray projection lithography and have already demonstrated a 0.5 µm replicated pattern using a reflection mask. To obtain smaller features, we have designed a Schwarzschild typed demagnifying objective with a numerical aperture size of 0.1 and fabricated a Mo/B4C multilayer very precisely on its optics.
{"title":"Soft X-ray reduction lithography using a reflection mask","authors":"H. Kinoshita, K. Kurihara, T. Mizota, T. Haga, Y. Torii","doi":"10.1364/sxray.1991.wd2","DOIUrl":"https://doi.org/10.1364/sxray.1991.wd2","url":null,"abstract":"We have conducted the research work on X-ray projection lithography and have already demonstrated a 0.5 µm replicated pattern using a reflection mask. To obtain smaller features, we have designed a Schwarzschild typed demagnifying objective with a numerical aperture size of 0.1 and fabricated a Mo/B4C multilayer very precisely on its optics.","PeriodicalId":409291,"journal":{"name":"Soft-X-Ray Projection Lithography","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1992-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130241335","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：