Fabrication and metrology of diffraction limited soft x-ray optics for the EUV microlithography

Dinger, Udo; Seitz, Gabriele; Schulte, Stefan; Eisert, F.; Muenster, Christian; Burkart, Stefan; Stacklies, Siegfried; Bustaus, Christian; Hoefer, Hubert; Mayer, Maximilian; Fellner, Bernhard; Hocky, Oliver; Rupp, Markus; Riedelsheimer, Klaus; Kuerz, Peter

doi:10.1117/12.511489

Cited by 21 publications

(8 citation statements)

References 9 publications

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“…Precondition for achieving the figure requirements is the availability of the corresponding surface metrology. In the last years we have developed this technology and have now qualified all six interferometers for the alpha demo tool [5,15]. The performance of an interferometer is determined by the repeatability and the reproducibility of the measurement.…”

Section: Projection Opticsmentioning

confidence: 99%

Development of the ASML EUV alpha demo tool

Meiling

Banine

Harned³

et al. 2005

SPIE Proceedings

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As the predecessor for Extreme Ultraviolet Lithography (EUVL) production tools, ASML is realizing a development exposure tool, the alpha demo tool. The main objectives for undertaking this effort are to minimize the risks of changing to a new lithographic technology in production and to support the development ofthe global infrastructure of masks, sources, and resist. For this, initial imaging of the alpha demo tool is aimed at features consistent with the 45-nm technology node. In this paper we will present the status of the realization of the alpha demo tool. Several modules of the system have been integrated in the main body, and results of the system (vacuum) performance will be presented along with the wafer stage servo performance and wafer handler performance. We will summarize the current status of EUV sources including the recent work on alternatives to using Xe, report on our in-house source research, and provide an update on the fabrication of EUV optics. Polishing data of the projection optics mirrors shows that not only have we realized the requirements for 45-nm imaging, but also are we well underway in meeting the imaging requirements for production EUVL at the 32-nm node and beyond. Finally, since key to the commercial success of EUVL will be the availability of the infrastructure for reticles and resist, we will summarize the general status of EUV masks and resist.

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Section: Projection Opticsmentioning

confidence: 99%

Development of the ASML EUV alpha demo tool

Meiling

Banine

Harned³

et al. 2005

SPIE Proceedings

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“…In order to compare the four test results, eventually a polynomial is fitted to the data sets in the spatial frequency domain, 10μm -1~1 2.8μm -1 , and the PSD cover the whole spatial frequency is gotten [3] . So using the whole PSD directly, the results can be compared with each other conveniently.…”

Section: Psd Evaluation In An Extended Frequency Bandmentioning

confidence: 99%

Quantitative characterization of supersmooth surface with roughness in the sub-nanometer range

Shen

Wang

et al. 2009

SPIE Proceedings

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There is an increasing necessity to use supersmooth surfaces, and quantitative Characterization of surpersmooth surface with roughness in the sub-nanometer range plays an important role in the controlling the super-polishing process and raising the final surface quality. So it is necessary to improve the methods of measuring and specifying the highly smooth optical surfaces. The estimating system based on the Power Spectral Density (PSD) function is introduced in this paper, including the basic theory and the physical meaning. Two kinds of supersmooth surface, isotropy and anisotropy, are measured by optical profiler and the topographies are gotten. Then PSD curves calculated from the discrete profile data and light scattering properties are discussed in detail. Furthermore, optical profiler and AFM are adopted to test the same sample with different measurement parameters to investigate the PSD analysis method. Eventually a polynomial is fitted to the data sets in an extanted spatial frequency domain, 10μm -1~1 2.8μm -1 , including low frequency, mid-frequency, and high frequency band. Although the frequency response of the instruments and the scanning area can affect the test results, the results can still be compared with each other directly using the PSD. The research gives a powerful support to selecting appropriate measurement instrument and parameters in the interested frequency regime during the surface test, which is useful at controlling and giving feedback on the fabrication of supersmooth surface.

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“…The asphere MET M1, measured at Carl Zeiss based on the methods described above, was also measured at the Lawrence Livermore National Lab (LLNL) 1,5,7 . The asphere MET M1 is of convex shape with a clear aperture (CA) of 54 mm and a departure from the best fit sphere of 3.8 µm.…”

Section: (68/76mentioning

confidence: 99%

EUV microlithography: a challenge for optical metrology

et al. 2004

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%675$&7EUVL (extreme ultraviolet lithography), utilizing an actinic wavelength of about 13 nm , appears to be the most promising technology approach to reach the 30 nm node.Calling for diffraction limited imaging performance, EUV demand unprecedented requirements for figure metrology and fabrication technology. This paper gives an overview over problems rising from the interferometric measurement of aspheric EUV mirrors. ,1752'8&7,21The resolution of a optical projection system is given bywhere λ is the wavelength of the radiation used for imaging, and NA is the numerical aperture of the imaging system. k 1 is a process factor. The resolution RES can be increased by decreasing the operation wavelength λ or by increasing the NA of the system. But increasing of the NA is limited due to physical constraints. Beyond this, increasing the NA reduces the depth of focus (DOF) of the system, with k 2 being also a process factor:In the semiconductor manufacturing technology, the DOF determines the process window and is therefore decisive for performance and throughput of the projection system 6 .Assuming an actinic wavelength of λ=13.4 nm, table 1 shows a comparison between EUV-and the contemporary VUV-technology. Obviously, the EUV-technology increases the resolution by a factor of at least 2 without reducing the DOF.1

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Fabrication and metrology of diffraction limited soft x-ray optics for the EUV microlithography

Cited by 21 publications

References 9 publications

Development of the ASML EUV alpha demo tool

Development of the ASML EUV alpha demo tool

Quantitative characterization of supersmooth surface with roughness in the sub-nanometer range

EUV microlithography: a challenge for optical metrology

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