Dr. Lutz Aschke Profile

Dr. Lutz Aschke

CEO at Photonics Systems Holding GmbH

SPIE Involvement:

Editor | Author

Publications (39)

Proceedings Article | 12 March 2013 Paper

Brilliant green laser lines for surface processing

Mikhail Ivanenko, Wyacheslav Grimm, Lisa Kleinschmidt, Alexei Krasnaberski, Lutz Aschke, Vitalij Lissotschenko

Proceedings Volume 8600, 86000Z (2013) https://doi.org/10.1117/12.2004092

KEYWORDS: Diode pumped solid state lasers, Nd:YAG lasers, Silicon, Laser processing, Excimer lasers, Laser applications, Annealing, Optical design, Laser crystals, Homogenization

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Proceedings Article | 15 October 2012 Paper

Monolithic optical components for splitting of high-power beams

M. Jarczynski, T. Mitra, M. Ivaneko, L. Aschke, C. Wächter, U. Fuchs, T. Linke, S. Kiontke

Proceedings Volume 8490, 84900Q (2012) https://doi.org/10.1117/12.932256

KEYWORDS: Beam splitters, High power lasers, Aspheric lenses, Optics manufacturing, Silica, Diffraction, Optical components, Optical design, Glasses, Diffractive optical elements

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Proceedings Article | 23 March 2011 Paper

Beam shaping: top hat and customized intensity distributions for semiconductor manufacturing and inspection

Ansgar Teipel, Lutz Aschke

Proceedings Volume 7973, 797321 (2011) https://doi.org/10.1117/12.879640

KEYWORDS: Beam shaping, Beam splitters, Optics manufacturing, Diffractive optical elements, Diffraction, Inspection, Optical design, Semiconducting wafers, Objectives, Phase shifting

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Proceedings Article | 19 February 2011 Paper

Multistage phased electro-optical planar arrays for the manipulation of high power laser beams

M. Ivanenko, A. Krasnaberski, A. Mikhailov, Y. Miklyaev, L. Aschke, V. Lissotschenko

Proceedings Volume 7913, 79130E (2011) https://doi.org/10.1117/12.874629

KEYWORDS: Waveguides, Electro optics, Phased arrays, Control systems, Switching, Electrodes, Wavefronts, High power lasers, Optical resolution, Planar waveguides

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Proceedings Article | 19 February 2011 Paper

Efficient diffractive optical elements from glass with continuous surface profiles

Yu. Miklyaev, A. Krasnaberski, M. Ivanenko, A. Mikhailov, W. Imgrunt, L. Aschke, V. Lissotschenko

Proceedings Volume 7913, 79130B (2011) https://doi.org/10.1117/12.874642

KEYWORDS: Diffractive optical elements, Beam splitters, Diffraction, Glasses, Attenuators, Laser damage threshold, Diffraction gratings, Manufacturing, Laser processing, Etching

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Proceedings Article | 13 May 2010 Paper

Novel approach for manufacturing of continuously shaped diffractive optical elements

Vladimir Pavelyev, Yuri Miklyaev, Waleri Imgrunt, Maxim Bolshakov, Denis Kachalov, Victor Soifer, Lutz Aschke, Vitaly Lissotschenko

Proceedings Volume 7716, 77161N (2010) https://doi.org/10.1117/12.854836

KEYWORDS: Beam splitters, Diffractive optical elements, Optics manufacturing, Lithographic illumination, Optical design, Diffraction gratings, Optical components, Manufacturing, Micro optics, Lithography

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Optical lithography with its 193nm technology is pushed to reach and shift its limits even further. There is strong demand on innovations in illumination part of exposure tools. Current illumination systems consisting of diffractive and refractive optical elements offer numerous benefits such as optimized laser beam shape with high homogeneity and high numerical aperture enabling high efficiency. LIMO's unique production technology is capable to manufacture free form surfaces on monolithic arrays larger than 250mm with high precision and reproducibility. Different kinds of intensity distributions with best uniformities or customized profiles have been achieved by using LIMO's refractive optical elements. Recently LIMO pushed the limits of this lens production technology and was able to manufacture first diffractive optical elements (DOE) based on continuous relief's profile. Beside for the illumination devices in lithography, DOEs find wide use in optical devices for other technological applications, such as optical communications and data processing. Up to now DOE designs follow the principle of phase diffraction gratings. Its diffraction structure with a periodic phase profile performs a superposition of beams with predefined energy ratios. Due to the application for high precise laser-beam shaping and beam splitting in optical technologies and optical fiber networks, number of grating orders is increased up to some tens or even hundreds. Classic lithographic technologies lead to quantized (step-like) profiles of diffractive micro-reliefs, which causes a decrease of beam splitter's diffractive efficiency. The newest development of LIMO's microlens fabrication technology allows us to make a step from free programmable microlens profiles to diffractive optical elements with high efficiency. Our first results of this approach are demonstrated in this paper. Diffractive beam splitters are presented. A special mathematical method is used to design diffractive optical elements with continuous surface profiles. Comparison between theoretical simulations and experimental results shows very good correlation.

Proceedings Article | 4 March 2010 Paper

Novel continuously shaped diffractive optical elements enable high efficiency beam shaping

Yuri Miklyaev, Waleri Imgrunt, Vladimir Pavelyev, Denis Kachalov, Tanja Bizjak, Lutz Aschke, Vitalij Lissotschenko

Proceedings Volume 7640, 764024 (2010) https://doi.org/10.1117/12.846573

KEYWORDS: Beam splitters, Diffractive optical elements, Manufacturing, Beam shaping, Optics manufacturing, Optical components, Lithographic illumination, Micro optics, Diffraction gratings, Lithography

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Proceedings Article | 18 February 2010 Paper

Overview: process-optimized beam transformers and their impact on high-power laser applications

O. Homburg, T. Mitra, L. Aschke

Proceedings Volume 7579, 75790O (2010) https://doi.org/10.1117/12.841772

KEYWORDS: Solar cells, Gaussian beams, Optical lithography, Semiconducting wafers, Beam shaping, Laser processing, Silicon, Laser ablation, Lenses, Manufacturing

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Proceedings Article | 24 March 2009 Paper

Inspection and metrology tools benefit from free-form refractive micro-lens and micro-lens arrays

Tanja Bizjak, Thomas Mitra, Lutz Aschke

Proceedings Volume 7272, 72723Q (2009) https://doi.org/10.1117/12.814264

KEYWORDS: Inspection, Metrology, Micro optics, Lenses, Sensors, Semiconducting wafers, Aspheric lenses, Optics manufacturing, Metals, Manufacturing

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Proceedings Article | 24 February 2009 Paper

Improvements of high-power diode laser line generators open up new application fields

J. Meinschien, A. Bayer, P. Bruns, L. Aschke, V. Lissotschenko

Proceedings Volume 7198, 71980N (2009) https://doi.org/10.1117/12.809574

KEYWORDS: Semiconductor lasers, Beam shaping, High power diode lasers, Laser applications, Laser cutting, Silicon, Laser processing, Glasses, Micro optics, Annealing

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Proceedings Article | 20 February 2009 Paper

ZnSe aspherical microlens systems enable new beam-shaping approaches for CO2-lasers

O. Homburg, B. Guetlich, F. Toennissen, T. Mitra, L. Aschke

Proceedings Volume 7196, 71960B (2009) https://doi.org/10.1117/12.808164

KEYWORDS: Carbon dioxide lasers, Beam shaping, Gaussian beams, Phase shifting, Materials processing, Wafer-level optics, Manufacturing, Computer aided design, Laser sources, Semiconducting wafers

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Proceedings Article | 19 February 2009 Paper

Scanner deflection of top-hat converted single-mode lasers for cost-effective micro-machining at highest quality

B. Guetlich, T. Mitra, F. Toennissen, O. Homburg, L. Aschke

Proceedings Volume 7194, 71940A (2009) https://doi.org/10.1117/12.808163

KEYWORDS: Gaussian beams, Micromachining, Beam shaping, Optical lithography, Nd:YAG lasers, Scanners, Laser scanners, 3D scanning, Solar cells, Optical design

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Proceedings Article | 12 September 2008 Paper

Free form micro-optics enables uniform off-axis illumination and superposition of high power laser devices

Tanja Bizjak, Oliver Homburg, Andreas Bayer, Thomas Mitra, Lutz Aschke

Proceedings Volume 7062, 70620T (2008) https://doi.org/10.1117/12.794686

KEYWORDS: High power lasers, Beam shaping, Spherical lenses, Homogenization, Superposition, Laser cutting, Lithographic illumination, Semiconductor lasers, Aspheric lenses, Micro optics

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Proceedings Article | 7 March 2008 Paper

Novel refractive optics enable multipole off-axis illumination

T. Bizjak, T. Mitra, D. Hauschild, L. Aschke

Proceedings Volume 6924, 69242J (2008) https://doi.org/10.1117/12.771213

KEYWORDS: Micro optics, Lens design, Chemical elements, Deep ultraviolet, Optical components, Beam shaping, Manufacturing, Optics manufacturing, Semiconducting wafers, Lithographic illumination

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Optical lithography in the deep ultraviolet (DUV) region is being pushed to reach the limits of printing resolution. The effort required to achieve the 32 nm structure with this technology puts very hard conditions and requests on the illumination optics. Different kinds of illumination modes are combined to get into a regime of extreme numerical aperture (hyper NA). Arrays of refractive micro-optics have been and continue to be the ideal solution for high transmission homogenizing elements for several tool generations. Illumination of the masks with high numerical aperture is critical for achieving the smallest structure on the semiconductor material. Exposure tools use different illumination modes to get better imaging of certain mask structures. The beam shaping necessary to create these illumination modes is achieved mostly with diffractive elements. Most of the currently used modes can also be created with arrays of refractive micro-optics, manufactured from fused silica and calcium fluoride. The advantage over the diffractive optical elements lies in efficiency, which comes close to 90%. An important prerequisite for these special types of optical elements is LIMO's unique production technology which can manufacture free form surfaces on monolithic arrays exceeding 200 mm edge length with high precision and reproducibility. These homogenizing elements in the illumination optics can provide a custom designed intensity distribution, and offer the possibility to correct the failure of other optical elements. Each lens can be designed individually and can also be shaped asymmetrically. Thus unusual lens sizes and shapes can be produced, and various far fields such as rectangles, lines, hexagons or multi-poles can be achieved. In this paper we present novel refractive micro-optical elements which create rectangular dipole illumination. They can also be combined in such a way as to create a quadrupole with variable intensity ratio between the vertical and horizontal poles. The huge advantage of such a multipole illumination is polarization control and variable intensity in poles. Working on this combination, the resolution can be enhanced even further.

Proceedings Article | 25 February 2008 Paper

Beam shaping of high power diode lasers benefits from asymmetrical refractive micro-lens arrays

O. Homburg, A. Bayer, T. Mitra, J. Meinschien, L. Aschke

Proceedings Volume 6876, 68760B (2008) https://doi.org/10.1117/12.762892

KEYWORDS: Beam shaping, High power diode lasers, Homogenization, Semiconductor lasers, Lenses, Laser sources, Manufacturing, Laser processing, High power lasers, Semiconductors

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Proceedings Article | 12 September 2007 Paper

Refractive beam shaping: from Maxwell's Equations to products and applications in laser materials processing

O. Homburg, D. Hauschild, P. Harten, L. Aschke, V. Lissotschenko

Proceedings Volume 6663, 66630D (2007) https://doi.org/10.1117/12.737783

KEYWORDS: Beam shaping, Micromachining, Laser sources, Gaussian beams, Annealing, Laser processing, Silicon, Phase shifting, Laser ablation, Optics manufacturing

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Proceedings Article | 27 March 2007 Paper

Novel high-throughput micro-optical beam shapers reduce the complexity of macro-optics in hyper-NA illumination systems

T. Bizjak, T. Mitra, L. Aschke

Proceedings Volume 6520, 65202X (2007) https://doi.org/10.1117/12.712124

KEYWORDS: Lenses, Semiconducting wafers, Polarization, Spherical lenses, Beam shaping, Photomasks, Micro optics, Microlens array, Lens design, Microlens

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Uniform illumination of the mask is a key factor for the lithography process. The requirements of Immersion Lithography make illumination systems even more complex e.g. by adding additional parameters like polarization and improved throughput. Arrays of refractive microoptics are the ideal solution for high transmission homogenizing elements since several tool generations. These arrays can provide very steep intensity profiles (top hat and other profiles), enable lossless polarization control and do not suffer from zero order losses like diffractive elements. Usually refractive microlens arrays are used with macrooptical field lenses in order to illuminate a field very uniformly or with a customized intensity distribution. High numerical apertures create the necessity for aspherical surfaces which leads to significantly higher lens cost especially for the macrooptics. In this paper we present novel microoptical homogenizers which create extremely uniform intensity distributions for high numerical apertures without any field lens or at least only with spherical field lenses. Especially multi-pole off-axis illumination can be improved with less optical components. An important prerequisite for these special types of homogenizers is that LIMO can produce free form surfaces on monolithic arrays larger than 200 mm with high precision and reproducibility. Every lens can be designed individually and can also be shaped asymmetrically. We will present surface test methods and the final UV tests, guaranteeing the performance for the applications. Example data gained with these tests will be shown with regard to: meeting the design parameters, reproducibility over one wafer and reproducibility in large lots. Monolithic elements based on crossed cylindrical lenses provide a fill factor close to 100%. Simulations and measurements prove that microoptic arrays can be produced which provide a uniformity of the homogenized laser light of significantly better than 1% P-V at numerical apertures above 0.35. Refractive microoptic arrays do not change the polarization state of the transmitted light which is an important prerequisite in immersion exposure tools. LIMO homogenizer sets are manufactured from fused silica and Calcium Fluoride thus they are suitable for all DUV wavelengths at highest laser fluxes.

Proceedings Article | 15 January 2007 Paper

Refractive microlens structures with high-damage thresholds enable flexible beam shaping of high-power lasers

O. Homburg, L. Aschke, V. Lissotschenko

Proceedings Volume 6403, 640324 (2007) https://doi.org/10.1117/12.695972

KEYWORDS: Beam shaping, High power lasers, Semiconductor lasers, Laser sources, Microlens array, Optics manufacturing, Gas lasers, Collimation, Excimer lasers, Gaussian beams

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Proceedings Article | 21 June 2006 Paper

How refractive microoptics enable lossless hyper-NA illumination systems for immersion lithography

H. Ganser, M. Darscht, Y. Miklyaev, D. Hauschild, L. Aschke

Proceedings Volume 6281, 62810P (2006) https://doi.org/10.1117/12.692704

KEYWORDS: Semiconducting wafers, Micro optics, Photomasks, Microlens, Cylindrical lenses, Beam shaping, Lithographic illumination, Chemical elements, Polarization, Immersion lithography

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Proceedings Article | 15 March 2006 Paper

High-throughput homogenizers for hyper-NA illumination systems

H. Ganser, M. Darscht, Y. Miklyaev, D. Hauschild, L. Aschke

Proceedings Volume 6154, 61542N (2006) https://doi.org/10.1117/12.656402

KEYWORDS: Semiconducting wafers, Photomasks, Microlens, Cylindrical lenses, Micro optics, Polarization, Beam shaping, Chemical elements, Microlens array, Sodium

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Proceedings Article | 6 December 2004 Paper

SiO2 buffer-etch processes with a TaN absorber for EUV mask fabrication

Florian Letzkus, Joerg Butschke, Corinna Koepernik, Christian Holfeld, Josef Mathuni, Lutz Aschke, Frank Sobel

Proceedings Volume 5567, (2004) https://doi.org/10.1117/12.569265

KEYWORDS: Etching, Photomasks, Silicon, Dry etching, Extreme ultraviolet, Scanning electron microscopy, Semiconducting wafers, Extreme ultraviolet lithography, Chemistry, Mask making

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Proceedings Article | 6 December 2004 Paper

Absorber stack optimization toward EUV lithography mask blank pilot production

Frank Sobel, Lutz Aschke, Markus Renno, Holger Seitz, Hans Becker, Nathalie Olschewski, Torsten Reichardt, Guenter Hess, Ute Buttgereit, Konrad Knapp, Florian Letzkus, Joerg Butschke, Corinna Koepernik

Proceedings Volume 5567, (2004) https://doi.org/10.1117/12.568787

KEYWORDS: Coating, Reflectivity, Etching, Extreme ultraviolet, Extreme ultraviolet lithography, Photomasks, Dry etching, Inspection, Manufacturing, Multilayers

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Proceedings Article | 2 June 2004 Paper

Production challenges of making an EUV mask blank

Lutz Aschke, Hans Becker, Falk Friemel, Thomas Leutbecher, Nathalie Olschewski, Markus Renno, Frauke Rueggeberg, Mario Schiffler, Frank Schmidt, Frank Sobel, Kurt Walter, Guenter Hess, Frank Lenzen, Konrad Knapp, Jochen Alkemper, Hrabanus Hack, Klaus Megges, Ina Mitra, Rolf Mueller, Uwe Nolte, Joerg Schumacher, Wolfgang Pannhorst

Proceedings Volume 5504, (2004) https://doi.org/10.1117/12.568007

KEYWORDS: Extreme ultraviolet, Photomasks, Multilayers, Extreme ultraviolet lithography, Zerodur, Reflectivity, Polishing, Temperature metrology, Surface finishing, Glasses

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Proceedings Article | 2 June 2004 Paper

Effect of electrostatic chucking on EUVL mask flatness

Andrew Mikkelson, Roxann Engelstad, Edward Lovell, Lutz Aschke, Frauke Rueggeberg, Frank Sobel

Proceedings Volume 5504, (2004) https://doi.org/10.1117/12.568014

KEYWORDS: Photomasks, Extreme ultraviolet lithography, Polishing, Multilayers, Surface finishing, Data modeling, Finite element methods, Standards development, Mask making, Semiconductors

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Proceedings Article | 20 May 2004 Paper

Production of low-thermal-expansion EUVL mask blanks with low-defect multilayer, buffer, and absorber

Frank Sobel, Lutz Aschke, Frauke Rueggeberg, Holger Seitz, Nathalie Olschewski, Torsten Reichhardt, Hans Becker, Markus Renno, Steffen Kirchner, Thomas Leutbecher, Guenter Hess, Konrad Knapp

Proceedings Volume 5374, (2004) https://doi.org/10.1117/12.533292

KEYWORDS: Multilayers, Photomasks, Extreme ultraviolet lithography, Polishing, Extreme ultraviolet, Surface finishing, Magnetorheological finishing, Surface roughness, Silica, Optical coatings

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Proceedings Article | 20 May 2004 Paper

Optimized glass-ceramic substrate materials for EUVL applications

Ina Mitra, Jochen Alkemper, Rolf Mueller, Uwe Nolte, Axel Engel, Hrabanus Hack, Heiko Kohlmann, Volker Wittmer, Wolfgang Pannhorst, Mark Davis, Lutz Aschke, Konrad Knapp

Proceedings Volume 5374, (2004) https://doi.org/10.1117/12.535193

KEYWORDS: Zerodur, Surface roughness, Temperature metrology, Extreme ultraviolet lithography, Extreme ultraviolet, Glasses, Metrology, Surface finishing, Refractive index, Crystals

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EUV substrate materials have to meet enhanced requirements with respect to extreme low thermal expansion, high homogeneity and superior surface quality. A SCHOTT R&D program aims at the development of advanced materials covering these various aspects. The glass-ceramic Zerodur (registered trademark) of SCHOTT represents a substrate material currently used for EUV masks and optics of first generation tools due to its extremely low coefficient of thermal expansion (CTE) and its excellent homogeneity. Zerodur(registered trademark) even allows continuous shifting of the position of zero crossing of the CTE-slope to control the thermal expansion behavior according to varying customer requirements: As a result of specifically adjusted process parameters, samples of Zerodur (registered trademark) exhibit a coefficient of thermal expansion CTE < 5 ppb/K corresponding to the lowest expansion class of the SEMI standard P37 (19 to 25°C) for EUV mask blanks. By further variation of process parameters, the position of zero crossing, e.g. at 22.5°C or 30°C, can be varied, revealing an attractive attribute feature of Zerodur (registered trademark). A new dilatometer type reveals an improved reproducibility of ~ 1ppb/K in the temperature range of 0 to 50°C. A series of CTE(0;50°C) measurements with a test-cube of Zerodur (registered trademark) provides information on CTE homogeneity on a cm-scale: no CTE variation was observed within the error of measurements (1ppb/K) for a block exhibiting ± 3.5*10^-6 variation in refractive index. CTE variation can cause surface deformations during changing temperature conditions. A Fizeau-Interferometer was used to record surface roughness at two different temperatures. This non- destructive metrology is regarded as a method to distinguish CTE variation < 1ppb/K. The surface deformation of Zerodur (registered trademark) due to elevated temperature was determined to be lower than the resolution. Both methods to analyze the CTE homogeneity of Zerodur (registered trademark) lead to the result of CTE variation below 1 ppb/K. Surface treatment of glass-ceramic material is a major challenge as final finishing of EUV substrates may increase roughness of super-polished surfaces significantly. Improved new glass-ceramic materials demonstrate optimization of glass-ceramic compositions to nearly meeting the specification of surface roughness after a standard finishing process. Recent achievements of material development reveal CTE-performance of this new glass-ceramic to also be adjustable to varying customer needs as already known for Zerodur (registered trademark). These results are regarded as a promising milestone to develop an optimized glass-ceramic material, because the features of the modified New-Glass Ceramic now better match the key requirements of EUVL substrate materials.

Proceedings Article | 20 May 2004 Paper

High-throughput EUV reflectometer for EUV mask blanks

Rainer Lebert, Christian Wies, Larissa Juschkin, Bernhard Jaegle, Manfred Meisen, Lutz Aschke, Frank Sobel, Holger Seitz, Frank Scholze, Gerhard Ulm, Konstantin Walter, Willi Neff, Klaus Bergmann, Wolfgang Biel

Proceedings Volume 5374, (2004) https://doi.org/10.1117/12.537012

KEYWORDS: Reflectometry, Photomasks, Extreme ultraviolet, Mirrors, Spectrographs, Charge-coupled devices, Metrology, Extreme ultraviolet lithography, Photons, Reflectivity

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Proceedings Article | 17 December 2003 Paper

Update on the EUVL mask blank activity at Schott Lithotec

Frank Sobel, Lutz Aschke, Hans Becker, Markus Renno, Frauke Ruggeberg, Steffen Kirchner, Thomas Leutbecher, Nathalie Olschewski, Mario Schiffler, Kurt Walter, Guenter Hess, Ute Buttgereit, Konrad Knapp, Rainer Lebert, Larissa Juschkin, Christian Wies, Bernhard Jagle

Proceedings Volume 5256, (2003) https://doi.org/10.1117/12.518061

KEYWORDS: Extreme ultraviolet, Photomasks, Multilayers, Extreme ultraviolet lithography, Coating, Reflectivity, Polishing, Reflectometry, Surface finishing, Metrology

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Proceedings Article | 16 June 2003 Paper

Improved materials meeting the demands for EUV substrates

Ina Mitra, Jochen Alkemper, Uwe Nolte, Axel Engel, Rolf Mueller, Simone Ritter, Hrabanus Hack, Klaus Megges, Heiko Kohlmann, Wolfgang Pannhorst, Mark Davis, Lutz Aschke, Konrad Knapp

Proceedings Volume 5037, (2003) https://doi.org/10.1117/12.484728

KEYWORDS: Zerodur, Surface roughness, Temperature metrology, Extreme ultraviolet, Metrology, Glasses, Standards development, Extreme ultraviolet lithography, Surface finishing, Crystals

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The enhanced demands for substrate materials for next-generation optics and masks have initiated detailed investigations on Zerodur as a proposed EUVL substrate material with focus on thermal expansion behavior and surface roughness. As a result of specifically adjusted process parameters, the coefficient of thermal expansion (CTE) was tailored to be a minimum at 22.5°C. Laboratory samples of Zerodur exhibit a CTE < 5 ppb/K corresponding to the lowest expasnion class of the SEMI standard P37 (19 to 25°C) for EUV mask blanks. By further variation of process parameters, the position of zero crossing, e.g. at 30°C, can be varied, revealing an attractive attribute feature of Zerodur. A new dilatometer type was mounted in 2002 with first operatinoal results revealing an improved reproducibility of ~1ppb/K in the temperature range of 0 to 50°C. A series of CTE measurements with a small block of Zerodur provides information on CTE homogeneity on a cm-scale: No CTE variation was observed within the error of measurements for a block exhibiting ± 3.5*10^-6 vairtion in refractinve index. CTE variation can cause surface deformations during changing temperature conditions. A first setup of Fizeau-Interferometer with a current resolution of 0.3 nm rms was used to record surface deformation of Zerodur due to elevated temperature was determined to be lower than the current resolution. Both methods to analyze the CTE homogeneity of Zerodur lead to the result of CTE variation below 1 ppb/K, still identifying today's need to improve metrology further. Final finishing of EUV substrates may increase roughness of super-polished surfaces significantly. Using appropriate processes a to surface roughness < 0.25 nm rms under production conditions can be achieved after final finishing of Zerodur. As an improved Zerodur-type material, recent achievements of material development demonstrate the optimization of glass-ceramic composition to nearly meeting the specification of surface roughness after a standard finishing process. These results are regarded as a promising milestone to develop an optimized glass-ceramic material providnig adjusted thermal expansion behavior and surface processability according to the specific demands of EUV technology.

Proceedings Article | 27 December 2002 Paper

High-performance 6-in. EUV mask blanks produced under real production conditions by ion-beam sputter deposition

Hans Becker, Frank Sobel, Lutz Aschke, Markus Renno, Juergen Krieger, Ute Buttgereit, Guenter Hess, Frank Lenzen, Konrad Knapp, Sergey Yulin, Torsten Feigl, Thomas Kuhlmann, Norbert Kaiser

Proceedings Volume 4889, (2002) https://doi.org/10.1117/12.467578

KEYWORDS: Reflectivity, Multilayers, Particles, Extreme ultraviolet, Ion beams, Transmission electron microscopy, Silicon, Sputter deposition, Interfaces, Reflectometry

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Proceedings Article | 16 August 2002 Paper

Cleaning of low thermal expansion materials for low-defect EUVL mask substrates

Eva Krueger-Velthusen, Falk Friemel, Lutz Aschke, Frank Lenzen

Proceedings Volume 4764, (2002) https://doi.org/10.1117/12.479359

KEYWORDS: Zerodur, Ultrasonics, Unmanned aerial vehicles, Photomasks, Extreme ultraviolet lithography, Atomic force microscopy, Particles, Quartz, Glasses, Radium

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Proceedings Article | 1 July 2002 Paper

Thermal expansion behavior of proposed EUVL substrate materials

Ina Mitra, Mark Davis, Jochen Alkemper, Rolf Mueller, Heiko Kohlmann, Lutz Aschke, Ewald Moersen, Simone Ritter, Hrabanus Hack, Wolfgang Pannhorst

Proceedings Volume 4688, (2002) https://doi.org/10.1117/12.472322

KEYWORDS: Zerodur, Temperature metrology, Glasses, Critical dimension metrology, Extreme ultraviolet lithography, Extreme ultraviolet, Solids, Refractive index, Crystals, Photomasks

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Proceedings Article | 1 July 2002 Paper

Ion beam sputter deposition of low-defect EUV mask blanks on 6-in. LTEM substrates in a real production environment

Hans Becker, Lutz Aschke, Birgit Schubert, Juergen Krieger, Frank Lenzen, Sergey Yulin, Torsten Feigl, Thomas Kuhlmann, Norbert Kaiser

Proceedings Volume 4688, (2002) https://doi.org/10.1117/12.472326

KEYWORDS: Multilayers, Extreme ultraviolet, Ion beams, Reflectivity, Transmission electron microscopy, Molybdenum, Interfaces, Atomic force microscopy, Reflection, Sputter deposition

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Proceedings Article | 2 November 2001 Paper

Thermal expansion and internal quality of a proposed EUVL mask substrate material: Zerodur

Mark Davis, Alexander Marker, Lutz Aschke, Fredi Schubert, Ewald Moersen, Heiko Kohlmann, Ina Mitra, Jochen Alkemper, Rudolf Mueller, John Taylor, Kenneth Blaedel, Scott Hector

Proceedings Volume 4452, (2001) https://doi.org/10.1117/12.446884

KEYWORDS: Zerodur, Extreme ultraviolet lithography, Temperature metrology, Refractive index, Photomasks, Glasses, Polishing, Error analysis, Projection systems, Interferometers

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Proceedings Article | 14 September 2001 Paper

Development and investigation of high-quality CaF2 used for 157-nm microlithography

Axel Engel, Konrad Knapp, Lutz Aschke, Ewald Moersen, Wolfgang Triebel, Christoph Chojetzki, Sven Brueckner

Proceedings Volume 4346, (2001) https://doi.org/10.1117/12.435711

KEYWORDS: Absorption, Birefringence, Lithography, Annealing, Pulsed laser operation, Polishing, Crystals, Optical lithography, Vacuum ultraviolet, Calcium

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Proceedings Article | 20 August 2001 Paper

Flatness correction of NZTE mask blank substrates

Lutz Aschke, Fredi Schubert, Joerg Kegeler, Axel Schindler, Thomas Haensel, Konrad Knapp

Proceedings Volume 4343, (2001) https://doi.org/10.1117/12.436634

KEYWORDS: Ion beams, Etching, Ion beam finishing, Polishing, Zerodur, Surface finishing, Photomasks, Spatial frequencies, Extreme ultraviolet lithography, Ions

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Proceedings Article | 26 April 2001 Paper

Final inspection of photomask blanks

Fredi Schubert, Hartmut Sauerbrei, Lutz Aschke, Konrad Knapp

Proceedings Volume 4404, (2001) https://doi.org/10.1117/12.425223

KEYWORDS: Inspection, Photomasks, Manufacturing, Light scattering, Defect detection, Particles, Laser scattering, Semiconductor lasers, Solid state lasers, Laser systems engineering

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Proceedings Article | 26 April 2001 Paper

Development and investigation of high-quality CaF2 used for 157-nm microlithography

Axel Engel, Konrad Knapp, Lutz Aschke, Ewald Moersen, Wolfgang Triebel, Christoph Chojetzki, Sven Brueckner

Proceedings Volume 4404, (2001) https://doi.org/10.1117/12.425218

KEYWORDS: Absorption, Birefringence, Lithography, Annealing, Vacuum ultraviolet, Pulsed laser operation, Polishing, Crystals, Calcium, Photovoltaics

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Proceedings Article | 23 April 2001 Paper

Time evolution of colliding laser-produced magnesium plasmas

S. Harilal, L. Aschke, T. Atwee, Hans-Joachim Kunze

Proceedings Volume 4424, (2001) https://doi.org/10.1117/12.425546

KEYWORDS: Plasmas, Magnesium, Pulsed laser operation, Photography, Glasses, Ruby lasers, Beam splitters, Laser ablation, Extreme ultraviolet, Laser applications

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Showing 5 of 39 publications

Proceedings Volume Editor (10)

SPIE Conference Volume | 4 June 2018

Laser Resonators, Microresonators, and Beam Control XX

SPIE Conference Volume | 7 April 2017

Laser Resonators, Microresonators, and Beam Control XIX

SPIE Conference Volume | 15 July 2016

Laser Resonators, Microresonators, and Beam Control XVIII

SPIE Conference Volume | 16 April 2015

Laser Resonators, Microresonators, and Beam Control XVII

SPIE Conference Volume | 18 March 2014

Laser Resonators, Microresonators, and Beam Control XVI

Showing 5 of 10 publications

Conference Committee Involvement (15)

Laser Resonators, Microresonators, and Beam Control XXV

31 January 2023 | San Francisco, California, United States

Laser Resonators, Microresonators, and Beam Control XXIV

24 January 2022 | San Francisco, California, United States

Laser Resonators, Microresonators, and Beam Control XXIII

6 March 2021 | Online Only, California, United States

Laser Resonators, Microresonators, and Beam Control XXII

3 February 2020 | San Francisco, California, United States

Laser Resonators, Microresonators, and Beam Control XXI

4 February 2019 | San Francisco, California, United States

Laser Resonators, Microresonators, and Beam Control XX

29 January 2018 | San Francisco, California, United States

Laser Resonators, Microresonators, and Beam Control XIX

30 January 2017 | San Francisco, California, United States

Laser Resonators, Microresonators, and Beam Control XVIII

15 February 2016 | San Francisco, California, United States

Laser Resonators, Microresonators, and Beam Control XVII

9 February 2015 | San Francisco, California, United States

Laser Resonators, Microresonators, and Beam Control XVI

3 February 2014 | San Francisco, California, United States

Laser Resonators, Microresonators, and Beam Control XV

3 February 2013 | San Francisco, California, United States

Laser Resonators, Microresonators, and Beam Control XIV

22 January 2012 | San Francisco, California, United States

Laser Resonators and Beam Control XIII

23 January 2011 | San Francisco, California, United States

Laser Resonators and Beam Control XII

24 January 2010 | San Francisco, California, United States

Laser Resonators and Beam Control XI

26 January 2009 | San Jose, California, United States

Showing 5 of 15 Conference Committees

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