Dr. Christian Peth Profile

Dr. Christian Peth

at Laser-Lab Göttingen eV

SPIE Involvement:

Author

Publications (19)

Proceedings Article | 31 December 2009 Paper

Damage and degradation of optics and sensors under intense EUV radiation from a table-top laser produced plasma source

Frank Barkusky, Armin Bayer, Bernhard Flöter, Christian Peth, Klaus Mann

Proceedings Volume 7504, 75041J (2009) https://doi.org/10.1117/12.837357

KEYWORDS: Extreme ultraviolet, Mirrors, Gold, Etching, Plasma, Multilayers, Polymethylmethacrylate, EUV optics, Solids, Objectives

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Proceedings Article | 18 May 2009 Paper

Direct structuring of solids by EUV radiation from a table-top laser produced plasma source

Frank Barkusky, Armin Bayer, Christian Peth, Klaus Mann

Proceedings Volume 7361, 73610D (2009) https://doi.org/10.1117/12.822243

KEYWORDS: Extreme ultraviolet, Polymethylmethacrylate, Etching, Polymers, Gold, Plasma, Mirrors, Solids, Objectives, FT-IR spectroscopy

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Proceedings Article | 18 May 2009 Paper

Applications of compact laser-driven EUV/XUV plasma sources

Frank Barkusky, Armin Bayer, Stefan Döring, Bernhard Flöter, Peter Großmann, Christian Peth, Michael Reese, Klaus Mann

Proceedings Volume 7361, 736112 (2009) https://doi.org/10.1117/12.833645

KEYWORDS: Extreme ultraviolet, Plasma, Solids, Gold, Mirrors, Wavefronts, Liquids, Laser applications, Reflectivity, Extreme ultraviolet lithography

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In recent years, technological developments in the area of extreme ultraviolet lithography (EUVL) have experienced great improvements. So far, intense light sources based on discharge or laser plasmas, beam steering and imaging optics as well as sensitive detectors are available. Currently, applications of EUV radiation apart from microlithography, such as metrology, high-resolution microscopy, or surface analysis come more and more into focus. In this contribution we present an overview on the EUV/XUV activities of the Laser-Laboratorium Göttingen based on table-top laser-produced plasma (LPP) sources. As target materials gaseous or liquid jets of noble gases or solid Gold are employed. Depending on the applications, the very clean but low intense gaseous targets are mainly used for metrology, whereas the targets for high brilliances (liquid, solid) are used for microscopy and direct structuring. For the determination of interaction mechanisms between EUV radiation and matter, currently the solid Gold target is used. In order to obtain a small focal spot resulting in high EUV fluence, a modified Schwarzschild objective consisting of two spherical mirrors with Mo/Si multilayer coatings is adapted to this source. By demagnified (10x) imaging of the Au plasma an EUV spot of 3 μm diameter with a maximum energy density of ~1.3 J/cm² is generated (pulse duration 8.8 ns). First applications of this integrated source and optics system reveal its potential for high-resolution modification and direct structuring of solid surfaces. For chemical analysis of various samples a NEXAFS setup was developed. It consists of a LPP, using gaseous Krypton as a broadband emitter in the water-window range, as well as a flat field spectrograph. The laboratory system is set to the XUV spectral range around the carbon K-edge (4.4 nm). The table-top setup allows measurements with spectral accuracy comparable to synchrotron experiments. NEXAFS-experiments in transmission and reflection are demonstrated. Beside chemical investigations, also microscopy applications are performed within the XUV spectral range. For this reason a water-window microscope was developed, based on a liquid argon LPP target. The XUV radiation is focused by a Cr/Sc multilayer mirror, leading to spectral narrow band radiation on the sample. For magnifying the sample, a Fresnel zone plate will be used with an outer zone width of 50 nm. Additionally to these applications, an EUV/XUV setup for structural analysis was developed. Using a spectral broad band emitting Xenon gaseous target combined with a grazing incidence optics (Kirkpatrick-Baez arrangement), it offers the possibility to perform angular resolved reflectivity-, diffraction- and scattering experiments as well as NEXAFS analysis in one setup. In completion to these experiments with LPP sources, an EUV/XUV Hartmann-type wavefront sensor has been developed in collaboration with DESY HASYLAB. It consists of a pinhole array, positioned in front of a XUV sensitive CCD camera with quantum converter. With custom-developed software the incident wavefront can be determined. This sensor is currently used at the free electron laser FLASH in Hamburg for beam characterization.

Proceedings Article | 18 May 2009 Paper

XUV metrology: surface analysis with extreme ultraviolet radiation

M. Banyay, L. Juschkin, T. Bücker, P. Loosen, A. Bayer, F. Barkusky, S. Döring, C. Peth, K. Mann, H. Blaschke, I. Balasa, D. Ristau

Proceedings Volume 7361, 736113 (2009) https://doi.org/10.1117/12.833648

KEYWORDS: Extreme ultraviolet, Reflectivity, Carbon, Silicon, Reflectometry, Sensors, Absorption, Metrology, Plasmas, Mirrors

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Proceedings Article | 30 April 2009 Paper

Material analysis with EUV/XUV radiation using a broadband laser plasma source and optics system

A. Bayer, F. Barkusky, J.-O. Dette, S. Döring, B. Flöter, C. Peth, K. Mann

Proceedings Volume 7360, 736004 (2009) https://doi.org/10.1117/12.822585

KEYWORDS: Extreme ultraviolet, Plasma, Mirrors, Carbon, Spectroscopy, Reflection, Krypton, Absorption, Laser development, X-rays

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Proceedings Article | 27 September 2008 Paper

Active beam control for the EUV/XUV spectral range using an adaptive Kirkpatrick-Baez arrangement

Armin Bayer, Frank Barkusky, Stefan Döring, Bernhard Flöter, Christian Peth, Klaus Mann

Proceedings Volume 7100, 71001F (2008) https://doi.org/10.1117/12.797703

KEYWORDS: Mirrors, Extreme ultraviolet, Zemax, Wavefronts, Plasma, Wavefront sensors, Laser development, Wafer-level optics, Extreme ultraviolet lithography, Materials analysis

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Proceedings Article | 7 March 2008 Paper

Direct photo-etching of PMMA by focused EUV radiation from a compact laser plasma source

Frank Barkusky, Armin Bayer, Christian Peth, Klaus Mann

Proceedings Volume 6879, 68791M (2008) https://doi.org/10.1117/12.762553

KEYWORDS: Extreme ultraviolet, Polymethylmethacrylate, Plasma, Diffraction, Optical filters, Etching, Zirconium, Mirrors, Extreme ultraviolet lithography, Objectives

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Proceedings Article | 18 May 2007 Paper

Compact EUV source and Schwarzschild objective for modification and ablation of various materials

Frank Barkusky, Armin Bayer, Christian Peth, Holger Töttger, Klaus Mann

Proceedings Volume 6586, 65860B (2007) https://doi.org/10.1117/12.723010

KEYWORDS: Extreme ultraviolet, Mirrors, Objectives, Plasmas, Color centers, Extreme ultraviolet lithography, Reflectivity, Laser induced fluorescence, Laser ablation, Polymethylmethacrylate

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In recent years technological developments in the area of extreme ultraviolet lithography (EUVL) have experienced great improvements. So far, intense light sources based on discharge or laser plasmas, light guiding and imaging optics, as well as detection devices are already available. Currently, the application of EUV radiation apart from microlithography, such as metrology, high-resolution microscopy, or surface analysis comes more and more into focus. The aim is to make use of the strong interaction between soft x-ray radiation and matter for surface-near probing, modification or structuring techniques. In this contribution, we demonstrate the surface-near direct structuring of different polymeric materials as well as lithium fluoride crystals using EUV radiation with a wavelength of 13.5 nm. The setup consists of a table-top EUV source based on a laser-induced plasma and a modified Schwarzschild objective with a resolution down to 130 nm. The mirrors of the employed objective were coated with Mo/Si multilayers, providing a transmittance of around 42 % (reflectivity ~65 % @ 13.5 nm per mirror). With a demagnification factor of 10 small foci are generated, leading to spot diameters of 30 &mgr;m in plasma imaging mode and down to 1 &mgr;m in mask imaging mode, respectively. The EUV energy density of ~100 mJ/cm² obtained in the focus is sufficient to observe direct photo-etching of polymers, e.g. PMMA. Thus, material interaction studies are currently in progress. The investigations revealed already that in contrast to common excimer laser ablation there are no incubation pulses when using EUV radiation. For lower energies the ablation rate is found to be linear with respect to the applied dose, whereas for higher energies a saturation behavior is observed. By EUV irradiation of LiF samples surface-near defects within the crystal lattice are formed. These color-centers (mainly F₂- and F₃ ⁺-color centers) are known to be stable at room temperature. They are able to emit characteristic radiation in the visible range after optical excitation with a wavelength around 450 nm. In the future structured areas of such color centers could be used as laser-active gain medium in distributed feedback lasers. For measuring the radiation resistence of Mo/Si mirrors, the setup was used as a top-illuminated microscope at 13.5 nm. By placing the analyzing Mo/Si mirror into the image plane of the objective, the change in reflectivity due to irradiation at a fluence of 20mJ/cm² could be observed.

Proceedings Article | 13 March 2007 Paper

Compact EUV source and optics for direct structuring of surfaces

Armin Bayer, Frank Barkusky, Christian Peth, Holger Töttger, Klaus Mann

Proceedings Volume 6458, 64580Z (2007) https://doi.org/10.1117/12.701971

KEYWORDS: Extreme ultraviolet, Mirrors, Plasmas, Objectives, Color centers, Extreme ultraviolet lithography, Laser induced fluorescence, Reflectivity, EUV optics, Visible radiation

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In recent years technological developments in the area of extreme ultraviolet lithography (EUVL) have experienced great improvements. So far, intense light sources based on discharge or laser plasmas, light guiding and imaging optics, as well as detection devices are already available. Currently, the application of EUV radiation apart from microlithography, such as metrology, high-resolution microscopy, or surface analysis comes more and more into focus. The aim is to make use of the strong interaction between soft x-ray radiation and matter for surface-near probing, modification or structuring techniques. In this contribution, we demonstrate the surface-near direct structuring of different polymeric materials as well as lithium fluoride crystals using EUV radiation with a wavelength of 13.5 nm. The setup consists of a table-top EUV source based on a laser-induced plasma and a modified Schwarzschild objective with a resolution down to 1 μm. The mirrors of the employed objective were coated with Mo/Si multilayers, providing a transmittance of around 42 % (reflectivity ~65 % @ 13.5 nm per mirror). With a demagnification factor of 10 small foci are generated, leading to spot diameters of 30 μm in plasma imaging mode and down to 1 μm in mask imaging mode, respectively. The EUV energy density of ~100 mJ/cm² obtained in the focus is sufficient to observe direct photo-ablation of polymers, e.g. PMMA. Thus, material interaction studies are currently in progress. The investigations revealed already that in contrast to common excimer laser ablation there are no incubation pulses when using EUV radiation. For lower energies the ablation rate is found to be linear with respect to the applied dose, whereas for higher energies a saturation behavior is observed. The mechanism of the process is briefly discussed. An additional diffraction experiment revealed the potential of the setup to generate periodic interference patterns with feature sizes in the sub-μm-range. By EUV irradiation of LiF samples surface-near defects within the crystal lattice are formed. These color-centers (mainly F₂- and F₃ ⁺ -color centers) are known to be stable at room temperature. They are able to emit characteristic radiation in the visible range after optical excitation with a wavelength around 450 nm. In the future structured areas of such color centers could be used as laser-active gain medium in distributed feedback lasers.

Proceedings Article | 29 August 2006 Paper

Compact EUV source and optics for applications apart from lithography

Armin Bayer, Frank Barkusky, Christian Peth, Holger Töttger, Klaus Mann

Proceedings Volume 6317, 631706 (2006) https://doi.org/10.1117/12.683682

KEYWORDS: Extreme ultraviolet, Mirrors, Objectives, Plasmas, Color centers, EUV optics, Extreme ultraviolet lithography, Laser induced fluorescence, Reflectivity, Polymethylmethacrylate

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In recent years technological developments in the area of extreme ultraviolet lithography (EUVL) have experienced great improvements. So far there are already intense light sources based on discharge or laser plasmas, light guiding and imaging optics, and detection equipment. Currently, the application of EUV radiation apart from microlithography, such as metrology, high-resolution microscopy, or surface analysis comes more and more into focus. The aim is to make use of the strong interaction between soft x-ray radiation and matter for surface-near probing, modification or structuring techniques. In this contribution, along with first applications, we present a comparison of different optical setups capable of guiding and imaging EUV radiation. A table-top EUV source based on a laser plasma was used for the experimental investigations. A modified Schwarzschild objective is adapted to this source in order to produce a focus of high energy density. The objective consists of two spherical mirrors with Mo/Si-multilayer coatings, providing a transmittance of around 42 % (reflectivity ~ 65 % @ 13.5 nm per mirror). With a demagnification of 10x a small spot is created (diameter ~ 30 μm, energy density ~ 100 mJ/cm²), which can be used in material interaction studies. First experiments showed the potential of this setup - color centers in LiF were generated and the ablation of polymers (PMMA, polyimide) could be shown. In the latter case the influence of out-of-band radiation was determined. A sample holder with a precision translation stage allows high-resolution direct structuring. Another promising optics for guiding EUV radiation consists of two grazing incidence cylindrical mirrors (Kirkpatrick-Baez arrangement). In contrast to the Schwarzschild objective it is able to transmit over a broad spectral range, accomplishing alternative experimental techniques. A spectrally resolving reflectometer with a Kirkpatrick-Baez module as condensing optic is currently being built.

Proceedings Article | 23 March 2006 Paper

Compact source and beam delivery system for EUV radiation

Klaus Mann, Frank Barkusky, Armin Bayer, Christian Peth, Holger Töttger

Proceedings Volume 6151, 61511T (2006) https://doi.org/10.1117/12.651054

KEYWORDS: Extreme ultraviolet, Color centers, Plasma, Mirrors, Objectives, Laser induced fluorescence, Extreme ultraviolet lithography, Polymethylmethacrylate, Luminescence, EUV optics

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Proceedings Article | 15 October 2005 Paper

Imaging properties of different optics for EUV radiation

Armin Bayer, Frank Barkusky, Christian Peth, Holger Töttger, Klaus Mann, Torsten Feigl, Norbert Kaiser

Proceedings Volume 5962, 59620R (2005) https://doi.org/10.1117/12.624497

KEYWORDS: Extreme ultraviolet, Mirrors, Color centers, Plasma, Objectives, Laser induced fluorescence, EUV optics, Extreme ultraviolet lithography, Reflectivity, Visible radiation

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Triggered by the roadmap of the semiconductor industry, tremendous progress has been achieved in the development of Extreme Ultraviolet (EUV) sources and high-quality EUV optical coatings in recent years, opening up also new fields of applications apart from microlithography, such as metrology, high-resolution microscopy, or surface analysis. In all these research areas the quality and imaging properties of the employed optics play a crucial role. In this contribution we present a comparison of different optical setups capable of guiding and imaging EUV radiation, which were tested in combination with a miniaturized laser-produced plasma source with high pulse energy (~ 3.5 mJ @ 13.5 nm) and a plasma size of about 300 μm. First, a modified EUV Schwarzschild objective with a numerical aperture of 0.44 and a demagnification factor of 10 was developed within the research project "KOMPASS". After adaptation to the table-top EUV source, a focus with a diameter < 30 μm at energy densities of several mJ/cm² could be produced. The setup is currently being used for comparative investigations of the interaction of EUV radiation with different materials, as e.g. the color center formation in LiF crystals. An attempt to use the Schwarzschild objective in reverse geometry as a EUV microscope will be part of future work. Second, a Kirkpatrick-Baez arrangement was realized, using the reflections from two curved silicon wafers under grazing incidence (about 5°). The cylindrical curvature is obtained by bending the thin substrates, allowing for a continuous tuning to the desired radii. Due to an Au coating a high reflectivity (theoretically ~ 80 % per reflection) over a broad EUV spectral range can be achieved. For reduction of aberrations the optical systems were fine-adjusted with the help of a Hartmann-Shack wavefront sensor both in the visible and in the EUV spectral range. The imaging properties in the EUV range were determined and compared to ray tracing calculations performed with ZEMAX.

Proceedings Article | 31 August 2005 Paper

Compact source and beam delivery system for EUV radiation using a Schwarzschild objective

K. Mann, F. Barkusky, A. Bayer, C. Peth, H. Toettger, T. Feigl, N. Kaiser

Proceedings Volume 5918, 59180F (2005) https://doi.org/10.1117/12.614989

KEYWORDS: Extreme ultraviolet, Mirrors, Color centers, Plasma, Objectives, Laser induced fluorescence, Extreme ultraviolet lithography, Luminescence, EUV optics, Reflectivity

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Proceedings Article | 20 May 2004 Paper

Compact laser-induced EUV source for metrology

Klaus Mann, F. Barkusky, Stefan Doering, Sebastian Kranzusch, A. Meyer, Christian Peth

Proceedings Volume 5374, (2004) https://doi.org/10.1117/12.532871

KEYWORDS: Extreme ultraviolet, Plasma, Sensors, Wavefronts, Gas lasers, Coded apertures, Laser drilling, Xenon, Laser development, Wavefront sensors

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Proceedings Article | 7 January 2004 Paper

Plasma generation and characterization in the extreme ultraviolet spectral range

Sebastian Kranzusch, Christian Peth, Stefan Doering, Klaus Mann

Proceedings Volume 5196, (2004) https://doi.org/10.1117/12.509324

KEYWORDS: Extreme ultraviolet, Plasma, Coded apertures, Laser induced fluorescence, Gas lasers, Luminescence, Xenon, Cameras, X-rays, Visualization

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Proceedings Article | 16 June 2003 Paper

Spatial emission characteristics of EUV plasma sources

Klaus Mann, Sebastian Kranzusch, Christian Peth, Max Schurmann, Thomas Missalla

Proceedings Volume 5037, (2003) https://doi.org/10.1117/12.482748

KEYWORDS: Extreme ultraviolet, Plasma, Coded apertures, Laser induced fluorescence, Xenon, Gas lasers, Luminescence, Visualization, Absorption, Laser development

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Proceedings Article | 11 November 2002 Paper

Optical metrology in the VUV and EUV spectral range

Klaus Mann, Sebastian Kranzusch, G. Eckert, Christian Gorling, Uwe Leinhos, Christian Peth, Bernd Schafer

Proceedings Volume 4779, (2002) https://doi.org/10.1117/12.455923

KEYWORDS: Absorption, Fluorine, Photons, Vacuum ultraviolet, Laser induced fluorescence, Solar thermal energy, Thermal effects, Wavefront sensors, Optical metrology, Extreme ultraviolet

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