PTB-Seminar on VUV and EUV Metrology 2025

Session

Postersession

Poster

14 Oct 2025, 13:00

Lecture Hall in Hermann-von-Helmholtz Building (PTB Berlin)

27. Reminisce - Refurbishment of Mirrors to Increase Sustainability at Light Sources - Introduction of a European collaboration project

Silja Schmidtchen (European X-Ray Free Electron Laser Facility)

14/10/2025, 13:00

poster

The degradation and Carbon contamination of X-ray optics is a well-known problem in X-ray beamlines that has been detrimental to beamline performance for several decades. This is particularly problematic, as such optics are usually highly specialized and coated with various materials. Consequences of such contamination include loss of flux, distortion of the wavefront, and reduction in...

13. New online polarization diagnostics for 3rd harmonic afterburner radiation

Markus Braune

14/10/2025, 13:06

poster

Measurements of the photoionization of rare gases have been an essential method for photon diagnostics at FLASH since the start of operation in 2005. Particularly at FLASH2, photoelectron TOF spectroscopy has been used for non-destructive monitoring of the FEL wavelength. With the online-photo-ionization spectrometer OPIS – a 4-channel eTOF spectrometer device – information about beam...

21. In-situ Cryogenic Cleaning of Tin-Contaminated EUV Optics

Dr Norbert Böwering (Fakultät für Physik, Universität Bielefeld)

14/10/2025, 13:12

poster

Norbert Böwering(1) and Christian Meier(1)
Bowering@physik.uni-bielefeld.de
(1) Bielefeld University, Universitätsstraße, 33615 Bielefeld, Germany

Considerable tin-splash contamination can occur on multilayer-coated optics when used with tin-based plasma light sources in EUV lithography applications. Generally, thick tin deposits cannot be removed sufficiently fast by plasma etching;...

23. Ultra-compact inline transmission grating spectrograph for extreme ultraviolet wavelengths

Sascha Brose (RWTH Aachen University - Chair for Technology of Optical Systems TOS)

14/10/2025, 13:18

poster

For the measurement of the spectral distribution in a broadband wavelength range, spectrographs are typically used. Depending on the target application, the spectrograph can be designed for reflection or transmission mode. Although reflective spectrographs generally offer a higher resolution due to the possibility of applying aberration corrections and focusing options, the main advantages of...

15. Stand-alone extreme ultraviolet (EUV) metrological system for optical characterization of lithography materials

Wooram Kim (Korea Research Institute of Standards and Science (KRISS))

14/10/2025, 13:24

poster

With the rapid growth of data-intensive applications such as autonomous driving and artificial intelligence, the performance requirements of semiconductor devices have significantly escalated. In parallel, the critical dimensions of circuit patterns have been reduced to the nanoscale, necessitating the adoption of extreme ultraviolet (EUV) lithography to overcome the resolution limits of...

26. Influence of experimental conditions on EUV / X-ray fluorescence yields investigated with the WDSX-300

Valentin Stoytschew (IAP-Adlershof e.V.)

14/10/2025, 13:30

poster

The WDSX-300 spectrometer, developed at the Institute for Applied Photonics (IAP) in cooperation with Nano Optics Berlin (NOB), has been designed for wavelength dispersive X-ray fluorescence analysis with a scanning electron microscope (SEM-WDX) in the EUV and soft X-ray range. With the currently installed setup, an energy range from 30 eV to 400 eV can be covered, including K fluorescence...

32. Enhanced thin film characterization through combined S- and P-polarized EUV reflectometry

Samira Naghdi (Physikalisch-Technische Bundesanstalt (PTB) Berlin)

14/10/2025, 13:36

poster

This work investigates the potential benefits of employing combined s- and p-polarized extreme ultraviolet (EUV) reflectometry for the accurate and efficient determination of thin film optical constants and geometrical parameters. EUV reflectometry (EUVR) is a powerful non-destructive technique for characterizing thin films, which is crucial for advancements in fields such as lithography and...

37. Investigation of the Optical Constants of Amorphous SiO₂ and Y-Cut Quartz from the Extreme to the Vacuum Ultraviolet Spectral Region

Najmeh Abbasirad (PTB)

14/10/2025, 13:42

poster

Fused silica (amorphous SiO₂) and quartz crystal both feature ultra-low thermal expansion and exceptional transparency from the visible to the deep-ultraviolet. Quartz additionally offers strong piezoelectricity and pronounced birefringence, making both materials cornerstones of modern optics. Yet their optical properties in the extreme- and vacuum-ultraviolet (35–140 nm) remain largely...

1. Simulated XUV spectroscopy in the laboratory with a polycapillary half lens and reflection zone plates

Jürgen Probst (NOB Nano Optics Berlin GmbH)

14/10/2025, 13:48

poster

We design a wavelength dispersive spectrometer for the extreme ultraviolet, based on a collimating polycapillary lens (PCL) and an array of reflection zone plates (RZPs). The two-channel instrument is optimized for narrow-band fluorescence or inverse photoelectron spectroscopy around 15 eV and 36 eV, respectively. The halved PCL is composed of $\sim 10^{6}$ tapered borosilicate glass tubes...

2. X-ray standing wave coherence length in grazing exit geometry

Timur Terentev (University of Twente)

14/10/2025, 13:54

poster

Angle-resolved X-ray fluorescence is a powerful tool for elemental depth distribution characterization of thin films. This technique is based on the formation of an X-ray standing wave (XSW), which is strictly dependent on the coherence length of the propagating wave. In grazing incidence geometry finite coherence length leads to a wave modulation which reduces interference fringes contrast...

34. Exploring the soft X-ray energy range for next generation nanostructure metrology

Dr Analía Fernández Herrero (PTB)

14/10/2025, 14:00

poster

The continuously shrinking dimensions of the features in the semiconductor industry as well as their increasing complexity require innovative metrology solutions. Non-destructive methods with high throughput that are able to assess complex 3D structures are of major importance. Measurement techniques based on light-structure interaction allow fast and non-destructive inspection of structured...

20. Scatterometry Applications: Addressing Model Inaccuracies

Maren Casfor (Physikalisch-Technische Bundesanstalt)

14/10/2025, 14:06

poster

Scatterometry provides a fast and indirect method for nano-optical shape reconstruction from measured light intensities. The shape parameters are determined by solving an inverse problem, that is based on the forward model. Bayesian inversion is a powerful tool for solving inverse problems but limited by the complexity of the forward model. As nanotechnology advances and structures become...

12. Calibration of a broadband reflective spectrometer for high-resolution spectral characterization of radiation sources

Sophia Schröder (RWTH Aachen University - Chair for Technology of Optical Systems TOS)

14/10/2025, 14:12

poster

The development of compact radiation sources has enabled a multitude of lab-size applications, especially in the field of metrology [1]. A broadband spectral characterization of the source emission is of utmost importance for the investigation of photon-induced processes and metrology [2].
In this study, the authors present a unique setup and corresponding measurement results for the...

39. Using Monte Carlo-based Uncertainty Quantification for Free-Form XRR

Hendrik Willem Lokhorst (University of Twente)

14/10/2025, 14:18

poster

X-Ray Reflectivity (XRR) is a well-established metrology method for multilayer characterization. With XRR, we determine the structural parameters describing the optical structure of a given sample (i.e., layer thickness, intermixing/roughness and optical density); we do so by solving the related inverse problem. To do so, one uses a model which calculates the reflectivity given a set of...

40. On the way to automatized optics adjustment at FEL sources

Klaus Mann (Ifnano)

14/10/2025, 14:24

poster

In recent years, the Institut für Nanophotonik Göttingen e.V. (formerly Laser-Laboratorium Göttingen) has successfully developed several Hartmann wavefront sensors in collaboration with DESY. These sensors have been designed for the precise focus characterization and optics alignment of the FEL FLASH in the soft X-ray spectral range, with a wavelength of approximately 5 - 40 nm. Even when...