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Wilfried Noell

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Publications associées (35)

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Printing sub-micron structures using Talbot mask-aligner lithography with a 193 nm CW laser light source

Toralf Scharf, Wilfried Noell, Raoul Kirner

A continuous improvement of resolution in mask-aligner lithography is sought after to meet the requirements of an ever decreasing minimum feature size in back-end processes. For periodic structures, utilizing the Talbot effect for lithography has emerged a ...

2018

Tolerancing the surface form of aspheric microlenses manufactured by wafer-level optics techniques

Toralf Scharf, Wilfried Noell, Jeremy Béguelin

Tolerancing is an important step toward the fabrication of high-quality and cost-effective lens surfaces. It is critical for wafer-level optics, when up to tens of thousands microlenses are fabricated in parallel and whose surfaces cannot be formed individ ...

OPTICAL SOC AMER2020

Large micromirror array for generating programmable slit masks for Multi-Object Spectroscopy

Nico de Rooij, Wilfried Noell, Michael David Canonica

Multi-object spectroscopy (MOS) is a powerful tool for space and ground-based telescopes for the study of the formation and evolution of galaxies. This technique requires a programmable slit mask for astronomical object selection. We are engaged in a Europ ...

Spie-Int Soc Optical Engineering2012

Refraction limit of miniaturized optical systems: a ball-lens example

Hans Peter Herzig, Toralf Scharf, Wilfried Noell, Myun Sik Kim, Roland Andreas Bitterli

We study experimentally and theoretically the electromagnetic field in amplitude and phase behind ball-lenses across a wide range of diameters, ranging from a millimeter scale down to a micrometer. Based on the observation, we study the transition between ...

Optical Society of America2016

Specification of aspherical surfaces used as refractive elements in micro-optical systems

Toralf Scharf, Wilfried Noell, Jeremy Béguelin

The optical performance of refractive plano-convex microlenses is mainly related to the quality of their (a)spherical surface. An efficient tolerancing of this surface is a key step towards the manufacturing of high quality microlenses. However, we demonst ...

SPIE-INT SOC OPTICAL ENGINEERING2019

High power modular LED-based illumination system for lithography applications

Hans Peter Herzig, Toralf Scharf, Wilfried Noell, Raoul Kirner, Johana Bernasconi

Mask-aligner lithography is a technology used to transfer patterns with critical dimensions in the micrometer range from below 1 micron for contact printing to a dozen of microns in proximity printing. This technology is widely used in the fabrication of M ...

2018

Mask-aligner Talbot lithography using a 193 nm CW light source

Toralf Scharf, Wilfried Noell, Raoul Kirner

We present and discuss Talbot mask-aligner lithography, relying on a continuous wave laser emitting at 193nm for the illumination. In this source, a diode laser at 772nm is amplified by a tapered amplifier in master-oscillator power-amplifier configuration ...

2018

Array imaging system for lithography

Toralf Scharf, Wilfried Noell, Raoul Kirner

We present an integrated array imaging system based on a stack of microlens arrays. The microlens arrays are manufactured by melting resist and reactive ion etching (RIE) technology on 8'' wafers (fused silica) and mounted by wafer-level packaging (WLP)(1) ...

Spie-Int Soc Optical Engineering2016

Lightfields behind amplitude masks: Creating phase discontinuities

Hans Peter Herzig, Toralf Scharf, Wilfried Noell, Myun Sik Kim, Krishnaparvathy Puthankovilakam

Shaping of light fields behind amplitude and phase masks the basis the lithographic structure reproduction. The aerial image or better the intensity distribution defines the resolution of the structure to be printed. Contrast is the main parameter and to a ...

Ieee2016

Thermal Characterization of Polycrystalline CVD Diamond Thin Films

Nico de Rooij, Danick Briand, Wilfried Noell, Caglar Ataman, Sébastien Lani

An experimental thermal characterization method is developed for high thermal conductivity thin films. The method utilizes Ta/Pt resistors on microfabricated free-standing thin film structures both for heating and temperature monitoring at different positi ...

Elsevier Science, Reg Sales Off, Customer Support Dept, 655 Ave Of The Americas, New York, Ny 10010 Usa2009

Semiconductor-based narrow-line and high-brilliance 193-nm laser system for industrial applications

Toralf Scharf, Wilfried Noell, Raoul Kirner, Xiaolong Wang

We present a novel industrial-grade prototype version of a continuous-wave 193 nm laser system entirely based on solid state pump laser technology. Deep-ultraviolet emission is realized by frequency-quadrupling an amplified diode laser and up to 20 mW of o ...

2018

Optical characterization of high numerical aperture microlenses for quality assessment and fabrication process optimization

Toralf Scharf, Wilfried Noell, Jeremy Béguelin

Accurate characterization of high numerical aperture aspheric microlenses currently is a nonstandard procedure that remains an open challenge. Here, we present and discuss a characterization method based on interferometric and point spread function measure ...

OPTICAL SOC AMER2020

Assessing microlens quality based on 3D irradiance measurement at the focal spot area

Toralf Scharf, Wilfried Noell, Jeremy Béguelin, Michail Symeonidis

During the fabrication process of microlenses, characterization is essential for two purposes: evaluate the optical quality of the element and provide surface information feedback for process optimization. However, no technique can fulfill these two object ...

2018

Leveraging wafer-level manufacturing process limitations to increase large scale fused silica microlens array uniformity

Toralf Scharf, Wilfried Noell, Raoul Kirner, Jeremy Béguelin

The wafer-level production of Fused Silica microlens arrays is limited by systematic process non-uniformities. The common molten resist-reflow process with subsequent dry-etching allows for manufacturing of microlens arrays on 200 mm wafers. A thorough pro ...

SPIE-INT SOC OPTICAL ENGINEERING2019

Spatial coherence properties of an LED-based illumination system for mask-aligner lithography

Hans Peter Herzig, Toralf Scharf, Wilfried Noell, Raoul Kirner, Johana Bernasconi

A high-power LED-based illumination system has been developed as a replacement for the mercury arc lamps used in mask-aligner lithography. LEDs are arranged in a grid array and placed in the entrance aperture of individual reflectors. Those reflectors decr ...

SPIE2019

Spectral phase, amplitude, and spatial modulation from ultraviolet to infrared with a reflective MEMS pulse shaper

Nico de Rooij, Wilfried Noell, Luigi Bonacina, Jérôme Extermann, Sébastien Lani, Fabio Jutzi

We describe the performance of a reflective pulse-shaper based on a Micro-ElectroMechanical System (MEMS) linear mirror array. It represents a substantial upgrade of a preceding release [Opt. Lett. 35, 3102 (2010)] as it allows simultaneous piston and tilt ...

Optical Society of America2011

Correction of spherical surface measurements by confocal microscopy

Toralf Scharf, Wilfried Noell, Jeremy Béguelin

Refractive microlenses are nowadays widely used in optical systems. Characterizing their surface is essential to ensure their quality and to optimize their fabrication process. This is realized by optical surface profilers thanks to their vertical resoluti ...

IOP Publishing2020

MEMS for space

Nico de Rooij, Herbert Shea, Danick Briand, Wilfried Noell, Sebastian Gautsch

Future space exploration will emphasize on cost effectiveness and highly focused mission objectives. Missions costs are directly proportional to its total weight, thus, the trend will be to replace bulky and heavy components of space carriers, communicatio ...

2009

Improvements on the uniformity of large-area microlens arrays in Fused Silica

Toralf Scharf, Wilfried Noell, Raoul Kirner, Jeremy Béguelin

The uniformity of large microlens arrays in Fused Silica is governed by the production process. It comprises photolithographic patterning of a spin-coated layer of photoresist on a 200mm wafer with a molten resist reflow process and subsequent dry etching. ...

OPTICAL SOC AMER2019

Optical characterization of fully programmable MEMS diffraction gratings

Wilfried Noell, Robert Andrew Lockhart, Michael David Canonica

We have fabricated and characterized fully programmable diffraction gratings consisting of 64 silicon micro-mirrors. The mirrors are 700 mu m long and 50 mu m wide with a fill factor of 90%. They are actuated electrostatically and move down by 1.25 mu m wh ...

Optical Society of America2012