Publications associées à Stepper

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

On Advanced Large-Field Photolithography

Raoul Kirner

The information age we live in today relies on highly integrated devices. They are fabricated with the help of photolithography, the patterning technique at the heart of their production. With the continuous demand for higher integration density to achieve ...

EPFL2019

Optical-stack optimization for improved SPAD photon detection efficiency

Edoardo Charbon, Claudio Bruschini, Ivan Michel Antolovic, Ekin Kizilkan, Rolando Ferrini, Scott Anthony Lindner, Arin Can Ülkü, Marc Schnieper, Frédéric Zanella

Single-photon avalanche diodes (SPADs) are direct photon-to-digital detectors that enable scalable arrays with Poisson-limited signal-to-noise ratio and picosecond timing resolution. However, SPAD detectors require a guard-ring structure to prevent lateral ...

2019

Computational rule-based approach for corner correction of non-Manhattan geometries in mask aligner photolithography

Toralf Scharf, Wilfried Noell, Chen Yan, Raoul Kirner, Andreas Vetter

In proximity mask aligner photolithography, diffraction of light at the mask pattern is the predominant source for image shape distortions such as line end shortening and corner rounding. One established method to mitigate the impact of diffraction is opti ...

2019

Wafer-scale MOCVD growth of monolayer MoS2 on sapphire and SiO2

Aleksandra Radenovic, Andras Kis, Thomas La Grange, Ke Liu, Michal Daniel Macha, Yanfei Zhao, Hokwon Kim, Huanyao Cun

High-quality and large-scale growth of monolayer molybdenum disulfide (MoS2) has caught intensive attention because of its potential in many applications due to unique electronic properties. Here, we report the wafer-scale growth of high-quality monolayer ...

2019

High-power modular LED-based illumination systems for mask-aligner lithography

Hans Peter Herzig, Johana Bernasconi, Toralf Scharf

Mask-aligner lithography is traditionally performed using mercury arc lamps with wavelengths ranging from 250 nm to 600 nm with intensity peaks at the i, g and h lines. Since mercury arc lamps present several disadvantages, it is of interest to replace the ...

2018

Improving the resolution in mask-aligner lithography

Toralf Scharf, Wilfried Noell, Raoul Kirner, Andreas Vetter

For the back-end microfabrication in integrated circuits and for the manufacturing of light emitting diodes, proximity mask-aligner lithography is still the tool of choice, due to its simplicity and low costs. However, the downscaling of functional element ...

IEEE2018

High power ultraviolet LED illumination systems: coherence properties and applications in photolithography

Johana Bernasconi

Mask-aligner photolithography is a technology used to replicate patterns from a mask to a photosensitive substrate. It is widely used in the fabrication of MEMS and micro-optical components, and for other applications with dimensions in the micrometer rang ...

EPFL2018

High power modular LED-based illumination system for lithography applications

Hans Peter Herzig, Marcel Groccia, 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

Variable-height microfluidic channels for accurate immobilization of C. elegans worms by using a single dry etching step

Martinus Gijs, Rongrong Xiang, Hüseyin Baris Atakan

We present an aspect ratio dependent etching (ARDE) method, utilizing the Bosch dry etching process of silicon, to create the optimal silicon master microstructures for replication of polydimethylsiloxane (PDMS) microchannels that allow immobilizing C. ele ...

2018