Publications de Johana Bernasconi

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

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

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

High power modular LED-based illumination system for lithography applications

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

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

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

Hans Peter Herzig, Toralf Scharf, Johana Bernasconi

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

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

Coherence management in lithography printing systems

Hans Peter Herzig, Toralf Scharf, Johana Bernasconi

In proximity lithography, interference and diffraction effects arise when printing small features because of the proximity gap. Different techniques are used in order to control and take advantage of theses effects. In this paper, the focus is set on the M ...

Spie-Int Soc Optical Engineering2016

Structured amplitude and phase fields behind microstructures: The quest for high contrast modulation at proximity

Hans Peter Herzig, Myun Sik Kim, Toralf Scharf, Johana Bernasconi, Krishnaparvathy Puthankovilakam

Microstructures can be used to realize repetitive and singular high contrast features at different distances behind a structure. For practical applications, the amplitude field needs to be considered. To realize defined amplitude features at long distances ...

Spie-Int Soc Optical Engineering2016