000263791 001__ 263791
000263791 005__ 20190510114054.0
000263791 0247_ $$2doi$$a10.1117/12.2319288
000263791 02470 $$2isi$$a000453566400007
000263791 037__ $$aCONF
000263791 245__ $$aHigh power modular LED-based illumination system for lithography applications
000263791 260__ $$c2018-09-14
000263791 269__ $$a2018-09-14
000263791 336__ $$aConference Papers
000263791 520__ $$aMask-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 MEMS, micro-optical components, and similar fields. Traditionally, the light sources used for mask-aligners are high-pressure mercury arc lamps, which emit in the UV rang of the spectrum with peaks at 365 nm, 405 nm and 435 nm, respectively the g-, h- and i- lines. These lamps suffer from several disadvantages (inefficient, bulky, dangerous), which makes alternatives interesting. In recent years, high power UV LEDs at the same wavelengths appeared on the market, opening the door to new illumination systems for mask-aligners. We have developed a modular 250 W LED-based illumination system, which can advantageously replace a 1 kW mercury arc lamp illumination. LEDs, arranged in a 7x7 grid array, are placed in the entrance apertures of individual reflectors, which collimate the individual irradiation to an output angle of 10◦. A subsequent fly’s eye integrator homogenizes the illumination in the mask plane. It is followed by a Fourier lens, superimposing the individual channels in the mask plane, and a field lens to ensure telecentric illumination. This multisource approach allows the shaping of the source by switching individual illumination channels, determining the illumination angles and the spatial coherence in the mask plane. This concept can be used, for example, to do source-mask optimization. Compared to mercury arc lamp illumination, our system is simultaneously more efficient, compact, versatile, economic and sustainable. In our contribution, we present the design of the system as well as lithographic test prints done with different illumination patterns.
000263791 6531_ $$aNanophotonics
000263791 6531_ $$aPlasmonics
000263791 700__ $$aBernasconi, Johana
000263791 700__ $$aScharf, Toralf
000263791 700__ $$aGroccia, Marcel
000263791 700__ $$aKirner, Raoul
000263791 700__ $$aNoell, Wilfried
000263791 700__ $$aHerzig, Hans Peter
000263791 7112_ $$aConference on Nonimaging Optics - Efficient Design for Illumination and Solar Concentration XV$$cSan Diego, CA$$dAug 19-20, 2018
000263791 773__ $$q107580A$$j10758$$tProceedings of SPIE
000263791 8564_ $$s658491$$uhttps://infoscience.epfl.ch/record/263791/files/High%20power%20modular%20LED-based%20illumination%20system%20for%20lithography%20applications.pdf
000263791 8560_ $$fbeatrice.marselli@epfl.ch
000263791 909C0 $$zMarselli, Béatrice$$xU10373$$pNAM$$molivier.martin@epfl.ch$$0252353
000263791 909c0 $$xU11965
000263791 909C0 $$pOPT$$0252204
000263791 909CO $$qGLOBAL_SET$$pSTI$$pconf$$ooai:infoscience.epfl.ch:263791
000263791 960__ $$abeatrice.raball@epfl.ch
000263791 961__ $$afantin.reichler@epfl.ch
000263791 973__ $$rREVIEWED$$aEPFL
000263791 981__ $$aoverwrite
000263791 980__ $$aCONF