21 July 2000 EUV mask fabrication using Be-based multilayer mirrors
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Extreme Ultra-Violet lithography is one of the leading next generation lithography options. Currently, EUV masks are routinely made of reflective mirrors made of Mo/Si multi- layers, which have a peak reflectivity of 67.5% at a wavelength of 13.4 nm. However, in order to increase the throughput of an EUVL system, a new set of Be-based multi- layers are being developed, which have a peak reflectivity of near 70% at 11.4. The two materials that have recently been developed are Mo/Be and MoRu/Be multi-layers. Beryllium based multi-layer masks show great promise for a significant increase in the lithography system throughput (2 - 3X over the current Mo/Si multi-layer mask) due to their increased reflectivity and bandwidth at 11.4 nm where the xenon laser plasma source is more intense. We have successfully developed a process to fabricate masks using Be-based multi-layers. The absorber stack consists of TaSiN (absorber), SiON (repair buffer) and Cr (conductive etch stop) deposited on the multi- layer mirror. Lawrence Livermore National Laboratory supplied the Mo/Be and MoRu/Be multi-layer mirrors used to fabricate the masks. Completed masks were exposed at Sandia National Laboratories' 10X EUV exposure system and equal lines and spaces down to 80 nm were successfully printed. The paper addresses the issues and challenges to fabricate the mask using Be-based multi-layers and a comparison will be made with the Mo/Si multi-layer mask patterning process.
© (2000) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Pawitter J. S. Mangat, Pawitter J. S. Mangat, James R. Wasson, James R. Wasson, Scott Daniel Hector, Scott Daniel Hector, Gregory Frank Cardinale, Gregory Frank Cardinale, Sasa Bajt, Sasa Bajt, } "EUV mask fabrication using Be-based multilayer mirrors", Proc. SPIE 3997, Emerging Lithographic Technologies IV, (21 July 2000); doi: 10.1117/12.390123; https://doi.org/10.1117/12.390123


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