LONDON Carl Zeiss SMT said Wednesday (Dec. 7) that it has shipped the first optical system for an extreme ultra violet (EUV) lithography tool to ASML Holding NV.
ASML (Veldhoven, The Netherlands) is developing two alpha EUV lithography tools for delivery some time in the second quarter with one going to the IMEC research center (Leuven, Belgium) and the other headed to University of Albany nanotechnology campus, New York.
Carl Zeiss did not say when it would ship the second optical system.
EUV lithography is a likely next-generation chip processing technology, based on 13-nanometer wavelength illumination, allowing chip makers to print features sizes of 32 nm and below on integrated circuits.
The EUV projection optical systems are made of reflective surfaces as there are no optically transparent materials at this wavelength. The asphericly curved surfaces of the reflective elements need to be produced with a contouring accuracy of only a few atoms; surface roughness may also not exceed a few atoms in order to precisely image the mask structures onto the wafer without blurs. The whole projection system, comprising six mirrors, positioned and adjusted with extreme accuracy, works in high vacuum since even minute amounts of residual gas would absorb the EUV radiation. The coatings on the mirror-substrates also play a decisive role. Sufficient reflectivity can only be reached with a stack of more than 50 double-layers consisting of alternating layers of molybdenum and silicon; each of these double-layers has a thickness of less than 10 nanometers.
“Delivery of the first projection optics from Carl Zeiss SMT is a milestone in ASML's EUV program. Design and production of the most sophisticated optical systems is the long proven core competence of Carl Zeiss SMT AG,” said Noreen Harned, vice president of marketing, technology and new business at ASML, in a statement issued by Carl Zeiss.
Carl Zeiss SMT began research & development for EUV optics in mid-1990. To date, the company has invested more than 100 million euro (about $117 million) in basic research and production technology. The German Federal Ministry of Education and Research (BMBF) has supported the development with more than 22 million euro (about $26 million), Carl Zeiss said.