JOINT UNIVERSITY OF MARYLAND-NIST PROJECT PROVIDES DETAILS ON EFFICIENCY OF LASER PLASMA EUV SOURCE.
Extreme ultraviolet (EUV EUV Extreme Ultraviolet
EUV Exclusive Use Vehicle
EUV Extreme Ultra Violet ) lithography is a promising candidate as the next-generation patterning tool for microelectronics. A large effort to develop this tool has been under way for several years by a team at Sandia and Lawrence Livermore National Laboratories. Finding a suitable source of EUV radiation for the tool has been one of the major challenges; the source must be compact, bright, and free of contaminating debris. The team has chosen a laser plasma source in which a 10 ns laser irradiates a target of tiny, micron-sized droplets of liquid xenon xenon (zē`nŏn) [Gr.,=strange], gaseous chemical element; symbol Xe; at. no. 54; at. wt. 131.29; m.p. −111.9°C;; b.p. −107.1°C;; density 5.86 grams per liter at STP; valence usually 0. . The source is compact and the xenon plasma is practically debris-free, but greater brightness is desired for higher throughput.
Researchers at the University of Maryland University of Maryland can refer to: - University of Maryland, College Park, a research-extensive and flagship university; when the term "University of Maryland" is used without any qualification, it generally refers to this school
and NIST (National Institute of Standards & Technology, Washington, DC, www.nist.gov) The standards-defining agency of the U.S. government, formerly the National Bureau of Standards. It is one of three agencies that fall under the Technology Administration (www.technology. have shown that EUV emission from laser-irradiated micrometer-sized droplets of krypton krypton (krĭp`tŏn) [Gr.,=hidden], gaseous chemical element; symbol Kr; at. no. 36; at. wt. 83.80; m.p. −156.6°C;; b.p. −152.3°C;; density 3.73 grams per liter at STP; valence usually 0. is a strong function of pulse duration. Using a very specialized laser that allows varying the pulse duration from 100 fs to 10 ns while keeping the pulse energy constant at 50 mJ showed that the EUV emission of krypton is greatest at 300 ps and is approximately five times brighter than the emission created by 10 ns pulses. Similar measurements soon will be undertaken for xenon that is being supplied by the Livermore-Sandia team.
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