Ultraviolet rays do more than cause sunburns

As I write this in early June, the morning heat promises the third straight 90 day, with an ultraviolet index of 8 or 9, which the weather forecasters say is "high." I'm not sure I understand how they derive the numbers for this UV index—do they use a spectrometer and power meter combination? I do know, however, that the laser and electro-optics community's current interest in UV laser radiation is more than high—it's verging on extreme.

As manufacturers strive to increase the density of components on next-generation computer chips, they necessarily turn to shorter wavelengths. Current state-of-the art manufacturing relies on 248-nm radiation from krypton fluoride excimer lasers; the next step in UV lithography will be to short-wavelength 193-nm argon fluoride lasers. In the special report beginning on p. 82, associate editor Kristin Lewotsky looks in detail at some of the issues that manufacturers must tackle to bring 193-nm processes to fruition. In addition to reliable laser sources, projection optics, optical materials, photomasks, and photoresists all require modification and further development before 193-nm manufacturing can come on-line. Because 193-nm excimer lasers are already in use for ophthalmologic procedures such as photorefractive keratectomy, some materials problems have been solved. Lithography, however, requires many more steps and therefore presents new levels of challenges.

The use of UV lasers for Raman spectroscopy provides researchers with new tools and opens new materials to study. But these lasers have taken some time to realize; the article on p. 99 traces the development of scientific lasers in the authors` laboratory and others and explains the benefits of UV excitation when capturing Raman spectra.

Have a hot product? CTA award deadline approaches

Entries for the 1998 Commercial Technology Achievement (CTA) awards are due September 15, 1997. These awards are bestowed on products deemed by our judges to have lasting commercial significance to the industry. The CTA awards recognize products introduced between January 1 of last year and July 1 of this year. To receive an entry form contact Carole Root at (603) 891-9138; e-mail: [email protected]. We will present the awards to winners at a special ceremony at Photonics West `98 in San Jose, CA—I'm sure that the glow of the winners will be from excitement, not from a UV-induced sunburn!