Newest nano-tool is a laser you can’t see
Jan. 23, 2008
Colorado State University scientists have found a way to dramatically
improve the quality of laser light at extremely short wavelengths,
according to a paper that was published Sunday online by Nature
Photonics.
The groundbreaking discovery covers very short
wavelengths of light near 13 nm that are valuable particularly for the
semiconductor manufacturing industry, which aims to develop the next
generation of faster computer chips using that type of light by 2010 or
2011, said CSU Univ. Distinguished Professor Jorge Rocca, senior author
of the research. Rocca collaborated on the Nature Photonics paper with
CSU colleagues Yong Wang, Brad Luther, Francesco Pedacci, Mark Berrill,
Eduardo Granados and David Alessi.
"The potential applications are many—ultra-high resolution microscopy,
patterning to make nano-devices, and semiconductor industry
measurements," Rocca says. "There are many other possibilities that in
the future will also include biology."
The technology involves the generation of short wavelength light in the
extreme ultraviolet or soft x-ray range of the electromagnetic spectrum
with wavelengths about 50 times shorter than visible light. These
lasers can be used to "see" tiny features, create extremely small
patterns and manipulate materials in ways that visible light can't.
The research reported in the Nature Photonics paper focused on making
the light of lasers operating at 18.9 and 13.9 nm more coherent.
Rocca's team generated a little seed of coherent x-ray light, converted
the frequency of a visible laser beam to soft x-ray light and obtained
a very coherent light at a low intensity. That seed was injected
through a plasma amplifier and grew to produce a very high intensity
beam of soft x-ray light with extraordinarily high coherence.
"Coherent soft x-ray light can be used to measure the properties of
materials and directly write patterns with nanoscale dimension," Rocca
says. "It can be used to look for extremely small defects in the masks
that will be used to print the future generations of semiconductor
chips."
The work is part of the research conducted at the National Science
Foundation's Center for Extreme Ultraviolet Science and Technology—a
partnership between Colorado State Univ. in Fort Collins, the Univ. of
Colorado-Boulder and the Unive. of California Berkeley—that combines
the expertise of researchers who are among the world leaders in
developing compact extreme ultraviolet coherent light sources, optics
and optical systems for nanoscience, nanotechnology and other
applications.
The center also has significant industry and national laboratory
involvement. The largest computer chip manufacturers, such as Intel,
Advanced Micro Devices Inc, IBM and Samsung, are industrial members of
the EUV ERC, joining a set of industries that include small- and
medium-sized companies.
SOURCE: Colorado State Univ.
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