NEW TECHNIQUE PRODUCING SMALL THINGS IN
UH-Developed Nanopantography Can Create Billions of Nanotech Devices
HOUSTON, September 4, 2007 – Although relatively new to
the market, liquid crystal display (LCD) televisions soon may be
obsolete, thanks to a new technique created by University of Houston
Vincent Donnelly, Demetre Economou and Paul Ruchhoeft, all of the
Cullen College of Engineering, have developed a technique that allows
nanotech devices to be mass-produced, which could move the television
industry away from the LCD display to the superior field emission
display (FED). FEDs use a large array of carbon nanotubes –
the most efficient emitters known – to create a higher resolution
picture than an LCD.
The nanotech fabrication technique that can mass produce an ordered
array of carbon nanotubes and make FEDs happen promises to remove
some of the largest practical barriers to mass-producing nanotech
devices, Economou said.
Dubbed nanopantography, the method uses standard photolithography
to selectively remove parts of a thin film and etching to create
arrays of ion-focusing micro-lenses – small round holes through
a metal structure – on a substrate, such as a silicon wafer.
“These lenses act as focusing elements,” Donnelly said.
“They focus the beamlets to fabricate a hole 100 times smaller
than the lens size.”
A beam of ions is then directed at the substrate. When the wafer
is tilted, the desired pattern is replicated simultaneously in billions
of many closely spaced holes over an area, limited only by the size
of the ion beam.
“The nanostructures that you can form out of that focusing
can be written simultaneously over the whole wafer in predetermined
positions,” Economou said. “Without our technique, nanotech
devices can be made with electron-beam writing or with a scanning
tunneling microscope. However, the throughput, or fabrication speed,
is extremely slow and is not suitable for mass production or for
producing nanostructures of any desired shape and material.”
With the right ions and gaseous elements, the nanotech fabrication
method can be used to etch a variety of materials and virtually
any shape with nanosize dimensions. A standard printing technique
that can create lenses measuring 100 nanometers wide could be used
to draw features just one nanometer wide if combined with nanopantography.
“We expect nanopantography to become a viable method for
rapid, large-scale fabrication,” Donnelly said.
Economou, Donnelly and Ruchhoeft have been working on the technology
for four years. UH filed the patent application in December 2006.
They hope the technology can become commercially available in five
to 10 years and expect it to become a viable method for large-scale
About the University of Houston
The University of Houston, Texas’ premier metropolitan research
and teaching institution, is home to more than 40 research centers
and institutes and sponsors more than 300 partnerships with corporate,
civic and governmental entities. UH, the most diverse research university
in the country, stands at the forefront of education, research and
service with more than 35,000 students.
About the Cullen College of Engineering
UH Cullen College of Engineering has produced five U.S. astronauts,
ten members of the National Academy of Engineering, and degree programs
that have ranked in the top ten nationally. With more than 2,600
students, the college offers accredited undergraduate and graduate
degrees in biomedical, chemical, civil and environmental, electrical
and computer, industrial, and mechanical engineering. It also offers
specialized programs in aerospace, materials, petroleum engineering
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