Tuesday, December 20, 2011
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Electrothermal cantilever with nanometer-scale electrode tip integrated onto a microheater.
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Atomic
force microscope cantilever tips with integrated heaters are widely
used to characterize polymer films in electronics and optical devices,
pharmaceuticals, paints, and coatings. These heated tips are also used
in research labs to explore new ideas in nanolithography and data
storage, and to study fundamentals of nanometer-scale heat flow. Until
now, however, no one has used a heated nano-tip for electronic
measurements.
“We
have developed a new kind of electro-thermal nanoprobe,” according to
William King, a College of Engineering Bliss Professor in the Department
of Mechanical Science and Engineering at Illinois. “Our electro-thermal
nanoprobe can independently control voltage and temperature at a
nanometer-scale point contact. It can also measure the
temperature-dependent voltage at a nanometer-scale point contact.”
“Our
goal is to perform electro-thermal measurements at the nanometer
scale,” according to Patrick Fletcher, first author of the paper,
“Thermoelectric voltage at a nanometer-scale heated tip point contact,”
published in the journal Nanotechnology.
“Our electro-thermal nanoprobe can be used to measure the
nanometer-scale properties of materials such as semiconductors,
thermoelectrics, and ferroelectrics.”
The
electro-thermal probes are different than thermal nanoprobes typically
used in King’s group and elsewhere. They have three electrical paths to
the cantilever tip. Two of the paths carry heating current, while the
third allows the nanometer-scale electrical measurement. The two
electrical paths are separated by a diode junction fabricated into the
tip. While the cantilever design is complex, the probes can be used in
any atomic force microscope.
In
addition to Fletcher, co-authors of the paper include Byeonghee Lee,
and William King. The research was performed in the Nanoengineering
laboratory as well as the Micro and Nanotechnology Laboratory and the
Materials Research Laboratory at Illinois.
The
research was sponsored by the Office of Naval Research and the Air Force
Office of Scientific Research.
Thermoelectric voltage at a nanometer-scale heated tip point contact
SOURCE
