Electron beam 'carves' the world's smallest devices

Jun 18, 2007

Physicists at the University of Pennsylvania are using a new technique to craft some of the tiniest metal nanostructures ever created, none larger than 10 nanometers.

The technique employs transmission electron beam ablation lithography, or TEBAL, to "carve" nanostructures from thin sheets of gold, silver, aluminum and other metals. TEBAL provides a more dependable method for producing quality versions of these microscopic devices, which are studied for their novel mechanical properties and their potential use in next-generation sensors and electronics. The method also permits simultaneous, real-time atomic imaging of the devices as they are made.

Traditional techniques for building nanodevices employ electron beam lithography but also require the use of polymers and chemicals in which the metal is evaporated. Typical results are closer to 50 nanometers in size and rarely as small as 10.

Marija Drndić, professor of physics at Penn, and her team created nanodisks, nanorings, nanowires, nanoholes and multi-terminal nano-transistors. The results were published in the journal Nano Letters.

"Many different approaches have been undertaken to fabricate the small structures needed to probe the phenomena that take place at the nanoscale, but the most widely used and versatile techniques are limited to tens of nanometers," Drndić said. "Reliably and consistently fabricating devices at the sub-10-nanometer scale from the top down is generally still challenging, but our technique offers a route to this regime."

Furthermore, the TEBAL method creates a resistance-free connection between the nanostructure and an electrical lead that might provide power to the device. The more parts involved, the greater the chance of a drop in electrical conduction between parts. Plus, structures made from bottom-up techniques, i.e., assembled from smaller components, typically first need to be placed on a chip and then connected to larger circuitry. Working with a single piece of metal means there are no additional parts to reduce efficiency.

The team used the superior control of the electron beam to reproduce multiple, identical copies of each structure. The ability to rapidly produce these tiny devices will provide the samples needed for a better understanding of the mechanical and conductive properties of metal at the molecular scale. Future research may lead to computer-based creation of such devices with more intricacy and faster production cycles.

Superconducting circuits, magnets and molecule-sized transistors are among the real-world applications that may result from this research. Penn physicists also propose that a more rapid method of DNA sequencing can be developed from this process, by threading DNA strands through an electronic "nanoport" that could read the base pairs that constitute a species' genetic code.

The study was conducted by Drndić and Michael Fischbein of Penn's Department of Physics in the School of Arts and Sciences.

Source: University of Pennsylvania

Explore further: Technique for quantification of erythrocyte zinc protoporphyrin IX and protoporphyrin IX

add to favorites email to friend print save as pdf

Related Stories

Charging electric cars efficiently inductive

14 hours ago

We already charge our toothbrushes and cellphones using contactless technology. Researchers have developed a particularly efficient and cost-effective method that means electric cars could soon follow suit.

US spy agency patents car seat for kids

Jul 30, 2014

Electronic eavesdropping is the National Security Agency's forte, but it seems it also has a special interest in children's car seats, Foreign Policy magazine reported Wednesday.

A transistor-like amplifier for single photons

Jul 29, 2014

Data transmission over long distances usually utilizes optical techniques via glass fibres – this ensures high speed transmission combined with low power dissipation of the signal. For quite some years ...

Building 'invisible' materials with light

Jul 28, 2014

A new method of building materials using light, developed by researchers at the University of Cambridge, could one day enable technologies that are often considered the realm of science fiction, such as invisibility ...

Recommended for you

A new way to make microstructured surfaces

Jul 30, 2014

A team of researchers has created a new way of manufacturing microstructured surfaces that have novel three-dimensional textures. These surfaces, made by self-assembly of carbon nanotubes, could exhibit a ...

User comments : 0