Nanobridges Show Way to Nano Mass Production

April 7, 2005

They look like an elegant row of columns, tiny enough for atomic-scale hide-and-seek, but these colonnades represent a new way to bring nanotechnology into mass production.
Nanotechnology, the ability to create and work with structures and materials on an atomic scale, holds the promise of extreme miniaturization for electronics, chemical sensors and medical devices. But while researchers have created tiny silicon wires and connected them together one at a time, these methods cannot easily be scaled up.

"It takes weeks to make one or two, and you end up with different sizes and characteristics," said M. Saif Islam, assistant professor of electrical and computer engineering, who joined UC Davis from Hewlett-Packard Laboratories in 2004.

Like handmade shoes, every manually assembled nanostructure comes out slightly different. Engineers would rather build devices the way cars or computers are built, with every item as consistent as possible.

While working at the Quantum Science Research group of Hewlett-Packard Laboratories, Islam and colleagues came up with a new approach. Silicon wafers used for building microcircuits are usually polished at one specific angle to the atomic planes of silicon. Instead, the group used a wafer that was polished at a different angle, changing the orientation of silicon atomic planes to the surface. Using a chemical vapor deposition technique, they could then grow identical, perpendicular columns of silicon.

The researchers have used this method to grow "nanobridges" across a gap between two vertical silicon electrodes. The nanobridges are strong, chemically stable and show better electrical properties than previous approaches, Islam said. They could be used for nanosized transistors, chemical sensors or lasers.

Taking the approach a step further, Islam and his colleagues at Hewlett-Packard made sandwiches of silicon and insulator and partly etched away the top layer to create awning-shaped structures of silicon supported by insulator. Silicon columns grown under the awnings form miniature colonnades.

The method allows engineers to combine nanowires of precise length with other silicon structures such as integrated circuits, he said.

At UC Davis, Islam plans to continue work on converting the technology into practical devices. The "nanobridge" technique was reported most recently in the March 2005 issue of the journal Applied Physics Part A. The nanocolonnade work was presented April 1 at the spring meeting of the Materials Research Society in San Francisco.

Source: UC Davis

Explore further: Cutting-edge startup aims for nano-close shave

Related Stories

Cutting-edge startup aims for nano-close shave

September 18, 2012

(Phys.org)—A new startup company at UC Davis aims to bring you a better shave through semiconductor manufacturing technology. Nano-Sharp Inc. plans to use silicon wafers to make razor blades and surgical tools far more ...

Synbio and biosecurity

February 7, 2017

The world in 1918 was emerging from under the pall of a World War that had claimed 38 million lives, and yet in the span of only one year, just as many lives would be lost to the Spanish Flu—an influenza pandemic that is ...

Recommended for you

China auto show highlights industry's electric ambitions

April 22, 2018

The biggest global auto show of the year showcases China's ambitions to become a leader in electric cars and the industry's multibillion-dollar scramble to roll out models that appeal to price-conscious but demanding Chinese ...

Robot designed for faster, safer uranium plant pipe cleanup

April 21, 2018

Ohio crews cleaning up a massive former Cold War-era uranium enrichment plant in Ohio plan this summer to deploy a high-tech helper: an autonomous, radiation-measuring robot that will roll through miles of large overhead ...

After Facebook scrutiny, is Google next?

April 21, 2018

Facebook has taken the lion's share of scrutiny from Congress and the media about data-handling practices that allow savvy marketers and political agents to target specific audiences, but it's far from alone. YouTube, Google ...

How social networking sites may discriminate against women

April 20, 2018

Social media and the sharing economy have created new opportunities by leveraging online networks to build trust and remove marketplace barriers. But a growing body of research suggests that old gender and racial biases persist, ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.