Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Findings suggest nanowires ideal for electronics manufacturing

14.11.2008
Researchers from IBM and Purdue University have discovered that tiny structures called silicon nanowires might be ideal for manufacturing in future computers and consumer electronics because they form the same way every time.

The researchers used an instrument called a transmission electron microscope to watch how nanowires made of silicon "nucleate," or begin to form, before growing into wires, said Eric Stach, an assistant professor of materials engineering at Purdue University.

The work is based at IBM's Thomas J. Watson Research Center in Yorktown Heights, N.Y., and at Purdue's Birck Nanotechnology Center in the university's Discovery Park. The research is funded by the National Science Foundation through the NSF's Electronic and Photonic Materials Program in the Division of Materials Research.

The nucleation process can be likened to the beginning of ice forming in a pool of water placed in a freezer. The liquid undergoes a "phase transition," changing from the liquid to the solid phase.

"What's unusual about this work is that we are looking at these things on an extremely small scale," Stach said. "The three major findings are that you can see that the nucleation process on this small scale is highly repeatable, that you can measure and predict when it's going to occur, and that those two facts together give you a sense that you could confidently design systems to manufacture these nanowires for electronics."

It was the first time researchers had made such precise measurements of the nucleation process in nanowires, he said.

Findings will be detailed in a research paper appearing Friday (Nov. 14) in the journal Science. The paper was written by Purdue doctoral student Bong Joong Kim, Stach and IBM materials scientists Frances Ross, Jerry Tersoff, Suneel Kodambaka and Mark Reuter from the physical sciences department at the Watson Research Center.

The silicon nanowires begin forming from tiny gold nanoparticles ranging in size from 10 to 40 nanometers, or billionths of a meter. By comparison, a human red blood cell is more than 100 times larger than the gold particles.

The gold particles are placed in the microscope's vacuum chamber and then exposed to a gas containing silicon, and the particles act as a catalyst to liberate silicon from the gas to form into solid wires. The particles are heated to about 600 degrees Celsius, or more than 1,100 degrees Fahrenheit, causing them to melt as they fill with silicon from the gas. With increasing exposure, the liquid gold eventually contains too much silicon and is said to become "supersaturated," and the silicon precipitates as a solid, causing the nanowire to begin forming.

"We found that there is a single nucleation event in each little droplet and that all of the nucleation events occur in a very controllable fashion," Stach said. "The implication is that if you are trying to create electronic devices based on these technologies, you could actually predict when things are going to start their crystal growth process. You can see that it's going to happen the same way every time, and thus that there is some potential for doing things in a repeatable fashion in electronics manufacturing."

Although the researchers studied silicon, the same findings could be applied to manufacturing nanowires made of other semiconducting materials. The electron microscope is the only instrument capable of observing the nanowire nucleation process, which would have to be a thousand times larger to be seen with a light microscope, Stach said.

Nanowires might enable engineers to solve a problem threatening to derail the electronics industry. New technologies will be needed for industry to keep pace with Moore's law, an unofficial rule stating that the number of transistors on a computer chip doubles about every 18 months, resulting in rapid progress in computers and telecommunications. Doubling the number of devices that can fit on a computer chip translates into a similar increase in performance. However, it is becoming increasingly difficult to continue shrinking electronic devices made of conventional silicon-based semiconductors.

"In something like five to, at most, 10 years, silicon transistor dimensions will have been scaled to their limit," Stach said.

Transistors made of nanowires represent one potential way to continue the tradition of Moore's law.

"Nanowires of silicon and things like gallium arsenide, gallium nitride or indium arsenide, or other types of exotic semiconductors, are being investigated as a step toward continuing to scale electronics down," Stach said. "If you want to manufacture devices made of nanowires, make them the same way every time on a 12-inch wafer, then you need to understand the basic physics of how to start their growth, the kinetics of their continued growth, how to quantify that, how to understand it. We are looking at all steps in nucleation."

One challenge to using nanowires in electronics will be replacing gold as a catalyst with other metals that are better suited for the electronics industry, Stach said.

The gold particles are created inside the microscope chamber, but future research may use gold nanoparticles manufactured to more uniform standards using a different technology.

The research was conducted using an IBM microscope. The researchers also are extending the observations using a transmission electron microscope at the Birck Nanotechnology Center to look at smaller nanoparticles.

Writer: Emil Venere, (765) 494-4709, venere@purdue.edu
Source: Eric Stach, (765) 494-1466, eastach@purdue.edu
Purdue News Service: (765) 494-2096; purduenews@purdue.edu

Emil Venere | EurekAlert!
Further information:
http://www.purdue.edu

More articles from Power and Electrical Engineering:

nachricht Researchers pave the way for ionotronic nanodevices
23.02.2017 | Aalto University

nachricht Microhotplates for a smart gas sensor
22.02.2017 | Toyohashi University of Technology

All articles from Power and Electrical Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Stingless bees have their nests protected by soldiers

24.02.2017 | Life Sciences

New risk factors for anxiety disorders

24.02.2017 | Life Sciences

MWC 2017: 5G Capital Berlin

24.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>