Navigation Links
New silicon-germanium nanowires could lead to smaller, more powerful electronic devices
Date:12/9/2009

Microchip manufacturers have long faced challenges miniaturizing transistors, the key active components in nearly every modern electronic device, which are used to amplify or switch electronic signals.

Now, researchers from the UCLA Henry Samueli School of Engineering and Applied Science, Purdue University and IBM have successfully grown silicon-germanium semiconducting nanowires for potential use in next-generation transistors.

These nanowires which measure from a few tens to a few hundreds of nanometers in diameter and up to several millimeters in length could help speed the development of smaller, faster and more powerful electronics, according to study co-author Suneel Kodambaka, a UCLA professor of materials science and engineering.

The team's research appears in the Nov. 27 issue of the journal Science.

"We are excited for two reasons," said Frances Ross, manager of IBM's Nanoscale Materials Analysis department and corresponding author of the study. "One is that we have extended our knowledge of the fundamental physics of the process by which nanowires grow. The other is the improved prospect of using nanowires in high-performance electronic devices."

"The nanowires are so small you can place them in virtually anything," Kodambaka said. "Because of their small size, they are capable of having distinctly different properties, compared to their bulk counterparts."

The team showed they could create nanowires with layers of different materials, specifically silicon and germanium, that were defect-free and atomically sharp at the junction critical requirements for making efficient transistors out of the tiny structures. The "sharper" the interface between the material layers in this case, just one atom, or close to one atom, thick the better the electronic properties.

"We think this study is significant because it provides a solution to the problem of growing sharp interfaces in nanowires, thereby addressing an important limitation in the growth of nanowires," Ross said.

According to Kodambaka, silicon-germanium nanostructures also have thermoelectric applications, in which heat is converted into electricity.

"The Jet Propulsion Laboratory uses bulk chunks of silicon-germanium to power their satellites, and now there is a lot of interest in using a similar technology in automobiles. These nanowires have great potential in any area involving electronics," Kodambaka said.

To grow the silicon-germanium nanowires, tiny particles of a gold-aluminum alloy are first heated to temperatures above 370 degrees Celsius and melted inside a vacuum chamber. A silicon-containing gas is then introduced into the chamber, causing silicon to precipitate and form wires under the droplets. A germanium-containing gas is used to form the germanium wires.

"Think of it as ice growing from water vapor or the formation of ice crystals during a snow storm. You can get forests of ice wires under the right conditions instead of getting snow flakes or flat films of sleet," Kodambaka said. "But instead of water vapor, we introduced silicon vapor to get the silicon wire."

"The challenge was to create a really sharp interface between the silicon and germanium in each wire," Kodambaka said. "So we cooled the liquid droplets until they solidified. This allowed us to get rid of excess silicon in the alloy. Then, germanium wire segments could be grown on the silicon with the introduction of germanium vapor, and sharp interfaces formed."

The next step for the team is to grow the same structures over larger areas in a conventional growth reactor rather than in a tiny area under the microscope.

"This will allow my colleagues at IBM to process the wires into devices and measure their electronic properties," Ross said. "Of course, we would hope that the properties are improved, compared to conventional nanowires; and if this works out, we will look into new devices and try out different metal alloys to determine which is best for making devices."


'/>"/>

Contact: Wileen Wong Kromhout
wwkromhout@support.ucla.edu
310-206-0540
University of California - Los Angeles
Source:Eurekalert

Related biology technology :

1. Carbon nanotubes to be replaced by MoSIx nanowires in high-tech devices says new study
2. High Q NIST nanowires may be practical oscillators
3. Chemists measure copper levels in zinc oxide nanowires
4. Carbon nanotubes outperform copper nanowires as interconnects
5. Engineers make first active matrix display using nanowires
6. Spiraling nanotrees offer new twist on growth of nanowires
7. Nanowires may boost solar cell efficiency, UC San Diego engineers say
8. Strong elasticity size effects in ZnO nanowires
9. Researchers peer into nanowires to measure dopant properties
10. Self-assembled nanowires could make chips smaller and faster
11. Evidence of macroscopic quantum tunneling detected in nanowires
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:6/24/2016)... Brooklyn, NY (PRWEB) , ... June 24, 2016 , ... ... 15mm, machines such as the Cary 5000 and the 6000i models are higher end ... height is the height of the spectrophotometer’s light beam from the bottom of the ...
(Date:6/23/2016)... , June 23, 2016 /PRNewswire/ - FACIT ... Ontario biotechnology company, Propellon Therapeutics ... development and commercialization of a portfolio of first-in-class ... Epigenetic targets such as WDR5 represent an exciting ... significantly in precision medicine for cancer patients. Substantial ...
(Date:6/23/2016)... June, 23, 2016  The Biodesign Challenge (BDC), a ... ways to harness living systems and biotechnology, announced its ... in New York City . ... students, showcased projects at MoMA,s Celeste Bartos Theater during ... , MoMA,s senior curator of architecture and design, and ...
(Date:6/23/2016)... 2016 Apellis Pharmaceuticals, Inc. today announced ... of its complement C3 inhibitor, APL-2. The trials ... dose studies designed to assess the safety, tolerability, ... in healthy adult volunteers. Forty subjects ... single dose (ranging from 45 to 1,440mg) or ...
Breaking Biology Technology:
(Date:4/28/2016)... -- First quarter 2016:   , Revenues ... first quarter of 2015 The gross margin was 49% ... and the operating margin was 40% (-13) Earnings per ... from operations was SEK 249.9 M (21.2) , Outlook ... 7,000-8,500 M. The operating margin for 2016 is estimated ...
(Date:4/15/2016)... -- Research and Markets has announced the ...  report to their offering.  ,      ... gait biometrics market is expected to grow at ... Gait analysis generates multiple variables such ... compute factors that are not or cannot be ...
(Date:3/29/2016)... Florida , March 29, 2016 ... the "Company") LegacyXChange "LEGX" and SelectaDNA/CSI Protect are pleased ... in ink used in a variety of writing instruments, ... Buyers of originally created collectibles from athletes on LegacyXChange ... forensic analysis of the DNA. Bill ...
Breaking Biology News(10 mins):