Featured Research

from universities, journals, and other organizations

Nano 'pin art': Arrays are step toward mass production of nanowires

Date:
August 2, 2010
Source:
National Institute of Standards and Technology (NIST)
Summary:
Researchers have cultivated many thousands of nanocrystals in what looks like a pinscreen or "pin art" on silicon, a step toward reliable mass production of semiconductor nanowires for millionths-of-a-meter-scale devices such as sensors and lasers.

This is a colorized micrograph of semiconductor nanowires grown at NIST in a precisely controlled array of sizes and locations.
Credit: K. Bertness, NIST

NIST researchers grow nanowires made of semiconductors -- gallium nitride alloys -- by depositing atoms layer-by-layer on a silicon crystal under high vacuum. NIST has the unusual capability to produce these nanowires without using metal catalysts, thereby enhancing luminescence and reducing defects. NIST nanowires also have excellent mechanical quality factors.

The latest experiments, described in Advanced Functional Materials,* maintained the purity and defect-free crystal structure of NIST nanowires while controlling diameter and placement better than has been reported by other groups for catalyst-based nanowires. Precise control of diameter and placement is essential before nanowires can be widely used.

The key trick in the NIST technique is to grow the wires through precisely defined holes in a stencil-like mask covering the silicon wafer. The NIST nanowires were grown through openings in patterned silicon nitride masks. About 30,000 nanowires were grown per 76-millimeter-wide wafer. The technique controlled nanowire location almost perfectly. Wires grew uniformly through most openings and were absent on most of the mask surface.

Mask openings ranged from 300 to 1000 nanometers (nm) wide, in increments of 100 nm. In each opening of 300 nm or 400 nm, a single nanowire grew, with a well-formed hexagonal shape and a symmetrical tip with six facets. Larger openings produced more variable results. Openings of 400 nm to 900 nm yielded single-crystal nanowires with multifaceted tops. Structures grown in 1,000-nm openings appeared to be multiple wires stuck together. All nanowires grew to about 1,000 nm tall over three days.

NIST researchers analyzed micrographs to verify the uniformity of nanowire shape and size statistically. The analysis revealed nearly uniform areas of wires of the same diameter as well as nearly perfect hexagonal shapes.

Growing nanowires on silicon is one approach NIST researchers are exploring for making "nanowires on a chip" devices. Although the growth temperatures are too high -- over 800 degrees Celsius -- for silicon circuitry to tolerate, there may be ways to grow the nanowires first and then protect them during circuitry fabrication, lead author Kris Bertness says. The research was partially supported by the Defense Advanced Research Projects Agency (DARPA) Center on NanoscaleScience and Technology for Integrated Micro/Nano-Electromechanical Transducers (iMINT) at the University of Colorado at Boulder.


Story Source:

The above story is based on materials provided by National Institute of Standards and Technology (NIST). Note: Materials may be edited for content and length.


Journal Reference:

  1. K. A. Bertness, A. W. Sanders, D. M. Rourke, T. E. Harvey, A. Roshko, J.B. Schlager and N. A. Sanford. Controlled Nucleation of GaN Nanowires Grown with Molecular Beam Epitaxy. Advanced Functional Materials, 2010; DOI: 10.1002/adfm.201000381

Cite This Page:

National Institute of Standards and Technology (NIST). "Nano 'pin art': Arrays are step toward mass production of nanowires." ScienceDaily. ScienceDaily, 2 August 2010. <www.sciencedaily.com/releases/2010/07/100730191704.htm>.
National Institute of Standards and Technology (NIST). (2010, August 2). Nano 'pin art': Arrays are step toward mass production of nanowires. ScienceDaily. Retrieved July 22, 2014 from www.sciencedaily.com/releases/2010/07/100730191704.htm
National Institute of Standards and Technology (NIST). "Nano 'pin art': Arrays are step toward mass production of nanowires." ScienceDaily. www.sciencedaily.com/releases/2010/07/100730191704.htm (accessed July 22, 2014).

Share This




More Matter & Energy News

Tuesday, July 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Government Approves East Coast Oil Exploration

Government Approves East Coast Oil Exploration

AP (July 18, 2014) The Obama administration approved the use of sonic cannons to discover deposits under the ocean floor by shooting sound waves 100 times louder than a jet engine through waters shared by endangered whales and turtles. (July 18) Video provided by AP
Powered by NewsLook.com
Sunken German U-Boat Clearly Visible For First Time

Sunken German U-Boat Clearly Visible For First Time

Newsy (July 18, 2014) The wreckage of the German submarine U-166 has become clearly visible for the first time since it was discovered in 2001. Video provided by Newsy
Powered by NewsLook.com
Obama: U.S. Must Have "smartest Airports, Best Power Grid"

Obama: U.S. Must Have "smartest Airports, Best Power Grid"

Reuters - US Online Video (July 17, 2014) President Barak Obama stopped by at a lunch counter in Delaware before making remarks about boosting the nation's infrastructure. Mana Rabiee reports. Video provided by Reuters
Powered by NewsLook.com
Crude Oil Prices Bounce Back After Falling Below $100 a Barrel

Crude Oil Prices Bounce Back After Falling Below $100 a Barrel

TheStreet (July 16, 2014) Oil Futures are bouncing back after tumbling below $100 a barrel for the first time since May yesterday. Jeff Grossman is the president of BRG Brokerage and trades at the NYMEX. Grossman tells TheStreet the Middle East is always a concern for oil traders. Oil prices were pushed down in recent weeks on Libya increasing its production. Supply disruptions in Iraq fading also contributed to prices falling. News from China's economic front showing a growth for the second quarter also calmed fears on its slowdown. Jeff Grossman talks to TheStreet's Susannah Lee on this and more on the Energy Department's Energy Information Administration (EIA) report. Video provided by TheStreet
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins