Nanotechnology Now

Our NanoNews Digest Sponsors



Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > Radiation damage bigger problem in microelectronics than previously thought

Silicon wafer with radiation damage. (Meroli Stefano / CERN)
Silicon wafer with radiation damage.

(Meroli Stefano / CERN)

Abstract:
The amount of structural damage that radiation causes in electronic materials at the atomic level may be at least ten times greater than previously thought.

Radiation damage bigger problem in microelectronics than previously thought

Nashville, TN | Posted on July 21st, 2012

That is the surprising result of a new characterization method that uses a combination of lasers and acoustic waves to provide scientists with a capability tantamount to X-ray vision: It allows them to peer through solid materials to pinpoint the size and location of detects buried deep inside with unprecedented precision.

The research, which was conducted by post-doctoral fellow Andrew Steigerwald under the supervision of Physics Professor Norman Tolk, was published online on July 19 in the Journal of Applied Physics.

"The ability to accurately measure the defects in electronic materials becomes increasingly important as the size of microelectronic devices continues to shrink," Tolk explained. "When an individual transistor contains millions of atoms, it can absorb quite a bit of damage before it fails. But when a transistor contains a few thousand atoms, a single defect can cause it to stop working."

Previous methods used to study damage in electronic materials have been limited to looking at defects and deformations in the atomic lattice. The new method is the first that is capable of detecting disruption in the positions of the electrons that are attached to the atoms. This is particularly important because it is the behavior of the electrons that determine a material's electrical and optical properties.

"An analogy is a thousand people floating in a swimming pool. The people represent the atoms and the water represents the electrons," said Steigerwald. "If another person - representing an energetic particle - jumps into the pool, the people in his vicinity change their positions slightly to make room for him. However, these shifts can be fairly subtle and difficult to measure. But the jumper will also cause quite a splash and cause the level of the water in the pool to rise. Much like the water in the pool, the electrons in a material are more sensitive to defects than the atoms."

To detect the electron dislocations, the physicists upgraded a 15-year-old method called coherent acoustic phonon spectroscopy (CAPS).

"CAPS is similar to the seismic techniques that energy companies use to search for underground oil deposits, only on a much smaller scale," said Steigerwald.

Oil explorers set off a series of small explosions on the surface and measure the sound waves that are reflected back to the surface. That allows them to identify and map the layers of different types of rock thousands of feet underground.

Similarly, CAPS generates a pressure wave that passes through a chunk of semiconductor by blasting its surface with an ultrafast pulse of laser light. As this happens, the researchers bounce a second laser off the pressure wave and measure the strength of the reflection. As the pressure wave encounters defects and deformities in the material, its reflectivity changes and this alters the strength of the reflected laser light. By measuring these variations, the physicists can detect individual defects and measure the effect that they have on the material's electrical and optical properties.

The physicists tested their technique on a layer of gallium arsenide semiconductor that they had irradiated with high-energy neon atoms. They found that the structural damage caused by an embedded neon atom spread over a volume containing 1,000 atoms - considerably more extensive than that shown by other techniques.

"This is significant because today people are creating nanodevices that contain thousands of atoms," said Steigerwald. One of these devices is a solar collector made from quantum dots, tiny semiconductor beads that each contains a few thousand atoms. "Our results may explain recent studies that have found that these quantum-dot solar collectors are less efficient than predicted," he said.

"The fact is that we really don't understand how any atomic-scale defect affects the performance on an optoelectronic device," said Tolk. "Techniques like the one that we have developed will give us the detailed information we need to figure this out and so help people make nanodevices that work properly."

Research Associate Professor Anthony B. Hmelo, Assistant Professor Kalman Varga and Stevenson Professor of Physics Leonard Feldman also contributed to the research.

The research was supported by Department of Energy grant FG02-99ER45781, Army Research Office grant W911NF-07-R-0003-02 and National Science Foundation grant ECCS0925422. In addition, portions of the work were performed at the Vanderbilt Institute of Nanoscale Science and Engineering, using facilities renovated with the NSF grant ARI-RW DMR-096331.

Visit Research News @ Vanderbilt for more research news from Vanderbilt. [Media Note: Vanderbilt has a 24/7 TV and radio studio with a dedicated fiber optic line and ISDN line. Use of the TV studio with Vanderbilt experts is free, except for reserving fiber time.]

####

For more information, please click here

Contacts:
David Salisbury

615-343-6803

Copyright © Vanderbilt University

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Vegetable oil ingredient key to destroying gastric disease bacteria: In mice, therapeutic nanoparticles dampen H. pylori bacteria and inflammation that lead to ulcers and gastric cancer November 25th, 2014

Research yields material made of single-atom layers that snap together like Legos November 25th, 2014

Blu-ray disc can be used to improve solar cell performance: Data storage pattern transferred to solar cell increases light absorption November 25th, 2014

A*STAR SIMTech wins international award for breaking new ground in actuators: SIMTech invention can be used in an array of industries, and is critical for next generation ultra-precision systems November 24th, 2014

Govt.-Legislation/Regulation/Funding/Policy

Vegetable oil ingredient key to destroying gastric disease bacteria: In mice, therapeutic nanoparticles dampen H. pylori bacteria and inflammation that lead to ulcers and gastric cancer November 25th, 2014

Research yields material made of single-atom layers that snap together like Legos November 25th, 2014

Researchers engineer improvements of technology used in digital memory November 24th, 2014

An Inside Job: UC-Designed Nanoparticles Infiltrate, Kill Cancer Cells From Within November 24th, 2014

Chip Technology

Nanometrics Announces Upcoming Investor Events November 19th, 2014

A novel method for identifying the body’s ‘noisiest’ networks November 19th, 2014

Researchers create & control spin waves, lifting prospects for enhanced info processing November 17th, 2014

VDMA Electronics Production Equipment: Growth track for 2014 and 2015 confirmed: Business climate survey shows robust industry sector November 14th, 2014

Optical computing/ Photonic computing

Penn engineers efficiently 'mix' light at the nanoscale November 17th, 2014

Nanoparticles Break the Symmetry of Light October 6th, 2014

Speed at its limits September 30th, 2014

'Pixel' engineered electronics have growth potential: Rice, Oak Ridge, Vanderbilt, Penn scientists lead creation of atom-scale semiconducting composites September 29th, 2014

Discoveries

Vegetable oil ingredient key to destroying gastric disease bacteria: In mice, therapeutic nanoparticles dampen H. pylori bacteria and inflammation that lead to ulcers and gastric cancer November 25th, 2014

Research yields material made of single-atom layers that snap together like Legos November 25th, 2014

Blu-ray disc can be used to improve solar cell performance: Data storage pattern transferred to solar cell increases light absorption November 25th, 2014

An Inside Job: UC-Designed Nanoparticles Infiltrate, Kill Cancer Cells From Within November 24th, 2014

Announcements

Vegetable oil ingredient key to destroying gastric disease bacteria: In mice, therapeutic nanoparticles dampen H. pylori bacteria and inflammation that lead to ulcers and gastric cancer November 25th, 2014

Research yields material made of single-atom layers that snap together like Legos November 25th, 2014

Blu-ray disc can be used to improve solar cell performance: Data storage pattern transferred to solar cell increases light absorption November 25th, 2014

Cooling with the coldest matter in the world November 24th, 2014

Military

NRL Scientists Discover Novel Metamaterial Properties within Hexagonal Boron Nitride November 20th, 2014

Two sensors in one: Nanoparticles that enable both MRI and fluorescent imaging could monitor cancer, other diseases November 18th, 2014

Researchers create & control spin waves, lifting prospects for enhanced info processing November 17th, 2014

Penn engineers efficiently 'mix' light at the nanoscale November 17th, 2014

Photonics/Optics/Lasers

NRL Scientists Discover Novel Metamaterial Properties within Hexagonal Boron Nitride November 20th, 2014

Penn engineers efficiently 'mix' light at the nanoscale November 17th, 2014

'Direct writing' of diamond patterns from graphite a potential technological leap November 5th, 2014

Outsmarting Thermodynamics in Self-assembly of Nanostructures: Berkeley Lab reports method for symmetry-breaking in feedback-driven self-assembly of optical metamaterials November 4th, 2014

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More












ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







© Copyright 1999-2014 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE