Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New sensor bares faults in smallest possible, most advanced circuits

12.05.2003


A new scanning microscope developed at Brown University can uncover defects in the smallest and most complex integrated circuits at a resolution 1,000 times greater than current technology. The scanner removes a barrier to further shrinking of integrated circuits: As circuits get smaller, non-visual defects become harder to find.


Micro mouse bite
A current-density image, taken with a Circuit Scan 1000 high-resolution magnetic microscope, reveals a tiny flaw in one of two 0.25-micron metal wires in an integrated circuit chip. Further magnification (detail) shows the right-hand wire has a “mouse bite” along one of its edges, where the electrical current shows up as a tiny hot spot



“This microscope will allow manufacturers to find defects in each embedded wire in ever-tinier circuits,” said Brown University professor Gang Xiao. He developed the instrument’s hardware and software with Ben Schrag, who will receive his Ph.D. at Brown this month.

The microscope’s magnetic-scanning technology suggests a new small, non-invasive form of remote detection, said the researchers, who envision a “pass-over and detect” magnetic-sensor-tipped pen, for use in finding internal cracks within aircraft, sensing biological agents in the environment or body, or recognizing counterfeit bills or other objects.


Although magnetic sensing is used extensively, it is not applied widely for imaging electrical current flow, said Schrag. The only method that uses magnetic imaging to see current flow is restricted to extremely low temperatures, employing cryogenic aids such as liquid nitrogen. However, the Brown device works at room temperature. This design opens the way to greater use of magnetic sensing technology, he said.

“The factor of 1,000 improvement in spatial resolution is how much better we can do than this cryogenic technology,” Schrag said. “We are just scratching the surface of potential applications.”

Xiao and Schrag are using the technology to pinpoint how electrical current can form pinholes in state-of-the-art devices called magnetic tunnel junctions. These tiny sandwiches of ferromagnetic layers and insulating material are candidate memory storage cells to replace standard cells used in computer memory chips.

The researchers have “imaged” current flow in electrical components as small as 50 nanometers, the smallest commercially available components, half the size of conventional chips.

Until now, little or no technology existed for actually “watching” electrical current flow, said Schrag. Whenever current runs through wires, such as those embedded within the semiconducting material of an integrated circuit, it creates a magnetic field. By measuring spatial changes in that magnetic field, the microscope visualizes electrical current, even within wires buried under layers of advanced materials, he said.

“The device allows us to see the evolution of hot spots on each wire in a circuit and how each defect moves down the wire in the form of electrons moving atoms,” said Xiao. “To see a collection of atoms moving as a function of time is a capability that did not exist until now. We are witnessing the flow of electricity. It appears similar to an image of human blood flowing.”

The microscope is described in a paper in the May 12, 2003, issue of Applied Physics Letters. It features some of the same magnetic-scanning technology found in computer hard drives. A scanner does not touch what it reads. Instead, a magnetic sensor the size of a small pea moves quickly back and forth over a circuit through which current flows. The sensor collects information, which is then converted by algorithms into a color picture of electron flow. Color changes in the image reflect the intensity of electron flow as well as the presence of defects.

About the size of a refrigerator, the microscope is being reduced to the size of a desktop computer. “The new design will allow a technician to sit in front of a monitoring screen, as integrated circuits pass through a small open door, under a scanner and out the door,” Xiao said. Currently, the microscope takes a few minutes to scan a circuit. The researchers are working to reduce that time to as little as 30 seconds.

Xiao and Schrag have filed patents on several aspects of the technology, which has been transferred to Micro Magnetics, a Fall River, Mass., company that makes scanning devices for manufacturers of integrated circuits (computer chips). Images produced by the microscope may be viewed at http://www.micromagnetics.com/.

The National Science Foundation funded this work.

Scott Turner | Brown University
Further information:
http://www.brown.edu/Administration/News_Bureau/2002-03/02-125.html
http://www.micromagnetics.com/

More articles from Power and Electrical Engineering:

nachricht Waste from paper and pulp industry supplies raw material for development of new redox flow batteries
12.10.2017 | Johannes Gutenberg-Universität Mainz

nachricht Low-cost battery from waste graphite
11.10.2017 | Empa - Eidgenössische Materialprüfungs- und Forschungsanstalt

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: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Terahertz spectroscopy goes nano

20.10.2017 | Information Technology

Strange but true: Turning a material upside down can sometimes make it softer

20.10.2017 | Materials Sciences

NRL clarifies valley polarization for electronic and optoelectronic technologies

20.10.2017 | Interdisciplinary Research

VideoLinks
B2B-VideoLinks
More VideoLinks >>>