Graphene-metal combination may shrink electronics


Researchers have discovered that creating a graphene-copper-graphene “sandwich” strongly enhances the heat conducting properties of copper, a discovery that could further help in the downscaling of electronics.

 

The ideal crystalline structure of graphene is...

The ideal crystalline structure of graphene is a hexagonal grid. (Photo credit: Wikipedia)

The work was led by Alexander A. Balandin, a professor of electrical engineering at the Bourns College of Engineering at the University of California, Riverside and Konstantin S. Novoselov, a professor of physics at the University of Manchester in the United Kingdom. Balandin and Novoselov are corresponding authors for the paper just published in the journal Nano Letters. In 2010, Novoselov shared the Nobel Prize in Physics with Andre Geim for their discovery of graphene.

In the experiments, the researchers found that adding a layer of graphene, a one-atom thick material with highly desirable electrical, thermal and mechanical properties, on each side of a copper film increased heat conducting properties up to 24 percent.

Continuous casting copper disc (99.95% pure), ...

Continuous casting copper disc (99.95% pure), macro etched, ∅ ≈83 mm. (Photo credit: Wikipedia)

“This enhancement of copper’s ability to conduct heat could become important in the development of hybrid copper — graphene interconnects for electronic chips that continue to get smaller and smaller,” said Balandin, who in 2013 was awarded the MRS Medal from the Materials Research Society for discovery of unusual heat conduction properties of graphene.

Whether the heat conducting properties of copper would improve by layering it with graphene is an important question because copper is the material used for semiconductor interconnects in modern computer chips. Copper replaced aluminum because of its better electrical conductivity.

Downscaling the size of transistors and interconnects and increasing the number of transistors on computer chips has put an enormous strain on copper’s interconnect performance, to the point where there is little room for further improvement. For that reason there is a strong motivation to develop hybrid interconnect structures that can better conduct electrical current and heat.

From left: (1) copper before any processing, (2) copper after thermal processing; (3) copper after adding graphene.

In the experiments conducted by Balandin and the other researchers, they were surprised that the improvement of thermal properties of graphene coated copper films was significant despite the fact that graphene’s thickness is only one atom. The puzzle was solved after they realized the improvement is the result of changes in copper’s nano- and microstructure, not from graphene’s action as an additional heat conducting channel.

After examining the grain sizes in copper before and after adding graphene, the researcher found that chemical vapor deposition of graphene conducted at high temperature stimulates grain size growth in copper films. The larger grain sizes in copper coated with graphene results in better heat conduction.

Additionally, the researchers found that the heat conduction improvement by adding graphene was more pronounced in thinner copper films. This is significant because the enhancement should further improve as future copper interconnects scale down to the nanometers-range, which is 1/1000thof the micrometer range.

In the future, Balandin and the team would like to investigate how heat conduction properties change in nanometer-thick copper films coated with graphene. They also plan to develop a more accurate theoretical model to explain how thermal conductivity scales with the grain sizes.

The work at UC Riverside on this project was supported by the National Science Foundation and by STARnet Center for Function Accelerated nanoMaterial Engineering (FAME), a Semiconductor Research Corporation (SRC) program sponsored by Microelectronics Advanced Research Corporation (MARCO) and Defense Advanced Research Projects Agency (DARPA).

Story Source:

The above story is based on materials provided by University of California – Riverside. Note: Materials may be edited for content and length.

Enhanced by Zemanta

Trackbacks

  1. […] Graphene-metal combination may shrink electronics […]

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

Nota Bene

NOTES, COMMENT AND BUZZ FROM EUGENE KASPERSKY – OFFICIAL BLOG

Yanis Varoufakis

THOUGHTS FOR THE POST-2008 WORLD

CL Health News

Υγεία και Ενημέρωση - Medical reportage, headlines, research, interviews, conferences, tributes and tips, Doctor's Opinion

Hot Tall Blonde's Blog

ThE miNdS Eye: mY PoeTry, PerSpecTives & Journey into higher consciousness

Genetic Discovery SF

What's going on in the world of mental health and genetics

Coco J. Ginger Says

Poems and stories of love & heartbreak.

Watts Up With That?

The world's most viewed site on global warming and climate change

Dark Matters a Lot

Dark Energy: It created us, it connects us, it is killing us, and it just might save us.

Science Springs

Dedicated to spreading the Good News of Basic and Applied Science at great research institutions world wide. Good science is a collaborative process.

ROAM ABOUT MIKE

Adventures From Around the Globe

%d bloggers like this: