Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Designing diamond circuits for extreme environments

05.08.2011
There is a new way to design computer chips and electronic circuitry for extreme environments: make them out of diamond.

A team of electrical engineers at Vanderbilt University has developed all the basic components needed to create microelectronic devices out of thin films of nanodiamond. They have created diamond versions of transistors and, most recently, logical gates, which are a key element in computers.

"Diamond-based devices have the potential to operate at higher speeds and require less power than silicon-based devices," Research Professor of Electrical Engineering Jimmy Davidson said. "Diamond is the most inert material known, so our devices are largely immune to radiation damage and can operate at much higher temperatures than those made from silicon."

Their design of a logical gate is described in the Aug. 4 issue of the journal Electronics Letters. Co-authors of the paper are graduate student Nikkon Ghosh, Professor of Electrical Engineering Weng Poo Kang.

Not an engagement ring

Davidson was quick to point out that even though their design uses diamond film, it is not exorbitantly expensive. The devices are so small that about one billion of them can be fabricated from one carat of diamond. The films are made from hydrogen and methane using a method called chemical vapor deposition that is widely used in the microelectronics industry for other purposes. This deposited form of diamond is less than one-thousandth the cost of "jewelry" diamond, which has made it inexpensive enough so that companies are putting diamond coatings on tools, cookware and other industrial products. As a result, the cost of producing nanodiamond devices should be competitive with silicon.

Potential applications include military electronics, circuitry that operates in space, ultra-high speed switches, ultra-low power applications and sensors that operate in high radiation environments, at extremely high temperatures up to 900 degrees Fahrenheit and extremely low temperatures down to minus 300 degrees Fahrenheit.

Hybrid of old and new

The nanodiamond circuits are a hybrid of old fashioned vacuum tubes and modern solid-state microelectronics and combine some of the best qualities of both technologies. Nanodiamond devices consist of a thin film of nanodiamond that is laid down on a layer of silicon dioxide. Much as they do in vacuum tubes, the electrons move through vacuum between the nanodiamond components, instead of flowing through solid material the way they do in normal microelectronic devices. As a result, they require vacuum packaging to operate.

"The reason your laptop gets hot is because the electrons pumping through its transistors bump into the atoms in the semiconductor and heat them up," Davidson said. "Because our devices use electron transport in vacuum they don't produce nearly as much heat."

This transmission efficiency is also one reason why the new devices can run on very small amounts of electrical current. Another is that diamond is the best electron emitter in the world so it doesn't take much energy to produce strong electron beams. "We think we can make devices that use one tenth the power of the most efficient silicon devices," said Davidson.

The design is also largely immune to radiation damage. Radiation disrupts the operation of transistors by inducing unwanted charge in the silicon, causing an effect like tripping the circuit breaker in your home. In the nanodiamond device, on the other hand, the electrons flow through vacuum so there is nothing for energetic particles to disrupt. If the particles strike the nanodiamond anode or cathode, the impact is limited to a small fluctuation in the electron flow, not complete disruption, as is the case with silicon devices.

"When I read about the problems at the Fukushima power plant after the Japanese tsunami, I realized that nanodiamond circuits would be perfect for failsafe circuitry in nuclear reactors," Davidson said. "It wouldn't be affected by high radiation levels or the high temperatures created by the explosions."

Nanodiamond devices can be manufactured by processes that the semiconductor industry currently uses. The one exception is the requirement to operate in vacuum, which would require some modification in the packaging process. Currently, semiconductor chips are sealed in packages filled with an inert gas like argon or simply encapsulated in plastic, protecting them from chemical degradation. Davidson and his colleagues have investigated the packaging process and have found that the metallic seals used in military-grade circuitry are strong enough to hold an adequate vacuum for centuries.

The research was supported by grants from the U.S. Army.

Visit Research News @ Vanderbilt for more research news from Vanderbilt.

David Salisbury | Vanderbilt University
Further information:
http://www.vanderbilt.edu

More articles from Power and Electrical Engineering:

nachricht Team develops fast, cheap method to make supercapacitor electrodes
18.07.2017 | University of Washington

nachricht Magic off the cuff
11.07.2017 | 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: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

Im Focus: On the way to a biological alternative

A bacterial enzyme enables reactions that open up alternatives to key industrial chemical processes

The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....

Im Focus: The 1 trillion tonne iceberg

Larsen C Ice Shelf rift finally breaks through

A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...

Im Focus: Laser-cooled ions contribute to better understanding of friction

Physics supports biology: Researchers from PTB have developed a model system to investigate friction phenomena with atomic precision

Friction: what you want from car brakes, otherwise rather a nuisance. In any case, it is useful to know as precisely as possible how friction phenomena arise –...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

Leipzig HTP-Forum discusses "hydrothermal processes" as a key technology for a biobased economy

12.07.2017 | Event News

 
Latest News

Researchers create new technique for manipulating polarization of terahertz radiation

20.07.2017 | Information Technology

High-tech sensing illuminates concrete stress testing

20.07.2017 | Materials Sciences

First direct observation and measurement of ultra-fast moving vortices in superconductors

20.07.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>