Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > Graphitic memory techniques advance at Rice

Abstract:
Researchers simplify fabrication of nano storage, chip-design tools

Graphitic memory techniques advance at Rice

Houston, TX | Posted on September 9th, 2009

Advances by the Rice University lab of James Tour have brought graphite's potential as a mass data storage medium a step closer to reality and created the potential for reprogrammable gate arrays that could bring about a revolution in integrated circuit logic design.

In a paper published in the online journal ACS Nano, Tour and postdoctoral associate Alexander Sinitskii show how they've used industry-standard lithographic techniques to deposit 10-nanometer stripes of amorphous graphite, the carbon-based, semiconducting material commonly found in pencils, onto silicon. This facilitates the creation of potentially very dense, very stable nonvolatile memory for all kinds of digital devices.

With backing from a major manufacturer of memory chips, Tour and his team have pushed the technology forward in several ways since a paper that appeared last November first described two-terminal graphitic memory. While noting advances in other molecular computing techniques that involve nanotubes or quantum dots, he said none of those have yet proved practical in terms of fabrication.

Not so with this simple-to-deposit graphite. "We're using chemical vapor deposition and lithography -- techniques the industry understands," said Tour, Rice's Chao Professor of Chemistry and a professor of mechanical engineering and materials science and of computer science. "That makes this a good alternative to our previous carbon-coated nanocable devices, which perform well but are very difficult to manufacture."

Graphite makes a good, reliable memory "bit" for reasons that aren't yet fully understood. The lab found that running a current through a 10-atom-thick layer of graphite creates a complete break in the circuit -- literally, a gap in the strip a couple of nanometers wide. Another jolt repairs the break. The process appears to be indefinitely repeatable, which provides addressable ones and zeroes, just like today's flash memory devices but at a much denser scale.

Graphite's other advantages were detailed in Tour's earlier work: the ability to operate with as little as three volts, an astoundingly high on/off ratio (the amount of juice a circuit holds when it's on, as opposed to off) and the need for only two terminals instead of three, which eliminates a lot of circuitry. It's also impervious to a wide temperature range and radiation; this makes it suitable for deployment in space and for military uses where exposure to temperature extremes and radiation is a concern.

Tour's graphite-forming technique is well-suited for other applications in the semiconductor industry. One result of the previous paper is a partnership between the Tour group and NuPGA (for "new programmable gate arrays"), a California company formed around the research to create a new breed of reprogrammable gate arrays that could make the design of all kinds of computer chips easier and cheaper.

The Tour lab and NuPGA, led by industry veteran Zvi Or-Bach (founder of eASIC and Chip Express), have applied for a patent based on vertical arrays of graphite embedded in "vias," the holes in integrated circuits connecting the different layers of circuitry. When current is applied to a graphite-filled via, the graphite alternately splits and repairs itself (a process also described in the latest paper), just like it does in strip form. Essentially, it becomes an "antifuse," the basic element of one type of field programmable gate array (FPGA), best described as a blank computer chip that uses software to rewire the hardware.

Currently, antifuse FPGAs can be programmed once. But this graphite approach could allow for the creation of FPGAs that can be reprogrammed at will. Or-Bach said graphite-based FPGAs would start out as blanks, with the graphite elements split. Programmers could "heal" the antifuses at will by applying a voltage, and split them with an even higher voltage.

Such a device would be mighty handy to computer-chip designers, who now spend many millions to create the photolithography mask sets used in chip fabrication. If the design fails, it's back to square one.

"As a result of that, people are only hesitantly investing in new chip designs," said Tour. "They stick with the old chip designs and make modifications. FPGAs are chips that have no specific ability, but you use software to program them by interconnecting the circuitry in different ways." That way, he said, fabricators don't need expensive mask sets to try new designs.

"The No. 1 problem in the industry, and one that gives an opportunity for a company like ours, is that the cost of masks keeps moving up as people push semiconductors into future generators," said Or-Bach. "Over the last 10 years, the cost of a mask set has multiplied almost 10 times.

"If we can really make something that will be an order of magnitude better, the markets will be happy to make use of it. That's our challenge, and I believe the technology makes it possible for us to do that."

The ACS Nano paper appears here:
pubs.acs.org/doi/pdf/10.1021/nn9006225

Read more about Tour's research of graphitic memory here:
www.media.rice.edu/media/NewsBot.asp?MODE=VIEW&ID=11817

####

About Rice University
Rice has from its inception been dedicated to three missions: educating and preparing outstanding students for diverse careers and lives; contributing to the advancement of knowledge across a wide range of fields; and being of service to our city, our state, our nation, and our world. The Call to Conversation posed the question whether our current mission statement fully encompassed our ambitions, particularly our commitment as a research university to creating new knowledge and our obligation to train future leaders across a range of endeavors. It states: “The mission of Rice University, shaped largely by its founder and the first president, is to provide an unsurpassed undergraduate education in science, engineering, the arts, humanities, and social sciences; to produce internationally distinguished scholarship and research and excellent graduate education in carefully focused areas; to ensure that such an education remains affordable; to maintain the distinctive character of a community of learning that is relatively small in scale; and to serve the continuing educational needs of the larger community.”

Based on many conversations and after reviewing the comments on this topic submitted by all segments of our community, it has become clear that although our mission statement describes our three core missions, it does not fully reflect the goals we should now have before us.

For more information, please click here

Contacts:
David Ruth
713-348-6327

Copyright © Rice 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

Scientists create antilaser for ultracold atoms condensate August 16th, 2018

Research brief: UMN researchers use green gold to rapidly detect and identify harmful bacteria August 15th, 2018

Particles pull last drops of oil from well water: Rice University engineers find nanoscale solution to 'produced water' problem August 15th, 2018

CTI Materials drives nano commercialization with it's patented surfactant free nanoparticle dispersions August 15th, 2018

Possible Futures

Scientists create antilaser for ultracold atoms condensate August 16th, 2018

Research brief: UMN researchers use green gold to rapidly detect and identify harmful bacteria August 15th, 2018

Particles pull last drops of oil from well water: Rice University engineers find nanoscale solution to 'produced water' problem August 15th, 2018

How hot is Schrödinger's coffee? August 15th, 2018

Chip Technology

Scientists create antilaser for ultracold atoms condensate August 16th, 2018

Flipping the switch on supramolecular electronics August 14th, 2018

Breaking down the Wiedemann-Franz law: In a study exploring the coupling between heat and particle currents in a gas of strongly interacting atoms, physicists at ETH Zurich find puzzling behaviours August 10th, 2018

Scientists squeeze nanocrystals in a liquid droplet into a solid-like state and back again: Simple chemical technique transforms crystal mixture where 2 liquids meet August 9th, 2018

Memory Technology

Leti & CMP Announce World’s First Multi-Project-Wafer Service with Integrated Silicon OxRAM: Oxide-Based Resistive Ram Memory Platform Development for Backend Memories To Offer Non-Volatility Associated with Embedded Designs August 2nd, 2018

A molecular switch at the edge of graphene July 27th, 2018

Magnetic skyrmions: Not the only ones of their class: Jülich researchers discover a new type of magnetic particle-like object for data storage devices of the future June 28th, 2018

Tunable diamond string may hold key to quantum memory: A process similar to guitar tuning improves storage time of quantum memory May 24th, 2018

Nanotubes/Buckyballs/Fullerenes/Nanorods

Nanotube 'rebar' makes graphene twice as tough: Rice University scientists test material that shows promise for flexible electronics August 3rd, 2018

Carbon is the new black: Researchers use carbon nanotubes to develop clothing that can double as batteries July 10th, 2018

Nano-saturn: Supramolecular complex formation: Anthracene macrocycle and C60 fullerene June 8th, 2018

Unzipping graphene nanotubes into nanoribbons: New study shows elegant mathematical solution to understand how the flow of electrons changes when carbon nanotubes turn into zigzag nanoribbons June 6th, 2018

Nanoelectronics

Flipping the switch on supramolecular electronics August 14th, 2018

Quantum chains in graphene nanoribbons: Breakthrough in nanoresearch August 9th, 2018

Nanotube 'rebar' makes graphene twice as tough: Rice University scientists test material that shows promise for flexible electronics August 3rd, 2018

Leti & CMP Announce World’s First Multi-Project-Wafer Service with Integrated Silicon OxRAM: Oxide-Based Resistive Ram Memory Platform Development for Backend Memories To Offer Non-Volatility Associated with Embedded Designs August 2nd, 2018

Announcements

Scientists create antilaser for ultracold atoms condensate August 16th, 2018

Research brief: UMN researchers use green gold to rapidly detect and identify harmful bacteria August 15th, 2018

Particles pull last drops of oil from well water: Rice University engineers find nanoscale solution to 'produced water' problem August 15th, 2018

How hot is Schrödinger's coffee? August 15th, 2018

Quantum Dots/Rods

Individual quantum dots imaged in 3-D for first time February 28th, 2018

Moving nanoparticles using light and magnetic fields January 25th, 2018

Tweaking quantum dots powers-up double-pane solar windows: Engineered quantum dots could bring down the cost of solar electricity January 2nd, 2018

Quantum communications bend to our needs: By changing the wavelengths of entangled photons to those used in telecommunications, researchers see quantum technology take a major leap forward September 28th, 2017

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



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project