Nanotechnology Now

Our NanoNews Digest Sponsors


Heifer International

Wikipedia Affiliate Button

Home > Press > Silicon oxide memories transcend a hurdle: Embedded diodes boost Rice University invention’s potential as robust, roomy memory

Rice University has built crossbar memory chips based on silicon oxide that show potential for next-generation 3-D memories for computers and consumer devices. Credit: Tour Group/Rice University
Rice University has built crossbar memory chips based on silicon oxide that show potential for next-generation 3-D memories for computers and consumer devices.

Credit: Tour Group/Rice University

Abstract:
A Rice University laboratory pioneering memory devices that use cheap, plentiful silicon oxide to store data has pushed them a step further with chips that show the technology's practicality.

Silicon oxide memories transcend a hurdle: Embedded diodes boost Rice University invention’s potential as robust, roomy memory

Houston, TX | Posted on July 9th, 2013

The team led by Rice chemist James Tour has built a 1-kilobit rewritable silicon oxide device with diodes that eliminate data-corrupting crosstalk.

A paper on the new work appears this week in the journal Advanced Materials.

With gigabytes of flash memory becoming steadily cheaper, a 1k nonvolatile memory unit has little practical use. But as a proof of concept, the chip shows it should be possible to surpass the limitations of flash memory in packing density, energy consumption per bit and switching speed.

The technique is based on an earlier discovery by the Tour lab: When electricity passes through a layer of silicon oxide, it strips away oxygen molecules and creates a channel of pure metallic phase silicon that is less than five nanometers wide. Normal operating voltages can repeatedly break and "heal" the channel, which can be read as either a "1" or "0" depending upon whether it is broken or intact.

The circuits require only two terminals instead of three, as in most memory chips. The crossbar memories built by the Rice lab are flexible, resist heat and radiation and show promise for stacking in three-dimensional arrays. Rudimentary silicon memories made in the Tour lab are now aboard the International Space Station, where they are being tested for their ability to hold a pattern when exposed to radiation.

The diodes eliminate crosstalk inherent in crossbar structures by keeping the electronic state on a cell from leaking into adjacent cells, Tour said. "It wasn't easy to develop, but it's now very easy to make," he said.

The device built by Rice postdoctoral researcher Gunuk Wang, lead author of the new paper, sandwiches the active silicon oxide between layers of palladium. The silicon-palladium sandwiches rest upon a thin layer of aluminum that combines with a base layer of p-doped silicon to act as a diode. Wang's 32 x 32-bit test arrays are a little more than a micrometer deep with crossbar line widths of 10 to 100 micrometers for testing purposes.

"We didn't try to miniaturize it," Tour said. "We've already demonstrated the native sub-5-nanometer filament, which is going to work with the smallest line size industry can make."

The devices have proven to be robust, with a high on/off ratio of about 10,000 to 1, over the equivalent of 10 years of use, low-energy consumption and even the capability for multibit switching, which would allow higher density information storage than conventional two-state memory systems.

The devices dubbed "one diode-one resistor" (1D-1R) worked especially well when compared with test versions (1R) that lacked the diode, Wang said. "Using just the silicon oxide was not enough," he said. "In a (1R) crossbar structure with just the memory material, if we made 1,024 cells, only about 63 cells would work individually. There would be crosstalk, and that was a problem."

To prove the 1D-1R's capabilities, Wang isolated 3 x 3 grids and encoded ASCII letters spelling out "RICE OWLS" into the bits. Setting adjacent bits to the "on" state - usually a condition that leads to voltage leaks and data corruption in a 1R crossbar structure - had no effect on the information, he said.

"From the engineering side of this, integrating diodes into a 1k memory array is no small feat," Tour said. "It will be industry's job to scale this into commercial memories, but this demonstration shows it can be done."

Co-authors of the paper are Rice graduate student Adam Lauchner; postdoctoral researcher Jian Lin; Douglas Natelson, a professor of physics and astronomy and of electrical and computer engineering, and Krishna Palem, the Ken and Audrey Kennedy Professor of Computer Science and Electrical and Computer Engineering and a professor of statistics. Tour is the T.T. and W.F. Chao Chair in Chemistry as well as a professor of mechanical engineering and materials science and of computer science at Rice.

The Boeing Corp. and the Air Force Office of Scientific Research funded the work.

####

About Rice University
Located on a 300-acre forested campus in Houston, Rice University is consistently ranked among the nation's top 20 universities by U.S. News & World Report. Rice has highly respected schools of Architecture, Business, Continuing Studies, Engineering, Humanities, Music, Natural Sciences and Social Sciences and is home to the Baker Institute for Public Policy. With 3,708 undergraduates and 2,374 graduate students, Rice's undergraduate student-to-faculty ratio is 6-to-1. Its residential college system builds close-knit communities and lifelong friendships, just one reason why Rice has been ranked No. 1 for best quality of life multiple times by the Princeton Review and No. 2 for "best value" among private universities by Kiplinger's Personal Finance. To read "What they're saying about Rice," go to tinyurl.com/AboutRiceU.

For more information, please click here

Contacts:
David Ruth
713-348-6327


Jade Boyd
713-348-6778

Copyright © AlphaGalileo

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 Links

Read the abstract at:

Tour Group:

In situ imaging of the conducting filament in a silicon oxide resistive switch:

Related News Press

News and information

New remote-controlled microrobots for medical operations July 23rd, 2016

New superconducting coil improves MRI performance: UH-led research offers higher resolution, shorter scan time July 23rd, 2016

New probe developed for improved high resolution measurement of brain temperature: Improved accuracy could allow researchers to measure brain temperature in times of trauma when small deviations in temperature can lead to additional brain injury July 23rd, 2016

Quantum drag:University of Iowa physicist says current in one iron magnetic sheet can create quantized spin waves in another, separate sheet July 22nd, 2016

Govt.-Legislation/Regulation/Funding/Policy

Quantum drag:University of Iowa physicist says current in one iron magnetic sheet can create quantized spin waves in another, separate sheet July 22nd, 2016

New reaction for the synthesis of nanostructures July 21st, 2016

Weird quantum effects stretch across hundreds of miles July 21st, 2016

Scientists glimpse inner workings of atomically thin transistors July 21st, 2016

Chip Technology

Quantum drag:University of Iowa physicist says current in one iron magnetic sheet can create quantized spin waves in another, separate sheet July 22nd, 2016

New Yale-developed device lengthens the life of quantum information July 22nd, 2016

New reaction for the synthesis of nanostructures July 21st, 2016

Research team led by NUS scientists develop plastic flexible magnetic memory device: Novel technique to implant high-performance magnetic memory chip on a flexible plastic surface without compromising performance July 21st, 2016

Memory Technology

Research team led by NUS scientists develop plastic flexible magnetic memory device: Novel technique to implant high-performance magnetic memory chip on a flexible plastic surface without compromising performance July 21st, 2016

The birth of quantum holography: Making holograms of single light particles! July 21st, 2016

Smallest hard disk to date writes information atom by atom July 20th, 2016

Atomic bits despite zero-point energy? Jülich scientists explore novel ways of developing stable nanomagnets July 11th, 2016

Discoveries

New remote-controlled microrobots for medical operations July 23rd, 2016

New superconducting coil improves MRI performance: UH-led research offers higher resolution, shorter scan time July 23rd, 2016

Nanoparticle versus cancer: Scientists have created nanoparticles which cure cancer harmlessly July 22nd, 2016

Quantum drag:University of Iowa physicist says current in one iron magnetic sheet can create quantized spin waves in another, separate sheet July 22nd, 2016

Announcements

New remote-controlled microrobots for medical operations July 23rd, 2016

New superconducting coil improves MRI performance: UH-led research offers higher resolution, shorter scan time July 23rd, 2016

New probe developed for improved high resolution measurement of brain temperature: Improved accuracy could allow researchers to measure brain temperature in times of trauma when small deviations in temperature can lead to additional brain injury July 23rd, 2016

Quantum drag:University of Iowa physicist says current in one iron magnetic sheet can create quantized spin waves in another, separate sheet July 22nd, 2016

Military

Scientists develop way to upsize nanostructures into light, flexible 3-D printed materials: Virginia Tech, Livermore National Lab researchers develop hierarchical 3-D printed metallic materials July 20th, 2016

Rice's 'antenna-reactor' catalysts offer best of both worlds: Technology marries light-harvesting nanoantennas to high-reaction-rate catalysts July 18th, 2016

'Green' electronic materials produced with synthetic biology July 16th, 2016

New method can identify chemical warfare agents more easily: The method could help governments protect people from horrifying toxic effects July 15th, 2016

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







Car Brands
Buy website traffic