The '50-50' chip: Memory device of the future?

Sep 13, 2013
The '50-50' chip: Memory device of the future?
This is an image of the phase-change memory arrays. Credit: SIMIT/Xilin Zhou

A new, environmentally-friendly electronic alloy consisting of 50 aluminum atoms bound to 50 atoms of antimony may be promising for building next-generation "phase-change" memory devices, which may be the data-storage technology of the future, according to a new paper published in the journal Applied Physics Letters, which is produced by AIP Publishing.

Phase-change memory is being actively pursued as an alternative to the ubiquitous flash memory for data storage applications, because flash memory is limited in its and phase-change memory can operate much faster.

Phase-change memory relies on materials that change from a disordered, amorphous structure to a crystalline structure when an is applied. The material has high in its amorphous state and low resistance in its —corresponding to the 1 and 0 states of binary data.

Flash memory has problems when devices get smaller than 20 nanometers. But a phase-change memory device can be less than 10 nanometers—allowing more memory to be squeezed into tinier spaces. "That's the most important feature of this kind of memory," said Xilin Zhou of the Shanghai Institute of Microsystem and Information Technology at the Chinese Academy of Sciences. Data can also be written into phase-change memories very quickly and the devices would be relatively inexpensive, he added.

So far, the most popular material for phase-change memory devices contains germanium, antimony, and tellurium. But compounds with three elements are more difficult to work with, Zhou said.

"It's difficult to control the phase-change memory manufacturing process of ternary alloys such as the traditionally used germanium-antimony-tellurium material. Etching and polishing of the material with chalcogens can change the material's composition, due to the motion of the atoms," explained Zhou.

Zhou and his colleagues turned to a material with just two elements: aluminum and antimony. They studied the material's phase-changing properties, finding that it's more thermally stable than the Ge-Sb-Te compound. The researchers discovered that Al50Sb50, in particular, has three distinct levels of resistance—and thus the ability to store three bits of data in a single memory cell, instead of just two. This suggests that this material can be used for multilevel data storage.

"A two-step resistance drop during the crystallization of the material can be used for multilevel data storage (MLS) and, interestingly, three distinct resistance levels are achieved in the phase-change memory cells," Zhou says. "So the aluminum-antimony material looks promising for use in high-density nonvolatile memory applications because of its good thermal stability and MLS capacity."

The researchers are now investigating the endurance or reversible electrical switching of the phase-change memory cell with MLS capacity.

Explore further: A bump circuit with flexible tuning ability that uses 500 times less power

More information: Applied Physics Letters. DOI: 10.1063/1.4818662

Related Stories

Recommended for you

Google to help boost Greece's tourism industry

3 hours ago

Internet giant Google will offer management courses to 3,000 tourism businesses on the island of Crete as part of an initiative to promote the sector in Greece, industry union Sete said on Thursday.

Enabling a new future for cloud computing

3 hours ago

The National Science Foundation (NSF) today announced two $10 million projects to create cloud computing testbeds—to be called "Chameleon" and "CloudLab"—that will enable the academic research community ...

Hitchhiking robot reaches journey's end in Canada

7 hours ago

A chatty robot with an LED-lit smiley face sent hitchhiking across Canada this summer as part of a social experiment reached its final destination Thursday after several thousand kilometers on the road.

Microsoft to unveil new Windows software

7 hours ago

A news report out Thursday indicated that Microsoft is poised to give the world a glimpse at a new-generation computer operating system that will succeed Windows 8.

Music site SoundCloud to start paying artists

9 hours ago

SoundCloud said Thursday that it will start paying artists and record companies whose music is played on the popular streaming site, a move that will bring it in line with competitors such as YouTube and Spotify.

User comments : 2

Adjust slider to filter visible comments by rank

Display comments: newest first

atomsk
1 / 5 (3) Sep 14, 2013
...has three distinct levels of resistance—and thus the ability to store three bits of data in a single memory cell

Should be 1,5 bits in a single memory cell.
ppnlppnl
not rated yet Sep 14, 2013
It would actually be 1.5849625007 bits.

That is the base 2 logarithm of 3.