Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New method of self-assembling nanoscale elements could transform data storage industry

23.02.2009
An innovative and easily implemented technique in which nanoscale elements precisely assemble themselves over large surfaces could soon open doors to dramatic improvements in the data storage capacity of electronic media, according to scientists at the University of California, Berkeley, and the University of Massachusetts Amherst (UMass Amherst).

"I expect that the new method we developed will transform the microelectronic and storage industries, and open up vistas for entirely new applications," said co-lead investigator Thomas Russell, director of the Materials Research Science and Engineering Center at UMass Amherst, visiting Miller Professor at UC Berkeley's Department of Chemistry, and one of the world's leading experts on the behavior of polymers. "This work could possibly be translated into the production of more energy-efficient photovoltaic cells, for instance."

Russell conceived of this new approach with co-lead investigator Ting Xu, a UC Berkeley assistant professor with joint appointments in the Department of Material Sciences and Engineering and the Department of Chemistry. They describe their work in the Feb. 20 issue of the journal Science.

"The density achievable with the technology we've developed could potentially enable the contents of 250 DVDs to fit onto a surface the size of a quarter," said Xu, who is also a faculty scientist at Lawrence Berkeley National Laboratory.

Xu explained that the molecules in the thin film of block copolymers - two or more chemically dissimilar polymer chains linked together - will self-assemble into an extremely precise, equidistant pattern when spread out on a surface, much like a regiment of disciplined soldiers lining up in formation. For more than a decade, researchers have been trying to exploit this characteristic for use in semiconductor manufacturing, but they have been constrained because the order starts to break down as the size of the area increases.

Once the formation breaks down, the individual domains cannot be read or written to, rendering them useless as a form of data storage.

To overcome this size constraint, Russell and Xu conceived of the elegantly simple solution of layering the film of block copolymers onto the surface of a commercially available sapphire crystal. When the crystal is cut at an angle - a common procedure known as a miscut - and heated to 1,300 to 1,500 degrees Centigrade (2,372 to 2,732 degrees Fahrenheit) for 24 hours, its surface reorganizes into a highly ordered pattern of sawtooth ridges that can then be used to guide the self-assembly of the block polymers.

With this technique, the researchers were able to achieve defect-free arrays of nanoscopic elements with feature sizes as small as 3 nanometers, translating into densities of 10 terabits per square inch. One terabit is equal to 1 trillion bits, or 125 gigabytes.

Because crystals come in a variety of sizes, there are few limitations to how large this block copolymer array can be produced, the researchers said. They also noted that the angle and depth of the sawtooth ridges can be easily varied by changing the temperature at which the crystal is heated to fine tune the desired pattern.

"We can generate nearly perfect arrays over macroscopic surfaces where the density is over 15 times higher than anything achieved before," said Russell. "With that order of density, one could get a high-definition picture on a screen the size of a JumboTron."

"It's one thing to get dozens of soldiers to stand in perfect formation in an area the size of a classroom, each person equidistant from the other, but quite another to get tens of trillions of individuals to do so on the field in a football stadium," Xu added. "Using this crystal surface as a guide is like giving the soldiers a marker so they know where to stand."

Other research teams across the country are engaged in similar efforts to break the size barrier of self-assembled block copolymers, but this new project by the UMass Amherst-UC Berkeley scientists differs in that it does not rely upon advances in lithography to achieve its goals.

In the semiconductor industry, optical lithography is a process in which light passes through a mask with a desired circuit pattern onto a photosensitive material, or photoresist, that undergoes a chemical change. Several steps of chemical treatment are then used to develop the desired pattern for subsequent use.

To keep up with Moore's Law and the demand for increasingly smaller features for semiconductors and microprocessors, industry has turned to nanolithography and the use of ever-shorter wavelengths of light at greater cost.

"The challenge with photolithography is that it is rapidly approaching the resolution limits of light," said Xu. "In our approach, we shifted away from this 'top down' method of producing smaller features and instead utilized advantages of a 'bottom up' approach. The beauty of the method we developed is that it takes from processes already in use in industry, so it will be very easy to incorporate into the production line with little cost."

An added benefit, said Xu, is that "our technique is more environmentally friendly than photolithography, which requires the use of harsh chemicals and acids."

Sarah Yang | EurekAlert!
Further information:
http://www.berkeley.edu

More articles from Physics and Astronomy:

nachricht From rocks in Colorado, evidence of a 'chaotic solar system'
23.02.2017 | University of Wisconsin-Madison

nachricht Prediction: More gas-giants will be found orbiting Sun-like stars
22.02.2017 | Carnegie Institution for Science

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Safe glide at total engine failure with ELA-inside

On January 15, 2009, Chesley B. Sullenberger was celebrated world-wide: after the two engines had failed due to bird strike, he and his flight crew succeeded after a glide flight with an Airbus A320 in ditching on the Hudson River. All 155 people on board were saved.

On January 15, 2009, Chesley B. Sullenberger was celebrated world-wide: after the two engines had failed due to bird strike, he and his flight crew succeeded...

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

New pop-up strategy inspired by cuts, not folds

27.02.2017 | Materials Sciences

Sandia uses confined nanoparticles to improve hydrogen storage materials performance

27.02.2017 | Interdisciplinary Research

Decoding the genome's cryptic language

27.02.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>