Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Taking Nanolithography Beyond Semiconductors

18.12.2006
A new process for chemical patterning combines molecular self-assembly with traditional lithography to create multifunctional surfaces in precise patterns at the molecular level.

The process allows scientists to create surfaces with varied chemical functionalities and promises to extend lithography to applications beyond traditional semiconductors. The new technique, which could have a number of practical chemical and biochemical applications, will be described in the 22 December 2006 issue of the journal Advanced Materials by a team led by Paul S. Weiss, distinguished professor of chemistry and physics at Penn State and Mark Horn, associate professor of engineering science and mechanics at Penn State.

The technique uses self-assembled monolayers (SAM) -- chemical films that are one molecule thick -- to build a layer on a surface, followed by the addition of a photolithographic resist that protects the covered parts of the film during subsequent processing. The resist acts as a shield during processing, allowing the cleaning and then self-assembly of different chemical functions on the unprotected parts of the surface. "Other chemical patterning processes on surfaces suffer from cross-reactions and dissolution at their boundaries," says Weiss. "In our process, the resist provides a barrier and prevents interactions between the molecules already on the surface and the chemistry being done elsewhere. The resist is placed on top of the pattern by standard photolithographic techniques. After the resist is placed, molecules are removed from the exposed areas of the surface. Subsequent placement of a different SAM on the exposed surface creates a pattern of different films, with different functionalities.

Because the resist protects everything it covers, the layer under it does not have to be a single functionality. As a result, a series of pattern/protect/remove/repattern cycles can be applied, allowing complex patterns of functional monolayers on the surface of the substrate. "It allows us to work stepwise across a surface, building complex patterns," says Weiss. "We have demonstrated patterns at the micrometer scale and have the potential to go down to nanometer-scale patterns." While the two processes used by the team -- molecular self-assembly and photolithography -- are individually well-developed, the team's innovation is the successful combination of the techniques to build well-defined surfaces.

Chemical functionalities are distributed across the surface in high-quality layers as a result of the self-assembly process and in high-resolution patterns due to the use of the specialized resists. Different chemical functionalities can be used to detect or to separate a variety of species from a mixture. "The product of the process can be used to create a multiplexed, patterned, capture surface," says Weiss. "We could expose the entire surface to one mixture and capture different parts of the mixture in each region."

The work was a collaborative effort between the Weiss group, specializing in surface chemistry, and the Horn group, specializing in nanolithography. In addition to Weiss and Horn, the Penn State research team included graduate students Mary E. Anderson (now graduated), Charan Srinivasan, and J. Nathan Hohman, as well as undergraduate researcher Erin Carter. The work was performed as a part of both the National Science Foundation supported Center for Nanoscale Science and Penn State's node of the National Nanofabrication Infrastructure Network.

Barbara K. Kennedy | EurekAlert!
Further information:
http://www.psu.edu

More articles from Materials Sciences:

nachricht Switched-on DNA
20.02.2017 | Arizona State University

nachricht Using a simple, scalable method, a material that can be used as a sensor is developed
15.02.2017 | University of the Basque Country

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

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

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...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

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

Switched-on DNA

20.02.2017 | Materials Sciences

Second cause of hidden hearing loss identified

20.02.2017 | Health and Medicine

Prospect for more effective treatment of nerve pain

20.02.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>