Oct. 20, 2009

New technique for making thin electronics supported by stimulus funds

The National Science Foundation's Materials World Network program is supporting Cornell scientists who have invented a reliable way of processing organic devices with a patent-pending process called orthogonal lithography. The grant of $900,000 is from the American Recovery and Reinvestment Act and lasts through 2013.

Scientists who study electronics made of organic materials -- based on carbon, as opposed to traditional silicon -- can make some of the most lightweight, inexpensive and flexible semiconductors the world has seen.

But the ability to mass-produce these organic devices is another story. A well-known nanofabrication method called photolithography, in which patterns are transferred into a material coated with a light-sensitive photoresist, has so far been problematic for the delicate, easily contaminated organic materials. This has hindered organic materials' entry into the market for such things as flat-panel displays.

In orthogonal lithography, materials are patterned using a particular patent-pending photoresist that is soluble in environmentally safe fluorinated solvents. This protects the organic material and dramatically eases production challenges.

"We've identified a family of orthogonal solvents that is very different than water and very different than the non-polar organics -- the solvents usually used in these processes," said Chris Ober, co-leader of the grant with George Malliaras, both Cornell professors of materials science and engineering, and Richard Friend of the University of Cambridge.

The grant will fund the group's continued study of increasingly complex organic devices using orthogonal lithography. Thanks to the stimulus funding, Ober will also be able to retain a postdoctoral associate in his lab, he said. Indirectly, the funds may aid job creation at a new Ithaca startup company, Orthogonal Inc., that is based in the technology.

To date, Cornell has received 120 grants on the Ithaca campus, totaling almost $99 million.