www.pcworld.com/article/17...om_dna.html

IBM Scientists Build Computer Chips From DNA

Agam Shah, IDG News Service

Aug 17, 2009 1:20 am

Scientists at IBM are experimenting with using DNA molecules as a way to create tiny circuits that could form the basis of smaller, more powerful computer chips.

The company is researching ways in which DNA can arrange itself into patterns on the surface of a chip, and then act as a kind of scaffolding on to which millions of tiny carbon nanotubes and nanoparticles are deposited. That network of nanotubes and nanoparticles could act as the wires and transistors on future computer chips, the IBM scientists said.

For decades chip makers have been etching smaller and smaller patterns onto the surface of chips to speed performance and reduce power consumption. The fastest PC chips today are manufactured using a 45 nanometer process, but as the process dips below 22 nanometers in a few years, the assembly and fabrication of chips becomes far more difficult and expensive, said Bob Allen senior manager of chemistry and materials at IBM Research.

The new technique builds on work done several years ago by Paul Rothmund, a scientist at the California Institute of Technology, who figured out that DNA molecules can be made to "self-assemble" into tiny forms such as triangles, squares and stars. The approach takes advantage of DNA's natural ability to incorporate large amounts of complex information that can be applied to different types of activities.

To make a chip, the scientists first create lithographic templates -- the patterns from which circuits are made -- using traditional chip making techniques. After, they pour a DNA solution over the surface of the silicon and the tiny triangles and squares -- what the scientists call DNA origami -- line themselves up to the patterns etched out using lithography.

The IBM scientists, working with Rothmund, then figured out how to layer millions of nanotubes or nanoparticles over the DNA scaffold, where they adhere to form tiny integrated circuits.

"If we can properly, with incredible precision, place these little origami on the wafer surface, then you can use the properties of DNA to generate nanocircuit boards," Allen said.

The ability for the DNA structures to self-assemble is a key element needed for achieving greater precision in the design and manufacture of chips, said Greg Wallraff, an IBM research scientist and co-author of a paper about their achievements.

"The degree of difficulty of nanofabrication is going up rapidly," Wallraff said.

While the technology shows promise, it is years away from practical use, the scientists warned. "It's too early to say whether this will be a game changer," Allen said. "But we're pretty enthusiastic about the potential of this technique."

If it works as planned, it could lead to a new way of fabricating features on the surface of chips that allows semiconductors to be made even smaller, faster and more power-efficient than they are today.

A paper describing the scientists' achievements was due to be published Sunday in the journal Nature Nanotechnology.