IBM scientists and a collaborator from the California Institute of Technology have created a computer chip utilizing synthesized DNA molecules. The approach could pave the way to create tiny circuits that could form the basis of smaller, more powerful computer chips.
The DNA acts as scaffolding where millions of carbon nanotubes could be deposited and self-assembled into precise patterns that stick to the DNA molecules, and may provide a way to overcome the challenges of common techniques to manufacturing of sub-22nm chips. The fastest PC chips today are manufactured using a 45 nanometer process.
The partners have researched the combination between lithographic patterning (a series of processes that shape or alter the existing shape of the deposited materials) and self assembly, a method to arrange DNA origami structures on surfaces compatible with today's semiconductor manufacturing equipment.
The breakthrough lies in the fact that the positioned DNA nanostructures can serve as scaffolds, or miniature circuit boards, for the precise assembly of components – such as carbon nanotubes, nanowires and nanoparticles – at dimensions significantly smaller than possible with conventional semiconductor fabrication techniques, according to IBM.
To make the chip, the scientists first create the patterns from which circuits are made, or lithographic templates, using traditional chip making techniques at IBM. Then, they pour a DNA solution over the surface of the silicon and the tiny DNA nanostuctures such as triangles, squares, and stars (what the scientists call DNA origami) line themselves up to the patterns etched out using lithography where they adhere to form tiny integrated circuits.
The discovery of the template material and deposition conditions to afford high selectivity so that the origami binds only to the patterns of "sticky patches" and nowhere else were instrumental in this process.
“The cost involved in shrinking features to improve performance is a limiting factor in keeping pace with Moore’s Law and a concern across the semiconductor industry,” said Spike Narayan, manager, Science & Technology, IBM Research - Almaden.
“The combination of this directed self-assembly with today’s fabrication technology eventually could lead to substantial savings in the most expensive and challenging part of the chip-making process,” Narayan added.
The paper on this work, “Placement and orientation of DNA nanostructures on lithographically patterned surfaces,” by scientists at IBM Research and the California Institute of Technology, will be published in the September issue of Nature Nanotechnology and is currently available here.