How to build chips with DNA and why

Using a technique developed three years ago by Paul W.K. Rothemund at CalTech, Gregory Wallraff and his IBM Research colleagues at Almaden in San Jose have developed a chemical scaffold that will let them build chips with components just a few nanometers apart.

The technique could overcome one of the big problems in moving Moore’s Law forward, which is the problem of placing components together on a nanoscale.

Etching components closer together, the production method Gordon Moore himself wrote about, can be done, but each generation of chip-making gear then costs a lot more money than the previous generation.

I call this relationship Moore’s Second Law, and its capital requirements advantage political systems that can crush local dissent, like China, in order to keep other costs low. Pollution is also high with chemical  etching, with damage to groundwater common when photoresists are disposed of.

Rothemund calls his work “DNA Origami,” because it involves folding DNA molecules into specific shapes. The more common term is Molecular Programming. The folded DNA becomes a substrate engineers can then build on, with circuits that assemble themselves based on the DNA’s chemical instructions

Rothemund demonstrated this with the figure above, a detailed picture of North America built at nano-scale.

What is exciting about the new work is that, as the title of the IBM-CalTech paper illustrates, basic DNA shapes like triangles can now be placed and oriented on patterns produced by lithographics. This brings us a lot closer to actually producing chips (as opposed to art) using the Rothemund technique as a base.

The resulting chips could “self-arrange” on the DNA substrate with components like carbon nanotubes, silicon nanowires and quantum dots becoming a circuit.

DNA in this case is just a chemical compound. But you are using organic chemistry to create electronic circuits for the first time, and the hope is that production costs can eventually drop using the technique.

If we can actually get circuit densities down from 35 nm to 6 nm while cutting production costs I think Gordon Moore would be very happy to see his Second Law go away.