UAlberta physicist Robert Wolkow. Image credit: John Ulan / UAlberta

A group of researchers led by University of Alberta physicist Robert Wolkow has found a way to delete and replace out-of-place atoms in circuitry designs. The group’s findings may potentially lead the way to faster, smaller and greener electronics.

When working at the atomic scale, Wolkow notes, silicon chip printing errors are inevitable—and may serve as a make-or-break in terms of whether a revolutionary circuitry design will work.

“We were making things that were close to perfect but not quite there,” he says. “Now that we have the ability to make corrections, we can ensure perfect patterns. It is this new ability to edit at the atom scale that makes all the difference."

Producing ultra-low power atomic circuitry has been limited by the inherent imperfection of the systems designed to produce it. The required precision was possible for simple materials that could be maintained at ultra-low temperatures, but impractical for applications in computers and personal digital devices. Wolkow’s team has worked with material and methods that ensure stability at room temperature.

The team had previously worked on improving accuracy of atomic silicon printing, but misplaced-atom errors always occurred at the one percent level. That tiny imperfection—a placement error of around one-third of a nanometer—was enough to upset circuit operation.

Enter the white-out. The researchers’ discovery is discussed in a paper called “Atomic White-Out,” a nod to the white correction fluid used for covering mistakes in writing or typing. Having created a reliable procedure for picking up single hydrogen atoms with an atomically sharp probe, the team can replace one or more hydrogen atoms—thereby erasing atomic misprints in a circuit's communication pathways.

"We can precisely erase any errors and reprint that atom in the correct place. It's not even a compromise like whiteout, where you either have a gooey layer or indentation,” Wolkow says. “It's actually perfect."