Stanford researchers identify 'ultrathin' semiconductor materials that could enable transistors ten times smaller than anything possible today

Materials could help shrink electrical circuits from five nanometers to three atoms thick

Researchers at Stanford University have uncovered two new semiconductor materials that could be used to bust the impending limits of silicon, enabling transistors 10 times smaller than anything possible with silicon today.

The two new materials, hafnium diselenide and zirconium diselenide share and "even exceed" some of silicon's desirable traits, the researchers claim, starting with the fact that all three materials can "rust" in a manner that enhances their performance.

"It's a bit like rust, but a very desirable rust," said Eric Pop, an associate professor of electrical engineering and director of Stanford's Pop Lab, who co-authored the research paper with post-doctoral scholar Michal Mleczko. The paper appears in the journal Science Advances.

While 'rust' doesn't sound like a desirable feature, it's encouraged in semiconductors as it isolates and protects the circuitry. In the case of the two new materials, they form what are called "high-K" insulators, which enable lower power operation than is possible with silicon and its silicon oxide insulator.

The new materials also outperform silicon with their ability to be shrunk to functional circuits just three atoms thick, which the researchers claim "could be a step toward the kinds of thinner, more energy-efficient chips demanded by devices of the future".

This discovery doesn't mean that the death of silicon is coming any time soon, though, and the researchers note that a combination of these three materials could lead to far more complex microprocessors and vast improvements in device battery life.

"Engineers have been unable to make silicon transistors thinner than about five nanometers, before the material properties begin to change in undesirable ways," Pop said.

"Silicon won't go away," he added, "but for consumers this could mean much longer battery life and much more complex functionality if these semiconductors can be integrated with silicon.

It's unlikely you'll be seeing these semiconductors any time soon, as the Stanford team says it needs to improve the contact between transistors and these circuits, and the reliability of the insulation.

"These connections have always proved a challenge for any new semiconductor, and the difficulty becomes greater as we shrink circuits to the atomic scale," said Mleczko.