Select your localized edition:

Close ×

More Ways to Connect

Discover one of our 28 local entrepreneurial communities »

Be the first to know as we launch in new countries and markets around the globe.

Interested in bringing MIT Technology Review to your local market?

MIT Technology ReviewMIT Technology Review - logo

 

Unsupported browser: Your browser does not meet modern web standards. See how it scores »

{ action.text }

The logic gate relies on carbon nanotubes. The nanotubes are the faint vertical lines stretching between the circuit traces.

It is inevitable that eventually Moore’s Law will fail–at least for silicon technology. Further miniaturizing silicon transistors to fit more of them on a microchip will become impossible, or at least too expensive. Researchers are anticipating that day by developing alternative materials such as gallium arsenide, graphene, and carbon nanotubes. The hope is that transistors made from these materials will be smaller, faster, and more energy efficient than anything that could ever be made from silicon. “We need to add more materials to the toolbox,” says Michael Mayberry, director of components research at Intel.

One challenge is to make these materials work with the infrastructure built for silicon, which represents billions of dollars in investment for chip makers (see “The High Cost of Upholding Moore’s Law”). Intel, for one, has developed expertise in compound semiconductors, such as gallium arsenide, that operate at higher speeds and lower voltages than silicon. But gallium arsenide is brittle, so devices made from it are difficult to manufacture in volume. Intel is trying to get around the problem by growing thin layers of this material on top of silicon wafers, hoping to improve silicon chips by adding a few high-­performance gallium arsenide elements.

Other major contenders to replace silicon are based on carbon. In February, IBM made transistors from graphene, a one-atom-thick mesh of carbon; they are much faster than silicon transistors, switching at the rate of 100 gigahertz. Crucially, the IBM researchers built the transistor arrays on wafers, using a manufacturing-friendly process. These graphene transistors are still much bigger than their silicon counterparts, however, and an integrated circuit hasn’t been made from them yet.

Researchers are also working on making transistors from carbon nanotubes. Like the graphene transistors, these are speedy, but they are much smaller. At Stanford University, scientists are developing techniques for fabricating three-dimensional integrated circuits based on these cylindrical molecules of carbon.

It’s still uncertain what will ultimately replace silicon. But this once dominant material is already looking too fragile, too power hungry, and too expensive to drive our computers forever.

0 comments about this story. Start the discussion »

Credit: Nishant Patil, Albert Lin, Hai Wei, Stanford University

Tagged: Computing

Reprints and Permissions | Send feedback to the editor

From the Archives

Close

Introducing MIT Technology Review Insider.

Already a Magazine subscriber?

You're automatically an Insider. It's easy to activate or upgrade your account.

Activate Your Account

Become an Insider

It's the new way to subscribe. Get even more of the tech news, research, and discoveries you crave.

Sign Up

Learn More

Find out why MIT Technology Review Insider is for you and explore your options.

Show Me