Published in PC Hardware

Georgia Tech boffins claim to make the first graphene chip

by on22 January 2024

Could be ten times faster 

Boffins at Georgia Tech, in Atlanta, have made what they call the world's first working graphene-based chip.

They say this could change the world of electronics, making computers faster and giving a new material for future quantum computers. The research, published in Nature and led by Walt de Heer, a physics professor at Georgia Tech, uses epitaxial graphene, a crystal of carbon stuck to silicon carbide (SiC).

This new chip material, called semiconducting epitaxial graphene (SEC) -- or epigraphene for short -- lets electrons move faster than in old-fashioned silicon, with less resistance. The result is transistors that can work at terahertz frequencies, offering speeds 10 times faster than the silicon-based transistors in today's chips.

De Heer says the method they used is a tweaked version of a very simple technique that has been around for over 50 years.

"When silicon carbide is heated to well over 1,000C, silicon evaporates from the surface, leaving a carbon-rich surface which then turns into graphene," says de Heer.

This heating step is done with an argon quartz tube with two SiC chips in a graphite pot, according to de Heer. Then a high-frequency current is run through a copper coil around the quartz tube, which heats the graphite pot by induction. The process takes about an hour.

De Heer says the SEC made this way is basically neutral, and when exposed to air, it will get doped by oxygen.

This oxygen doping is easily removed by heating it at about 200C in vacuum. "The chips we use cost about [US] $10, the pot about $1, and the quartz tube about $10," said de Heer. 

De Heer and his team admit, however, that they need to do more research to see if graphene-based chips can beat the current superconducting tech used in advanced quantum computers.

The Georgia Tech team don't plan to mix graphene-based chips with standard silicon or compound semiconductor lines. Instead, they want to go beyond silicon, using silicon carbide. They are working on ways, such as coating SEC with boron nitride, to make it work better with normal semiconductor lines.

Comparing their work with graphene field-effect transistors (GFETs) that you can buy, de Heer says there is a big difference:

"Normal GFETs don't use semiconducting graphene, making them useless for digital electronics that need a complete transistor shutdown."

He says that the SEC made by his team allows for a complete shutdown, meeting the tough requirements of digital electronics. De Heer admits that it will take time to develop the tech. 

Last modified on 22 January 2024
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