Graphene used to create tiny transistor

Graphene has been used to create an even smaller transistor than the device reported in Electroline last year (click here to view article).

According to Dr Kostya Novoselov and Prof Andre Geim from The School of Physics and Astronomy at The University of Manchester, they have built a transistor that is one atom thick and 10 atoms wide.

With manufacturers trying to cram more and more components into integrated circuits, they are reaching the physical limits of silicone that becomes unstable at nanoscale levels.

And with the speed of cramming decreasing further, miniaturisation of electronics is to experience its most fundamental challenge in the next 10 to 20 years, according to the semiconductor industry roadmap.

Four years ago, Geim and his colleagues discovered graphene, the first known one-atom-thick material which can be viewed as a plane of atoms pulled out from graphite.

More recently, the Manchester team has shown that it is possible to carve out nanometre-scale transistors from a single graphene crystal. Unlike all other known materials, graphene remains highly stable and conductive even when it is cut into devices one nanometre wide.

The smaller the size of their transistors the better they perform, according to the Manchester researchers.

Graphene transistors start showing advantages and good performance at sizes below 10 nm, the miniaturisation limit at which the silicon technology is predicted to fail.

“Previously, researchers tried to use large molecules as individual transistors to create a new kind of electronic circuits. It is like a bit of chemistry added to computer engineering,” said Novoselov.

“Now one can think of designer molecules acting as transistors connected into designer computer architecture on the basis of the same material (graphene) and use the same fabrication approach that is currently used by the semiconductor industry.”

“Unfortunately, no existing technology allows cutting materials with true nanometre precision. But this is exactly the same challenge that every post-silicon electronics has to face. At least we now have a material that can meet such a challenge,” Geim said.

Geim predicts we won't see these graphene chips any earlier than 2020 — more likely around 2025 — and that until then, silicon technology will remain dominant. He believes graphene is probably the only viable approach after the silicon era comes to an end.