We know graphene is the best thing since sliced gallium arsenide to hit the electronics industry, thanks to the speed with which it dispatches electrons across its famous chickenwire network of carbon atoms. But so far, making transistors from the stuff live up to the promise it holds has been problematic.
The trouble is that it is very very hard to make sheets of graphene that are free of errors, which in turn impacts on the quality of the devices built.
But now a group of scientists at UCLA has demonstrated transistors with a cut off frequency of 300GHz, comparable to the top end of more traditional materials such as gallium arsenide or indium phosphide.
According to research published in the September 1 issue of Nature, the new manufacturing method uses a nanowire as the self aligned gate. This method doesn't introduce “appreciable defects” into the graphene meaning it retains the extremely high carrier mobility for which it is famous.
“Second, by using a self-aligned approach with a nanowire as the gate, the group was able to overcome alignment difficulties previously encountered and fabricate very short-channel devices with unprecedented performance,” commented UCLA professor of chemistry and biochemistry and lead researcher Xiangfeng Duan.