Chenming Hu, a professor of electrical engineering and computer sciences at the University of California, Berkeley, said the tiny transistor was much smaller than any other ever developed. "It's a new world record," Hu said of the prototype, dubbed "Finfet". Details of the invention, which was funded by the US defence advanced research project agency, will be unveiled next month at the international electronic devices meeting in Washington.

The Berkeley breakthrough, announced in a news release, changed the design of the "gate", or switch, on the transistor which controls the flow of electric current in electronic devices.

While previously this gate was a flat conductor that controlled only one side of the passage through which the current flows, the Berkeley team has redesigned it as a fork-shaped prong straddling both sides of the passage. This gives much better control and reduced current leakage, meaning the transistor can be made much smaller.