Ferroelectric capacitors promise ultra-cool computers

Good news from the research labs of the University of California, Berkeley: the scientists buried deep within the University’s electrical engineering department might have found a way to cool all our computers down, and get us back on the Moore’s Law highway.

(And speaking as someone whose laptop keyboard is currently almost too hot to type on, this news seems very good indeed).

The researchers have shown that it is possible to reduce the voltage required to keep a charge stored in a capacitor; this has been stalled at around 1 volt per transistor for some time. As the density of transistors increases, so both the power required to operate them, and the amount of heat they throw out rises.

This bottleneck is one of the main triggers for interest in spintronics and quantum computing. But what if conventional silicon can just be made to work better?

From the University’s press release : The solution proposed by [Sayeef Salahuddin, UC Berkeley assistant professor of electrical engineering] and his team is to modify current transistors so that they incorporate ferroelectric materials in their design, a change that could potentially generate a larger charge from a smaller voltage. This would allow engineers to make a transistor that dissipates less heat, and the shrinking of this key computer component could continue.

Ferroelectric materials are those which can hold both positive and negative charge, and can hold that charge even without a voltage being applied. The researchers found that layering a ferroelectric material and an electrical insulator in a capacitor resulted in this negative capacitance – a phenomenon theorised by Salahuddin when he was a graduate student at Purdue University.

"This work is the proof-of-principle we have needed to pursue negative capacitance as a viable strategy to overcome the power draw of today’s transistors," said Salahuddin. "If we can use this to create low-power transistors without compromising performance and the speed at which they work, it could change the whole computing industry.”