Power cut

A new material could improve the performance of transistors by up to a factor of five and allow them to consume 10 times less power, according to research by Intel and Qinetiq.

A new material could improve the performance of transistors by up to a factor of five and allow them to consume 10 times less power, according to research by Intel and Qinetiq.

In a two-year project researchers built quantum well transistors incorporating the material indium antimonide (InSb), which has the highest electron mobility of any known semiconductors.

Electrons can move through the material very quickly without being pushed hard, said Tim Phillips, business manager of Qinetiq’s Fast Transistors group. ‘So you can make the device operate at high speeds but with low voltage.’

Compared with a silicon device of the same size, an indium antimonide transistor would be much faster and consume 10 times less power. This is of particular interest to Intel, as the company attempts to ensure that Moore’s Law (that transistor density doubles every 18 months) continues to hold true.

‘The one thing that doesn’t scale as you make the devices smaller is the power consumption. So from Intel’s point of view the fact that by operating these devices at a lower voltage you can reduce the power consumption by 10 is key — it is a huge difference,’ said Phillips.

The material could be used in microprocessors by 2012-2015, although it could be introduced into less complex electronic devices much sooner, he said.

Despite its obvious advantages, InSb has not yet been used in transistors, as it can be difficult to work with. If the transistors are not designed properly the devices will not turn off very well, making it difficult to build an on-off switch, said Phillips. This is because the material contains a lot of extra electrons. These are difficult to get rid of and can harm the device’s performance.

‘We have a way of getting rid of them, making sure they don’t ruin performance. It’s like attaching a pump to make sure the extra electrons are sucked out,’ he said.

The technology was developed as part of a research project for the MoD. Qinetiq is considering a number of options for taking it forward, including further work with Intel.

The transistors are applied to a gallium arsenide substrate, but if the company did opt for continued collaboration with Intel, the aim would be to make them as compatible with silicon and the microchip giant’s fabrication processes as possible, said Phillips.