Diamond chips could replace silicon

It could happen that the microchips of tomorrow could be made out of diamond rather than silicon.

According to the New Scientist, pure diamond is an electrical insulator, but given the right impurities is has the capability of being a semiconductor – and diamonds are the best thermal conductors on earth.

What this means is that synthetic diamonds could be used to create microchips which handle high-power, but do not need “power-hungry cooling systems”.

“Diamond-based control modules in electric cars and industrial machinery could lead to considerable energy savings,” said Japanese scientist Hideaki Yamada, from the Institute of Advanced Industrial Science and Technology.

The problem so far though has been making diamond wafers big enough to carve thousands of microchips and make it economically viable. 

Synthetic diamonds are made using chemical vapour deposition (CVD) where plasma of methane or another hydrocarbon gas deposits carbon on a surface which is seeded with diamond particles.

The wafer is grown and etched off the seed layer, but so far the largest diamond wafers have been too small. This changed when scientists tried to use CVD to bond a series of identical small wafers together, and managed to make 25mm square wafers.

“It certainly has sufficient potential for fabricating electronic devices,” says Yamada, saying that the method could make bigger wafers.

In the next year his group is aiming to produce 50-by-50 millimetre and 75-by-75 millimetre wafers.