Breakthrough promises hotter, tougher, faster chips

Powerful processors that run hot but need no cooling and devices capable of withstanding extreme environments may be the result of new research reported today in Nature, the science journal.

Researchers led by Daisuke Nakamura of Toyota Central R&D Laboratories Inc. of Aichi, Japan, have described a way to build up very low defect wafers of silicon carbide (SiC), an essential step in mass-producing electronic devices from the compound. The researchers said it may be up to six years before the process is commercialised.

The new process involves building up layers of SiC from a high temperature gas, allowing the crystallisation of the compound to happen only on the cleanest faces. By this method, the researchers say, wafers can be made with levels of defect factors of two to three times fewer than previously.

"This has been an immense challenge for many years, and it will have major implication for society," Nick Wright, an electronics expert at the University of Newcastle upon Tyne, told Nature. New applications including much more efficient control of domestic equipment and engines running at high temperatures will be possible, he said. Experimental SiC transistors developed by the Japanese National Institute of Advanced Industrial Science and Technology have shown much lower power loss, better efficiency and high voltage capabilities than their silicon counterparts.

SiC -- also known as carborundum -- is a semiconductor, but its use in electronics has been restricted because of its extreme toughness. With a melting point of 2,700 degrees Celsius, twice that of silicon, and a hardness close to diamond, it has proved almost impossible to work with. The only mass-market electronic devices to use it so far have been some types of blue LED and laser diodes, with diodes and transistors beginning to appear. World production of SiC wafers last year was around 250,000 wafers, according to market research company Yole Développement.