Breakthrough promises hotter, tougher, faster chips

Researchers led by Daisuke Nakamura of Toyota Central R&D Laboratories of Aichi, Japan, have described a way to build up wafers of silicon carbide, SiC, with a very low number of defects--an essential step in mass-producing electronic devices from the compound, the science journal Nature reported on Thursday. The researchers said it may be up to six years before the process is commercialized.

The new process involves building up layers of SiC from a high-temperature gas, which allows the crystallization of the compound to happen only on the cleanest faces. By this method, the researchers said, wafers can be made with lower levels of defects--by factors of two to three times less.

"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, Wright 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 higher 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 that of 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 light-emitting diodes 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 Developpement.

Rupert Goodwins of ZDNet UK reported from London.