In an advance that could lead to lighter spacecraft and smarter cars, researchers have developed a new technique for producing a high-quality computer chip that is much more resistant to extreme conditions than the silicon found in most of today’s electronics.
Devices built with the rugged material would not require cooling and other protections that add size, weight and cost to traditional silicon electronics in power systems, jet engines, rockets, wireless transmitters and other equipment exposed to harsh environments.
And because the material — silicon carbide — can be made with fewer flaws than ever before, more reliable and more complex electronics can be built with it, according to the Japanese researchers who reported their findings in Thursday’s issue of the journal Nature.
In fact, the discovery paves the way for commercial adoption of the material that has stymied engineers for decades, Roland Madar, a physics professor at the National Polytechnic Institute in Grenoble, France, said in a commentary accompanying the research.
“These results are spectacular: The ... process is a major innovation,” he said. “Silicon carbide has become, at last, a contender for silicon’s crown.”
Still, the Japanese researchers, led by Daisuke Nakamura of Toyota Central R&D Laboratories Inc., believe practical uses are at least six years away, said Masato Kimura, a spokesman for the lab based in Aichi, Japan.
The problem with silicon — the basic building block of most electronics today — is that it becomes less reliable and less efficient when exposed to high temperatures or radiation.
Silicon carbide, which is so resistant to heat that it is used to protect space shuttles, is a semiconductor like silicon. It is also nearly as hard as diamonds.
But those unique properties make it difficult to use in electronics. Because it does not become liquid under high heat, it cannot undergo the traditional process that silicon undergoes that leads to nearly flaw-free chips.
The Japanese researchers discovered that they can build silicon carbide wafers by using a multiple-step process in which the crystal is grown in several stages. As a result, defects are minimized.
Using the technique, the researchers were able to build near-perfect wafers of up to 3 inches (7.5 centimeters) in diameter. There is still considerable work to be done to catch up with silicon: The semiconductor industry today uses silicon wafers of up to 12 inches (30 centimeters) in diameter. Chips are formed after being cut out of the wafers.
“Granted, this may not be large volume for commercial (use), but even on a demonstration basis this is very significant,” said T.S. Sudarshan, an electrical engineering professor at the University of South Carolina who was not affiliated with the research.