The National Institute of Advanced Industrial Science and Technology said it successfully grew a diamond crystal at the same rate as that announced last year by the Carnegie Institution of Washington in the United States.

"We believe this should help Japan become more competitive in the area" of developing diamond semiconductors, said Yuji Horino, who led a diamond research team at the Japanese institute.

Diamond is seen as the next generation semiconductor material because of its high thermal conductivity and mechanical strength, compared with existing materials such as silicon, used widely in computer chips and other electronic devices.

To grow artificial diamonds, the institute heated up methane, hydrogen and nitrogen gases to create a plasma, which was then passed over a small diamond deposit on a heated board.

As a result, the size of a seed diamond crystal -- 4.0 millimeters by 4.0 millimeters by 0.5 millimeters (roughly 0.16 inch by 0.16 inch by 0.02 inch) -- grew to 7.0 millimeters by 7.0 millimeters by 2.8 millimeters in 55 hours.

That rate of growth was five times faster than current conventional methods in Japan, according to the institute.

"We concentrated the plasma and experimented with the content ratio of the gas," Horino said.

"The result is a major step forward in our efforts to grow large diamond crystals," he said, adding that he hopes to see "a major turning point in five years" in development of diamond semiconductors.

The institute will aim to apply the technology to develop one-inch diamond semiconductor wafers, he said.

A diamond crystal has to grow at least 10 millimeters by 10 millimeters in order for it to have industrial applications.

SPACE.WIRE