Designfax weekly eMagazine

Subscribe Today!

Archives

View Archives

Partners

Manufacturing Center
Product Spotlight

Modern Applications News
Metalworking Ideas For
Today's Job Shops

Tooling and Production
Strategies for large
metalworking plants

Diamond-based circuits take the heat for advanced applications

Researchers at Japan's National Institute for Materials Science developed a hydrogenated diamond circuit operational at 300 C.

When power generators like windmills and solar panels transfer electricity to homes, businesses, and the power grid, they lose almost 10 percent of the generated power. To address this problem, scientists are researching new diamond semiconductor circuits to make power conversion systems more efficient.

A team of researchers from Japan successfully fabricated a key circuit in power conversion systems using hydrogenated diamond (H-diamond.) Furthermore, they demonstrated that it functions at temperatures as high as 300 C. These circuits can be used in diamond-based electronic devices that are smaller, lighter, and more efficient than silicon-based devices. The researchers reported their findings April 10 in Applied Physics Letters.

The view of the H-diamond MOSFET NOR logic circuit from above (left), and the operation of the NOR logic circuits, showing that the circuit only produces voltage when both inputs are at zero. [Credit: Liu, et al]

 

 

 

 

Silicon's material properties make it a poor choice for circuits in high-power, high-temperature, and high-frequency electronic devices. "For the high-power generators, diamond is more suitable for fabricating power conversion systems with a small size and low power loss," said Jiangwei Liu, a researcher at Japan's National Institute for Materials Science and a co-author on the paper.

In the current study, researchers tested an H-diamond NOR logic circuit's stability at high temperatures. This type of circuit, used in computers, gives an output only when both inputs are zero. The circuit consisted of two metal-oxide-semiconductor field-effect transistors (MOSFETs), which are used in many electronic devices and in digital integrated circuits, like microprocessors. In 2013, Liu and his colleagues were the first to report fabricating an E-mode H-diamond MOSFET.

When the researchers heated the circuit to 300 C, it functioned correctly, but it failed at 400 C. They suspect that the higher temperature caused the MOSFETs to break down. Higher temperatures may be achievable, however, as another group reported successful operation of a similar H-diamond MOSFET at 400 C. For comparison, the maximum operation temperature for silicon-based electronic devices is about 150 C.

In the future, the researchers plan to improve the circuit's stability at high temperatures by altering the oxide insulators and modifying the fabrication process. They hope to construct H-diamond MOSFET logic circuits that can operate above 500 C and at 2.0 kV.

"Diamond is one of the candidate semiconductor materials for next-generation electronics, specifically for improving energy savings," said Yasuo Koide, a director at the National Institute for Materials Science and co-author on the paper. "Of course, in order to achieve industrialization, it is essential to develop inch-sized single-crystal diamond wafers and other diamond-based integrated circuits."

Source: American Institute of Physics

Published April 2018

Rate this article