Japanese company develops world’s largest diamond substrate

Orbray, a Japanese precision parts manufacturer, has developed the world’s largest diamond substrate for electronic products.

The size is 2 cm square. In the future, it will be enlarged to 2 inches (about 5 cm) in diameter, and it will be commercialized for power semiconductors and quantum computers in 2026.

The research results were presented at the Spring Academic Lecture of the Society of Applied Physics on March 14.

The crystal structure of diamond is a cubic lattice expansion with carbon atoms as vertices. There are two main types of substrate surfaces, one is composed of the “(100) face” equivalent to the side of the crystal structure, and the other is composed of the oblique cross-section “(111) face”.

Although the oblique cross-section type is suitable for industrial applications such as electronics, there is a problem that it is difficult to increase the size.

According to Orbray, the company has independently developed a technology to grow diamond crystals on a “special sapphire substrate”.

The company has not released details of the technology, but it is believed to be a modified version of the “step-flow growth method”, which reduces the stress applied to the diamond crystal by growing the crystal on a slightly tilted sapphire substrate.