First 4-inch aluminium nitride substrate

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Crystal IS, an Asahi Kasei company, has announced the successful production of a 4-inch (100 mm) diameter single-crystal aluminium nitride (AlN) substrate.

This is the first reported aluminium nitride substrate at this size and demonstrates the scalability of Crystal IS processes for growing AlN bulk single-crystals to meet production demands for this semiconductor material.

Aluminium nitride substrates have low defect densities, high UV transparency, and low concentrations of impurities and is attractive for a variety of industries, such as UVC LEDs and power devices, due to its ultra-wide bandgap and very high thermal conductivity. The 4-inch substrate produced shows a usable area of over 80% based on current requirements for UVC LEDs.

“We are extremely excited to announce the achievement of a 4-inch bulk aluminium nitride substrate,” said Dr Naohiro Kuze, Executive Fellow, Research Laboratory of Advanced Science and Technology of Asahi Kasei. “This accomplishment signifies that aluminium nitride is commercially viable for new industries beyond just UVC LEDs.”

Founded in 1997 to develop native aluminium nitride substrates, Crystal IS manufactures UVC LEDs on its commercial process for 2-inch diameter substrates. These LEDs are able to provide both reliability and performance at the germicidal wavelengths from 260 nm – 270 nm. The current capacity of the facility can meet the volume requirements for consumer devices using UVC LEDs based on the existing 2-inch production line.

“This indicates the scalability of our processes to deliver quality devices on Aluminium Nitride,” said Eoin Connolly, President and CEO of Crystal IS.

Crystal IS currently produces thousands of 2-inch substrates annually to support the production of its Klaran and Optan product lines. The commercialisation of 4-inch AlN substrates will quadruple the device output of the existing footprint of the Green Island facility. It will also enable the development of new applications on aluminium nitride substrates as it integrates into existing fabrication lines for power and RF devices using alternative materials.