Crystal IS, an Asahi Kasei company, has announced a major milestone in the production of a 4-inch (100 mm) diameter single-crystal aluminum nitride (AlN) substrate. This achievement represents the first reported aluminum nitride substrate of this size, demonstrating the scalability of Crystal IS processes for growing AlN bulk single-crystals and meeting the increasing production demands for this semiconductor material.

The use of aluminum nitride substrates offers several advantages, including low defect densities, high UV transparency, and low impurity concentrations. These properties make AlN particularly attractive for various industries, such as UVC LEDs and power devices, thanks to its ultra-wide bandgap and remarkable thermal conductivity. The 4-inch substrate developed by Crystal IS exhibits a usable area of over 80% based on current requirements for UVC LEDs.

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

Crystal IS, founded in 1997 with the goal of developing native aluminum nitride substrates, already manufactures UVC LEDs using its commercial process for 2-inch diameter substrates. These LEDs offer industry-leading reliability and performance, especially within the germicidal wavelength range of 260 nm - 270 nm. The current production capacity of the facility can meet the volume requirements for consumer devices incorporating UVC LEDs based on the existing 2-inch production line.

Eoin Connolly, President and CEO of Crystal IS, highlighted the scalability of their processes, stating, "This indicates the scalability of our processes to deliver quality devices on Aluminum Nitride. We are proud of the team’s accomplishment and its impact on the semiconductor industry as a whole."

Crystal IS currently produces thousands of 2-inch substrates annually to support the production of its Klaran and Optan product lines. The commercialization of 4-inch AlN substrates will quadruple the device output of the existing Green Island facility, where Crystal IS operates. Additionally, it will pave the way for the development of new applications on aluminum nitride substrates by integrating them into existing fabrication lines for power and RF devices that use alternative materials.

Crystal IS will present the progress made on 4-inch substrates at the upcoming 23rd American Conference on Crystal Growth and Epitaxy, to be held in Tucson, Arizona this month.