Crystal IS, an Asahi Kasei company announced the successful production of a 4-inch (100 mm) diameter single-crystal aluminum nitride (AlN) substrate. This is the first reported aluminum 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. aluminum nitride substrates have low defect densities, high UV transparency, and low concentrations of impurities.

AlN 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. 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 footprint of the Green Island facility. It will also enable the development of new applications on aluminum nitride substrates as it integrates into existing fabrication lines for power and RF devices using alternative materials.