Mapping Analysis of Crystalline Perfection and UV‐C Transparency of 2‐in. Aluminum Nitride Substrates Grown by Physical Vapor Transport

Large‐diameter, single‐crystalline aluminum nitride (AlN) substrates are sought for growth of AlGaN‐based devices. A combination of high crystalline perfection and optical transparency is desired for UV‐C emitter applications. A mapping analysis of 2‐in. AlN substrates grown by physical vapor transport is performed to study the within‐wafer uniformity of structural and optical properties. Substrates with spatially uniform crystalline perfection and UV‐C absorption coefficients, as determined by typical X‐ray rocking curve widths below 15 arcsec and 4.68 eV absorption coefficients below 20 cm−1, are shown. These findings demonstrate a robust mass production process for high‐quality, 2 in. AlN substrates possessing uniform structural and UV optical properties, making them highly suited for growth of next‐generation, AlGaN‐based devices.