Mass production of AlN substrates by high speed homoepitaxial growth

The development of high-power and reliable deep-UV optical devices requires low dislocation density AlN substrates. In this study, thick AlN layers were homoepitaxially grown on PVT-AlN(0001) substrates by HVPE method at a growth rate above 100 μm/h. The grown layer showed low dislocation densities of less than 1E4 cm^-2 and a high deep-UV optical transparency. Recent expansions in both diameter of the substrate and size of the growth reactor have enabled mass-production of 2-inch-diameter HVPE-AlN substrates for deep-UV optical devices. This work was partially supported by Innovative Science and Technology Initiative for Security Grant Number JPJ004596, ATLA, Japan.