Integrated Approach to III-Nitride Crystal Growth and Wafering

摘要

Centimeter size, transparent AlN crystals were grown at NCSU. TEM and XRT examination performed at ASU and SUNYSB revealed that the crystals are of highest quality and do not contain any visible extended defects. GaN crystals grown at Clemson by ammonothermal growth method have been grown to up to 5 mm in size. PL studies at ASU showed sharp excitonic emission, indicative of good quality. XRT showed mosaicity in some crystals. Work at Cornell was focusing on the development of equipment. A sandwich type reactor for vapor growth of GaN and a reactor for flux based growth are near the completion. Reaction modeling efforts have identified equilibrium species in the AlN sublimation growth while the reactor modeling has developed thermal model for the high temperature AlN reactor and flow dynamics for the ammonothermal growth.