Gallium Nitride (GaN) and Aluminum Nitride (AlN) Templates In the field of nitride semiconductors, “template” refers to a composite substrate which includes a thin layer of GaN or AlN deposited epitaxially on a foreign substrate such as sapphire or silicon carbide. The thickness of the nitride layer is usually between 1 and 250 microns. Kyma’s GaN templates are built on sapphire and are available in 2”, 3”, and 4” diameter. They exhibit industry leading low defect densities of ~107 cm-2 or lower and are epi ready with low surface roughness.