NUCLEATION OF EARLY STAGES AND GROWTH OF GAN BY HOT-WALL EPITAXY

GaN epilayers were prepared on sapphire substrate by Hot Wall Epitaxy technique using Ga and NH3 gas as source materials. The initial layer was needed to grow a high quality GaN epilayers on a sapphire substrat e, because it has an important affect in the crystallinity of the epil ayers. We grow the separated and combined initial layers on nitrided s apphire substrate and performed the measured. We certify that from the se data the crystallinity of GaN epilayers grown on separated initial layers was better than that on combined initial layer.