Buffer Free MOCVD Growth of GaN on 4H-SiC: Effect of Substrate Treatments and UV-Photoirradiation

GaN has been grown directly on the Si-face 4H-SiC(0001) substrates using remote plasma-assisted metal-organic chemical vapour deposition (RP-MOCVD) with UV-light irradiation. The effects of substrate pre-treatments and UV-photoirradiation of the growth surface on GaN nucleation and film morphology are investigated. Optical data from spectroscopic ellipsometry measurements and morphological data show an improvement in nucleation and material quality with UV-light irradiation.