Growth of GaN films on porous 4H-SiC substrate by metal-organic chemical vapor deposition

摘要

High quality GaN epitaxial film was successfully grown directly on porous 4H-SiC (PSC) substrate. The difficulty in the nucleation of GaN islands, which is typically observed during metal-organic chemical vapor deposition (MOCVD), was solved by using the concept of facet-controlled epitaxial lateral overgrowth (FACELO) technique. The continuous GaN epitaxial film was obtained at reduced chamber pressure and lower N/Ga ratio. The full-width-half-maximum (FWHM) of (10-13) rocking curve of GaN epitaxial film on PSC substrate at the optimized condition was 220 arcsec under a skew symmetric diffraction geometry and the intense bound exciton lines with FWHM of 10 meV and LO phonon replica lines appeared in GaN layer, which indicates that GaN film on PSC substrate is of very high quality.