Influence of chamber pressure on the crystal quality of homo-epitaxial GaN grown by radical-enhanced MOCVD (REMOCVD)

Abstract

III-nitride was grown by radical-enhanced metalorganic chemical vapor deposition (REMOCVD) with a very high-frequency electric source 100 MHz, using nitrogen and hydrogen as a source gas free from ammonia gas. Applying radio frequency (RF) power at the top electrode generates activated nitrogen, hydrogen, and other nitrogen species. Homoepitaxial gallium nitride (GaN) growth was studied as a function of chamber pressure by REMOCVD. The grown GaN was characterized by scanning electron microscope (SEM), atomic force microscope (AFM), and double crystal X-ray diffraction (XRD). Ga radicals and N radicals were detected by optical emission spectroscopy (OES) as a function of chamber pressure. The V/III ratio changes with the N2*/Ga* ratio, and the step flow growth of GaN was achieved under the chamber pressure of 300 Pa.