Incorporation of carbon on a (11¯01) facet of GaN by MOVPE

The incorporation of carbon using CCl4 or C2H2 in metal-organic vapor phase epitaxy is studied on (11¯01) facets of a GaN stripe formed by selective area growth. The optical spectra of the sample were examined by cathode luminescence spectroscopy (CL). An edge emission peak specific to the (11¯01) facet was tentatively assigned to the acceptor bound exciton (ABE). The peak intensity was enhanced by the increase of the carbon doping and determined by the ratio of the carbon source and the NH3 flow rate. The CL image showed that the doping had been achieved uniformly on the (11¯01) facets but affected by the stress/strain due to the large lattice mismatch against the Si substrate.