Growth of GaN films by hot-mesh chemical vapor deposition using ruthenium-coated tungsten mesh

GaN films were grown on AlN/SiC/Si substrates by hot-mesh chemical vapor deposition (CVD) using ruthenium (Ru)-coated tungsten (W)-mesh. When using the Ru-coated mesh, the crystallinity of the GaN films did not degrade until a mesh temperature of 1000°C, while the crystallinity markedly degraded at lower than 1100°C when using the W-mesh. From the photoluminescence (PL) spectra of GaN films grown using the Ru-coated W-mesh, strong near-band-edge emission without yellow luminescence can be observed. In order to elucidate the difference in the decomposition efficiency of ammonia gas, the hydrogen radical density generated by the heated W-mesh and Ru-coated mesh was also evaluated using tungsten phosphate glass plates.