An investigation of sol–gel spin coating growth of wurtzite GaN thin film on 6H–SiC substrate

• Details of growth process from spin coating until nitridation process was studied.
• A simple and cost-effective method was used to grow GaN thin film.
• Directly growth of GaN thin film on bare 6H–SiC substrate without buffer layer.
• Structural and lattice vibrational properties show GaN thin film was formed.

In this study, wurtzite gallium nitride (GaN) thin film was directly grown on hexagonal silicon carbide (6H–SiC) substrate without buffer layer using sol–gel spin coating method followed by annealing and nitridation process. The entire growth process was investigated in-depth. The results revealed that the conversion of GaN thin film proceeds through an intermediate of amorphous gallium(I) sub-oxide (Ga2O). In this case, the amorphous Ga2O was converted into GaN thin film after being nitridated at 950 °C under ammonia ambient. The intermediate of amorphous Ga2O can only be identified through infrared reflectance measurements.