Liquid phase epitaxy of GaN films on sapphire substrates under an atmospheric pressure nitrogen ambience

GaN films were grown on sapphire substrates using liquid phase epitaxy under an atmospheric pressure nitrogen ambience, employing molten Ga and Fe3N as a source mixture. Single-crystal GaN (0001) films were successfully grown on sapphire (0001) substrates within a growth temperature (Tg) range of 750 to 900 oC. When varying the Fe3N concentration in the range of 0.05 to 3 mol%, lower iron nitride resulted in high crystallinity of GaN (0001) films. The incorporation of iron atoms in GaN can negatively impact crystal quality. Parameterizing Tg at a concentration of 0.1 mol% Fe3N showed that a reduction in the peak width of GaN (0002) X-ray rocking curves. However, at 3 mol%, elevating Tg resulted in the degradation of the crystallinity of GaN. This degradation may be attributed to the increased solubility of iron atoms in GaN with increasing Tg.