Influence of silane flow on MOVPE grown GaN on sapphire substrate by an in situ SiN treatment

In this paper, the influence of silane flow on metalorganic vapour phase epitaxy (MOVPE) grown GaN on sapphire substrate by an in situ SiN treatment has been investigated. A flow of 10 sccm with treatment duration of 120 s appears to be the optimal value and improves the crystal quality. The dislocation density, determined by atomic force microscopic (AFM), is as low as 5×108 cm−2. A reduction of I2 full width at half maximum (FWHM) to 4 meV and an increase of both BE/YL and BE/DAP intensity ratio are also obtained.