Initial growth behaviors of GaN layers overgrown by HVPE on one-dimensional nanostructures

We developed a novel technique for obtaining a residual-strain-free GaN layer by the hydride vapor phase epitaxy (HVPE) method using one-dimensional nanostructures. The GaN layer was grown on a Si(111) substrate with a conventional AlN film and one-dimensional GaN nanostructures. The nanostructures were grown for 2h with a HCl:NH3 gas flow ratio of 1:50. The growth rate of nanoneedles at 600°C and nanorods at 650°C were 2.553 and 2.193μm/h, respectively. The overgrown GaN layer was grown at 1050°C for 5 and 10min. We obtained a GaN layer of 1.833μm thickness and c=5.1849Å. The morphology, crystalline structure, and optical characteristics of the GaN layer were examined by field emission scanning electron microscopy, X-ray diffraction, and photoluminescence.