Fabrication and characterization of Mn-implanted GaN layers followed by annealing

We report the effect of Mn incorporation on the structural and optical properties of GaN grown on a sapphire substrate in a plasma-enhanced molecular-beam epitaxy system followed by Mn ion implantation and annealing. The crystalline quality and phase purity were determined by high-resolution X-ray diffraction (XRD). The XRD results indicated that no macroscopic second phases were present in the Mn-implanted GaN layer after the annealing process. High-resolution transmission microscopy and energy dispersive X-ray spectroscopy revealed that the as-grown GaN epilayer and Mn-implanted GaN layer after annealing were single crystals with a hexagonal wurtzite structure, and they grew with a c-axis orientation perpendicular to the sapphire substrate. The Raman and photoluminescence spectra showed that the Mn-implanted GaN layer fabricated with a Mn ion dose of 5 x 10(15) cm(-2) followed by annealing at 800 degrees C for 30 min had higher crystalline quality than the Mn-implanted GaN layers fabricated with Mn ion doses of 5 x 10(15) and 2 x 10(16) cm(-2) followed by annealed at 900 degrees C for 30 and 80 min.