Effect of H implantation on the structural properties of GaN

High-resolution X-ray diffraction and Raman scattering techniques have been used to analyse the impact of multiple energy hydrogen implantation with energy ranging from 40 to 120 keV on the structural properties of metal organic chemical vapour deposition grown unintentionally doped n-type Gallium Nitride (GaN) epitaxial layers. The full-width at half-maximum (FWHM) value of GaN rocking curves increases with ion dose indicating the damage in the crystal matrix due to hydrogen ion implantation. E₂ (high) and A₁(LO) Raman modes of GaN have been analysed. The behaviour of Raman shift, FWHM and area of GaN modes with H⁺ dose are explained on the basis of hydrogen substituting nitrogen atom, implantation-induced lattice damage and light attenuation by lattice damage in GaN layer. The influences of H⁺ implantation on the Raman mode parameters of sapphire substrate have also been analysed.