SINGLE-CRYSTALLINE SUBSTRATE FOR MANUFACTURING GAN BASED EPILAYER, THE METHOD OF MANUFACTURING THE EPILAYER, LED AND LD COMPRISING THE GAN BASED EPILAYER

A single-crystal substrate for use in manufacturing a gallium-nitride thin film is provided to enhance crystalline of high gallium-nitride thin film and an optical characteristic through a rapid growth of gallium-nitride thin film. A single-crystal substrate(11) for use in manufacturing a gallium-nitride thin film(23) includes a nitrogen ion implantation pattern unit(19) and a nitrogen ion non-implantation section unit(21). The nitrogen ion implantation pattern unit is comprised of sapphire, silicon carbide, zinc oxide, silicon or GaAs, and has a plurality of patterns formed regularly and repeatedly on the same flat face. The nitrogen ion non-implantation section unit is adapted to distinguish between the patterns. A shape of the pattern is a circle, oval, stripe or polygonal shape. Material of the substrate is sapphire, and on the surface of the nitrogen ion implantation pattern unit, a nitride aluminum film is formed. A dose amount of nitrogen ion for the nitrogen ion implantation pattern unit is 1x10^15/cm^2 or 1x10^17/cm^2, and implantation energy is within a range of 10 through 100 keV.