US Patent 7615772 Nitride semiconductor LED and fabrication method thereof

A nitride semiconductor LED includes a substrate; a GaN-based buffer layer formed on the substrate; AlyGa1−yN/GaN short period superlattice (SPS) layers formed on the GaN-based buffer layer in a sandwich structure of upper and lower parts having an undoped GaN layer or an indium-doped GaN layer interposed therebetween (where 0≦y≦1); a first electrode layer of an n-GaN layer formed on the upper AlyGa1−yN/GaN SPS layer; an active layer formed on the first electrode layer; and a second electrode layer of a p-GaN layer formed on the active layer.