Nitride-based semiconductor light emitting device with light extraction layer formed within

A nitride-based semiconductor light emitting device comprising:

• an n-clad layer, an active layer, and a p-clad layer, which are sequentially stacked on a substrate,
• wherein the n-clad layer comprises a first n-clad layer, an array of a plurality of nano-posts formed on an upper surface of the first n-clad layer and a second n-clad layer on the upper surface of the first n-clad layer on which the nano-posts are formed, whereby the nano-posts are interposed between the first and second n-clad layers,
• wherein the nano-posts are formed of a material having a different refraction index from a material used in forming the first n-clad layer and the second n-clad layer to diffract and/or scatter light generated in the active layer and each of nano-posts has a cylindrical shape by etching using a lithography method,
• wherein the first n-clad and the second n-clad layer are formed of substantially the same material,
• wherein the nano-posts are wholly encompassed by the substantially the same material forming the first and second n-clad layers.