Nitride-based semiconductor light emitting device and method of manufacturing the same
View Patent ↗A nitride-based semiconductor light emitting device having an improved structure in which light extraction efficiency is improved and a method of manufacturing the same are provided. The nitride-based semiconductor light emitting device comprises 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 clad layer, a second clad layer, and a light extraction layer interposed between the first clad layer and the second clad layer and composed of an array of a plurality of nano-posts, the light extraction layer diffracting or/and scattering light generated in the active layer.
1. A method of manufacturing a nitride-based semiconductor light emitting device, the method comprising sequentially forming an n-clad layer, an active layer, and a p-clad layer on a substrate, wherein the forming of the n-clad layer comprises:
forming a first clad layer on the substrate;
forming a light transmission material layer on an upper surface of the first clad layer;
patterning the light transmission material layer to form a light extraction layer composed of an array of a plurality of nano-posts and diffracting or/and scattering light generated in the active layer; and
forming a second clad layer for embedding the light extraction layer on the first clad layer,
wherein the first clad layer and the second clad layer are formed of substantially the same material,
wherein the plurality of nano-posts are wholly encompassed by the substantially same material forming the first and second clad layers.
2. The method of claim 1 , wherein the patterning of the light transmission material layer is performed using a hologram lithography method.
3. The method of claim 1 , wherein the light transmission material layer is formed of a material having different refraction index from a material used in forming the first clad layer and the second clad layer.
4. The method of claim 3 , wherein the light transmission material layer is formed of a light transmission material having a refraction index of approximately 2.5 or less.
5. The method of claim 4 , wherein the light transmission material layer is formed of a transparent material with respect to a wavelength in a range of approximately 200-780 nm.
6. The method of claim 3 , wherein the light transmission material layer is formed of a material selected from the group consisting of SiO 2 , SIN x , Al 2 O 3 , HfO, TiO 2 , ZrO, and ZnO or by adding a material selected from the group consisting of Mg, Ag, Zn, Sc, Hf, Zr, Te, Se, Ta, W, Nb, Cu, Si, Ni, Co, Mo, Cr, Mn, Hg, Pr, and La to an indium oxide.
7. The method of claim 1 , wherein an arrangement period of the nano-posts is approximately 100-2000 nm.
8. The method of claim 7 , wherein an arrangement period of the nano-posts is approximately 700 nm.
9. The method of claim 1 , wherein a height of each of the nano-posts is approximately 100-1000 nm.
10. The method of claim 9 , wherein a height of each of the nano-posts is approximately 300 nm.
11. The method of claim 1 , wherein a diameter of each of the nano-posts is approximately 100-1000 nm.
12. The method of claim 1 , wherein the first clad layer and the second clad layer are formed of an AlInGaN-based III-V-group nitride semiconductor material.
13. A nitride-based semiconductor light emitting device manufactured by the method of claim 1 .