GaN series surface-emitting laser diode having spacer for effective diffusion of holes between P-type electrode and active layer, and method for manufacturing the same

1. A method for manufacturing a surface-emitting laser diode, the method comprising the steps of:

(a) sequentially forming a p-type material layer for lasing, an active layer, and an n-type material layer for lasing on a substrate;

(b) forming a first distributed Bragg reflector (DBR) on the n-type material layer, around which an n-type electrode is formed;

(c) forming a laser output window on a bottom surface of the substrate, the laser output window having a shape suitable for compensating for a drop in characteristics of a laser beam caused by the presence of the substrate;

(d) forming a p-type electrode on the bottom surface of the substrate to surround the laser output window; and

(e) forming a second DBR layer on the laser output window.

2. The method of claim 1 , wherein step (b) comprises:

forming a conductive layer on the n-type material layer;

forming a mask pattern on the conductive layer to expose a portion of the conductive layer in which the first DBR layer is to be formed;

removing the portion of the conductive layer which is exposed through the mask pattern, using the mask pattern as an etch mask;

forming the first DBR layer on a portion of the n-type material layer from which the conductive layer is removed; and

removing the mask pattern.

3. The method of claim 1 , wherein step (b) comprises:

forming the first DBR layer on the n-type material layer;

forming a mask pattern on the first DBR layer to expose a portion of the first DBR layer, in which the n-type electrode is to be formed;

removing the portion of the first DBR layer which is exposed through the mask pattern, using the mask pattern as an etch mask;

forming a conductive layer on a portion of the n-type material layer, from which the first DBR layer is removed; and

removing the mask pattern.

4. The method of claim 1 , wherein step (c) comprises:

polishing the bottom surface of the substrate;

forming a mask pattern to cover a portion of the polished bottom surface of the substrate in which the laser output window is to be formed;

processing the mask pattern into a shape suitable for compensating for diffraction of the laser beam caused by the presence of the substrate; and

etching the bottom surface of the substrate on which the processed mask pattern is formed, by a predetermined thickness, to transfer the shape of the processed mask pattern to the bottom surface of the substrate.

5. The method of claim 1 , wherein, in step (c), the laser output window is formed in a convex lens-like shape having a predetermined curvature suitable for compensating for diffraction of the laser beam.

6. The method of claim 4 , wherein, in processing the mask pattern, the mask pattern is processed into a convex lens-like shape by reflowing, the convex lens-like shape having a predetermined curvature suitable for compensating for diffraction of the laser beam.

7. The method of claim 4 , wherein the substrate is formed of multiple layers including a first substrate and a second substrate on the first substrate.

8. The method of claim 7 , wherein etching the bottom surface of the substrate on which the processed mask pattern is formed is continued until the second substrate is exposed.

9. The method of claim 1 , wherein the substrate is a p-type doped substrate or an undoped substrate.

10. The method of claim 7 , wherein one of the first and second substrates is a p-type doped substrate or an undoped substrate.

11. The method of claim 7 , wherein the first substrate is formed as a substrate on which a gallium nitride based material is grown and the second substrate is formed as a p-type spacer.

12. A method for manufacturing a surface-emitting laser diode, the method comprising the steps of:

(a) sequentially forming on a substrate an n-type material layer for lasing, an active layer, a p-type material layer for lasing, and a p-type spacer;

(b) forming a laser output window in a predetermined area of the p-type spacer;

(c) forming a p-type electrode on the p-type spacer to surround the laser output window;

(d) forming a first distributed Bragg reflector (DBR) layer on the laser output window;

(e) removing the substrate; and

(f) forming a second DBR layer on a predetermined portion of a bottom surface of the n-type material layer and forming an n-type electrode around the second DBR layer.

13. The method of claim 12 , wherein the substrate is formed of an n-type substrate or a sapphire substrate and a gallium nitride based material is grown thereon.

14. The method of claim 12 , wherein step (b) comprises:

forming a mask pattern to cover a portion of the p-type spacer in which the laser output window is to be formed;

processing the mask pattern into a shape suitable for compensating for diffraction of a laser beam caused by the presence of the p-type substrate; and

etching the entire surface of the p-type spacer on which the processed mask pattern is formed, by a predetermined thickness, to transfer the shape of the processed mask pattern to the p-type spacer.

15. The method of claim 14 , wherein the laser output window is formed in a convex lens-like shape having a predetermined curvature suitable for compensating for diffraction of the laser beam.

16. The method of claim 14 , wherein, in processing the mask pattern, the mask pattern is processed into a lens-like shape by reflowing, the lens-like shape having a predetermined curvature suitable for compensating for the diffraction of the laser beam.

17. The method of claim 4 , wherein the substrate is a p-type doped substrate or an undoped substrate.