Submount for light emitting diode and method for fabricating the same

1. A method for fabricating a submount for a light emitting diode (LED), comprising:

(a) providing a silicon substrate;

(b) forming a mask layer on the silicon substrate to expose a part of the silicon substrate;

(c) forming a first silicon oxide layer in the part of the silicon substrate which is exposed; and

(d) removing the mask layer and the first silicon oxide layer, so as to form a recess in the silicon substrate to form said submount for said light emitting diode.

2. The method for fabricating the submount for the LED according to claim 1 , wherein the mask layer comprises a pad oxide layer and a silicon nitride layer, and the pad oxide layer is for med between the silicon substrate and the silicon nitride layer.

3. The method for fabricating the submount for the LED according to claim 2 , wherein a slope or a curvature of a sidewall of the recess is adjusted by controlling a thicknesses ratio between the pad oxide layer and the silicon nitride layer.

4. The method for fabricating the submount for the LED according to claim 2 , wherein the step (d) comprises:

removing the silicon nitride layer; and

removing the pad oxide layer and the first silicon oxide layer.

5. The method for fabricating the submount for the LED according to claim 1 , after the step (d), further comprising repeating the step (b) to the step (d) at least once.

6. The method for fabricating the submount for the LED according to claim 5 , wherein when the step (b) is repeated, a range of the part of the silicon substrate exposed by the mask layer is substantially identical to a range of the part of the silicon substrate exposed by the mask layer in the step (b) that is performed last time.

7. The method for fabricating the submount for the LED according to claim 5 , wherein when the step (b) is repeated, a range of the part of the silicon substrate exposed by the mask layer contracts towards a center of the recess as compared with a range of the part of the silicon substrate exposed by the mask layer in the step (b) that is performed last time.

8. The method for fabricating the submount for the LED according to claim 1 , wherein the step (c) comprises performing a thermal oxidation process to oxidize the silicon substrate that is not covered by the mask layer.

9. The method for fabricating the submount for the LED according to claim 1 , after the step (d), further comprising:

performing an ion implantation process to form a plurality of implantation regions in a part of a sidewall of the recess;

performing a thermal process to form a plurality of second silicon oxide layers in the implantation regions; and

removing the second silicon oxide layers to form a plurality of holes on the sidewall of the recess.

10. The method for fabricating the submount for the LED according to claim 9 , wherein the ion implantation process comprises an oxygen ion implantation process.

11. The method for fabricating the submount for the LED according to claim 9 , wherein the thermal process comprises an oxygen-free thermal process.

12. The method for fabricating the submount for the LED according to claim 1 , after the step (d), further comprising forming a planar surface at a bottom of the recess.

13. The method for fabricating the submount for the LED according to claim 1 , after the step (d), further comprising forming a reflective layer on a surface of the silicon substrate in a conformal manner.

14. The method for fabricating the submount for the LED according to claim 13 , wherein a material of the reflective layer comprises a metal.