Method of forming pattern on group III nitride semiconductor substrate and method of manufacturing group III nitride semiconductor light emitting device
There is provided a method of forming a pattern on a group III nitride semiconductor substrate. A method of forming a pattern on a group III nitride semiconductor substrate according to an aspect of the invention may include: irradiating a laser beam onto at least one first region for preventing etching in a group III nitride semiconductor substrate; and etching at least one second region exclusive of the first region using the first region irradiated with the laser beam as a mask.
1. A method of manufacturing a group III nitride semiconductor light emitting device, the method comprising:
growing a light emitting structure having a first group III nitride semiconductor layer, an active layer and a second group III nitride semiconductor layer on a nitride single crystal growth substrate;
forming a support substrate to support the light emitting structure on the second group III nitride semiconductor layer;
removing the nitride single crystal growth substrate from the light emitting structure;
irradiating a laser beam onto at least one first region for preventing etching in the light emitting structure exposed by removing the nitride single crystal growth substrate; and
etching at least one second region exclusive of the first region using the first region irradiated with the laser beam as a mask.
2. The method of claim 1 , wherein the light emitting structure comprises a first surface corresponding to one surface of the first group III nitride semiconductor layer and having nitrogen polarity, and a second surface opposing the first surface corresponding to one surface of the second group III nitride semiconductor layer and having group III polarity.
3. The method of claim 2 , wherein the at least one first region and the at least second region are located on the first surface of the light emitting structure, and the polarity of the first region is converted into group III polarity by the laser irradiation.
4. The method of claim 1 , wherein the etching of the at least one second region comprises forming an irregular pattern for light extraction by etching the second region to a predetermined depth on the first group III nitride semiconductor layer.
5. The method of claim 1 , wherein the etching of the at least one second region comprises forming a grooved pattern used to divide the light emitting structure into separate devices by etching the second region from the first group III nitride semiconductor layer to a predetermined depth below the second group III nitride semiconductor layer.
6. The method of claim 1 , wherein the nitride single crystal growth substrate is formed of a material selected from the group consisting of sapphire, SiC, Si, ZnO, MgAl 2 O 4 , MgO, LiAlO 2 and LiGaO 2 .
7. The method of claim 1 , wherein each of the first group III nitride semiconductor layer, the active layer and the second group III nitride semiconductor layer comprises a semiconductor having a composition represented by l x In y Ga (1-x-y) N(0≦x≦1, 0≦y≦1 and 0≦x+y≦1).
8. The method of claim 1 , wherein the etching of the at least second region is performed by wet etching using any one material of KOH, H 2 SO 4 and H 2 PO 4 .
9. The method of claim 1 , further comprising:
forming a first electrode on the first region irradiated with the laser beam; and
forming a second electrode on the support substrate.