Method for manufacturing high efficiency light-emitting diodes
View Patent ↗A method of manufacturing a light-emitting device comprising the steps of cutting a substrate by a laser beam to form a cavity in the substrate and generate a by-product directly on the substrate by the cutting, and removing the by-product by a chemical solution containing an acid under a predetermined cleaning temperature.
1. A method for manufacturing a light-emitting device comprising the steps of:
cutting a substrate by a laser beam to form a cavity in the substrate and generate a by-product by the cutting, wherein the by-product comprises a first by-product directly in the cavity and a second by-product on the substrate other than the cavity; and
removing the by-product by a chemical solution containing an acid under a predetermined cleaning temperature.
2. The method for manufacturing a light-emitting device according to claim 1 , further comprising forming a light-emitting stack on the substrate, wherein the step of forming the light-emitting stack comprises:
forming a first semiconductor layer on the substrate; and
forming a semiconductor light-emitting layer on the first semiconductor layer; and
forming a second semiconductor layer on the semiconductor light-emitting layer.
3. The method for manufacturing a light-emitting device according to claim 2 , further comprising the steps of:
removing a portion of the second semiconductor layer and the semiconductor light-emitting layer thereby exposing a portion of the first semiconductor layer; and
forming a second electrode on the second semiconductor layer and forming a first electrode on the exposed first semiconductor layer.
4. The method for manufacturing a light-emitting device according to claim 2 , wherein the step of forming the first semiconductor layer on the substrate is after the step of cutting the substrate by the laser beam.
5. The method for manufacturing a light-emitting device according to claim 1 , wherein the cavity comprises a cutting line.
6. The method for manufacturing a light-emitting device according to claim 1 , wherein the chemical solution comprises phosphoric acid.
7. The method for manufacturing a light-emitting device according to claim 1 , wherein the chemical solution comprises sulfuric acid.
8. The method for manufacturing a light-emitting device according to claim 1 , further comprising forming a protective layer on the substrate before the cutting.
9. The method for manufacturing a light-emitting device according to claim 1 , wherein the cavity and the light-emitting stack are on opposite sides of the substrate.
10. The method for manufacturing a light-emitting device according to claim 1 , wherein the cavity and the light-emitting stack are on the same side of the substrate.
11. The method for manufacturing a light-emitting device according to claim 1 , wherein the substrate comprises a material selected from the group consisting of sapphire, SiC, GaN, AlN, ZnO and MgO.
12. The method for manufacturing a light-emitting device according to claim 1 , wherein the predetermined cleaning temperature is not lower than 200° C.
13. The method for manufacturing a light-emitting device according to claim 1 , wherein the second by-product is capable of being removed at a cleaning temperature unable to remove the first by-product.
14. The method for manufacturing a light-emitting device according to claim 1 , wherein the predetermined cleaning temperature is not lower than 250° C.
15. The method for manufacturing a light-emitting device according to claim 1 , wherein the cavity comprises a plurality of cutting lines defining a plurality of chip regions.
16. The method for manufacturing a light-emitting device according to claim 1 , further comprising a grinding step to thin the substrate.
17. The method for manufacturing a light-emitting device according to claim 1 , further comprising a polishing step to flatten the substrate before the cutting.
18. The method for manufacturing a light-emitting device according to claim 3 , further comprising a breaking step to separate the substrate with the light-emitting stack into chips.
19. The method for manufacturing a light-emitting device according to claim 18 , wherein at least one side wall of one of the chips is rough.
20. The method for manufacturing a light-emitting device according to claim 1 , wherein the substrate has a diameter between 2 inches and 8 inches.