Method for manufacturing high efficiency light-emitting diodes
View Patent ↗A method for manufacturing a light-emitting device comprising the steps of: providing a substrate comprising a first surface and a second surface; forming a plurality of cutting lines on the substrate by a laser beam; cleaning the substrate by a chemical solution; and forming a light-emitting stack on an first surface of the substrate after cleaning the substrate.
1. A method for manufacturing a light-emitting device comprising the steps of and in sequence of:
providing a substrate comprising a first surface and a second surface;
forming a plurality of cutting lines on the substrate by a laser beam;
cleaning the substrate by a chemical solution; and
forming a light-emitting stack on the first surface of the substrate after cleaning the substrate.
2. The method for manufacturing a light-emitting device according to claim 1 , wherein cleaning the substrate by a chemical solution comprises cleaning the substrate by the chemical solution with a temperature not lower than 175° C.
3. The method for manufacturing a light-emitting device according to claim 1 , wherein the cutting lines defines a plurality of chip regions.
4. The method for manufacturing a light-emitting device according to claim 3 , further comprising patterning the light-emitting stack into a plurality of light-emitting units, wherein each of the light-emitting units substantially corresponds to the chip region.
5. The method for manufacturing a light-emitting device according to claim 4 , further comprising:
forming two electrodes on each of the light-emitting units; and
dicing the substrate with the light-emitting units into a plurality of separate chips along the cutting lines.
6. The method for manufacturing a light-emitting device according to claim 5 , further comprising a grinding step to thin the substrate and/or polishing step to flatten the substrate before the dicing.
7. The method for manufacturing a light-emitting device according to claim 1 , wherein forming the light-emitting stack comprises:
forming a first semiconductor layer;
forming a semiconductor light-emitting layer over the first semiconductor layer; and
forming a second semiconductor layer over the semiconductor light-emitting layer.
8. The method for manufacturing a light-emitting device according to claim 1 , wherein the plurality of cutting lines are formed on the first surface of the substrate.
9. The method for manufacturing a light-emitting device according to claim 8 , further comprising forming a protective layer over the first surface of the substrate before forming a plurality of cutting lines on the substrate by a laser beam.
10. The method for manufacturing a light-emitting device according to claim 1 , wherein the plurality of cutting lines are formed on the second surface of the substrate.
11. The method for manufacturing a light-emitting device according to claim 10 , further comprising forming a protective layer over the substrate before forming a plurality of cutting lines on the substrate by a laser beam.
12. The method for manufacturing a light-emitting device according to claim 8 , wherein the light-emitting stack is formed only on the first surface of the substrate other than the cutting lines.
13. The method for manufacturing a light-emitting device according to claim 1 , wherein a composition of the chemical solution includes phosphoric acid (H 3 PO 4 ) and sulfuric acid (H 2 SO 4 ).
14. The method for manufacturing a light-emitting device according to claim 2 , wherein the preferred temperature is 175˜300° C.
15. The method for manufacturing a light-emitting device according to claim 1 , wherein forming the light-emitting stack on the first surface of the substrate comprises fine tuning parameters for forming the light-emitting stack to form polycrystalline and/or amorphous materials of the light-emitting stack directly on the cutting lines and form single crystal materials of light-emitting stack on the first surface of the substrate other than the cutting lines.
16. The method for manufacturing a light-emitting device according to claim 15 , further comprising a breaking process to separate the substrate with the light-emitting stack into chips.
17. The method for manufacturing a light-emitting device according to claim 16 , wherein at least one side wall of one of the chips is rough.
18. The method for manufacturing a light-emitting device according to claim 1 , wherein the cutting lines have a depth of about 5%˜70% of the thickness of the substrate.
19. The method for manufacturing a light-emitting device according to claim 1 , wherein the substrate has a diameter between 2 inches and 8 inches.
20. The method for manufacturing a light-emitting device according to claim 1 , wherein forming the light-emitting stack on the first surface of the substrate comprises growing epitaxial layers on the substrate and cutting lines.