Epitaxiay wafer, method for manufacturing the same and method for manufacturing LED chip
View Patent ↗A method for manufacturing an epitaxial wafer for a light emitting diode (LED) is provided. The method may comprise: forming a back coating layer on a back surface of a substrate; forming a buffer layer on a top surface of the substrate; forming an N-type semiconductor layer on the buffer layer; forming a multi-quantum well layer on the N-type semiconductor layer; and forming a P-type semiconductor layer on the multi-quantum well layer. An epitaxial wafer and a method for manufacturing an LED chip are also provided.
1. A method for manufacturing an epitaxial wafer for a light emitting diode (LED), comprising:
forming a back coating layer on a back surface of a substrate;
forming a buffer layer on a top surface of the substrate;
forming an N-type semiconductor layer on the buffer layer;
forming a multi-quantum well layer on the N-type semiconductor layer; and
forming a P-type semiconductor layer on the multi-quantum well layer,
wherein the substrate includes a sapphire substrate; and
wherein the back coating layer comprises a copper tungsten alloy layer.
2. The method according to claim 1 , wherein the back coating layer has a thermal expansion coefficient less than the thermal expansion coefficient of the substrate.
3. The method according to claim 1 , wherein the back coating layer comprises an aluminum nitride layer.
4. The method according to claim 3 , wherein the aluminum nitride layer has a thickness ranging from about 0.27 μm to about 0.31 μm.
5. The method according to claim 1 , wherein the copper tungsten alloy layer comprises about 10% copper by weight.
6. The method according to claim 1 , wherein the copper tungsten alloy layer has a thickness ranging from about 0.51 μm to about 0.56 μm.
7. A method for manufacturing an LED chip, comprising:
forming a back coating layer on a back surface of a substrate;
forming a buffer layer on a top surface of the substrate;
forming an N-type semiconductor layer on the buffer layer;
forming a multi-quantum well layer on the N-type semiconductor layer;
forming a P-type semiconductor layer on the multi-quantum well layer;
partially etching the P-type semiconductor layer and the multi-quantum well layer to expose a part of the N-type semiconductor layer;
forming an N-type electrode on the exposed part of the N-type semiconductor layer;
forming a P-type electrode on the P-type semiconductor layer; and
thinning the back surface of the substrate to remove the back coating layer and a part of the substrate with a predetermined thickness.
8. The method according to claim 7 , wherein the back coating layer has a thermal expansion coefficient less than the thermal expansion coefficient of the substrate.
9. The method according to claim 7 , wherein the back coating layer comprises an aluminum nitride layer.
10. The method according to claim 9 , wherein the aluminum nitride layer has a thickness ranging from about 0.27 μm to about 0.31 μm.
11. The method according to claim 7 , wherein the back coating layer comprises a copper tungsten alloy layer.
12. The method according to claim 11 , wherein the copper tungsten alloy layer comprises about 10% copper by weight.
13. The method according to claim 11 , wherein the copper tungsten alloy layer has a thickness of about 0.51 μm to about 0.56 μm.
14. An epitaxial wafer for an LED, comprising:
a substrate;
a back coating layer formed on a back surface of the substrate;
a buffer layer formed on a top surface of the substrate;
an N-type semiconductor layer formed on the buffer layer;
a multi-quantum well layer formed on the N-type semiconductor layer; and
a P-type semiconductor layer formed on the multi-quantum well layer,
wherein the substrate includes a sapphire substrate; and
wherein the back coating layer comprises a copper tungsten alloy.
15. The epitaxial wafer according to claim 14 , wherein the back coating layer has a thermal expansion coefficient less than thermal expansion coefficient of the substrate.
16. The epitaxial wafer according to claim 14 , wherein the back coating layer comprises an aluminum nitride layer, wherein the aluminum nitride layer has a thickness ranging from about 0.27 μm to about 0.31 μm.
17. The epitaxial wafer according to claim 14 , wherein the copper tungsten alloy layer comprises about 10% copper by weight.
18. The epitaxial wafer according to claim 14 , wherein the copper tungsten alloy layer has a thickness ranging from about 0.51 μm to about 0.56 μm.