Light emitting diode
An LED comprises a substrate, a buffer layer, an epitaxial layer and a conductive layer. The epitaxial layer comprises a first N-type epitaxial layer, a second N-type epitaxial layer, and a blocking layer with patterned grooves sandwiched between the first and second N-type epitaxial layers. The first and second N-type epitaxial layers make contact each other via the patterned grooves. Therefore, the LED enjoys a uniform current distribution and a larger light emitting area. A manufacturing method for the LED is also provided.
1. An LED, comprising:
a substrate, having a top face and a bottom face;
a buffer layer, disposed on the top face of the substrate;
an epitaxial layer, disposed on the buffer layer, comprising:
a first N-type epitaxial layer and a second N-type epitaxial layer;
a blocking layer, having patterned grooves, sandwiched between the first and the second N-type epitaxial layers, wherein the first and the second N-type epitaxial layers contacts to each other via a portion of the second N-type epitaxial layer in the patterned grooves;
a light emitting layer, disposed on the second N-type epitaxial layer; and
a P-type epitaxial layer, disposed on the light emitting layer;
a conductive layer, disposed on the P-type epitaxial layer;
a P-type electrode disposed on the conductive layer; and
an N-type electrode disposed on the blocking layer opposite to the P-type electrode, wherein the N-type electrode is separated from the second N-type epitaxial layer and has a portion extending into the patterned grooves to contact with the first N-type epitaxial layer.
2. The LED as claimed in claim 1 , wherein the P-type electrode comprises a bonding portion located on one end of the conductive layer and an extending portion with a patterned structure.
3. The LED as claimed in claim 2 , wherein the patterned structure of the extending portion is staggered with the patterned grooves inside the epitaxial layer.
4. The LED as claimed in claim 1 , wherein the substrate is sapphire.
5. An LED, comprising:
a substrate, having a top face and a bottom face;
a buffer layer, disposed on the top face of the substrate;
an epitaxial layer, disposed on the buffer layer, comprising a first N-type epitaxial layer and a second N-type epitaxial layer, a blocking layer with patterned grooves and sandwiched between the first and the second N-type epitaxial layers, a light emitting layer disposed on the second N-type epitaxial layer and a P-type epitaxial layer disposed on the light emitting layer;
an N-type electrode, contacting to the first N-type epitaxial layer;
a conductive layer, disposed on the P-type epitaxial layer; and
a P-type electrode, disposed on the conductive layer;
wherein the first and the second N-type epitaxial layers contact to each other via the patterned grooves, and the N-type electrode is disposed inside the patterned grooves of the blocking layer to contact with the first N-type epitaxial layer.
6. The LED as claimed in claim 5 , wherein the P-type electrode comprises a bonding portion located on one end of the conductive layer and an extending portion with a patterned structure.
7. The LED as claimed in claim 6 , wherein the patterned structure of the extending portion is staggered with the patterned grooves inside the epitaxial layer.