Light emitting device and light emitting device package thereof
A light emitting device includes a light emitting structure including a second conduction type semiconductor layer, an active layer, and a first conduction type semiconductor layer, a second electrode layer arranged under the light emitting structure, a first electrode layer having at least portion extending to contact the first conduction type semiconductor layer passing the second conduction type semiconductor layer and the active layer, and an insulating layer arranged between the second electrode layer and the first electrode layer, between the second conduction type semiconductor layer and the first electrode layer, and between the active layer and the first electrode layer, wherein said at least one portion of the first electrode layer contacting the first conduction type semiconductor layer has a roughness.
1. A light emitting device comprising:
a light emitting structure including a second conduction type semiconductor layer, an active layer, and a first conduction type semiconductor layer;
a second electrode layer arranged under the light emitting structure;
at least one first recess provided to pass through the second electrode layer, the second conduction type semiconductor layer and the active layer and exposing the first conduction type semiconductor layer, wherein a plurality of second recesses are provided at a distal end of the at least one first recess;
a first electrode layer provided in the at least one first recess and the plurality of second recesses at the distal end of the at least one first recess and directly contacting an exposed region of the first conduction type semiconductor layer through the first recess; and
an insulating layer disposed adjacent a side surface of the at least one first recess, and arranged between the second electrode layer and the first electrode layer, between the second conduction type semiconductor layer and the first electrode layer, and between the active layer and the first electrode layer, wherein the insulating layer contacts exposed regions of the first conduction type semiconductor layer,
wherein the first electrode layer has a roughness provided in the plurality of second recesses, and the roughness provided in the plurality of second recesses increases a contact area with the first conduction type semiconductor layer and is in ohmic contact with the first conduction type semiconductor layer.
2. The light emitting device as claimed in claim 1 , further comprising a support substrate under the first electrode layer, wherein the first electrode layer includes at least one contact electrode in contact with the first conduction type semiconductor layer passing through the second electrode layer, the second conduction type semiconductor layer, and the active layer, and the at least one contact electrode has a top side with the roughness.
3. The light emitting device as claimed in claim 2 , wherein the first electrode layer includes;
a lower electrode layer arranged between the support substrate and the second electrode layer, and
the at least one contact electrode which is a branch from the lower electrode layer in contact with the first conduction type semiconductor layer.
4. The light emitting device as claimed in claim 3 , wherein the contact electrode has a width of 5 μm˜200 μm.
5. The light emitting device as claimed in claim 3 , wherein a height from a top side of the active layer to a top side of the contact electrode is 0.4 μm˜10 μm.
6. The light emitting device as claimed in claim 2 , wherein the roughness has a width of 0.02 μm˜100 μm, and a height of 0.2 μm˜10 μm.
7. The light emitting device as claimed in claim 3 , wherein the insulating layer is arranged between the lower electrode layer and the second electrode layer, between a side of the contact electrode and the second electrode layer, between the side of the contact electrode and the second conduction type semiconductor layer, and between the side of the contact electrode and the active layer.
8. The light emitting device as claimed in claim 2 , wherein the roughness has a vertical cross-section presenting a stepwise structure or a tiered structure.
9. The light emitting device as claimed in claim 1 , wherein the first electrode layer is arranged on the second electrode layer, and includes;
a contact portion in contact with the first conduction type semiconductor layer overlapped with the light emitting structure in a vertical direction, and
an exposed portion not overlapped with the light emitting structure in the vertical direction and exposed from the light emitting structure,
wherein the vertical direction is a direction facing from the second electrode layer toward the first conduction type semiconductor layer, and a top side of the contact portion has the roughness.
10. The light emitting device as claimed in claim 9 , wherein the first electrode layer has at least one further portion overlapped by the light emitting structure having a top side with a roughness in contact with the first conduction type semiconductor layer.
11. The light emitting device as claimed in claim 1 , wherein the first electrode layer includes;
a contact portion in contact with the first conduction type semiconductor layer, and
an exposed portion opened from the first conduction type semiconductor layer, wherein the contact portion has a roughness.
12. The light emitting device as claimed in claim 1 , wherein the light emitting structure is divided into a plurality of cell regions spaced from one another on the second electrode layer by predetermined distances, and
the first electrode layer includes;
a contact portion in contact with the first conduction type semiconductor layer passing through the second conduction type semiconductor layer and the active layer of each of the plurality of cell regions, and
an exposed portion exposed from the first conduction type semiconductor layer,
wherein the contact portion has a roughness.
13. The light emitting device as claimed in claim 3 , wherein the first electrode layer includes at least one of an ohmic layer, a reflective layer, and a bonding layer.
14. The light emitting device as claimed in claim 2 , wherein the at least one contact electrode has a top side higher than a top side of the active layer, and lower than a top side of the first conduction type semiconductor layer.
15. The light emitting device as claimed in claim 2 , wherein the second electrode layer has one side region opened from the light emitting structure, and further includes a second electrode pad arranged on the one opened side region.
16. The light emitting device as claimed in claim 2 , wherein the first electrode layer has one side opened from the light emitting structure, and further includes a first electrode pad arranged on the one opened side of the first electrode layer.
17. The light emitting device as claimed in claim 3 , wherein the insulating layer surrounds the at least one contact electrode, wherein a portion of the insulating layer which surrounds the side of the at least one contact electrode has a roughness in contact with the first conduction type semiconductor layer.
18. The light emitting device as claimed in claim 17 , wherein the roughness has a random irregular shape.
19. The light emitting device as claimed in claim 1 , further comprising a protective layer arranged at a sidewall of the light emitting structure.
20. The light emitting device as claims in claim 2 , wherein a portion of the insulating layer is arranged to surround a side of the at least one contact electrode except the top side of the at least one contact electrode for blocking electric shorts with the second electrode layer, the second conduction type semiconductor layer, and the active layer.