LIGHT EMITTING DIODE CHIP HAVING ELECTRODE PAD

• US 20130234192A1
• Filed: 02/28/2011
• Published: 09/12/2013
• Est. Priority Date: 11/18/2010
• Status: Active Grant

• Current Assignee: Seoul Viosys Co., Ltd. (Seoul Semiconductor Co., Ltd.)
• Original Assignee: Seoul Optodevice Company Limited (Seoul Semiconductor Co., Ltd.)
• Inventors: Kim, Ye Seul, Kim, Kyoung Wan, Yoon, Yeo Jin, Oh, Sang Hyun, Lee, Keum Ju, Lee, Jin Woong, Jeong, Da Yeon, Woo, Sang Won
• Granted Patent: US 8,987,772 B2
• Time in Patent Office: Days
• US Class Current: 257/98
• CPC Class Codes: H01L 2933/0016 relating to electrodes
• CPC Class Codes: H01L 2933/0066 relating to arrangements for conducting electric current to or from the semiconductor body
• CPC Class Codes: H01L 33/0008 having p-n or hi-lo junctions
• CPC Class Codes: H01L 33/10 with a light reflecting structure, e.g. semiconductor Bragg reflector
• CPC Class Codes: H01L 33/20 with a particular shape, e.g. curved or truncated substrate
• CPC Class Codes: H01L 33/36 characterised by the electrodes
• CPC Class Codes: H01L 33/38 with a particular shape
• CPC Class Codes: H01L 33/382 the electrode extending partially in or entirely through the semiconductor body
• CPC Class Codes: H01L 33/385 the electrode extending at least partially onto a side surface of the semiconductor body
• CPC Class Codes: H01L 33/387 with a plurality of electrode regions in direct contact with the semiconductor body and being electrically interconnected by another electrode layer
• CPC Class Codes: H01L 33/40 Materials therefor
• CPC Class Codes: H01L 33/405 Reflective materials
• CPC Class Codes: H01L 33/42 Transparent materials
• CPC Class Codes: H01L 33/44 characterised by the coatings, e.g. passivation layer or anti-reflective coating
• CPC Class Codes: H01L 33/46 Reflective coating, e.g. dielectric Bragg reflector
• CPC Class Codes: H01L 33/60 Reflective elements

Abstract

Disclosed herein is an LED chip including electrode pads. The LED chip includes a semiconductor stack including a first conductive type semiconductor layer, a second conductive type semiconductor layer on the first conductive type semiconductor layer, and an active layer interposed between the first conductive type semiconductor layer and the second conductive type semiconductor layer; a first electrode pad located on the second conductive type semiconductor layer opposite to the first conductive type semiconductor layer; a first electrode extension extending from the first electrode pad and connected to the first conductive type semiconductor layer; a second electrode pad electrically connected to the second conductive type semiconductor layer; and an insulation layer interposed between the first electrode pad and the second conductive type semiconductor layer. The LED chip includes the first electrode pad on the second conductive type semiconductor layer, thereby increasing a light emitting area.

Claims

1. A light emitting diode (LED) chip comprising:

a semiconductor stack comprising a first conductivity-type semiconductor layer, a second conductivity-type semiconductor layer, and an active layer interposed between the first conductivity-type semiconductor layer and the second conductivity-type semiconductor layer;

a first electrode pad disposed on the second conductivity-type semiconductor layer;

a first electrode extension extending from the first electrode pad, the first electrode extension connected to the first conductivity-type semiconductor layer;

a second electrode pad electrically connected to the second conductivity-type semiconductor layer; and

an insulation layer interposed between the first electrode pad and the second conductivity-type semiconductor layer.

2. The LED chip of claim 1, wherein the insulation layer comprises a distributed Bragg reflector.

3. The LED chip of claim 1, further comprising a transparent conductive layer interposed between the insulation layer and the second conductivity-type semiconductor layer.

4. The LED chip of claim 1, further comprising a reflector interposed between the insulation layer and the second conductivity-type semiconductor layer.

5. The LED chip of claim 1, further comprising a dot pattern interposed between the first electrode extension and the first conductivity-type semiconductor layer, the dot pattern partially separating the first electrode extension and the first conductivity-type semiconductor layer.

6. The LED chip of claim 5, wherein the dot pattern comprises an electrical insulator.

7. The LED chip of claim 5, wherein the dot pattern comprises a reflector.

8. The LED chip of claim 7, wherein the reflector comprises a distributed Bragg reflector.

9. The LED chip of claim 1, wherein the semiconductor stack further comprises through-holes extending through the second conductivity-type semiconductor layer and the active layer and exposing the first conductivity-type semiconductor layer, the through-holes being disposed along the first electrode extension, and

wherein the first electrode extension is connected to the first conductivity-type semiconductor layer through the through-holes.

10. The LED chip of claim 9, further comprising an insulation layer interposed between the first electrode extension and the second conductivity-type semiconductor layer.

11. The LED chip of claim 10, wherein the insulation layer is configured to insulate the first electrode extension from the sidewalls of the through-holes.

12. The LED chip of claim 9, wherein the insulation layer comprises a distributed Bragg reflector.

13. The LED chip of claim 12, wherein the distributed Bragg reflector is configured to insulate the first electrode extension from the sidewalls of the through-holes.

14. The LED chip of claim 9, further comprising a transparent conductive layer interposed between the insulation layer and the second conductivity-type semiconductor layer.

15. The LED chip of claim 1, further comprising:

a second electrode extension extending from the second electrode pad; and

a transparent conductive layer disposed on the second conductivity-type semiconductor layer,

wherein the second electrode pad and the second electrode extension are electrically connected to the second conductivity-type semiconductor layer by the transparent conductive layer.

16. The LED chip of claim 15, further comprising a current blocking layer interposed between the transparent conductive layer and the second conductivity-type semiconductor layer, the current blocking layer extending along the second electrode extension.

17. The LED chip of claim 16, wherein the current blocking layer is linear or disposed in a dot pattern.

18. The LED chip of claim 17, wherein the current blocking layer comprises a reflector.

19. The LED chip of claim 15, further comprising a current blocking layer disposed in a dot pattern between the transparent conductive layer and the second electrode extension, the current blocking layer extending along the second electrode extension.

20. The LED chip of claim 1, wherein the first electrode extension is connected to the first conductivity-type semiconductor layer in a first plurality of dot regions, the first plurality of dot regions comprising first dot regions being disposed closer to the first electrode pad than the second electrode pad and second dot regions being disposed closer to the second electrode pad than the first electrode pad, and the first dot regions increase in size as a distance between each of the first dot regions and the first electrode pad increases.

21. The LED chip of claim 20, wherein the second dot regions decrease in size as a distance between each of the second dot regions and the first electrode pad increases.

22. The LED chip of claim 21, further comprising:

a second electrode extension extending from the second electrode pad; and

a transparent conductive layer interposed between the second electrode extension and the second conductivity-type semiconductor layer,

the second electrode extension being connected to the second conductivity-type semiconductor layer through the transparent conductive layer in a second plurality of dot regions,

wherein the second plurality of dot regions comprise third and fourth dot regions disposed along the second electrode extension, the third dot regions being disposed closer to the second electrode pad than the first electrode pad, the fourth dot regions being disposed closer to the first electrode pad than the second electrode pad, and the third dot regions increase in size as a distance between each of the third dot regions and the second electrode pad increases.

23. The LED chip of claim 22, wherein the fourth dot regions decrease in size as a distance between each of the fourth dot regions and the second electrode pad increases.

24. The LED chip of claim 22, wherein the first to fourth dot regions increase in size as a distance between each of the first to fourth dot regions and a line crossing the first electrode pad and the second electrode pad increases.

25. A light emitting diode (LED) chip, comprising:

a first conductivity-type semiconductor layer;

a plurality of mesa structures arranged on the first conductivity-type semiconductor layer, each of the plurality of mesa structures comprising a second conductivity-type semiconductor layer and an active layer interposed between the first conductivity-type semiconductor layer and the second conductivity-type semiconductor layer;

a first electrode pad, at least a portion thereof being disposed on the second conductivity-type semiconductor layer;

a first electrode extension extending from the first electrode pad, the first electrode extension connected to the first conductivity-type semiconductor layer;

a second electrode pad electrically connected to the second conductivity-type semiconductor layer; and

an insulation layer interposed between the first electrode pad and the second conductivity-type semiconductor layer.

26. The LED chip of claim 25, further comprising a plurality of electrode pads disposed on the plurality of mesa structures, respectively.

27. The LED chip of claim 26, further comprising a plurality of electrode pads disposed on the plurality of mesa structures, respectively.

28. The LED chip of claim 25, wherein each of the plurality of the mesa structures are separated from each other by a separation region exposing the first conductivity-type semiconductor layer.

29. The LED chip of claim 28, wherein the first electrode extension comprises an electrode extension connected to the first conductivity-type semiconductor layer in the separation region.

30. The LED chip of claim 29, further comprising a dot pattern interposed between the first electrode extension and the first conductivity-type semiconductor layer, the dot pattern partially separating the first electrode extension and the first conductive type semiconductor layer.

31. The LED chip of claim 30, wherein the dot pattern comprises an electrical insulator.

32. The LED chip of claim 30, wherein the dot pattern comprises a distributed Bragg reflector.

33. The LED chip of claim 28, wherein the first electrode pad is partially disposed in the separation region.

34. The LED chip of claim 25, wherein the insulation layer comprises a distributed Bragg reflector.

35. The LED chip of claim 25, wherein each of the plurality of the mesa structures comprises through-holes extending through the second conductivity-type semiconductor layer and the active layer and exposing the first conductivity-type semiconductor layer, and the first electrode extension is connected to the first conductivity-type semiconductor layer through the through-holes.

36. The LED chip of claim 35, further comprising an insulation layer interposed between the second conductivity-type semiconductor layer and the first electrode extension.

37. The LED chip of claim 36, wherein the insulation layer comprises a distributed Bragg reflector.

38. The LED chip of claim 36, wherein the insulation layer is configured to insulate the first electrode extension from the sidewalls of the through-holes.

39. The LED chip of claim 36, further comprising a transparent conductive layer interposed between the insulation layer and the second conductivity-type semiconductor layer.

40. The LED chip of claim 25, further comprising:

a second electrode extension extending from the second electrode pad; and

a transparent conductive layer disposed on the second conductivity-type semiconductor layer,

wherein the second electrode pad and the second electrode extension are electrically connected to the second conductivity-type semiconductor layer by the transparent conductive layer.

41. The LED chip of claim 40, further comprising a current blocking layer interposed between the transparent conductive layer and the second conductivity-type semiconductor layer along the second electrode extension,

wherein the current blocking layer is linear or disposed in a dot pattern.

42. The LED chip of claim 41, wherein the current blocking layer comprises a reflector.

43. The LED chip of claim 42, wherein the reflector comprises a distributed Bragg reflector.

44. The LED chip of claim 40, further comprising a current blocking layer interposed between the transparent conductive layer and the second electrode extension, the current blocking layer extending along the second electrode extension.