Semiconductor light emitting device

• US 9,412,903 B2
• Filed: 01/20/2015
• Issued: 08/09/2016
• Est. Priority Date: 01/20/2014
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Joo, Dong Hyuk, Yoon, Ju Heon, Jeon, Joon Woo, Choi, Jin Young
• Primary Examiner(s): Lee, Kyoung
• Application Number:
  US14/601,190
• Publication Number:
  US 20150207051A1
• Time in Patent Office: 567 Days
• US Class Current: 1/1
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2924/10155 being other than a cuboid
• CPC Class Codes: H01L 33/14 with a carrier transport control structure, e.g. highly-doped semiconductor layer or current-blocking structure
• CPC Class Codes: H01L 33/382 the electrode extending partially in or entirely through the semiconductor body

Abstract

A semiconductor light emitting device includes a stacked semiconductor structure including a first conductivity-type semiconductor layer having a top surface divided into a first region and a second region, and an active layer and a second conductivity-type semiconductor layer disposed sequentially on the second region of the first conductivity-type semiconductor layer. First and second contact electrodes are disposed in the first region of the first conductivity-type semiconductor layer and the second conductivity-type semiconductor layer, respectively. A current spreading layer is disposed on the second contact electrode and comprises a first conductive layer having a first resistivity and a second conductive layer having a second resistivity smaller than the first resistivity alternately stacked.

Claims

1. A semiconductor light emitting device, comprising:

a stacked semiconductor structure including a first conductivity-type semiconductor layer having a top surface divided into a first region and a second region, and an active layer and a second conductivity-type semiconductor layer disposed sequentially on the second region of the first conductivity-type semiconductor layer;

a first contact electrode disposed in the first region of the first conductivity-type semiconductor layer;

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

a current spreading layer disposed on the second contact electrode and in which a first conductive layer having a first resistivity and a second conductive layer having a second resistivity smaller than the first resistivity are alternately stacked;

a first electrode pad electrically connected to the first contact electrode; and

a second electrode pad disposed on a portion of the current spreading layer and electrically connected to the second contact electrode.

2. The semiconductor light emitting device of claim 1, wherein a thickness of the first conductive layer is less than a thickness of the second conductive layer.

3. The semiconductor light emitting device of claim 2, wherein the thickness of the first conductive layer is about 30% or more of the thickness of the second conductive layer.

4. The semiconductor light emitting device of claim 1, wherein the first conductive layer includes at least one selected from the group consisting of Ti, V, Cr, Fe, Ni, Zn, Zr, Nb, Pt, Ta, Sn, TiN, Mn, Pb, and Te, and the second conductive layer includes at least one selected from the group consisting of Al, Cu, Cr, Ni, Au, Cu, W, Mo, Pd, Be, In, Os, Ir, Rh, TiW, and Ag.

5. The semiconductor light emitting device of claim 1, further comprising an insulating layer disposed on the stacked semiconductor structure and including a first opening exposing a portion of the first contact electrode and a second opening exposing a portion of the current spreading layer,

wherein the first electrode pad is connected to the first contact electrode through the first opening, and the second electrode pad is connected to the current spreading layer through the second opening.

6. The semiconductor light emitting device of claim 5, wherein a portion in which the first opening is disposed has a greater width than other portions of the first region adjacent to the first opening in the first region.

7. The semiconductor light emitting device of claim 5, wherein the first contact electrode includes at least one finger electrode, and the first opening includes a plurality of first openings, and

the plurality of first openings are arranged to be spaced apart from each other on the finger electrode.

8. The semiconductor light emitting device of claim 7, wherein the second opening includes a plurality of second openings, and

the finger electrode extends to between the plurality of second openings.

9. The semiconductor light emitting device of claim 8, wherein the first opening is located below the second electrode pad.

10. The semiconductor light emitting device of claim 8, wherein the finger electrode includes a plurality of finger electrodes.

11. The semiconductor light emitting device of claim 1, wherein the current spreading layer has at least one area substantially corresponding to an area of the second contact electrode.

12. The semiconductor light emitting device of claim 11, wherein the second contact electrode is disposed in an area other than an area adjacent to an edge of a top surface of the second conductivity-type semiconductor layer.

13. The semiconductor light emitting device of claim 1, wherein at least one of the first and second contact electrodes is at least one metal selected from the group consisting of Al, Ag, Ni, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au, Cr, and Ti.

14. The semiconductor light emitting device of claim 1, further comprising a barrier layer interposed between the second contact electrode and the current spreading layer, or between the current spreading layer and the second electrode pad.

15. The semiconductor light emitting device of claim 14, wherein the barrier layer is at least one metal selected from the group consisting of Ni, Al, Cu, Cr, Ti, and combinations thereof.

16. A light emitting module comprising:

a circuit board including a first electrode structure and a second electrode structure; and

a semiconductor light emitting device, mounted on the circuit board, described in claim 1,

wherein first and second electrode pads of the semiconductor light emitting device are respectively connected to the first and second electrode structures.

17. An illuminating apparatus, comprising:

a light emitting module including a semiconductor light emitting device described in claim 1;

a driving unit configured to drive the light emitting module; and

an external connection portion configured to supply an external voltage to the driving unit.

18. A semiconductor light emitting device, comprising:

a stacked semiconductor structure including a first conductivity-type semiconductor layer having a top surface divided into a first region and a second region, and an active layer and a second conductivity-type semiconductor layer disposed sequentially on the second region of the first conductivity-type semiconductor layer;

a first contact electrode disposed in the first region of the first conductivity-type semiconductor layer and including a plurality of finger electrodes;

a second contact electrode disposed on a top surface of the second conductivity-type semiconductor layer;

a current spreading layer disposed on the second contact electrode and in which a first conductive layer having a first resistivity and a second conductive layer having a second resistivity smaller than the first resistivity are alternately stacked;

an insulating layer disposed on the stacked semiconductor structure and including a first opening exposing a portion of the first contact electrode and a second opening exposing a portion of the current spreading layer;

a first electrode pad disposed on a portion of the insulating layer and electrically connected to the first contact electrode through the first opening; and

a second electrode pad disposed on another portion of the insulating layer and electrically connected to the current spreading layer.

19. The semiconductor light emitting device of claim 18, wherein the first and second openings include a plurality of first and second openings, respectively,

the plurality of first openings are arranged to be spaced apart from each other on the plurality of finger electrodes, and

the plurality of finger electrodes extend between the plurality of second openings.

20. The semiconductor light emitting device of claim 18, wherein the first and second electrode pads are disposed adjacently to two opposite edges of the semiconductor light emitting device, and

the plurality of finger electrodes extend from below the first electrode pad to below the second electrode pad.