Light emitting device, light emitting device package and lighting system including the same

• US 8,907,363 B2
• Filed: 08/09/2013
• Issued: 12/09/2014
• Est. Priority Date: 05/04/2009
• Status: Active Grant

• Current Assignee: Suzhou Lekin Semiconductor Company Limited
• Original Assignee: LG Innotek Company Limited (LG Corporation)
• Inventors: Hwang, Sung Min, Song, Hyun Don, Cho, Hyun Kyong
• Primary Examiner(s): Diaz, Jose R
• Application Number:
  US13/963,877
• Publication Number:
  US 20130328092A1
• Time in Patent Office: 487 Days
• Field of Search: 257/79, 257/94, 257/99, 257/103, 257/E33.072, 257/98
• US Class Current: 257/98
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/12032 Schottky diode
• CPC Class Codes: H01L 2933/0016 relating to electrodes
• CPC Class Codes: H01L 33/0033 having Schottky barriers
• CPC Class Codes: H01L 33/145 with a current-blocking structure
• 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 33/48 characterised by the semiconductor body packages
• CPC Class Codes: H01L 33/60 Reflective elements
• CPC Class Codes: H01L 33/62 Arrangements for conducting electric current to or from the semiconductor body, e.g. lead-frames, wire-bonds or solder balls

Abstract

A light emitting device is described, including a second conductive type semiconductor layer; an active layer over the second conductive type semiconductor layer; a first conductive type semiconductor layer over the active layer; a second electrode in a first region under the second conductive type semiconductor layer; a current blocking layer including a metal; and a first electrode over the first conductive type semiconductor layer. Further, the first electrode has at least one portion that vertically overlaps the current blocking layer.

Claims

1. A light emitting device, comprising:

a substrate;

a light emitting structure;

a first electrode on the light emitting structure;

a contact layer between the substrate and the light emitting structure;

a metal layer between the substrate and the light emitting structure;

a reflective layer between the substrate and the light emitting structure;

an adhesive layer between the substrate and the light emitting structure;

wherein the light emitting structure comprise a first region and a second region,

wherein the metal layer and the reflective layer are disposed under the light emitting structure at the first region of the light emitting structure,

wherein the contact layer contacts with the light emitting structure at the second region of the light emitting structure,

wherein a lateral width of the second region of the light emitting structure is smaller than a lateral width of the first region of the light emitting structure,

wherein the metal layer and the reflective layer vertically overlaps each other,

wherein a material of the contact layer is different from a material of the reflective layer, and

wherein at least one of the reflective layer or the metal layer does not vertically overlap the first electrode layer.

2. The light emitting device of claim 1, wherein the metal layer, the reflective layer and the adhesive layer constitute a second electrode.

3. The light emitting device of claim 1, wherein at least one side surface of the metal layer directly contacts with the contact layer and a material of the metal layer is different from a material of the reflective layer.

4. The light emitting device of claim 1, wherein the contact layer comprises at least one selected from the group consisting of titanium (Ti), zirconium (Zr), chrome (Cr), gold (Au) or tungsten (W).

5. The light emitting device of claim 1, wherein the thickness of the contact layer is thinner than the reflective layer.

6. The light emitting device of claim 1, wherein the thickness of the contact layer is thinner than the metal layer.

7. The light emitting device of claim 1, wherein a top surface of the contact layer is substantially flush with at least one of a top surface of the reflective layer or the metal layer, and wherein the contact layer is disposed on the adhesive layer.

8. The light emitting device of claim 1, wherein at least one portion of the adhesive layer is thicker than the reflective layer or the metal layer.

9. The light emitting device of claim 1, wherein the contact layer includes a metal, and

wherein a thickness of the adhesive layer at the second region of the light emitting structure is thicker than a thickness of the adhesive layer at the first region of the light emitting structure.

10. The light emitting device of claim 1, wherein the metal layer comprises nickel (Ni).

11. The light emitting device of claim 1, wherein at least one of a center axis of the reflective layer and a center axis of the metal layer does not vertically overlap the first electrode layer.

12. The light emitting device of claim 1, wherein the first electrode comprise both platinum (Pt) and gold (Au).

13. The light emitting device of claim 1, wherein the adhesive layer has a protrusion portion and the protrusion portion vertically overlaps the contact layer.

14. A light emitting device, comprising:

a substrate;

a light emitting structure on the substrate;

a first electrode on the light emitting structure;

a contact layer between the substrate and the light emitting structure;

a first metal layer between the substrate and the light emitting structure;

a second metal layer between the substrate and the light emitting structure;

wherein the light emitting structure comprise a first region and a second region,

wherein the first metal layer and the second metal layer are disposed under the light emitting structure at the first region of the light emitting structure,

wherein the contact layer has a contact portion and the contact portion contacts with the light emitting structure at the second region of the light emitting structure,

wherein a top surface of the contact layer is substantially flush with a top surface of the first metal layer or the second metal layer,

wherein a lateral width of the contact portion is smaller than a lateral width of the first metal layer or the second metal layer,

wherein the first metal layer and the second metal layer vertically overlap with each other,

wherein a material of the contact layer is different from a material of the second metal layer, and

wherein at least one of the first metal layer or the second metal layer does not vertically overlap with first electrode layer.

15. The light emitting device of claim 14, wherein both the first metal layer and the second metal layer are disposed between the light emitting structure and a first portion of the adhesive layer, and wherein the contact layer is disposed between the light emitting structure and a second portion of the adhesive layer.

16. The light emitting device of claim 14, the at least one side surface of the first metal layer is directly contact with the contact layer and a material of the first metal layer is different from a material of the second metal layer.

17. The light emitting device of claim 14, wherein the contact layer comprises at least one of titanium(Ti), Zirconium(Zr), chrome(Cr), gold(Au) or tungsten(W).

18. The light emitting device of claim 14, further comprising an adhesive layer between the substrate and the light emitting structure,

wherein the contact layer includes a metal, and

wherein a thickness of the adhesive layer at the second region of the light emitting structure is thicker than a thickness of the adhesive layer at the first region of the light emitting structure.

19. The light emitting device of claim 18, wherein the adhesive layer has a protrusion portion and the protrusion portion vertically overlaps the contact layer.

20. The light emitting device of claim 14, wherein at least one of the first metal layer and the second metal layer comprises nickel (Ni).

21. The light emitting device of claim 14, wherein at least one portion of the contact layer has a thickness thicker than a thickness of the first metal layer or the second metal layer.

22. The light emitting device of claim 14, wherein the first electrode comprises both platinum (Pt) and gold (Au).

23. A light emitting device, comprising:

a substrate;

a first nitride semiconductor layer on the substrate;

an active layer which including at least one of InGaN or AlGaN;

a second nitride semiconductor layer on the active layer;

a first electrode on the first nitride semiconductor layer;

a second electrode under the second nitride semiconductor layer and wherein the second electrode comprises a metal layer, a reflective layer and an adhesive layer;

a contact layer on the second electrode;

wherein the first nitride semiconductor layer, the active layer and the second nitride semiconductor layer constitute a light emitting structure,

wherein the metal layer is disposed between the substrate and the second nitride semiconductor layer,

wherein the reflective layer is disposed between the substrate layer and the second nitride semiconductor layer,

wherein the adhesive layer is disposed between the substrate and the second nitride semiconductor layer,

wherein both the metal layer and the reflective layer are disposed between the light emitting structure and a first portion of the adhesive layer, and wherein the contact layer is disposed between the light emitting structure and a second portion of the adhesive layer,

wherein the light emitting structure comprise a first region and a second region,

wherein a lateral width of the second region of the light emitting structure is smaller than a lateral width of the first region of the light emitting structure,

wherein the metal layer and the reflective layer are disposed under the first region of the light emitting structure,

wherein the contact layer has a contact portion and the contact portion contacts with the second region of the light emitting structure,

wherein the metal layer and the reflective layer vertically overlap with each other;

wherein at least one portion of the adhesive layer is thicker than the reflective layer or the metal layer,

wherein a lateral width of the contact portion is smaller than a lateral width of the reflective layer or the metal layer,

wherein the at least one side surface of the metal layer is directly contact with the contact layer,

wherein the adhesive layer has a protrusion portion and the protrusion portion vertically overlaps the contact portion,

wherein a material of the contact layer is different from a material of the reflective layer, and

wherein at least one of the reflective layer and the metal layer does not vertically overlap the first electrode layer.

24. The light emitting device of claim 23, wherein the contact layer includes a metal, and

wherein a thickness of the adhesive layer at the second region of the light emitting structure is thicker than a thickness of the adhesive layer at the first region of the light emitting structure.

25. The light emitting device of claim 23, wherein a top surface of the adhesive layer is not a flat surface and at least a thickness of one side of the adhesive layer is smaller than a thickness of a center axis of the adhesive layer.