Light emitting device and light emitting device package having the same

• US 8,901,597 B2
• Filed: 08/06/2012
• Issued: 12/02/2014
• Est. Priority Date: 02/09/2010
• Status: Active Grant

• Current Assignee: Suzhou Lekin Semiconductor Company Limited
• Original Assignee: LG Innotek Company Limited (LG Corporation)
• Inventors: Jeong, Hwan Hee
• Primary Examiner(s): Tran, Tony
• Application Number:
  US13/567,446
• Publication Number:
  US 20120299051A1
• Time in Patent Office: 848 Days
• Field of Search: 257/57, 257/59, 257/72, 257/83, 257/257, 257/290, 257/351, 257/368, 257/39
• US Class Current: 257/99
• CPC Class Codes: F21K 9/23 Retrofit light sources for lighting devices with a single fitting for each light source, e.g. for substitution of incandescent lamps with bayonet or threaded fittings
• CPC Class Codes: F21Y 2105/10 comprising a two-dimensional array of point-like light-generating elements
• CPC Class Codes: F21Y 2113/13 comprising an assembly of point-like light sources
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• 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 33/12 with a stress relaxation structure, e.g. buffer layer
• CPC Class Codes: H01L 33/405 Reflective 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 33/54 having a particular shape

Abstract

Disclosed are a light emitting device and a light emitting device package having the same. The light emitting device includes a light emitting structure including a first conductive semiconductor layer, a second conductive semiconductor layer, and an active layer interposed between the first conductive semiconductor layer and the second conductive semiconductor layer, an electrode electrically connected to the first conductive semiconductor layer, a reflective layer under the second conductive semiconductor layer, a protective layer disposed around a lower surface of the second conductive semiconductor layer, and a buffer layer disposed on at least one of top and lower surfaces of the protective layer.

Claims

1. A semiconductor light emitting device comprising:

a light emitting structure including;

a first conductive semiconductor layer;

a second conductive semiconductor layer under the first conductive semiconductor layer; and

an active layer between the first and second conductive semiconductor layers;

an electrode disposed on the first conductive semiconductor layer;

an electrode layer including at least one of an ohmic layer or a reflective layer contacting a lower surface of the second conductive semiconductor layer;

a conductive support member under the electrode layer;

an adhesion layer disposed between the electrode layer and the conductive support member;

a protective layer disposed on an outer portion of the lower surface of the second conductive semiconductor layer; and

a buffer layer disposed on a lower surface of the protective layer,

wherein the conductive support member includes a top surface having a horizontal width wider than a horizontal width of the lower surface of the second conductive semiconductor layer,

wherein the protective layer includes a first portion between the second conductive semiconductor layer and adhesion layer and a second portion extended outwardly beyond the lower surface of the second conductive semiconductor layer,

wherein the buffer layer includes a different material from the protective layer,

wherein the second portion of the protective layer outwardly extends in a horizontal direction from the first portion and is disposed outwardly of an outer sidewall of the second conductive semiconductor layer,

wherein the buffer layer is disposed outwardly of the outer sidewall of the second conductive semiconductor layer,

wherein the buffer layer is vertically overlapped with the conductive support member and the adhesion layer,

wherein the buffer layer is formed of a conductive material,

wherein the buffer layer is disposed between the protective layer and the adhesion layer,

wherein the buffer layer physically contacts the electrode layer and the protective layer,

wherein the buffer layer has a horizontal width smaller than a horizontal width of the protective layer,

wherein the buffer layer includes a first hole therein,

wherein the protective layer includes a second hole overlapped with the first hole in a vertical direction, and

wherein the first hole has a horizontal width wider than a horizontal width of the second hole.

2. The semiconductor light emitting device of claim 1, wherein the buffer layer and the protective layer are disposed around the electrode layer.

3. The semiconductor light emitting device of claim 1, wherein the buffer layer is formed of a metal material.

4. The semiconductor light emitting device of claim 3, wherein the protective layer is formed of an insulation material.

5. The semiconductor light emitting device of claim 1, further comprising a current blocking layer between the electrode layer and the second conductive semiconductor layer,

wherein the current blocking layer is vertically overlapped with a portion of the electrode and includes a different material from the buffer layer.

6. The semiconductor light emitting device of claim 1, wherein a portion of the electrode layer physically contacts the lower surface of the protective layer, and

wherein the buffer layer is disposed between the protective layer and a portion of the ohmic layer.

7. The semiconductor light emitting device of claim 1, wherein the electrode layer is disposed in the first hole and the second hole, and

wherein a portion of the electrode layer is protruded in a direction toward the lower surface of the second conductive semiconductor layer.

17. The semiconductor light emitting device of claim 1, wherein an entire area of a lower surface of the buffer layer is smaller than an entire area of the lower surface of the protective layer.

8. A semiconductor light emitting device comprising:

a light emitting structure including;

a first conductive semiconductor layer;

a second conductive semiconductor layer under the first conductive semiconductor layer; and

an active layer between the first and second conductive semiconductor layers;

an electrode disposed on the first conductive semiconductor layer;

an electrode layer including a first layer contacting a lower surface of the second conductive semiconductor layer and a second layer under the first layer, the first layer including a different material from the second layer;

a conductive support member under the electrode layer;

an adhesion layer disposed between the electrode layer and the conductive support member;

a protective layer disposed on an outer portion of the lower surface of the second conductive semiconductor layer; and

a buffer layer disposed on a lower surface of the protective layer,

wherein the conductive support member includes a top surface having a horizontal width wider than a horizontal width of the lower surface of the second conductive semiconductor layer,

wherein the protective layer includes a first portion between the second conductive semiconductor layer and the conductive support member and a second portion extended outwardly beyond the lower surface of the second conductive semiconductor layer,

wherein the buffer layer includes a conductive material and physically contacts a lower surface of the second portion of the protective layer,

wherein the second portion of the protective layer outwardly extends in a horizontal direction from the first portion and is disposed outwardly of an outer sidewall of the second conductive semiconductor layer,

wherein the buffer layer is vertically overlapped with the top surface of the conductive support member and a top surface of the adhesion layer,

wherein the buffer layer is formed of a conductive layer different from the protective layer and the adhesion layer,

wherein the buffer layer is disposed between the adhesion layer and the protective layer,

wherein the buffer layer physically contacts the electrode layer and the protective layer,

wherein the buffer layer is spaced apart from a lower surface of the first portion of the protective layer,

wherein the buffer layer includes a first hole therein,

wherein the electrode layer is disposed in the first hole and extends through the first hole,

wherein the protective layer includes a second hole corresponding to the first hole.,

wherein the first hole has a width wider than that of the second hole, and

wherein an entire region of the first hole is located at the lower position than that of the protective layer.

9. The semiconductor light emitting device of claim 8, wherein the buffer layer includes a metal material and the protective layer includes conductive material.

10. The semiconductor light emitting device of claim 8, further comprising a current blocking layer having electrical conductivity lower than electrical conductivity of the electrode layer,

wherein a portion of the current blocking layer is vertically overlapped with the electrode and includes a different material from the protective layer.

11. A semiconductor light emitting device comprising:

a light emitting structure including;

a first conductive semiconductor layer;

a second conductive semiconductor layer disposed under the first conductive semiconductor layer; and

an active layer between the first and second conductive semiconductor layers;

an electrode disposed on the first conductive semiconductor layer;

an electrode layer including a first layer having a metal material disposed under the second conductive semiconductor layer and a second layer having a metal material disposed under the first layer;

a conductive support member disposed under the electrode layer;

an adhesion layer disposed between the second layer and the conductive support member;

a protective layer disposed on an outer portion of a lower surface of the second conductive semiconductor layer; and

a buffer layer disposed on at least one of top and lower surfaces of the protective layer,

wherein the conductive support member includes a top surface having a horizontal width wider than a horizontal width of the lower surface of the second conductive semiconductor layer,

wherein the protective layer includes a first portion between the second conductive semiconductor layer and the conductive support member and a second portion extended outwardly beyond the lower surface of the second conductive semiconductor layer,

wherein the buffer layer includes a different material from the protective layer,

wherein the second portion of the protective layer outwardly extends in a horizontal direction from the first portion and is disposed outwardly of an outer sidewall of the second conductive semiconductor layer,

wherein the second portion of the protective layer is vertically overlapped with an outer portion of the top surface of the conductive support member,

wherein the buffer layer physically contacts the second portion of the protective layer which is disposed outwardly of the outer sidewall of the second conductive semiconductor layer,

wherein the buffer layer is formed of a conductive material and is formed of a different layer from the second layer and the adhesion layer,

wherein the buffer layer is vertically overlapped with the outer portion of the top surface of the conductive support member,

wherein the buffer layer is disposed between a portion of the protective layer and the adhesion layer,

wherein the buffer layer physically contacts the electrode layer and the protective layer, and

wherein the buffer layer is not between a portion of the light emitting structure and a portion of the conductive support member.

12. The semiconductor light emitting device of claim 11, wherein the first layer of the electrode layer physically contacts a lower surface of the second layer and a lower surface of the buffer layer.

13. The semiconductor light emitting device of claim 11, wherein the first layer is an ohmic layer and the second layer is a reflective layer.

14. The semiconductor light emitting device of claim 13, wherein the buffer layer includes a metal material different from the reflective layer and the adhesion layer.

15. The semiconductor light emitting device of claim 11, wherein the buffer layer is disposed between the protective layer and a portion of the adhesion layer, and

wherein the buffer layer has a thickness of about 1 μ

m to 10 μ

m and the protective layer has a thickness of about 0.02 μ

m to about 5 μ

m.

16. A semiconductor light emitting device comprising:

a light emitting structure including;

a first conductive semiconductor layer;

a second conductive semiconductor layer under the first conductive semiconductor layer; and

an active layer between the first and second conductive semiconductor layers;

an electrode disposed on the first conductive semiconductor layer;

an electrode layer including at least one of an ohmic layer or a reflective layer contacting a lower surface of the second conductive semiconductor layer;

a conductive support member under the electrode layer;

an adhesion layer disposed between the electrode layer and the conductive support member;

a protective layer disposed on an outer portion of a lower surface of the second conductive semiconductor layer; and

a buffer layer disposed on a lower surface of the protective layer,

wherein the conductive support member includes a top surface having a horizontal width wider than a horizontal width of the lower surface of the second conductive semiconductor layer,

wherein the protective layer includes a first portion between the second conductive semiconductor layer and adhesion layer and a second portion extended outwardly beyond the lower surface of the second conductive semiconductor layer,

wherein the buffer layer includes a different material from the protective layer

wherein the second portion of the protective layer outwardly extends in a horizontal direction from the first portion and is disposed outwardly of an outer sidewall of the second conductive semiconductor layer,

wherein the buffer layer is disposed outwardly of the outer sidewall of the second conductive semiconductor layer,

wherein the buffer layer is vertically overlapped with the conductive support member and the adhesion layer,

wherein the buffer layer is formed of a conductive material,

wherein the buffer layer is disposed between the protective layer and the adhesion layer,

wherein the buffer layer physically contacts the electrode layer and the protective layer,

wherein the electrode layer includes the ohmic layer and the reflective layer,

wherein the ohmic layer contacts the lower surface of the second conductive semiconductor layer, and

wherein the reflective layer is disposed between the ohmic layer and the adhesion layer.

18. The semiconductor light emitting device of claim 16, wherein the buffer layer has a horizontal width smaller than a horizontal width of the protective layer,

wherein the buffer layer includes a first hole therein,

wherein the protective layer includes a second hole overlapped with the first hole in a vertical direction, and

wherein the first hole has a horizontal width wider than a horizontal width of the second hole.

19. The semiconductor light emitting device of claim 18, wherein the electrode layer is disposed in the first hole and the second hole, and

wherein a portion of the electrode layer is protruded in a direction toward the lower surface of the second conductive semiconductor layer.