Nitride based semiconductor light emitting device

• US 20060145170A1
• Filed: 12/28/2005
• Published: 07/06/2006
• Est. Priority Date: 01/03/2005
• Status: Abandoned Application

• Current Assignee: Samsung Electro-Mechanics Co., Ltd. (Samsung Group)
• Original Assignee: Samsung Electro-Mechanics Co., Ltd. (Samsung Group)
• Inventors: Cho, Dong Hyun
• Application Number:
  US11/319,973
• Publication Number:
  US 20060145170A1
• Time in Patent Office: Days
• US Class Current: 257/95
• CPC Class Codes: H01L 2933/0091 Scattering means in or on the semiconductor body or semiconductor body package H01L33/22 takes precedence
• CPC Class Codes: H01L 33/20 with a particular shape, e.g. curved or truncated substrate
• CPC Class Codes: H01L 33/22 Roughened surfaces, e.g. at the interface between epitaxial layers
• 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

Abstract

The present invention provides a nitride-based semiconductor light emitting device basically comprising a first conductivity type nitride semiconductor layer, active layer and second conductivity type nitride semiconductor layer, which are sequentially formed on a light-permeable substrate in this order. The light emitting device further comprises an insulating light-scattering layer formed on at least one surface thereof. The insulating light-scattering layer is made of an insulating material having a light permeability of more than 50% and is formed at an outer surface thereof with a roughened pattern for the scattering of light.

Claims

1. A nitride-based semiconductor light emitting device comprising a first conductivity type nitride semiconductor layer, active layer and second conductivity type nitride semiconductor layer, which are sequentially formed on a light-permeable substrate in this order, further comprising:

an insulating light-scattering layer formed on at least one surface of the nitride-based semiconductor light emitting device, the light-scattering layer being made of an insulating material having a light permeability of more than 50% and being formed to have a roughened pattern for the scattering of light.

2. The device as set forth in claim 1, wherein the insulating light-scattering layer has a light permeability of more than 70%.

3. The device as set forth in claim 1, wherein the insulating light-scattering layer is made of a polymer material.

4. The device as set forth in claim 3, wherein the insulating light-scattering layer is made of epoxy resin, silicone based resin or PMMA resin.

5. The device as set forth in claim 4, wherein the insulating light-scattering layer further comprises a fluorescent material for exciting light.

6. The device as set forth in claim 1, wherein the insulating light-scattering layer is made of a material selected from the group consisting of GaN, AlN, InN, SiNx, SiC, diamond, Al₂O₃, SiO₂, SnO₂, TiO₂, ZrO₂, MgO, InO_x and CuO_x.

7. The device as set forth in claim 1, wherein the insulating light-scattering layer has a pattern pitch within a range of approximately 0.001 to 50 μ

m.

8. The device as set forth in claim 1, wherein the insulating light-scattering layer is made of a particle having a diameter of approximately 0.001 to 50 μ

m.

9. The device as set forth in claim 1, wherein the insulating light-scattering layer is formed on at least a lower surface of the light-permeable substrate.

10. The device as set forth in claim 9, wherein the insulating light-scattering layer is made of a material having a refraction index higher than that of the light-permeable substrate.

11. The device as set forth in claim 1, wherein the insulating light-scattering layer is formed at an upper surface of the nitride-based semiconductor light emitting device opposite to the light-permeable substrate.

12. The device as set forth in claim 11, wherein the insulating light-scattering layer extends from the upper surface of the nitride-based semiconductor light emitting device to at least a part of a sidewall of the light emitting device.

13. The device as set forth in claim 11, wherein the insulating light-scattering layer is made of a material having a refraction index higher than that of the first and second conductivity type nitride semiconductor layers.

14. The device as set forth in claim 1, further comprising:

a reflective metal layer formed on at least one surface of the nitride-based semiconductor light emitting device except for a light emitting surface.

15. The device as set forth in claim 14, wherein the reflective metal layer is formed on the insulating light-scattering layer.

16. The device as set forth in claim 14, wherein the reflective metal layer has a reflectivity of more than 90%.

17. The device as set forth in claim 14, wherein the reflective metal layer is made of at least one metal selected from the group consisting of Ag, Al, Rh, Ru, Pt, Au, Cu, Pd, Cr, Ni, Co, Ti, In and Mo or alloys thereof.

18. The device as set forth in claim 1,

wherein the light-permeable substrate has an inclined surface along at least a part of a lateral end of a lower surface thereof, and

wherein the insulating light-scattering layer is formed on at least the lower surface of the light-permeable substrate and the inclined surface.

19. The device as set forth in claim 18, wherein the insulating light-scattering layer is made of a material having a refraction index higher than the light-permeable substrate.

20. A flip-chip type nitride-based semiconductor light emitting device comprising:

a nitride-based semiconductor light emitting device having a first conductivity type nitride semiconductor layer, active layer and second conductivity type nitride semiconductor layer, which are sequentially formed on a light-permeable substrate in this order, and first and second electrodes connected to the first and second conductivity type nitride semiconductor layers, respectively;

a package substrate having first and second conductor lines to be connected to the first and second electrodes, respectively; and

an insulating light-scattering layer formed on at least a lower surface of the light-permeable substrate, the insulating light-scattering layer being made of an insulating material having a light permeability of more than 50% and being formed with a roughened pattern for the scattering of light.

21. The device as set forth in claim 20, wherein the insulating light-scattering layer is made of a material having a refraction index higher than that of the light-permeable substrate.

22. The device as set forth in claim 20, wherein the insulating light-scattering layer is made of a polymer material.

23. The device as set forth in claim 22, wherein the insulating light-scattering layer is made of epoxy resin, silicone based resin or PMMA resin.

24. The device as set forth in claim 23, wherein the insulating light-scattering layer further comprises a fluorescent material for exciting light.

25. The device as set forth in claim 20, wherein the insulating light-scattering layer is made of a material selected from the group consisting of GaN, AlN, InN, SiNx, SiC, diamond, Al₂O₃, SiO₂, SnO₂, TiO₂, ZrO₂, MgO, InO_x and CuO_x.

26. The device as set forth in claim 20, wherein the insulating light-scattering layer has a pattern pitch within a range of approximately 0.001 to 50 μ

m.

27. The device as set forth in claim 20, wherein the insulating light-scattering layer is made of a particle having a diameter of approximately 0.001 to 50 μ

m.