Thin film light emitting diode

• US 8,207,552 B2
• Filed: 05/18/2011
• Issued: 06/26/2012
• Est. Priority Date: 06/26/2002
• Status: Active Grant

• Current Assignee: Suzhou Lekin Semiconductor Company Limited
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Yoo, Myung Cheol
• Primary Examiner(s): Trinh, Hoa B
• Application Number:
  US13/110,545
• Publication Number:
  US 20110278620A1
• Time in Patent Office: 405 Days
• Field of Search: 257 79- 81, 257 98-100, 257/143, 257/E33.062, 257/E33.68, 257/E33.061
• US Class Current: 257/98
• CPC Class Codes: H01L 2224/05599 Material
• CPC Class Codes: H01L 2224/45099 Material
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48463 the connecting portion on the bonding area of the semiconductor or solid-state body being a ball bond
• CPC Class Codes: H01L 2224/49107 on the semiconductor or solid-state body
• CPC Class Codes: H01L 2224/4918 being disposed on at least two different sides of the body, e.g. dual array
• CPC Class Codes: H01L 2224/8592 Applying permanent coating, e.g. protective coating
• CPC Class Codes: H01L 24/48 of an individual wire connector
• CPC Class Codes: H01L 24/49 of a plurality of wire connectors
• 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 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• 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 2924/01029 Copper [Cu]
• CPC Class Codes: H01L 2924/12041 LED
• CPC Class Codes: H01L 2924/12042 LASER
• CPC Class Codes: H01L 2924/181 Encapsulation
• CPC Class Codes: H01L 33/06 within the light emitting region, e.g. quantum confinement structure or tunnel barrier
• CPC Class Codes: H01L 33/32 containing nitrogen
• 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 33/502 : Wavelength conversion materials
• CPC Class Codes: H01L 33/504 : Elements with two or more wavelength conversion materials
• CPC Class Codes: H01L 33/507 : the elements being in intimate contact with parts other than the semiconductor body or integrated with parts other than the semiconductor body
• 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

Light emitting LEDs devices comprised of LED chips that emit light at a first wavelength, and a thin film layer over the LED chip that changes the color of the emitted light. For example, a blue LED chip can be used to produce white light. The thin film layer beneficially consists of a florescent material, such as a phosphor, and/or includes tin. The thin film layer is beneficially deposited using chemical vapor deposition.

Claims

1. A vertical topology light emitting device, comprising:

a conductive support structure;

an adhesion structure comprising a first metallic layer on the conductive support structure and a second metallic layer on the first metallic layer;

a semiconductor structure over the adhesion structure, the semiconductor structure having a first surface, a second surface and a side surface, wherein the semiconductor structure comprises a first-type semiconductor layer, a light emitting layer on the first-type semiconductor layer, and a second-type semiconductor layer on the light emitting layer;

a reflective structure between the adhesion structure and the first surface of the semiconductor structure, the reflective structure also serving as a first electrode, wherein the reflective structure reflects the light from the semiconductor structure, and wherein the reflective structure comprises a reflective layer on the adhesion structure and a metal contact on the reflective layer;

a second electrode on the second surface of the semiconductor structure, the second surface being opposite the first surface, wherein the second electrode comprises a first layer and a second layer on the first layer;

a passivation layer on at least a portion of the second surface of the semiconductor structure; and

a wavelength converting layer over the second surface of the semiconductor structure, wherein the passivation layer is at least partially disposed between the semiconductor structure and the wavelength converting layer.

2. The device according to claim 1, wherein the passivation layer comprises an insulative material comprising at least one of Si, epoxy, oxides, and nitrides.

3. The device according to claim 1, wherein the first metallic layer is thicker than the second metallic layer.

4. The device according to claim 1, wherein the first metallic layer comprises Au.

5. The device according to claim 1, wherein the first-type semiconductor layer is an n-type GaN-based layer and the second-type semiconductor layer is a p-type GaN-based layer.

6. The device according to claim 1, wherein the wavelength converting layer comprises at least one of a fluorescent material, a tin-containing material, and a phosphor.

7. The device according to claim 1, wherein the wavelength converting layer has a substantially uniform thickness.

8. The device according to claim 1, wherein the passivation layer is disposed on substantially the entire second surface of the semiconductor structure not covered by the second electrode.

9. The device according to claim 1, wherein one of the reflective layer and the metal contact comprises Al or Ti.

10. The device according to claim 1, wherein the conductive support structure comprises a metal support layer.

11. A vertical topology light emitting device, comprising:

a conductive support structure;

an adhesion structure comprising a first metallic layer on the conductive support structure and a second metallic layer on the first metallic layer;

a semiconductor structure over the adhesion structure, the semiconductor structure having a first surface, a second surface and a side surface, wherein the semiconductor structure comprises a first-type semiconductor layer, a light emitting layer on the first-type semiconductor layer, and a second-type semiconductor layer on the light emitting layer;

a reflective structure between the adhesion structure and the first surface of the semiconductor structure, the reflective structure also serving as a first electrode, wherein the reflective structure reflects the light from the semiconductor structure;

a second electrode on the second surface of the semiconductor structure, the second surface being opposite the first surface;

a metal pad on the second electrode;

an inter-layer between the second electrode and the metal pad;

a passivation layer on at least a portion of the second surface of the semiconductor structure; and

a wavelength converting layer over the second surface of the semiconductor structure, wherein the passivation layer is at least partially disposed between the semiconductor structure and the wavelength converting layer.

12. The device according to claim 11, wherein the passivation layer comprises an insulative material comprising at least one of Si, epoxy, oxides, and nitrides.

13. The device according to claim 11, wherein the first metallic layer is thicker than the second metallic layer.

14. The device according to claim 11, wherein the first metallic layer comprises Au.

15. The device according to claim 11, wherein the first-type semiconductor layer is an n-type GaN-based layer and the second-type semiconductor layer is a p-type GaN-based layer.

16. The device according to claim 11, wherein the wavelength converting layer comprises at least one of a fluorescent material, a tin-containing material, and a phosphor.

17. The device according to claim 11, wherein the wavelength converting layer has a substantially uniform thickness.

18. The device according to claim 11, wherein the passivation layer is disposed on substantially the entire second surface of the semiconductor structure not covered by the second electrode.

19. The device according to claim 11, wherein the conductive support structure comprises a metal support layer.

20. The device according to claim 11, wherein the inter-layer comprises at least one of Cr or Au.

21. A vertical topology light emitting device, comprising:

a conductive support structure;

an adhesion structure comprising a first metallic layer on the conductive support structure and a second metallic layer on the first metallic layer, the first metallic layer being thicker than the second metallic layer;

a semiconductor structure over the adhesion structure, the semiconductor structure having a first surface, a second surface and a side surface, wherein the semiconductor structure comprises a first-type semiconductor layer, a light emitting layer on the first-type semiconductor layer, and a second-type semiconductor layer on the light emitting layer;

a reflective structure between the adhesion structure and the first surface of the semiconductor structure, the reflective structure also serving as a first electrode, wherein the reflective structure reflects the light from the semiconductor structure, and wherein the reflective structure comprises a reflective layer on the adhesion structure and a metal contact on the reflective layer;

a second electrode on the second surface of the semiconductor structure, the second surface being opposite the first surface;

a metal pad on the second electrode;

an inter-layer between the second electrode and the metal pad;

a passivation layer on at least a portion of the second surface of the semiconductor structure; and

a wavelength converting layer over the second surface of the semiconductor structure, wherein the passivation layer is at least partially disposed between the semiconductor structure and the wavelength converting layer.

22. The device according to claim 21, wherein the passivation layer comprises an insulative material comprising at least one of Si, epoxy, oxides, and nitrides.

23. The device according to claim 21, wherein the first metallic layer comprises Au.

24. The device according to claim 21, wherein the first-type semiconductor layer is an n-type GaN-based layer and the second-type semiconductor layer is a p-type GaN-based layer.

25. The device according to claim 21, wherein the wavelength converting layer has a substantially uniform thickness.

26. The device according to claim 21, wherein the wavelength converting layer is disposed on substantially the entire surface of the passivation layer.

27. The device according to claim 21, wherein the passivation layer is disposed on substantially the entire second surface of the semiconductor structure not covered by the second electrode.

28. The device according to claim 21, wherein one of the reflective layer and the metal contact comprises Al or Ti.

29. The device according to claim 21, wherein the conductive support structure comprises a metal support layer.

30. The device according to claim 21, wherein the inter-layer comprises at least one of Cr or Au.