Thin film light emitting diode

• US 8,384,091 B2
• Filed: 11/10/2009
• Issued: 02/26/2013
• 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): Weiss, Howard
• Assistant Examiner(s): Rao, Steven
• Application Number:
  US12/591,164
• Publication Number:
  US 20100129943A1
• Time in Patent Office: 1,204 Days
• Field of Search: 257/79
• US Class Current: 257/79
• 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 light emitting device, comprising:

a semiconductor structure having a first surface, a second surface, and a side surface, the semiconductor structure comprising a first-type semiconductor layer, an active layer, and a second-type semiconductor layer;

a first electrode electrically connected to the first-type semiconductor layer, the first electrode comprising a reflective layer, wherein the first electrode is arranged on the first surface that is opposite the second surface;

a second electrode electrically connected to the second-type semiconductor layer;

an insulative passivation layer on the second surface and the side surface of the semiconductor structure; and

a phosphor on the insulative passivation layer, the phosphor having an open space corresponding to the second electrode for an external electrical connection, wherein the external electrical connection comprises a bonding wire, wherein the open space prevents the phosphor from contacting the bonding wire, wherein the insulative passivation layer is arranged between the second surface of the semiconductor structure and the phosphor.

2. The device according to claim 1, wherein the open space is arranged near an edge of the second surface of the semiconductor structure.

3. The device according to claim 1, wherein the bonding wire is arranged over the open space of the phosphor.

4. The device according to claim 1, wherein the insulative passivation layer has an open space corresponding to the second electrode.

5. The device according to claim 4, wherein the open space of the phosphor and the open space of the insulative passivation layer have substantially the same size.

6. The device according to claim 1, wherein the insulative passivation layer has an open space corresponding to the second electrode, and wherein the bonding wire is arranged over the open space of the insulative passivation layer.

7. The device according to claim 1, wherein the open space of the phosphor is configured to reduce the possibility of direct contact between the bonding wire and the phosphor.

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

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

10. The device according to claim 1, further comprising a second insulative passivation layer on the phosphor.

11. The device according to claim 10, wherein the second insulative passivation layer covers the second electrode.

12. The device according to claim 1, wherein the phosphor is arranged with a substantially uniform thickness on at least one of the second surface, the side surface of the semiconductor structure, a side surface of the first electrode, and a side surface of the second electrode.

13. The device according to claim 1, wherein the phosphor is arranged with a substantially uniform thickness on the insulative passivation layer.

14. The device according to claim 1, wherein a portion of the insulative passivation layer electrically isolates the phosphor from the semiconductor structure.

15. The device according to claim 1, wherein the phosphor is arranged on substantially the entire surface of the insulative passivation layer.

16. The device according to claim 1, wherein the phosphor is about 10μ

m thick.

17. The device according to claim 1, wherein the insulative passivation layer is configured to reduce the possibility of direct contact between the semiconductor structure and the phosphor.

18. The device according to claim 1, wherein the thickness of the insulative passivation layer is about 1000 Å

.

19. The device according to claim 1, wherein the insulative passivation layer contacts the phosphor.

20. The device according to claim 1, wherein the second electrode is arranged on the second surface of the semiconductor structure.

21. The device according to claim 20, wherein the phosphor is arranged with a substantially uniform thickness on the second surface of the semiconductor structure.

22. The device according to claim 20, wherein the open space is arranged near an edge of the second surface of the semiconductor structure.

23. The device according to claim 20, wherein the first-type semiconductor layer has the first surface and the second-type semiconductor layer has the second surface.

24. The device according to claim 1, wherein the first-type semiconductor layer is p-type and the second-type semiconductor layer is n-type.

25. The device according to claim 1, wherein the reflective layer reflects light from the active layer back through the second surface.

26. The device according to claim 1, wherein a width of the open space is substantially the same as a width of the second electrode.

27. The device according to claim 1, wherein the insulative passivation layer is arranged over the active layer.

28. The device according to claim 1, wherein the insulative passivation layer is arranged on a side of the first electrode.

29. The device according to claim 1, wherein at least one of the second surface and the side surface is a light emitting surface.

30. The device according to claim 29, wherein the insulative passivation layer is arranged on the light emitting surface.

31. The device according to claim 1, wherein the insulative passivation layer and the phosphor is arranged over the reflective layer.

32. The device according to claim 1, wherein the open space comprises a portion not covered by the insulative passivation layer and the phosphor.