Thin film light emitting diode

• US 8,445,921 B2
• Filed: 11/10/2009
• Issued: 05/21/2013
• 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:
  US12/591,165
• Publication Number:
  US 20100127274A1
• Time in Patent Office: 1,288 Days
• Field of Search: 257/98, 257/81, 257/725
• US Class Current: 257/81
• 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 GaN-based semiconductor structure having a first surface, a second surface and a side surface, the semiconductor structure comprising an active layer, wherein the first surface is opposite the second surface;

a first electrode on the first surface of the semiconductor structure;

a second electrode on the second surface of the semiconductor structure;

an insulative layer on the first surface of the semiconductor structure;

a wavelength converting layer on the insulative layer, wherein the insulative layer is disposed between the first surface of the semiconductor structure and the wavelength converting layer; and

an open space corresponding to the first electrode, wherein the open space is a portion not covered by the insulative layer and the wavelength converting layer.

2. 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.

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

4. The device according to claim 1, further comprising a second insulative layer on the wavelength converting layer.

5. The device according to claim 1, wherein the second electrode comprises a reflective layer.

6. The device according to claim 1, wherein the insulative layer has a first part of the open space.

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

8. The device according to claim 7, wherein the wavelength converting layer has a substantially uniform thickness on at least one of the first surface, the side surface, a side surface of the first electrode, and a side surface of the second electrode, or portions thereof.

9. The device according to claim 1, wherein the insulative layer is disposed on the side surface of the semiconductor structure and extends to at least a portion of the first surface of the semiconductor structure.

10. The device according to claim 1, wherein the insulative layer electrically insulates the wavelength converting layer from the semiconductor structure.

11. The device according to claim 1, wherein the wavelength converting layer is disposed on substantially the entire surface of the insulative layer.

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

13. The device according to claim 1, wherein the insulative layer is disposed on substantially the entire side surface of the semiconductor structure.

24. The device according to claim 1, wherein the insulative layer is configured to reduce the possibility of direct contact between the semiconductor structure and the wavelength converting layer.

25. The device according to claim 1, wherein the open space is disposed for an external electrical connection.

27. The device according to claim 6, wherein the wavelength converting layer has a second part of the open space.

28. The device according to claim 27, wherein the first part is corresponding to the second part.

29. The device according to claim 28, wherein the first part is aligned with the second part.

30. The device according to claim 27, wherein the size of the first part is substantially the same as the size of the second part.

14. A light emitting device comprising:

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

a first electrode on the first surface of the semiconductor structure;

a second electrode on the second surface of the semiconductor structure;

a wavelength converting layer on the semiconductor structure;

an insulative layer between the semiconductor structure and the wavelength converting layer, wherein at least a portion of the insulative layer is configured to avoid direct contact between the semiconductor structure and the wavelength converting layer; and

an open space corresponding to the first electrode, wherein the open space is a portion not covered by the insulative layer and the wavelength converting layer.

15. The device according to claim 14, wherein at least a portion of the wavelength converting layer is disposed with a substantially uniform thickness on the semiconductor structure.

16. The device according to claim 15, wherein the insulative layer in association with the at least a portion of the wavelength converting layer is configured to enhance the uniformity of light emitted from the device.

17. The device according to claim 14, wherein the wavelength converting layer comprises at least one of a fluorescent material, a tin-containing material, and a phosphor.

18. The device according to claim 14, wherein at least a portion of the wavelength converting layer conforms to the insulative layer.

19. The device according to claim 14, wherein the insulative layer comprises at least one of Si, epoxy, oxides, and nitrides.

20. The device according to claim 14 further comprising a second insulative layer on the wavelength converting layer.

21. The device according to claim 14, wherein the second electrode comprises a reflective layer.

22. The device according to claim 14, wherein the insulative layer is disposed on the first surface and the side surface of the semiconductor structure, or portions thereof.

23. The device according to claim 14, wherein the wavelength converting layer is disposed on substantially the entire surface of the insulative layer.

26. The device according to claim 14, wherein the insulative layer is disposed on substantially the entire first surface of the semiconductor structure not covered by the first electrode.