LIGHT EMITTING DIODES INCLUDING TWO REFLECTOR LAYERS

• US 20090166658A1
• Filed: 01/27/2009
• Published: 07/02/2009
• Est. Priority Date: 02/01/2001
• Status: Active Grant

• Current Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Ibbetson, James, Swoboda, Charles M., Keller, Bernd, Slater, David B. JR., Tarsa, Eric J., Thibeault, Brian, Glass, Robert C.
• Granted Patent: US 8,426,881 B2
• Time in Patent Office: Days
• US Class Current: 257/98
• CPC Class Codes: H01L 2224/32014 the layer connector being smaller than the bonding area, e.g. bond pad
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/73265 Layer and 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 2924/00014 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 2924/01079 Gold [Au]
• CPC Class Codes: H01L 2924/01322 Eutectic Alloys, i.e. obtained by a liquid transforming into two solid phases
• CPC Class Codes: H01L 2924/10253 Silicon [Si]
• CPC Class Codes: H01L 2924/12032 Schottky diode
• CPC Class Codes: H01L 2924/12041 LED
• CPC Class Codes: H01L 33/10 with a light reflecting structure, e.g. semiconductor Bragg reflector
• CPC Class Codes: H01L 33/20 with a particular shape, e.g. curved or truncated substrate
• CPC Class Codes: H01L 33/405 Reflective materials
• CPC Class Codes: H01L 33/60 Reflective elements
• 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

A light emitting diode includes a diode region having a gallium nitride based n-type layer, an active region and a gallium nitride based p-type layer. A first reflector layer is provided on the gallium nitride based p-type layer, and a second reflector layer is provided on the gallium nitride based n-type layer. Bonding layers, a mounting support, a wire bond and/or transparent oxide layers also may be provided.

Claims

1. A light emitting diode comprising:

a diode region comprising a gallium nitride based n-type layer, an active region on the gallium nitride based n-type layer and a gallium nitride based p-type layer on the active region opposite the gallium nitride based n-type layer;

a first reflector layer on the gallium nitride based p-type layer opposite the active region; and

a second reflector layer on the gallium nitride based n-type layer opposite the active region.

2. A light emitting diode according to claim 1 further comprising:

a first bonding layer on the first reflector layer opposite the gallium nitride based p-type layer; and

a mounting support on the first bonding layer opposite the first reflector layer.

3. A light emitting diode according to claim 1 further comprising:

a second bonding layer on the second reflector layer opposite the gallium nitride based n-type layer; and

a wire bond on the second bonding layer opposite the second reflector layer.

4. A light emitting diode according to claim 2 further comprising:

a second bonding layer on the second reflector layer opposite the gallium nitride based n-type layer; and

a wire bond on the second bonding layer opposite the second reflector layer.

5. A light emitting diode according to claim 1 further comprising:

a bonding layer on the second reflector layer opposite the gallium nitride based n-type layer, wherein the bonding layer and the second reflector layer are congruent to one another.

6. A light emitting diode according to claim 1 wherein the second reflector layer is directly on an underlying layer and wherein the second reflector layer is of smaller area than the underlying layer.

7. A light emitting diode according to claim 1 further comprising:

a bonding layer on the second reflector layer opposite the gallium nitride based n-type layer, wherein the bonding layer and the second reflector layer each comprise a plurality of fingers.

8. A light emitting diode according to claim 1 further comprising:

a bonding layer on the second reflector layer opposite the gallium nitride based n-type layer, wherein the bonding layer and the second reflector layer each comprise a grid.

9. A light emitting diode according to claim 1 wherein the second reflector layer comprises a plurality of fingers.

10. A light emitting diode according to claim 1 wherein the second reflector layer comprises a grid.

11. A light emitting diode according to claim 5 further comprising:

a wire bond on the bonding layer opposite the second reflector layer.

12. A light emitting diode according to claim 1 further comprising:

a transparent oxide layer between the gallium nitride based p-type layer and the first reflector layer.

13. A light emitting diode according to claim 1 further comprising:

a transparent oxide layer between the gallium nitride based n-type layer and the second reflector layer.

14. A light emitting diode according to claim 12 wherein the transparent oxide layer comprises Indium Tin Oxide (ITO).

15. A light emitting diode according to claim 13 wherein the transparent oxide layer comprises Indium Tin Oxide (ITO).

16. A light emitting diode comprising:

a vertical gallium nitride based light emitting diode structure; and

a pair of reflector layers, a respective one of which is on an opposite side of the vertical gallium nitride based light emitting diode structure.

17. A light emitting diode according to claim 16 wherein the pair of reflector layers have different sizes and/or shapes.

18. A light emitting diode according to claim 16 further comprising a mounting support on one of the pair of reflector layers.

19. A light emitting diode according to claim 18 further comprising a wire bond on the other of the pair of reflector layers.