Semiconductor light emitting diodes with crack-tolerant barrier structures and methods of fabricating the same

• US 9,496,458 B2
• Filed: 03/08/2013
• Issued: 11/15/2016
• Est. Priority Date: 06/08/2012
• Status: Active Grant

• Current Assignee: CREE Led Incorporated (Smart Global Holdings Incorporated)
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Donofrio, Matthew, Bergmann, Michael, Haberern, Kevin, Schneider, Kevin
• Primary Examiner(s): Luu, Chuong A
• Application Number:
  US13/790,369
• Publication Number:
  US 20130328096A1
• Time in Patent Office: 1,348 Days
• Field of Search: 257/99, 257/79, 257/80, 257/82, 257/88, 257/98
• US Class Current: 1/1
• 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 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 2933/0025 relating to coatings
• CPC Class Codes: H01L 2933/0066 relating to arrangements for conducting electric current to or from the semiconductor body
• CPC Class Codes: H01L 33/12 with a stress relaxation structure, e.g. buffer layer
• CPC Class Codes: H01L 33/44 characterised by the coatings, e.g. passivation layer or anti-reflective coating
• 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 device includes an epitaxial region, an insulating layer on the epitaxial region, a bond pad on the insulating layer, and a crack reducing feature in the insulating layer. The crack reducing feature is configured to reduce the propagation of cracks in the insulating layer to an outside surface of the insulating layer. Related methods are also disclosed.

Claims

1. A light emitting device, comprising:

an epitaxial region;

an insulating layer on the epitaxial region;

a bond pad on the insulating layer; and

a crack reducing layer between the insulating layer and the bond pad, wherein the crack reducing layer is configured to reduce the propagation of cracks in the insulating layer between the epitaxial layer and the bond pad;

wherein the crack reducing layer is embedded within the insulating layer.

2. The light emitting device of claim 1, wherein the crack reducing layer is electrically isolated by the insulating layer from the bond pad and the epitaxial region.

3. The light emitting device of claim 1, wherein the insulating layer comprises an aperture, wherein the bond pad extends through the aperture, and wherein the bond pad extends laterally over the crack reducing layer so that the crack reducing layer is between the bond pad and the epitaxial region.

4. The light emitting device of claim 3, wherein an entire periphery of the bond pad lies within a periphery of the crack reducing layer.

5. The light emitting device of claim 1, wherein the bond pad comprises a cathode bond pad, the light emitting device further comprising an anode bond pad on the insulating layer;

wherein the crack reducing layer comprises a first portion between the anode bond pad and the epitaxial region and a second portion between the cathode bond pad and the epitaxial region, wherein the first and second portions of the crack reducing layer are separated from one another.

6. The light emitting diode of claim 5, wherein the first portion of the crack reducing layer is separated from the anode bond pad by the insulating layer and the second portion of the crack reducing layer is separated from the cathode bond pad by the insulating layer.

7. The light emitting diode of claim 5, wherein the first portion of the crack reducing layer is in contact with the anode bond pad and the second portion of the crack reducing layer is in contact with the cathode bond pad.

8. The light emitting device of claim 1, wherein the crack reducing layer comprises a conductive metal layer.

9. The light emitting device of claim 1, wherein the crack reducing layer comprises a polymer.

10. The light emitting diode of claim 1, further comprising a trench in the insulating layer surrounding the bond pad, wherein the trench is within the periphery of the light emitting diode.

11. The light emitting diode of claim 10, wherein the trench extends completely through the insulating layer.

12. The light emitting diode of claim 10, wherein the trench extends into, but not completely through the insulating layer.

13. The light emitting diode of claim 10, further comprising a metal layer on the epitaxial region, wherein the insulating layer is between the metal layer and the bond pad, and wherein the trench extends completely through the insulating layer to the metal layer.

14. The light emitting diode of claim 13, wherein the insulating layer covers an outermost edge of the metal layer.

15. The light emitting diode of claim 10, wherein the crack reducing layer is exposed in the trench.

16. The light emitting diode of claim 10, wherein the crack reducing layer is separated from the trench by the insulating layer.

17. The light emitting device of claim 1, wherein the crack reducing layer has a ductile fracture mode.

18. A light emitting device, comprising:

an epitaxial region;

an insulating layer on the epitaxial region;

a bond pad on the insulating layer; and

a crack reducing feature in the insulating layer, wherein the crack reducing feature is configured to stop the propagation of cracks in the insulating layer to an outside surface of the insulating layer;

wherein the crack reducing feature comprises a trench in the insulating layer, wherein the trench is within the periphery of the light emitting diode and mechanically isolates peripheral edges of the light emitting device from portions of the insulating layer underneath the bond pad.

19. The light emitting device of claim 18, wherein the crack reducing feature further comprises a crack reducing interlayer in the insulating layer.

20. The light emitting device of claim 18, wherein the trench surrounds the bond pad.

21. The light emitting diode of claim 20, wherein the trench extends completely through the insulating layer.

22. The light emitting diode of claim 20, wherein the trench extends into, but not completely through the insulating layer.

23. The light emitting diode of claim 20, further comprising a metal layer on the epitaxial region, wherein the insulating layer is between the metal layer and the bond pad, and wherein the trench extends completely through the insulating layer to the metal layer.

24. The light emitting diode of claim 23, wherein the insulating layer covers an outermost edge of the metal layer.

25. The light emitting device of claim 18, wherein the crack reducing layer has a ductile fracture mode.