Light-emitting diode chip comprising a contact structure

• US 8,581,279 B2
• Filed: 06/02/2006
• Issued: 11/12/2013
• Est. Priority Date: 06/02/2005
• Status: Expired due to Fees

• Current Assignee: Osram Opto Semiconductors GmbH (Ams-Osram AG)
• Original Assignee: Osram Opto Semiconductors GmbH (Ams-Osram AG)
• Inventors: Baur, Johannes, Hrle, Volker, Hahn, Berthold, Weimar, Andreas, Oberschmid, Raimund, Guenther, Ewald Karl Michael, Eberhard, Franz, Richter, Markus, Strauss, Jrg
• Primary Examiner(s): Karimy, Timor
• Application Number:
  US11/921,530
• Publication Number:
  US 20090212307A1
• Time in Patent Office: 2,720 Days
• Field of Search: 257/98, 257/E33.066, 257/E33.054, 257/E33.061
• US Class Current: 257/98
• 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 33/38 with a particular shape

Abstract

In a luminescence diode chip having a radiation exit area (1) and a contact structure (2, 3, 4) which is arranged on the radiation exit area (1) and comprises a bonding pad (4) and a plurality of contact webs (2, 3) which are provided for current expansion and are electrically conductively connected to the bonding pad (4), the bonding pad (4) is arranged in an edge region of the radiation exit area (1). The luminescence diode chip has reduced absorption of the emitted radiation (23) in the contact structure (2, 3, 4).

Claims

1. A luminescence diode chip having:

a radiation exit area, and

a contact structure which is arranged on the radiation exit area and comprises a bonding pad and a plurality of contact webs,

wherein the contact webs are provided for current expansion and are electrically conductively connected to the bonding pad,

wherein the bonding pad is arranged in an edge region of the radiation exit area,

wherein each contact web of the contact webs has a longitudinal direction and a width in a direction perpendicular the longitudinal direction of the each contact web and parallel to a plane of the radiation exit area,

wherein a first contact web of the contact webs has a width that varies along the longitudinal direction thereof and contains a plurality of partial regions having a different width, and

wherein at least one of the partial regions of the first contact web is located at a greater distance from the bonding pad and is wider than one of the partial regions of the first contact web located at a shorter distance from the bonding pad.

2. The luminescence diode chip as claimed in claim 1, wherein a distance d₁ between the bonding pad and at least one side flank of the luminescence diode chip is less than 30 μ

m.

3. The luminescence diode chip as claimed in claim 2, wherein a distance d₂ between the bonding pad and a further side flank of the luminescence diode chip is less than 30 μ

m.

4. The luminescence diode chip as claimed in claim 1, wherein at least one of the contact webs runs along a side edge of the luminescence diode chip, a distance from the side edge to the at least one of the contact webs being less than 15 μ

m.

5. The luminescence diode chip as claimed in claim 4, wherein the at least one of the contact webs adjoins the side edge of the luminescence diode chip.

6. The luminescence diode chip as claimed in claim 1, wherein the contact webs on the radiation exit area form a contour of at least one rectangle or square.

7. The luminescence diode chip as claimed in claim 6, wherein the contact webs form the contour of a plurality of rectangles or squares.

8. The luminescence diode chip as claimed in claim 7, wherein the plurality of rectangles or squares respectively have at least one common side edge.

9. The luminescence diode chip as claimed in claim 8, wherein the plurality of rectangles or squares respectively have two common side edges.

10. The luminescence diode chip as claimed in claim 6, wherein the bonding pad is arranged at a corner point of the at least one rectangle or square.

11. The luminescence diode chip as claimed in claim 1, wherein the contact webs enclose at least one partial region of the radiation exit area.

12. The luminescence diode chip as claimed in claim 11, wherein the contact webs enclose more than 80% of the radiation exit area.

13. The luminescence diode chip as claimed in claim 11, further comprising a luminescence conversion layer applied to a partial region of the radiation exit area enclosed by the contact webs.

14. The luminescence diode chip as claimed in claim 1, wherein the contact structure is in the form of a fork.

15. The luminescence diode chip as claimed in claim 14, further comprising a luminescence conversion layer applied to the radiation exit area between the contact webs.

16. The luminescence diode chip as claimed in claim 1, wherein the width of the first contact web increases continuously starting from the bonding pad.

17. The luminescence diode chip as claimed in claim 1, wherein the width of the partial regions of the first contact web is matched to a current intensity which occurs when the luminescence diode chip is being operated using the respective partial regions of the first contact web.

18. The luminescence diode chip as claimed in claim 1, wherein the contact webs have a width between 10 μ

m and 40 μ

m inclusive.

19. The luminescence diode chip as claimed in claim 1, wherein the luminescence diode chip is a thin-film luminescence diode chip.

20. The luminescence diode chip as claimed in claim 1, wherein the luminescence diode chip has an active layer containing In_xAl_yGa_1-x-yN wherein 0≦

x≦

1, 0≦

y≦

1 and x+y≦

1.

21. The luminescence diode chip as claimed in claim 1, wherein at least one side edge of the radiation exit area has a length of at least 400 μ

m.

22. The luminescence diode chip as claimed in claim 21, wherein the length of at least one side edge of the radiation exit area is at least 800 μ

m.

23. The luminescence diode chip as claimed in claim 1, wherein the luminescence diode chip is operated with a current intensity of at least 300 mA.

24. The luminescence diode chip as claimed in claim 1, wherein the contact structure is a patterned Ti—

Pt—

Au layer sequence.

25. The luminescence diode chip as claimed in claim 24, wherein the contact structure absorbs the radiation generated by the luminescence diode chip.

26. The luminescence diode chip as claimed in claim 1, wherein the contact structure is free of aluminum.

27. The luminescence diode chip as claimed in claim 1, wherein less than 15% of the radiation exit area is covered by the contact structure.

28. The luminescence diode chip as claimed in claim 1,

wherein the luminescence diode chip contains a semiconductor layer sequence which comprises an active layer, and

wherein a reflective contact layer is provided on a main area on a surface of the semiconductor layer sequence that is opposite a surface that the radiation exit area is on, a region of the main area that is opposite the bonding pad being spared from the contact layer.

29. The luminescence diode chip as claimed in claim 28,

wherein the contact webs enclose at least one partial region of the radiation exit area;

wherein a luminescence conversion layer is applied to the at least one partial region of the radiation exit area enclosed by the contact webs; and

wherein a region of the main area that is lateral of the luminescence conversion layer is spared from the contact layer.