Light-emitting diode chip comprising a contact structure

• US 20090212307A1
• Filed: 06/02/2006
• Published: 08/27/2009
• Est. Priority Date: 06/02/2005
• Status: Active Grant

• Current Assignee: Osram Opto Semiconductors GmbH (Ams-Osram AG)
• Original Assignee: Osram Opto Semiconductors GmbH (Ams-Osram AG)
• Inventors: Oberschmid, Raimund, Strauss, Jörg, Hárle, Volker, Guenther, Ewald Karl Michael, Hahn, Berthold, Weimar, Andreas, Baur, Johannes, Eberhard, Franz, Richter, Markus
• Granted Patent: US 8,581,279 B2
• Time in Patent Office: Days
• 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 which 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.

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

wherein

the 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

the 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 contact web runs along a side edge, the distance from the side edge being less than 15 μ

m.

5. The luminescence diode chip as claimed in claim 4,

wherein

the contact web 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 the 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,

wherein

a luminescence conversion layer is applied to that partial region of the radiation exit area which is 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,

wherein

a luminescence conversion layer is applied to the radiation exit area between the contact webs.

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

wherein

at least one of the contact webs has a variable width.

17. The luminescence diode chip as claimed in claim 16,

wherein

the width increases continuously starting from the bonding pad.

18. The luminescence diode chip as claimed in claim 16,

wherein

the contact web having a variable width contains a plurality of partial regions having a different width.

19. The luminescence diode chip as claimed in claim 18,

wherein

the partial region at a greater distance from the bonding pad is broader than the partial region at a shorter distance from the bonding pad.

20. The luminescence diode chip as claimed in claim 18,

wherein

the width of the partial regions of the contact web is matched to a current intensity which occurs when the luminescence diode chip is being operated using the respective partial region.

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

wherein

the width of the contact webs is between 10 μ

m and 40 μ

m inclusive.

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

wherein

the luminescence diode chip is a thin-film luminescence diode chip.

23. 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 where 0≦

x≦

1, 0≦

y≦

1 and x+y≦

1.

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

wherein

the length of at least one side edge of the radiation exit area is 400 μ

m or more.

25. The luminescence diode chip as claimed in claim 24,

wherein

the length of at least one side edge of the radiation exit area is 800 μ

m or more.

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

wherein

the luminescence diode chip is operated with a current intensity of 300 mA or more.

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

wherein

the contact structure is a patterned Ti—

Pt—

Au layer sequence.

28. The luminescence diode chip as claimed in claim 27,

wherein

the contact structure absorbs the radiation generated by the chip.

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

wherein

the contact structure is free of aluminum.

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

wherein

less than 15% of the radiation exit area is covered by the contact structure.

31. 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 the 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.

32. The luminescence diode chip as claimed in claim 31

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

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

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