Radiation-emitting semiconductor element and method for producing the same

• US 20040056254A1
• Filed: 01/07/2003
• Published: 03/25/2004
• Est. Priority Date: 04/26/2000
• Status: Active Grant

• Current Assignee: OSRAM OLED GMBH (Ams-Osram AG)
• Original Assignee: OSRAM GmbH (Ams-Osram AG)
• Inventors: Hahn, Berthold, Eisert, Dominik, Lugauer, Hans-Jurgen, Mundbrod-Vangerow, Manfred, Harle, Volker, Bader, Stefan
• Granted Patent: US 6,878,563 B2
• Time in Patent Office: Days
• US Class Current: 257/79
• CPC Class Codes: H01L 27/153 in a repetitive configuration, e.g. LED bars
• 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 33/0093 Wafer bonding; Removal of the growth substrate
• CPC Class Codes: H01L 33/02 characterised by the semiconductor bodies
• CPC Class Codes: H01L 33/22 Roughened surfaces, e.g. at the interface between epitaxial layers
• 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 33/46 Reflective coating, e.g. dielectric Bragg reflector

Abstract

This invention describes a radiation-emitting semiconductor component based on GaN, whose semiconductor body is made up of a stack of different GaN semiconductor layers (1). The semiconductor body has a first principal surface (3) and a second principal surface (4), with the radiation produced being emitted through the first principal surface (3) and with a reflector (6) being produced on the second principal surface (4).

The invention also describes a production method for a semiconductor component pursuant to the invention. An interlayer (9) is first applied to a substrate (8), and a plurality of GaN layers (1) that constitute the semiconductor body of the component are then applied to this. The substrate (8) and the interlayer (9) are then detached and a reflector (6) is produced on a principal surface of the semiconductor body.

Claims

1. Radiation-emitting semiconductor component whose semiconductor body is made up of a stack of different III-V nitride semiconductor layers (1) and that has a first principal surface (3) and a second principal surface (4), with at least a portion of the radiation (5) produced being emitted through the first principal surface (3), characterized by the fact that

a reflector (6) is applied to the second principal surface (4).

2. Radiation-emitting semiconductor component pursuant to claim 1, characterized by the fact that the semiconductor layers (1) consist of GaN, AlN, InN, AlGaN, InGaN, InAlN, or AlInGaN.

3. Radiation-emitting semiconductor component pursuant to claim 1 or 2, characterized by the fact that the reflector (6) is composed of a reflecting metallic contact surface.

4. Radiation-emitting semiconductor component pursuant to claim 3, characterized by the fact that the contact surface consists of Ag, Al, or an Ag or Al alloy.

5. Radiation-emitting semiconductor component pursuant to claim 1 or 2, characterized by the fact that the reflector (6) is made by dielectric vapor deposition, preferably that the dielectric vapor deposition is composed of a plurality of dielectric layers.

6. Radiation-emitting semiconductor component pursuant to claim 1 or 2, characterized by the fact that the reflector (6) has a transparent first layer applied to the second principal surface (4) and a second reflecting layer applied to this one.

7. Radiation-emitting semiconductor component pursuant to one of the claims 1 to 7, characterized by the fact that the entire free surface of the semiconductor body or a subregion thereof is roughened.

8. Method for producing a radiation-emitting semiconductor component whose semiconductor body is made up of a stack of different III-V nitride semiconductor layers (1) and that has a first principal surface (3) and a second principal surface (4), with at least a portion of the radiation (5) produced being emitted through the first principal surface (3) and with the second principal surface (4) having a reflector (6), characterized by the steps

application of an interlayer (9) on a substrate (8)

application of a plurality of different III-V nitride semiconductor layers (1) on the interlayer (9)

detachment of the substrate (8) including the interlayer (9)

application of the reflector (6) on the second principal surface (4) of the semiconductor body.

9. Method pursuant to claim 8, characterized by the fact that an Si substrate is used as the substrate (8).

10. Method pursuant to claim 8 or 9, characterized by the fact that an SiC interlayer is applied.

11. Method pursuant to claim 8 to 10, characterized by the fact that the interlayer (9) is applied by a wafer-bonding method.

12. Method pursuant to claim 8 to 10, characterized by the fact that the interlayer (9) is applied by epitaxy.

13. Method pursuant to claim 8 to 12, characterized by the fact that the reflector (6) is made by applying a layer of metal, which serves for contacting the semiconductor body at the same time.

14. Method pursuant to one of the claims 8 to 13, characterized by the fact that a mask (11) is applied to the interlayer (9) before producing the GaN layers (1).

15. Method pursuant to one of the claims 8 to 14, characterized by the fact that the semiconductor body is roughened.

16. Method pursuant to claim 15, characterized by the fact that the semiconductor body is roughened by etching.

17. Method pursuant to claim 15, characterized by the fact that the semiconductor body is roughened by a sand-blasting method.

18. Method for producing a radiation-emitting semiconductor component whose semiconductor body is made up of a stack of different III-V nitride semiconductor layers (1) and that has a first principal surface and a second principal surface, with at least a portion of the radiation produced being emitted through the first principal surface, and with the second principal surface having a reflector, characterized by the fact that the III-V nitride layers are applied to a composite substrate that has a substrate body and an interlayer, with the coefficient of thermal expansion of the substrate body being similar to or preferably greater than the coefficient of thermal expansion of the III-V nitride layers, and with the III-V nitride layers being deposited on the interlayer.

19. Method pursuant to claim 18, characterized by the fact that the thickness of the interlayer is so small that the coefficient of thermal expansion of the composite substrate is determined essentially by the substrate body.

20. Method pursuant to claim 18 or 19, characterized by the fact that the substrate body contains SiC, poly-SiC, sapphire, GaN, or AlN.

21. Method pursuant to one of the claims 18 to 20, characterized by the fact that the interlayer contains SiC, silicon, sapphire, MgO, GaN, or AlGaN.

22. Method pursuant to one of the claims 18 to 21, characterized by the fact that the interlayer has a monocrystalline surface at least in subregions.

23. Method pursuant to one of the claims 18 to 22, characterized by the fact that the III-V nitride layers are deposited on an Si(111) surface or on an SiC surface of the interlayer that is monocrystalline at least in subregions.

24. Method pursuant to one of the claims 18 to 23, characterized by the fact that the interlayer is applied to the substrate body by a wafer-bonding method.

25. Method pursuant to one of the claims 18 to 24, characterized by the fact that a bonding layer is produced between the substrate body and the interlayer.

26. Method pursuant to claim 25, characterized by the fact that the bonding layer contains silicon oxide.

27. Method pursuant to one of the claims 18 to 26, characterized by the fact that a mask layer is produced with epitaxy windows on the composite substrate before applying the III-V nitride layers, with the epitaxy surface of the composite substrate remaining uncovered within the epitaxy windows.

28. Method pursuant to one of the claims 18 to 27, characterized by the fact that the III-V nitride layers are structured into individual semiconductor layer stacks after being applied to the composite substrate.

29. Method pursuant to claim 28, characterized by the fact that the method is continued with the steps:

application of a carrier to the semiconductor layer stack,

detachment of the composite substrate.

30. Method pursuant to claim 28, characterized by the fact that the method is continued with the steps:

application of an interlayer on the semiconductor layer stack,

detachment of the composite substrate,

application of a carrier to the side of the semiconductor layer stack from which the composite substrate has been detached,

detachment of the interlayer.

31. Method pursuant to one of the claims 28 to 30, characterized by the fact that a reflector layer is produced on the semiconductor layer stack.

32. Method pursuant to claim 31, characterized by the fact that the reflector layer is produced by applying a metallic layer.

33. Method pursuant to claim 32, characterized by the fact that the metallic layer contains silver, aluminum or a silver or aluminum alloy.

34. Method pursuant to one of the claims 31 to 33, characterized by the fact that the reflector layer serves as a contact surface at the same time.

35. Method pursuant to claim 31, characterized by the fact that the reflector layer is produced by dielectric vapor deposition.

36. Method pursuant to claim 31, characterized by the fact that the reflector layer is produced by applying a transparent first layer to the semiconductor layer stack and applying a reflecting second layer to the first layer.

37. Method pursuant to one of the claims 28 to 36, characterized by the fact that the surface of the semiconductor layer stack is roughened at least regionally.

38. Method pursuant to claim 37, characterized by the fact that the surface of the semiconductor layer stack is roughened by etching.

39. Method pursuant to claim 37, characterized by the fact that the surface of the semiconductor layer stack is roughened by a sand-blasting method.