Method for fabricating a semiconductor component based on GaN

• US 7,691,656 B2
• Filed: 04/17/2003
• Issued: 04/06/2010
• Est. Priority Date: 10/17/2000
• Status: Expired due to Fees

• Current Assignee: OSRAM OLED GMBH (Ams-Osram AG)
• Original Assignee: OSRAM GmbH (Ams-Osram AG)
• Inventors: Hahn, Berthold, Bader, Stefan, Härle, Volker, Eisert, Dominik
• Primary Examiner(s): Mulpuri; Savitri
• Application Number:
  US10/417,611
• Publication Number:
  US 20040033638A1
• Time in Patent Office: 2,546 Days
• Field of Search: 438 22- 47, 438459-465
• US Class Current: 438/29
• CPC Class Codes: H01L 27/153 in a repetitive configuration, e.g. LED bars
• CPC Class Codes: H01L 33/0093 Wafer bonding; Removal of the growth substrate
• 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

Abstract

A semiconductor component has a plurality of GaN-based layers, which are preferably used to generate radiation, produced in a fabrication process. In the process, the plurality of GaN-based layers are applied to a composite substrate that includes a substrate body and an interlayer. A coefficient of thermal expansion of the substrate body is similar to or preferably greater than the coefficient of thermal expansion of the GaN-based layers, and the GaN-based layers are deposited on the interlayer. The interlayer and the substrate body are preferably joined by a wafer bonding process.

Claims

1. A method for an epitaxial fabrication of a radiation-emitting semiconductor component, the method comprising the steps of:

providing a composite substrate having a substrate body and an interlayer applied to the substrate body using a bonding process, the substrate body having a given coefficient of thermal expansion, the interlayer being formed from AlGaN;

applying GaN-based layers to the interlayer of the composite substrate, the GaN-based layers collectively having a bottom facing the composite substrate and a top facing away form the composite substrate;

applying a carrier to the GaN-based layers;

forming a reflector layer on the top of the GaN-based layers so that the GaN-based layers are arranged between the reflector layer and the composite substrate, and the reflector layer is disposed between the GaN-based layers and the carrier; and

arranging the reflector layer to reflect radiation generated in the GaN-based layers;

wherein the reflector layer is an electrical contact surface; and

wherein the given coefficient of thermal expansion of the substrate body is equal to or greater than a coefficient of thermal expansion of the GaN-based layers.

2. The method according to claim 1, which further comprises setting a thickness of the interlayer such that a coefficient of thermal expansion of the composite substrate is substantially determined by the substrate body.

3. The method according to claim 1, which further comprises forming the substrate body from a material selected from the group consisting of SiC, poly-SiC, Si, poly-Si, sapphire, GaN, poly-GaN and AlN.

4. The method according to claim 1, which further comprises forming the interlayer with a monocrystalline surface at least in partial regions.

5. The method according to claim 1, which further comprises forming a bonding layer between the substrate body and the interlayer.

6. The method according to claim 5, which further comprises forming the bonding layer from silicon oxide.

7. The method according to claim 1, which further comprises forming a mask layer with epitaxy windows before the GaN-based layers are applied to the composite substrate, an epitaxy surface of the composite substrate within the epitaxy windows remaining uncovered.

8. The method according to claim 1, which further comprises forming the carrier from a compound or element selected from the group consisting of GaAs, germanium, silicon, zinc oxide, molybdenum, aluminum, copper, iron, nickel, and cobalt.

9. The method according to claim 1, which further comprises forming the carrier from a material selected from the group consisting of GaAs, molybdenum, tungsten, and an Fe—

Ni—

Co alloy.

10. The method according to claim 1, which further comprises matching a coefficient of thermal expansion of the carrier to the coefficient of thermal expansion of the GaN-based layers.

11. The method according to claim 1, which further comprises matching a coefficient of thermal expansion of the carrier to the given coefficient of thermal expansion of the substrate body.

12. The method according to claim 1, which further comprises forming the carrier to have a coefficient of thermal expansion to be between the given coefficient of thermal expansion of the substrate body and the coefficient of thermal expansion of the GaN-based layers.

13. The method according to claim 1, which further comprises forming the reflector layer by applying a metal layer.

14. The method according to claim 13, which further comprises forming the metal layer from a material selected from the group consisting of silver, aluminum, silver alloy, and aluminum alloy.

15. A semiconductor component selected from the group consisting of radiation-emitting components, diodes, transistors, radiation-emitting diodes, LEDs, semiconductor lasers and radiation-detecting components produced according to the method of claim 1.

16. The method of claim 1, which further comprises applying a carrier to the GaN-based layers after formation of the reflector layer.

17. A semiconductor component selected from the group consisting of radiation-emitting components, diodes, transistors, radiation-emitting diodes, LEDs, semiconductor lasers and radiation-detecting components produced according to the method of claim 16.

18. The method according to claim 1, wherein the GaN-based layers have an output surface and the reflector layer reflects radiation generated in the GaN-based layers to the output surface.

19. The method of claim 18, which further comprises forming a contact surface to the, wherein the output surface is arranged at a surface of the GaN-based layers opposite from the contact surface.

20. The method according to claim 1, wherein the reflector layer extends parallel to the GaN-based layers.

21. The method of claim 1, which further comprises patterning the GaN-based layers into individual semiconductor layers stacks after the GaN-based layers have been applied to the composite substrate.

22. The method according to claim 21, which further comprises removing the composite substrate.

23. The method according to claim 21, which further comprises:

removing the composite substrate;

applying a carrier support to the side of the semiconductor layer stacks from which the composite substrate has been removed; and

remove the carrier.

24. The method of claim 21, which further comprises roughening a surface of the semiconductor layer stacks at least in regions.

25. The method according to claim 24, which further comprises etching a surface of the semi-conductor layer stacks for roughening the semiconductor layer stacks.

26. The method according to claim 24, which further comprises roughening a surface of the semiconductor layer stacks by performing a sand-blasting process.

27. The method according to claim 1, which further comprises applying the interlayer to the substrate body using a bonding process selected from the group consisting of an oxidic bonding process and a wafer bonding process.

28. The method of claim 21, wherein the reflector layer is formed on the GaN-based layers after patterning of said GaN-based layers into individual semiconductor layer stacks.