LIGHT-EMITTING-DIODE CHIP COMPRISING A SEQUENCE OF GaN-BASED EPITAXIAL LAYERS WHICH EMIT RADIATION AND A METHOD FOR PRODUCING THE SAME

• US 20110175058A1
• Filed: 04/04/2011
• Published: 07/21/2011
• Est. Priority Date: 05/26/2000
• Status: Active Grant

• Current Assignee: OSRAM OLED GMBH (Ams-Osram AG)
• Original Assignee: OSRAM GmbH (Ams-Osram AG)
• Inventors: Lugauer, Hans-Jürgen, Mundbrod-Vangerow, Manfred, Hahn, Berthold, Jacob, Ulrich
• Granted Patent: US 8,436,393 B2
• Time in Patent Office: Days
• US Class Current: 257/13
• CPC Class Codes: H01L 2224/32225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48227 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 24/73 Means for bonding being of different types provided for in two or more of groups H01L24/10, H01L24/18, H01L24/26, H01L24/34, H01L24/42, H01L24/50, H01L24/63, H01L24/71
• CPC Class Codes: H01L 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/01067 Holmium [Ho]
• CPC Class Codes: H01L 2924/12041 LED
• CPC Class Codes: H01L 33/0093 Wafer bonding; Removal of the growth substrate
• CPC Class Codes: H01L 33/32 containing nitrogen
• CPC Class Codes: H01L 33/405 Reflective materials
• CPC Class Codes: H01L 33/42 Transparent materials

Abstract

A light-emitting diode chip comprises a GaN-based, radiation-emitting epitaxial layer sequence, an active region, an n-doped layer and a p-doped layer. The p-doped layer is provided, on its main surface facing away from the active region, with a reflective contact metallization comprising a radioparent contact layer and a reflective layer. Methods for fabricating LED chips of this type by thin-film technology are provided, as are LED components containing such LED chips.

Claims

1. A light-emitting diode chip comprising:

a GaN-based, radiation-emitting epitaxial layer sequence comprising an active region, an n-doped layer and a p-doped layer; and

a reflective contact metallization assigned to said p-doped layer, said reflective contact metallization configured to reflect radiation emitted by the radiation-emitting layer sequence and comprising;

a radiation permeable contact layer and a reflective layer, wherein said radiation permeable contact layer is arranged between said p-doped layer and said reflective layer, and

wherein said radiation permeable contact layer has a thickness of 10 nm or more.

2. The light-emitting diode chip as recited in claim 1, wherein said radiation permeable contact layer substantially comprises at least one material from the group of materials including indium tin oxide (ITO) and ZnO.

3. The light-emitting diode chip as recited in claim 1, wherein said reflective layer comprises Ag.

4. The light-emitting diode chip as recited in claim 1, wherein said active region comprises one or more undoped layer(s).

5. The light-emitting diode chip as recited in claim 4, wherein said undoped layer(s) comprise or consist of InGaN or InGaAlN.

6. The light-emitting diode chip as recited in claim 4, wherein said active region comprises a double heterostructure, a single quantum well or a multi-quantum well.

7. The light-emitting diode chip as recited in claim 1, wherein said reflective contact metallization further comprises:

a diffusion barrier layer on a side of the reflective layer facing away from the radiation permeable contact layer, and

an additional metal layer on a side of the diffusion barrier layer facing away from the reflective layer wherein the additional metal layer improves a bondability of the light-emitting diode chip.

8. The light-emitting diode chip as recited in claim 7, wherein the diffusion barrier layer comprises at least one of the following materials:

Ti, Pt, W, TiWN.

9. The light-emitting diode chip as recited in claim 7, wherein the additional metal layer comprises or consists of Au or Al.

10. The light-emitting diode chip as recited in claim 7, wherein

the radiation permeable contact layer is in direct contact with the reflective layer,

the diffusion barrier layer is in direct contact with the reflective layer, and

the additional metal layer is in direct contact with the diffusion barrier layer.

11. A light-emitting diode chip comprising:

a GaN-based, radiation-emitting epitaxial layer sequence comprising an active region, an n-doped layer and a p-doped layer; and

a reflective contact metallization assigned to said p-doped layer, said reflective contact metallization configured to reflect radiation emitted by the radiation-emitting layer sequence and said reflective contact metallization further comprises

a diffusion barrier layer on a side of the reflective layer facing away from the radiation permeable contact layer, and

an additional metal layer on a side of the diffusion barrier layer facing away from the reflective layer wherein the additional metal layer improves a bondability of the light-emitting diode chip.

12. The light-emitting diode chip as recited in claim 11, wherein the diffusion barrier layer comprises at least one of the following materials:

Ti, Pt, W, TiWN.

13. The light-emitting diode chip as recited in claim 11, wherein the additional metal layer comprises or consists of Au or Al.

14. The light-emitting diode chip as recited in claim 11, wherein

the radiation permeable contact layer is in direct contact with the reflective layer,

the diffusion barrier layer is in direct contact with the reflective layer, and

the additional metal layer is in direct contact with the diffusion barrier layer.

15. The light-emitting diode chip as recited in claim 11, wherein said active region comprises one or more undoped layer(s).

16. The light-emitting diode chip as recited in claim 15, wherein said undoped layer(s) comprise or consist of InGaN or InGaAlN.

17. The light-emitting diode chip as recited in claim 15, wherein said active region comprises a double heterostructure, a single quantum well or a multi-quantum well.

18. The light-emitting diode chip as recited in claim 11, wherein said radiation permeable contact layer substantially comprises at least one material from the group of materials including indium tin oxide (ITO) and ZnO.

19. The light-emitting diode chip as recited in claim 11, wherein said radiation permeable contact layer has a thickness of 10 nm or more.

20. A light-emitting diode chip comprising:

a GaN-based, radiation-emitting epitaxial layer sequence comprising an active region, an n-doped layer and a p-doped layer, wherein said active region comprises one or more undoped layer(s); and

a reflective contact metallization assigned to said p-doped layer, said reflective contact metallization configured to reflect radiation emitted by the radiation-emitting layer sequence.