Vertical light-emitting diode

• US 8,378,376 B2
• Filed: 07/30/2010
• Issued: 02/19/2013
• Est. Priority Date: 07/31/2009
• Status: Active Grant

• Current Assignee: Tekcore Co Limited (Tekcore)
• Original Assignee: Tekcore Co Limited (Tekcore)
• Inventors: Chung, Wei-Jung, Lee, Shih-Hung, Li, Cheng-Hsien, Lin, Wen-Hsien, Yeh, Nien-Tze
• Primary Examiner(s): Dickey, Thomas L
• Assistant Examiner(s): YUSHIN, NIKOLAY K
• Application Number:
  US12/846,937
• Publication Number:
  US 20110163293A1
• Time in Patent Office: 935 Days
• Field of Search: 257/13, 257/79, 257/E33.008, 257/99, 257/E33.07, 257/E33.055
• US Class Current: 257/99
• CPC Class Codes: H01L 2933/0016 relating to electrodes
• CPC Class Codes: H01L 33/0093 Wafer bonding; Removal of the growth substrate
• CPC Class Codes: H01L 33/387 with a plurality of electrode regions in direct contact with the semiconductor body and being electrically interconnected by another electrode layer
• CPC Class Codes: H01L 33/405 Reflective materials
• CPC Class Codes: H01L 33/42 Transparent materials

Abstract

The present application describes a vertical light-emitting diode (VLED) and its manufacture method that use the combination of a reflective layer, a transparent conducting layer and transparent dielectric layer as structural layers for promoting uniform current distribution and increasing light extraction. In the VLED, a transparent conducting layer is formed on a first outer surface of a stack of multiple group III nitride semiconductor layers. A transparent dielectric layer is then formed on a side of the transparent conducting layer opposite the side of the multi-layer structure. A first electrode structure is then formed on the transparent dielectric layer in electrical contact with the transparent conducting layer via a plurality of contact windows patterned through the transparent dielectric layer. The transparent conducting layer and the transparent dielectric layer are used as structural layers for improving light extraction.

Claims

1. A vertical light-emitting diode comprising:

a multi-layer structure comprising a plurality of group III-nitride semiconductor compound layers, wherein the multi-layer structure has a first outer surface and a second outer surface opposite to the first outer surface;

a transparent conducting layer located on the first outer surface, the transparent conducting layer substantially covering the first outer surface;

a transparent dielectric layer in contact with the transparent conducting layer on a side opposite to the side of the multi-layer structure, wherein the transparent dielectric layer includes a plurality of contact windows;

a first electrode structure located on the transparent dielectric layer and in contact with the transparent conducting layer via the contact windows; and

a second electrode structure located on the second outer surface.

2. The vertical light-emitting diode of claim 1, wherein the first electrode structure comprises a reflective layer that substantially fills the contact windows, the reflective layer contacting with the transparent conducting layer through the contact windows.

3. The vertical light-emitting diode of claim 1, wherein the first electrode structure comprises a conducting substrate.

4. The vertical light-emitting diode of claim 3, wherein the conducting substrate is a metallic or semiconductor substrate.

5. The vertical light-emitting diode of claim 1, wherein the transparent dielectric layer contains SiO₂, Si₃N₄, or TiO₂.

6. The vertical light-emitting diode of claim 1, wherein the transparent dielectric layer has a thickness smaller than about 2 microns.

7. The vertical light-emitting diode of claim 1, wherein the transparent conducting layer has a thickness smaller than about 4000 Angstroms.

8. The vertical light-emitting diode of claim 1, wherein the multi-layer structure comprises a multiple quantum well structure.

9. The vertical light-emitting diode of claim 1, wherein the transparent conducting layer is made of a transparent conducting oxide material including indium tin oxide or aluminum zinc oxide.

10. A vertical light-emitting diode comprising:

a multi-layer structure comprising a plurality of group III-nitride semiconductor compound layers, wherein the multi-layer structure has a first outer surface and a second outer surface opposite to the first outer surface;

a transparent conducting layer in contact with the first outer surface;

a transparent dielectric layer in contact with the transparent conducting layer on a side opposite to the side of the multi-layer structure, the transparent dielectric layer being spaced apart from the first outer surface of the multi-layer structure and including a plurality of contact windows;

a first electrode structure located on the transparent dielectric layer and in contact with the transparent conducting layer through the contact windows; and

a second electrode structure located on the second outer surface.

11. The vertical light-emitting diode of claim 10, wherein the first electrode structure comprises a reflective layer that fills the contact windows, the reflective layer contacting with the transparent conducting layer through the contact windows.

12. The vertical light-emitting diode of claim 10, wherein the first electrode structure comprises a conducting substrate made of a metallic or semiconductor material.

13. The vertical light-emitting diode of claim 10, wherein the transparent dielectric layer contains SiO₂, Si₃N₄, or TiO₂.

14. The vertical light-emitting diode of claim 10, wherein the transparent dielectric layer has a thickness smaller than about 2 microns.

15. The vertical light-emitting diode of claim 10, wherein the transparent conducting layer entirely covers the first outer surface and has a thickness smaller than about 4000 Angstroms.

16. The vertical light-emitting diode of claim 10, wherein the multi-layer structure comprises a multiple quantum well structure.

17. The vertical light-emitting diode of claim 10, wherein the transparent conducting layer is made of a transparent conducting oxide including indium tin oxide or aluminum zinc oxide.

18. A vertical light-emitting diode comprising:

a multi-layer structure comprising a plurality of group III-nitride semiconductor compound layers, wherein the multi-layer structure has a first outer surface and a second outer surface opposite to the first outer surface;

a transparent conducting layer in contact with the first outer surface, the transparent conducting layer substantially covering the first outer surface;

the transparent conducting layer being made of a transparent conducting oxide material;

a transparent dielectric layer in contact with the transparent conducting layer on a side opposite to the side of the multi-layer structure, the transparent dielectric layer including a plurality of contact windows;

a first electrode structure located on the transparent dielectric layer and in contact with the transparent conducting layer through the contact windows; and

a second electrode structure located on the second outer surface.

19. The vertical light-emitting diode of claim 18, wherein the first electrode structure comprises a reflective layer that substantially fills the contact windows, the reflective layer contacting with the transparent conducting layer through the contact windows.

20. The vertical light-emitting diode of claim 19, wherein the reflective layer substantially cover the transparent dielectric layer at a side opposite to that of the transparent conducting layer.