Light emitting diode

• US 10,319,884 B2
• Filed: 04/19/2016
• Issued: 06/11/2019
• Est. Priority Date: 09/16/2011
• Status: Active Grant

• Current Assignee: Seoul Viosys Co., Ltd. (Seoul Semiconductor Co., Ltd.)
• Original Assignee: Seoul Viosys Co., Ltd. (Seoul Semiconductor Co., Ltd.)
• Inventors: Chae, Jong Hyeon, Jang, Jong Min, Roh, Won Young, Suh, Daewoong, Cho, Dae Sung, Lee, Joon Sup, Lee, Kyu Ho, In, Chi Hyun
• Primary Examiner(s): Campbell, Shaun M
• Assistant Examiner(s): Chi, Suberr L
• Application Number:
  US15/132,887
• Publication Number:
  US 20160233386A1
• Time in Patent Office: 1,148 Days
• CPC Class Codes: H01L 2224/1403 Bump connectors having different sizes, e.g. different diameters, heights or widths
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2933/0016 relating to electrodes
• CPC Class Codes: H01L 2933/0025 relating to coatings
• CPC Class Codes: H01L 2933/0058 relating to optical field-shaping elements
• CPC Class Codes: H01L 33/0075 comprising nitride compounds
• CPC Class Codes: H01L 33/08 with a plurality of light emitting regions, e.g. laterally discontinuous light emitting layer or photoluminescent region integrated within the semiconductor body H01L27/15 takes precedence
• CPC Class Codes: H01L 33/12 with a stress relaxation structure, e.g. buffer layer
• CPC Class Codes: H01L 33/14 with a carrier transport control structure, e.g. highly-doped semiconductor layer or current-blocking structure
• CPC Class Codes: H01L 33/20 with a particular shape, e.g. curved or truncated substrate
• 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 33/38 with a particular shape
• CPC Class Codes: H01L 33/405 Reflective materials
• CPC Class Codes: H01L 33/42 Transparent 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
• CPC Class Codes: H01L 33/486 adapted for surface mounting
• CPC Class Codes: H01L 33/62 Arrangements for conducting electric current to or from the semiconductor body, e.g. lead-frames, wire-bonds or solder balls

Abstract

A light emitting diode includes a first conductive type semiconductor layer and a mesa disposed on the first conductive type semiconductor layer. The mesa includes an active layer and a second conductive type semiconductor layer. A reflective electrode is disposed on the mesa to be in ohmic-contact with the second conductive type semiconductor layer. A current spreading layer is disposed on the mesa and the reflective electrode. A first portion of the current spreading layer is in ohmic-contact with an upper surface of an end portion of the first conductive type semiconductor layer. A lower insulating layer is disposed between the mesa and the current spreading layer, and the reflective electrode and the current spreading layer. An upper insulating layer covers the current spreading layer and includes a first hole exposing a second portion of the current spreading layer that is disposed on an upper portion of the mesa.

Claims

1. A light emitting diode, comprising:

a first conductive type semiconductor layer;

a mesa disposed on the first conductive type semiconductor layer, the mesa comprising an active layer and a second conductive type semiconductor layer;

a reflective electrode disposed on the mesa and configured to be in ohmic-contact with the second conductive type semiconductor layer;

a current spreading layer disposed on the mesa and the reflective electrode, the current spreading layer comprising a first portion configured to be in ohmic-contact with an upper surface of an end portion of the first conductive type semiconductor layer;

a lower insulating layer disposed between the mesa and the current spreading layer as well as the reflective electrode and the current spreading layer, the lower insulating layer configured to insulate the current spreading layer from the mesa and the reflective electrode; and

an upper insulating layer covering the current spreading layer, the upper insulating layer comprising a first hole exposing a second portion of the current spreading layer that is disposed on an upper portion of the mesa,

wherein the first hole of the upper insulating layer exposes a third portion of the current spreading layer that is disposed on a side wall of the mesa with the lower insulating layer disposed between the third portion of the current spreading layer and the side wall of the mesa.

2. The light emitting diode of claim 1, wherein the first portion of the current spreading layer is configured to be in ohmic-contact along a periphery of the first conductive type semiconductor layer.

3. The light emitting diode of claim 1, wherein

the upper insulating layer covers the first portion of the current spreading layer and the end portion of the first conductive type semiconductor layer.

4. The light emitting diode of claim 3, wherein the lower insulating layer covers part of the end portion of the first conductive type semiconductor layer.

5. The light emitting diode of claim 1, wherein the reflective electrode comprises a reflective metal.

6. A light emitting diode, comprising:

a first conductive type semiconductor layer;

a mesa disposed on the first conductive type semiconductor layer, the mesa comprising an active layer and a second conductive type semiconductor layer;

a reflective electrode disposed on the mesa and configured to be in ohmic-contact with the second conductive type semiconductor layer;

a current spreading layer disposed on the mesa and the reflective electrode, the current spreading layer comprising a first portion configured to be in ohmic-contact with an upper surface of an end portion of the first conductive type semiconductor layer;

a lower insulating layer disposed between the mesa and the current spreading layer as well as the reflective electrode and the current spreading layer, the lower insulating layer configured to insulate the current spreading layer from the mesa and the reflective electrode;

an upper insulating layer covering the current spreading layer, the upper insulating layer comprising a first hole exposing a second portion of the current spreading layer that is disposed on an upper portion of the mesa; and

a first pad disposed on the current spreading layer through the first hole of the upper insulating layer such that the first pad is in ohmic contact with the first portion of the current spreading layer that is disposed on the mesa.

7. The light emitting diode of claim 6, wherein:

the lower insulating layer comprises a first hole exposing the reflective electrode;

the upper insulating layer comprises a second hole also exposing the reflective electrode; and

the first hole of the lower insulating layer is different in area than the second hole of the upper insulating layer.

8. The light emitting diode of claim 7, further comprising:

a second pad disposed on the reflective electrode exposed through the first hole of the lower insulating layer and the second hole of the upper insulating layer.

9. The light emitting diode of claim 8, wherein the reflective electrode comprises a reflective metal layer and a barrier layer covering a top portion and a side portion of the reflective metal layer.

10. The light emitting diode of claim 9, wherein the reflective electrode further comprises a stress relieving layer disposed between the top portion of the reflective metal layer and the barrier layer.

11. A light emitting diode, comprising:

a first conductive type semiconductor layer;

a mesa disposed on the first conductive type semiconductor layer, the mesa comprising an active layer and a second conductive type semiconductor layer;

a reflective electrode disposed on the mesa and configured to be in ohmic-contact with the corresponding second conductive type semiconductor layer of the mesa;

a current spreading layer disposed on the mesa and the reflective electrode, the current spreading layer comprising;

a first portion configured to be in ohmic-contact with a first end portion of the first conductive type semiconductor layer;

a second portion configured to be in ohmic-contact with a second end portion of the first conductive type semiconductor layer; and

a third portion configured to be in ohmic-contact with an intermediate portion of the first conductive type semiconductor layer disposed between the first and second end portions, wherein the third portion is disposed between the first and second end portions of the first conductive type semiconductor layer;

an insulation layer disposed on the mesa and covering an edge of the first conductive type semiconductor layer, the insulation layer comprising;

a lower insulating layer disposed between the mesa and the current spreading layer as well as between the reflective electrode and the current spreading layer, the lower insulating layer configured to insulate the current spreading layer from the mesa and the reflective electrode; and

an upper insulating layer covering the current spreading layer, the upper insulating layer comprising a first hole exposing a fourth portion of the current spreading layer that is disposed on an upper portion of the mesa.

12. The light emitting diode of claim 11, wherein the upper insulating layer covers the first portion and the second portion of the current spreading layer as well as the first end portion and the second end portion of the first conductive type semiconductor layer.

13. The light emitting diode of claim 11, wherein the lower insulating layer covers a part of the first end portion of the first conductive type semiconductor layer and a part of the second end portion of the first conductive type semiconductor layer.

14. The light emitting diode of claim 13, wherein the lower insulating layer comprises:

a first hole exposing the reflective electrode disposed on the mesa; and

a second hole exposing the intermediate portion of the first semiconductor layer.

15. The light emitting diode of claim 14, wherein the upper insulating layer comprises a second hole exposing the reflective electrode, and the first hole of the lower insulating layer is at least different in area than the second hole of the upper insulating layer.

16. The light emitting diode of claim 15, further comprising:

a second pad disposed on the reflective electrode exposed through the first hole of the lower insulating layer and the second hole of the upper insulating layer.

17. The light emitting diode of claim 14, further comprising:

a first pad disposed on the current spreading layer through the first hole of the upper insulating layer such that the first pad is in ohmic contact with the second portion of the current spreading layer.

18. The light emitting diode of claim 11, wherein the reflective electrode comprises a reflective metal layer, and a barrier layer covers a top portion and a side portion of the reflective metal layer.

19. The light emitting diode of claim 18, wherein of the reflective electrode further comprises a stress relieving layer disposed between the top portion of the reflective metal layer and the barrier layer.