LIGHT EMITTING DIODE FOR SURFACE MOUNT TECHNOLOGY, METHOD OF MANUFACTURING THE SAME, AND METHOD OF MANUFACTURING LIGHT EMITTING DIODE MODULE

• US 20150108525A1
• Filed: 12/29/2014
• Published: 04/23/2015
• Est. Priority Date: 06/28/2012
• 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, Dae Woong, Kang, Min Woo, Lee, Joon Sub, Kim, Hyun A.
• Granted Patent: US 9,293,660 B2
• Time in Patent Office: Days
• US Class Current: 257/98
• 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 2933/0066 relating to arrangements for conducting electric current to or from the semiconductor body
• CPC Class Codes: H01L 33/005 Processes
• CPC Class Codes: H01L 33/007 comprising nitride compounds
• CPC Class Codes: H01L 33/06 within the light emitting region, e.g. quantum confinement structure or tunnel barrier
• CPC Class Codes: H01L 33/12 with a stress relaxation structure, e.g. buffer layer
• CPC Class Codes: H01L 33/20 with a particular shape, e.g. curved or truncated substrate
• CPC Class Codes: H01L 33/32 containing nitrogen
• CPC Class Codes: H01L 33/38 with a particular shape
• CPC Class Codes: H01L 33/382 the electrode extending partially in or entirely through the semiconductor body
• CPC Class Codes: H01L 33/40 Materials therefor
• 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
• CPC Class Codes: H01L 33/486 adapted for surface mounting
• CPC Class Codes: H01L 33/60 Reflective elements
• 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

Provided are a light emitting diode (LED) in which a conductive barrier layer surrounding a reflective metal layer is defined by a protective insulating layer, and a method of manufacturing the same. A reflection pattern including a reflective metal layer and a conductive barrier layer is formed on an emission structure in which a first semiconductor layer, an active layer, and a second semiconductor layer are formed. The conductive barrier layer prevents diffusion of a reflective metal layer and extends to a protective insulating layer recessed under a photoresist pattern having an overhang structure during a forming process. Accordingly, a phenomenon where the conductive barrier layer is in contact with sidewalls of the photoresist pattern having an over-hang structure and the reflective metal layer forms points is prevented. Thus, LED modules having various shapes may be manufactured.

Claims

1. A light emitting diode (LED) comprising:

a substrate;

a first semiconductor layer formed over the substrate and having a first conductivity type;

an active layer formed over the first semiconductor layer and configured to generate light;

a second semiconductor layer formed over the active layer and having a second conductivity type;

a protective insulating layer formed as multiple portions over at least the second semiconductor layer with the multiple portions spaced apart from each other; and

a reflection pattern formed between the multiple portions of the protective insulating layers configured, the reflection pattern configured to reflect light generated in the active layer, the reflection pattern including a conductive barrier layer contacting the protective insulating layer and extending over the second semiconductor layer.

2. The LED of claim 1, wherein the reflection pattern configured to reflect light generated in the active layer comprises a reflective metal layer formed between the second semiconductor layer and the conductive layer, wherein the conductive barrier layer contacts at least side surfaces of the reflective metal layer.

3. The LED of claim 2, wherein the reflection pattern further comprises a stress relaxation layer formed between the reflective metal layer and the conductive barrier layer and configured to absorb stress caused by a difference in coefficient of thermal expansion between the reflective metal layer and the conductive barrier layer.

4. The LED of claim 3, wherein a coefficient of thermal expansion of the stress relaxation layer is equal to or higher than a coefficient of thermal expansion of the conductive barrier layer and equal to or lower than a coefficient of thermal expansion of the reflective metal layer.

5. The LED of claim 1, wherein at least a portion of the reflection pattern is inclined at an angle of about 5°

to about 45°

with respect to a surface of the second semiconductor layer.

6. The LED of claim 1, wherein a thickness of the conductive barrier layer formed over the reflection pattern is greater than a thickness of the conductive barrier layer formed on the second semiconductor layer, and the thickness of the conductive barrier layer formed on the second semiconductor layer is greater than a thickness of the conductive barrier layer formed on a side of the reflection pattern.

7. The LED of claim 1, wherein the protective insulating layer extends to a surface of the first semiconductor layer.

8. The LED of claim 1, wherein the conductive barrier layer covers at least a part of the reflection pattern.

9. The LED of claim 1, wherein the conductive barrier layer further extends to each protective insulating layer portion such that the conductive barrier layer contacts with a sidewall of each protective insulating layer portion.

10. The LED of claim 1, further including:

an insulating material formed over and in contact with at least a portion of the first semiconductor layer, the second semiconductor layer, the protective insulating layer, and the reflective pattern;

wherein the insulating material and the protective insulating layer function together as a combined insulating layer.

11. The LED of claim 10, wherein a thickness of the combined insulating layer formed over the second semiconductor layer is greater than a thickness of the combined insulating layer formed over the first semiconductor layer.

12. A method of manufacturing a light emitting diode (LED), comprising:

forming a stacked structure including a first semiconductor layer, an active layer, a second semiconductor layer, and a protective insulating layer over a substrate;

etching a part of the stacked structure and forming mesa regions to be spaced apart from each other, each mesa region exposing at least a portion of a surface of the first semiconductor layer;

forming photoresist patterns on the mesa regions, each photoresist pattern having an overhang structure;

etching the protective insulating layer exposed by the photoresist patterns to expose a part of the second semiconductor layer, the protective insulating layer remaining in a recessed region under the photoresist patterns;

forming a reflective metal layer over the exposed part of the second semi-conductor layer; and

forming a conductive barrier layer over the reflective metal layer, the conductive barrier layer extending to the protective insulating layer.

13. The method of claim 12, wherein the etching of the protective insulating layer comprises etching the recessed region shielded by the photoresist pattern

14. The method of claim 12, further comprising, after the forming the reflective metal layer, forming a stress relaxation layer over the reflective metal layer to absorb stress caused by a difference in coefficient of thermal expansion between the reflective metal layer and the conductive barrier layer.

15. The method of claim 12, wherein the etching of the protective insulating layer includes performing an isotropic wet etching process.

16. A method of manufacturing a light emitting diode (LED), comprising:

forming a first semiconductor layer, an active layer, and a second semiconductor layer over a substrate;

etching the second semiconductor layer and the active layer and forming mesa regions to be spaced apart from each other, each mesa region exposing a surface of the first semiconductor layer;

forming a protective insulating layer over the mesa regions and the second semiconductor layer;

forming photoresist patterns on the mesa regions, each photoresist pattern having an overhang structure;

etching the protective insulating layer exposed through the photoresist patterns to expose a part of the second semiconductor layer and remain in a recessed region under the photoresist patterns;

forming a reflective metal layer over the exposed part of the second semi-conductor layer; and

forming a conductive barrier layer over the reflective metal layer, the conductive barrier layer configured to contact with the protective insulating layer without being attached to a sidewall of each photoresist pattern.

17. A method of manufacturing a light emitting diode (LED) module, comprising:

fabricating a stacked structure including a first semiconductor layer, an active layer, a second semiconductor layer, and a reflective pattern, wherein the reflective pattern includes a reflective metal layer and a conductive barrier layer, the conductive barrier layer surrounding at least a part of the reflective metal layer and shaped to continuously extend over the second semiconductor layer;

forming a first insulating layer over the stacked structure to expose the reflection pattern and the first semiconductor layer;

forming a conductive reflection layer and a reflective barrier layer over the first insulating layer to expose the reflection pattern, the reflective barrier layer electrically connected to the first semiconductor layer through the conductive reflection layer;

forming a second insulating layer over the reflective barrier layer to expose the reflection pattern and the reflective barrier layer electrically connected to the first semiconductor layer; and

forming a first pad over the reflective barrier layer and a second pad over the reflection pattern.

18. The method of claim 17, wherein the fabricating of the stacked structure includes:

forming the first semiconductor layer, the active layer, the second semiconductor layer, and a protective insulating layer over a substrate;

etching the protective insulating layer, the second semiconductor layer, and the active layer and forming mesa regions to be spaced apart from each other, each mesa region exposing at least a portion of a surface of the first semiconductor layer;

forming photoresist patterns on the mesa regions, each photoresist pattern having an overhang structure;

etching the protective insulating layer exposed by the photoresist patterns to expose a part of the second semiconductor layer and remain in a recessed region under the photoresist patterns;

forming a reflective metal layer over the exposed part of the second semi-conductor layer; and

forming a conductive barrier layer over the reflective metal layer, the conductive barrier layer extending to the protective insulating layer.

19. The method of claim 17, wherein the fabricating of the stacked structure includes:

forming the first semiconductor layer, the active layer, and the second semiconductor layer on the substrate;

etching the second semiconductor layer and the active layer and forming mesa regions to be spaced apart from each other, each mesa region exposing at least a part of a surface of the first semiconductor layer;

forming a protective insulating layer over the mesa regions and the second semiconductor layer;

forming photoresist patterns on the mesa regions, each photoresist pattern having an overhang structure;

etching the protective insulating layer exposed through the photoresist patterns to expose a part of the second semiconductor layer and remain in a recessed region under the photoresist patterns;

forming a reflective metal layer over the exposed part of the second semi-conductor layer; and

forming a conductive barrier layer over the reflective metal layer, the conductive barrier layer extending to the protective insulating layer.

20. The method of claim 17, further comprising, after forming the first pad and the second pad, forming a pad barrier layer over at least one of the first and second pads to prevent diffusion of metal atoms during a bonding process or a soldering process.