Light emitting diode chip having distributed bragg reflector and method of fabricating the same

• US 10,128,306 B2
• Filed: 01/09/2017
• Issued: 11/13/2018
• Est. Priority Date: 11/13/2009
• Status: Active Grant

• Current Assignee: Seoul Viosys Co., Ltd. (Seoul Semiconductor Co., Ltd.)
• Original Assignee: Seoul Viosys Co., Ltd. (Seoul Semiconductor Co., Ltd.)
• Inventors: Lee, Sum Geun, Jin, Sang Ki, Shin, Jin Cheol, Kim, Jong Kyu, Lee, So Ra, Lee, Chung Hoon
• Primary Examiner(s): Gebremariam, Samuel
• Application Number:
  US15/401,599
• Publication Number:
  US 20170148845A1
• Time in Patent Office: 673 Days
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/48257 connecting the wire to a die pad of the item
• CPC Class Codes: H01L 27/153 in a repetitive configuration, e.g. LED bars
• 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 2933/0025 relating to coatings
• CPC Class Codes: H01L 2933/0033 relating to semiconductor body packages
• CPC Class Codes: H01L 2933/0041 relating to wavelength conversion elements
• CPC Class Codes: H01L 2933/0058 relating to optical field-shaping elements
• CPC Class Codes: H01L 33/0008 having p-n or hi-lo junctions
• CPC Class Codes: H01L 33/0093 Wafer bonding; Removal of the growth substrate
• CPC Class Codes: H01L 33/06 within the light emitting region, e.g. quantum confinement structure or tunnel barrier
• 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 33/42 Transparent materials
• CPC Class Codes: H01L 33/46 Reflective coating, e.g. dielectric Bragg reflector
• CPC Class Codes: H01L 33/505 characterised by the shape, e.g. plate or foil
• 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

A light-emitting diode package including a body and leads. The body comprising a mounting surface. The light emitting diode package also includes a light emitting diode chip including a substrate and a plurality of light emitting cells disposed on the substrate and positioned to be spaced apart from each other, each of the plurality of light emitting cells comprising an active layer disposed between a first conductive-type semiconductor layer and a second conductive-type semiconductor layer. The light emitting diode package also includes a phosphor member disposed on the light-emitting diode chip and a distributed Bragg reflector disposed on the substrate and between the plurality of light emitting cells.

Claims

1. A light-emitting diode package, comprising:

leads;

a package body comprising a mounting surface; and

a light emitting diode chip disposed on the mounting surface and connected to the leads, the light emitting diode chip comprising;

a substrate; and

a plurality of light emitting cells disposed on an upper surface of the substrate and positioned to be spaced apart from each other, each of the plurality of light emitting cells comprising an active layer disposed between a first conductive-type semiconductor layer and a second conductive-type semiconductor layer;

a phosphor member disposed on the light-emitting diode chip; and

a distributed Bragg reflector disposed on a lower surface of the substrate and disposed between the plurality of light emitting cells,

wherein the lower surface of the substrate has a root-mean-square (RMS) value of 3 nm or less.

2. The light-emitting diode package of claim 1, wherein the upper surface of the substrate is exposed in an exposed region between the plurality of light emitting cells.

3. The light-emitting diode package of claim 2, wherein the exposed region of the upper surface of the substrate overlaps the distributed Bragg reflector.

4. The light-emitting diode package of claim 3, wherein the light emitting diode chip further comprises:

a transparent electrode disposed on the second conductive-type semiconductor layer of each of the plurality of light emitting cells;

a first insulating layer disposed directly on the upper surface of the substrate in the exposed region between the plurality of light emitting cells and disposed on the transparent electrode exposing a surface of the transparent electrode,

an interconnect disposed on the first insulating layer and electrically connected at a first end to the first conductive-type semiconductor layer of a first light emitting cell of the plurality of light emitting cells and at a second end to the transparent electrode of a second light emitting cell of the plurality of light emitting cells, and

a second insulating layer disposed on the first insulating layer and the interconnect.

5. The light-emitting diode package of claim 3, wherein the distributed Bragg reflector comprises a first distributed Bragg reflector and a second distributed Bragg reflector.

6. The light-emitting diode package of claim 5, wherein:

the first distributed Bragg reflector is configured to reflect more light in a red wavelength range than light in a blue wavelength range,

the second distributed Bragg reflector is configured to reflect more light in the blue wavelength range than light in the red wavelength range.

7. The light-emitting diode package of claim 6, wherein the second distributed Bragg reflector is further configured to reflect more light in the blue wavelength range than light in a green wavelength range.

8. The light-emitting diode package of claim 7, wherein:

the first distributed Bragg reflector and the second distributed Bragg reflector each comprise a plurality of material layers, and

the plurality of material layers comprise a material selected from the group consisting of silicon dioxide (SiO₂), titanium dioxide (TiO₂), a silicon nitride (Si₃N₄), and some combination thereof.

9. The light-emitting diode package of claim 7, wherein:

the first distributed Bragg reflector is configured to reflect 90% or more of light having the red wavelength range of 600 nm to 700 nm,

the second distributed Bragg reflector is configured to reflect 90% or more of light having the blue wavelength range of 400 nm to 500 nm,

the green wavelength range is 500 nm to 600 nm.

10. A light-emitting diode chip, comprising:

a substrate;

a plurality of light emitting cells disposed on an upper surface of the substrate and positioned to be spaced apart from each other, each of the plurality of light emitting cells comprising an active layer disposed between a first conductive-type semiconductor layer and a second conductive-type semiconductor layer;

a phosphor member disposed on the plurality of light emitting cells; and

a distributed Bragg reflector disposed on a lower surface of the substrate and disposed between the plurality of light emitting cells

wherein the lower surface of the substrate has a root-mean-square (RMS) value of 3 nm or less.

11. The light-emitting diode chip of claim 10, wherein the upper surface of the substrate is exposed in an exposed region between the plurality of light emitting cells.

12. The light-emitting diode chip of claim 11, wherein the exposed region of the upper surface of the substrate overlaps the distributed Bragg reflector.

13. The light-emitting diode chip of claim 12, further comprising:

a transparent electrode disposed on the second conductive-type semiconductor layer of each of the plurality of light emitting cells;

a first insulating layer disposed directly on the upper surface of the substrate in the exposed region between the plurality of light emitting cells and disposed on the transparent electrode exposing a surface of the transparent electrode,

an interconnect disposed on the first insulating layer and electrically connected at a first end to the first conductive-type semiconductor layer of a first light emitting cell of the plurality of light emitting cells and at a second end to the transparent electrode of a second light emitting cell of the plurality of light emitting cells, and

a second insulating layer disposed on the first insulating layer and the interconnect.

14. The light-emitting diode chip of claim 12, wherein the distributed Bragg reflector comprises a first distributed Bragg reflector and a second distributed Bragg reflector.

15. The light-emitting diode chip of claim 14, wherein:

the first distributed Bragg reflector is configured to reflect more light in a red wavelength range than a blue wavelength range,

the second distributed Bragg reflector is configured to reflect more light in the blue wavelength range than light in the red wavelength range.

16. The light-emitting diode chip of claim 15, wherein the second distributed Bragg reflector is further configured to reflect more light in the blue wavelength range than light in a green wavelength range.

17. The light-emitting diode chip of claim 16, wherein:

the first distributed Bragg reflector and the second distributed Bragg reflector each comprise a plurality of material layers, and

the plurality of material layers comprise a material selected from the group consisting of silicon dioxide (SiO₂), titanium dioxide (TiO₂), a silicon nitride (Si₃N₄), and some combination thereof.

18. The light-emitting diode chip of claim 16, wherein:

the first distributed Bragg reflector is configured to reflect 90% or more of light having the red wavelength range of 600 nm to 700 nm,

the second distributed Bragg reflector is configured to reflect 90% or more of light having the blue wavelength range of 400 nm to 500 nm,

the green wavelength range is 500 nm to 600 nm.