Wafer-level light emitting diode package and method of fabricating the same

• US 10,879,437 B2
• Filed: 08/10/2018
• Issued: 12/29/2020
• Est. Priority Date: 09/24/2010
• Status: Active Grant

• Current Assignee: Seoul Semiconductor Co., Ltd.
• Original Assignee: Seoul Semiconductor Co., Ltd.
• Inventors: Seo, Won Cheol, Cho, Dae Sung
• Primary Examiner(s): Nguyen, Cuong Q
• Application Number:
  US16/101,287
• Publication Number:
  US 20180351057A1
• Time in Patent Office: 872 Days
• CPC Class Codes: H01L 27/15 including semiconductor components having potential barriers, specially adapted for light emission
• CPC Class Codes: H01L 27/153 in a repetitive configuration, e.g. LED bars
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 2933/0016 relating to electrodes
• 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 2933/005 relating to encapsulations
• CPC Class Codes: H01L 2933/0066 relating to arrangements for conducting electric current to or from the semiconductor body
• CPC Class Codes: H01L 2933/0075 relating to heat extraction or cooling elements
• CPC Class Codes: H01L 33/007 comprising nitride compounds
• CPC Class Codes: H01L 33/0093 Wafer bonding; Removal of the growth substrate
• CPC Class Codes: H01L 33/0095 Post-treatment of devices, e.g. annealing, recrystallisation or short-circuit elimination
• CPC Class Codes: H01L 33/06 within the light emitting region, e.g. quantum confinement structure or tunnel barrier
• CPC Class Codes: H01L 33/10 with a light reflecting structure, e.g. semiconductor Bragg reflector
• 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 33/22 Roughened surfaces, e.g. at the interface between epitaxial layers
• CPC Class Codes: H01L 33/24 of the light emitting region, e.g. non-planar junction
• 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 33/385 : the electrode extending at least partially onto a side surface of the semiconductor body
• 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 33/50 : Wavelength conversion elements
• CPC Class Codes: H01L 33/502 : Wavelength conversion materials
• CPC Class Codes: H01L 33/505 : characterised by the shape, e.g. plate or foil
• CPC Class Codes: H01L 33/507 : the elements being in intimate contact with parts other than the semiconductor body or integrated with parts other than the semiconductor body
• CPC Class Codes: H01L 33/56 : Materials, e.g. epoxy or silicone resin
• CPC Class Codes: H01L 33/58 : Optical field-shaping 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
• CPC Class Codes: H01L 33/642 : characterized by the shape
• CPC Class Codes: H01L 33/647 : the elements conducting electric current to or from the semiconductor body

Abstract

Exemplary embodiments of the present invention provide a wafer-level light emitting diode (LED) package and a method of fabricating the same. The LED package includes a semiconductor stack including a first conductive type semiconductor layer, an active layer, and a second conductive type semiconductor layer; a plurality of contact holes arranged in the second conductive type semiconductor layer and the active layer, the contact holes exposing the first conductive type semiconductor layer; a first bump arranged on a first side of the semiconductor stack, the first bump being electrically connected to the first conductive type semiconductor layer via the plurality of contact holes; a second bump arranged on the first side of the semiconductor stack, the second bump being electrically connected to the second conductive type semiconductor layer; and a protective insulation layer covering a sidewall of the semiconductor stack.

Claims

1. A light emitting diode (LED) package comprising one or more light emitting diodes to emit light, wherein each single light emitting diode includes:

a semiconductor stack including a first conductive type semiconductor layer and a mesa structure including a second conductive type semiconductor layer and an active layer interposed between the first and second conductive type semiconductor layers to generate light under an electrical current applied to the first and second conductive type semiconductor layers;

a first insulation layer structured to cover the semiconductor stack and to expose the first conductive type semiconductor;

a first electrode electrically connected to the first conductive type semiconductor layer exposed by the first insulation layer;

a second electrode disposed over the second conductive type semiconductor layer and electrically connected to the second conductive type semiconductor layer;

a second insulation layer disposed over the first electrode and the second electrode structured to expose a part of the first electrode and a part of the second electrode;

a second electrical contact layer disposed over the first insulation layer and electrically connected to a part of the second conductive type semiconductor layer exposed by the first insulation layer;

a first electrically conductive pad disposed on the first electrode layer to conduct the electrical current through the first conductive type semiconductor layer and including a portion located over the first electrode; and

a second electrically conductive pad disposed on the second electrode layer to conduct the electrical current through the second conductive type semiconductor layer and including a portion located over the first electrode.

2. The LED package of claim 1, wherein the first electrode includes a portion extending along the first conductive type semiconductor layer.

3. The LED package of claim 2, wherein the portion of the first electrode is disposed under the first electrically conductive pad and the second electrically conductive pad.

4. The LED package of claim 2, further comprising an additional semiconductor stack disposed adjacent to the semiconductor stack and electrically connected in series to the semiconductor stack through the portion of the first electrode of the semiconductor stack.

5. The LED package of claim 2, wherein the first insulation layer further comprising a portion having a varying thickness along the semiconductor stack.

6. The LED package of claim 2, wherein the portion of the first electrode comprises a same material as the second electrical contact layer.

7. The LED package of claim 1, wherein the first electrode further comprises a first electrical contact layer that covers the first insulation layer and is electrically connected to the first conductive type semiconductor layer exposed by the first insulation layer.

8. The LED package of claim 1, further comprising:

a first substrate located on a first side of the semiconductor stack, over which the semiconductor stack, the first and second electrodes, the first and second insulation layers, the first and second electrical contact layers, and the first and second electrically conductive pads are disposed;

a second substrate located on a second opposite side to the first side of the semiconductor stack, the second substrate including circuitry for supplying the electrical current to the semiconductor stack.

9. The LED package of claim 1, further comprising:

a wavelength converter located on an opposite side of the first conductive type semiconductor layer to the semiconductor stack and including a phosphor composition that converts light emitted from the active layer into a light at a different wavelength.

10. The LED package of claim 9, wherein the wavelength converter includes a first sidewall and a second sidewall that are externally facing sidewalls of the light emitting diode, and the second insulation layer has outer side walls aligned with the first sidewall and the second sidewall of the wavelength converter.

11. The LED package of claim 1, further comprising:

a substrate including a first sidewall and a second sidewall that are externally facing sidewalls of the light emitting diode and including a first surface and a second opposite surface, the semiconductor stack disposed over the second opposite surface, and

wherein the second insulation layer has outer sidewalls aligned with the first sidewall and the second sidewall of the substrate.

12. The LED package of claim 1, wherein the LED package is structured such that the electrical current passes through the second electrically conductive pad, the second electrical contact layer, and the second electrode, and the second conductive type semiconductor layer.

13. The LED package of claim 1, wherein the LED package is structured such that the electrical current passes through the first electrically conductive pad, the first electrode, and the first conductive type semiconductor layer.

14. The LED package of claim 1, wherein the first electrode is located between the first insulation layer and the second insulation layer.

15. The LED package of claim 1, wherein the second insulation layer includes a portion that is disposed on a sidewall of the semiconductor stack that is an externally facing sidewall of the light emitting diode.

16. The LED package of claim 15, wherein the portion of the second insulation layer has a varying thickness along the sidewall of the semiconductor stack.

17. The LED package of claim 1, wherein the semiconductor stack and the first insulation layer have inclined sidewalls.

18. The LED package of claim 1, further comprising:

a dummy bump that includes electrically conductive material and is arranged between the first and second electrically conductive pads, the dummy bump structured to dissipate heat from the LED device and electrically insulated from the first and second electrically conductive pads.

19. An LED package device comprising:

a light emitting structure formed over a substrate and patterned to include a first light emitting structure and a second light emitting structure disposed apart from the first light emitting structure by a cell separation region, each of the first light emitting structure and the second light emitting structure including a first conductivity type semiconductor layer, a second conductivity type semiconductor layer, and an active layer interposed between the first conductivity type semiconductor layer and the second conductivity type semiconductor layer and structured to generate light under an electrical signal applied to the first and second conductive type semiconductor layers;

a first electrode pad disposed over the first light emitting structure and electrically connected to the first conductivity type semiconductor layer of the first light emitting structure;

a second electrode pad disposed over the second light emitting structure and electrically connected to the second conductivity type semiconductor layer of the second light emitting structure; and

a connector disposed over the cell separation region and extending over the first light emitting structure and the second light emitting structure, the connector structured to electrically couple the first light emitting structure with the second light emitting structure, and

wherein the first electrode pad, the second electrode pad, and the connector occupy more than one half of a planar area of the substrate.

20. The LED package device of claim 19, wherein the connector has a dimension greater than a dimension of both the first electrode pad and the second electrode pad.

21. The LED package device of claim 19, further comprising:

an insulation structure formed to surround the first light emitting structure and the second light emitting structure and including openings, and

wherein each of the first electrode pad and the second electrode pad fills one of the openings of the insulation structure and the connector fills two of the openings of the insulation structure.

22. The LED package device of claim 19, wherein the connector is located between the first electrode pad and the second electrode pad along a direction parallel to a surface of the substrate.

23. The LED package device of claim 19, further comprising contact holes located in each of the first light emitting structure and the second light emitting structure and surrounded by the second conductivity type semiconductor layer and the active layer to pass therethrough so as to expose the first conductivity type semiconductor layer.

24. The LED package device of claim 23, wherein each of the first light emitting structure and the second light emitting structure comprises:

a first contact layer filling in the contact holes to be electrically coupled to the first conductive type semiconductor layer;

a second contact layer disposed over the second conductivity type semiconductor layer.

25. The LED package device of claim 24, further comprising:

an insulation structure formed to surround and protect the first light emitting structure and the second light emitting structure and including first openings exposing the first contact layer of the first light emitting structure or the second light emitting structure and second openings exposing the second contact layer of the first light emitting structure or the second light emitting structure.

26. The LED package device of claim 25,

wherein the connector fills in the first opening exposing the first contact layer of the first light emitting structure and fills in the second opening exposing the second contact layer of the second light emitting structure.

27. The LED package device of claim 25,

wherein the first electrode pad fills in the first opening exposing the first contact layer of the second light emitting structure and the second electrode pad fills in the second opening exposing the second contact layer of the first light emitting structure.

28. A light emitting diode (LED) package, comprising one or more light emitting diodes to emit light, wherein each single light emitting diode includes:

a semiconductor stack comprising a first conductive type semiconductor layer, an active layer, and a second conductive type semiconductor layer;

means for exposing the first conductive type semiconductor layer through the second conductive type semiconductor layer and the active layer;

a first bump arranged on a first side of the semiconductor stack, the first bump being electrically connected to an exposed part of the first conductive type semiconductor layer; and

a second bump arranged on the first side of the semiconductor stack, the second bump being electrically connected to the second conductive type semiconductor layer; and

wherein the LED package further includes a protective insulation layer covering each external side wall surface of the semiconductor stack facing externally of the LED package so that the protection insulation layer surrounds the LED package.

29. The LED package of claim 28, further comprising means for converting light at a first wavelength emitted by the semiconductor stack on a second side of the semiconductor stack into light of a different wavelength.

30. The LED package of claim 28, further comprising:

a first contact layer comprising first contact sections contacting exposed parts of the first conductive type semiconductor layer and a connecting section connecting the first contact sections; and

a second contact layer contacting the second conductive type semiconductor layer,

wherein the protective insulation layer comprises a first insulation layer and a second insulation layer, the first insulation layer being arranged between the first contact layer and the second contact layer and covering the second contact layer, and the second insulation layer being arranged between the semiconductor stack and the first contact layer and covering the first contact layer,

wherein the first bump is electrically connected to the first contact layer, and the second bump is electrically connected to the second contact layer.

31. The LED package of claim 30, further comprising:

a first electrode pad contacting the first contact layer through a first contact hole arranged in the second insulation layer; and

a second electrode pad contacting the second contact layer though a second contact hole arranged in the second insulation layer and the first insulation layer,

wherein the first bump and the second bump contact the first electrode pad and the second electrode pad, respectively.

32. The LED package of claim 30, wherein at least one of the first insulation layer and the second insulation layer comprises a distributed Bragg reflector.

33. A structure having light emitting diode (LED) packages, comprising:

a stack of layers formed over one another and patterned to include an array of LED package regions, each LED package region including (1) a LED package formed in the stack of layers in a central region of the LED package region and (2) a protective insulation structure formed to surround and protect the LED package from surroundings outside the protective insulation structure and to separate from adjacent LED packages,

wherein each LED package formed in the stack of layers includes;

a semiconductor stack including a first conductive type semiconductor layer, a second conductive type semiconductor layer and an active layer between the first and second semiconductor layers to generate light under an electrical signal applied to the first and second type semiconductor layers, wherein the semiconductor stack is located between a first side and a second side of the semiconductor stack that are on opposite sides of the semiconductor stack;

means in each semiconductor stack for exposing the first conductive type semiconductor layer through the second conductive type semiconductor layer and the active layer;

a first electrical contact layer material electrically coupled to an exposed part of the first conductive type semiconductor layer;

a first bump on the first side of the semiconductor stack and electrically coupled to the first conductive type semiconductor layer via the first electrical contact layer material; and

a second bump on the first side of the semiconductor stack and electrically insulated from the first bump to be electrically coupled to the second conductive type semiconductor layer, and

wherein the protective insulation structure includes a two-layer protective structure having a first protective insulation layer that surrounds and covers each external side wall surface of the semiconductor stack and a second protective insulation layer that forms on the first protective insulation layer to protect the semiconductor stack from an external environment.

34. The structure as in claim 33, comprising a wafer on which the stack of layers is formed and is patterned to include the array of LED package regions.

35. The structure as in claim 33, wherein:

the protective insulation structure further covers an entirety of each external side surface of an electrical contact structure that includes the first and second bumps on the first side of the semiconductor stack to protect the electrical contact structure from an external environment.

36. The structure as in claim 33, wherein each LED package formed in the stack of layers includes:

an electrically conductive structure formed on the first side of the semiconductor stack between the first and second bumps to be electrically insulated from the first and second bumps to dissipate heat from the LED package.

37. A light emitting diode (LED) package, comprising:

a semiconductor stack comprising a first conductive type semiconductor layer, a second conductive type semiconductor layer and an active layer that is interposed between the first and second semiconductor layers to generate light under an electrical signal applied to the first and second type semiconductor layers, wherein the semiconductor stack is located between a first side and a second side of the semiconductor stack that are on opposite sides of the semiconductor stack, and wherein the first side is closer to the second conductive type semiconductor layer than the first conductive type semiconductor layer and the second side is closer to the first conductive type semiconductor layer than the second conductive type semiconductor layer;

means in the semiconductor stack for exposing the first conductive type semiconductor layer;

an electrical contact structure on the first side of the semiconductor stack and electrically coupled to supply the electrical signal to the first and second type semiconductor layers, the electrical contact structure including (1) a first bump formed of an electrically conductive material and arranged on the first side of the semiconductor stack and electrically coupled to the first conductive type semiconductor layer as part of a first electrical contact path to the semiconductor stack, (2) a first electrical contact layer material disposed to electrically couple the first conductive type semiconductor layer and the first bump, (3) a second bump formed of the electrically conductive material of the first bump and arranged on the first side of the semiconductor stack and electrically insulated from the first bump to be electrically coupled to the second conductive type semiconductor, and (4) a second electrical contact layer material electrically coupled between the second bump and the second conductive type semiconductor layer; and

an external structure that covers (1) the second side of the semiconductor stack that exports light generated in the active layer outside the LED package, and (2) side wall surfaces of the semiconductor stack.

38. The LED package as in claim 37, wherein the external structure includes:

a first stacked protective insulation structure positioned to cover the entirety of each external side wall surface of the semiconductor stack to protect the semiconductor stack from an external environment; and

a second stacked protective insulation structure stacked over the first stacked protective insulation structure and located on the first side of the semiconductor stack to cover an entirety of each external side surface of the electrical contact structure to protect the electrical contact structure from an external environment.

39. The LED package as in claim 37, wherein:

the external structure further covers external side wall surfaces of the electrical contact structure on the first side of the semiconductor stack.

40. The LED package as in claim 37, wherein the external structure includes:

a first protective insulation layer covering an entirety of each external side wall surface of the semiconductor stack; and

a second protective insulation layer that surrounds the semiconductor stack and forms on the first protective insulation layer so that the second protective insulation layer and the first protective insulation collectively form a two-layer protection structure to cover the entirety of each external side wall surface of the semiconductor stack and to enclose external sides of the semiconductor stack.

41. The LED package as in claim 40, wherein the second protective insulation structure includes a phosphor structure that coverts light emitted from the active layer into light at a different wavelength to be exported on the second side out of the LED package.

42. The LED package as in claim 37, further comprising:

an electrically conductive material on the first side of the semiconductor stack near the first bump or second bump to dissipate heat from the LED package, wherein the electrically conductive material is not electrically connected to the first bump or the second bump.