Thin film light emitting diode

• US 9,281,454 B2
• Filed: 04/02/2013
• Issued: 03/08/2016
• Est. Priority Date: 06/26/2002
• Status: Active Grant

• Current Assignee: Suzhou Lekin Semiconductor Company Limited
• Original Assignee: LG Innotek Company Limited (LG Corporation)
• Inventors: Yoo, Myung Cheol
• Primary Examiner(s): Feeney, Brett
• Assistant Examiner(s): SALERNO, SARAH KATE
• Application Number:
  US13/855,637
• Publication Number:
  US 20130292725A1
• Time in Patent Office: 1,071 Days
• Field of Search: 257/81, 257/98, 257/100
• US Class Current: 1/1
• CPC Class Codes: H01L 2224/05599 Material
• CPC Class Codes: H01L 2224/45099 Material
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48463 the connecting portion on the bonding area of the semiconductor or solid-state body being a ball bond
• CPC Class Codes: H01L 2224/49107 on the semiconductor or solid-state body
• CPC Class Codes: H01L 2224/4918 being disposed on at least two different sides of the body, e.g. dual array
• CPC Class Codes: H01L 2224/8592 Applying permanent coating, e.g. protective coating
• CPC Class Codes: H01L 24/48 of an individual wire connector
• CPC Class Codes: H01L 24/49 of a plurality of wire connectors
• 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 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• 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 2924/01029 Copper [Cu]
• CPC Class Codes: H01L 2924/12041 LED
• CPC Class Codes: H01L 2924/12042 LASER
• CPC Class Codes: H01L 2924/181 Encapsulation
• CPC Class Codes: H01L 33/06 within the light emitting region, e.g. quantum confinement structure or tunnel barrier
• CPC Class Codes: H01L 33/32 containing nitrogen
• 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 33/502 : Wavelength conversion materials
• CPC Class Codes: H01L 33/504 : Elements with two or more wavelength conversion materials
• 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 33/62 : Arrangements for conducting electric current to or from the semiconductor body, e.g. lead-frames, wire-bonds or solder balls

Abstract

Light emitting devices comprise a substrate having a surface and a side surface; a semiconductor structure on the surface of the substrate, the semiconductor structure having a first surface, a second surface and a side surface, wherein the second surface is opposite the first surface, wherein the first surface, relative to the second surface, is proximate to the substrate, and wherein the semiconductor structure comprises a first-type layer, a light emitting layer and a second-type layer; a first and a second electrodes; and a wavelength converting element arranged on the side surface of the semiconductor structure, wherein the wavelength converting element has an open space, and wherein the open space is a portion not covered by the wavelength converting element.

Claims

1. A light emitting device, comprising:

a substrate;

a semiconductor structure on the substrate, the semiconductor structure comprising;

a first-type semiconductor layer;

a second-type semiconductor layer; and

a light emitting layer between the first-type semiconductor layer and the second-type semiconductor layer,

wherein a bottom surface of the semiconductor structure is closest to the substrate and a top surface of the semiconductor structure is opposite to the bottom surface, the top surface comprising;

an upper surface on one of the first-type semiconductor layer and the second-type semiconductor layer;

a lower surface stepped-down from the upper surface so as to be on the other of the first-type semiconductor layer and the second-type semiconductor layer; and

a side surface connected between the upper surface and the lower surface such that a portion of the light emitting layer is exposed thereon;

a transparent conductive layer on the upper surface of the top surface of the semiconductor structure;

a first electrode on the transparent conductive layer, the first electrode including platinum;

a second electrode on the lower surface of the top surface of the semiconductor structure, the second electrode including chromium;

a passivation layer from the upper surface of the top surface of the semiconductor structure to the lower surface of the top surface of the semiconductor structure so as to cover an entire side surface of the top surface of the semiconductor structure, the passivation layer including an opening to accommodate one of the first electrode and the second electrode; and

a wavelength converting layer on the passivation layer so as to cover the light emitting structure,

wherein the passivation layer comprises;

an upper passivation portion on the upper surface of the top surface of the semiconductor structure;

a lower passivation portion on the lower surface of the top surface of the semiconductor structure; and

a side passivation portion between the upper passivation portion and the lower passivation portion, the side passivation portion on the side surface of the top surface of the semiconductor structure, and

wherein the wavelength converting layer comprises;

an upper converting portion on the upper passivation portion;

a lower converting portion on the lower passivation portion; and

a side converting portion between the upper converting portion and the lower converting portion, the side converting portion on the side passivation portion.

2. The light emitting device according to claim 1, wherein the passivation layer contacts the second electrode.

3. The light emitting device according to claim 2, wherein the passivation layer extends to a top surface of the second electrode.

4. The light emitting device according to claim 1, wherein the wavelength converting layer is a thin film layer.

5. The light emitting device according to claim 1, wherein the upper surface of the top surface of the semiconductor structure, the passivation layer, and the wavelength converting layer overlap each other.

6. The light emitting device according to claim 1, wherein the passivation layer covers a side of the transparent conductive layer.

7. The light emitting device according to claim 2, wherein the passivation layer contacts a side of the second electrode.

8. The light emitting device according to claim 1, wherein the passivation layer contacts the first electrode.

9. The light emitting device according to claim 8, wherein the passivation layer contacts a side of the first electrode.

10. The light emitting device according to claim 1, wherein the passivation layer includes SiO₂ or Si_xN_y.

11. The light emitting device according to claim 1, wherein the wavelength converting layer is thicker than the passivation layer.

12. The light emitting device according to claim 11, wherein a thickness of the passivation layer is 100 nm.

13. The light emitting device according to claim 11, wherein a thickness of the wavelength converting layer is 10 μ

m or less.

14. The light emitting device according to claim 1, wherein the transparent conductive layer includes a material selected from the group consisting of Ru/Au, Ni/Au, and indium-thin-oxide.

15. The light emitting device according to claim 1, wherein the passivation layer on the upper surface of the top surface of the semiconductor structure has a stepped shape.

16. The light emitting device according to claim 1, wherein the passivation layer comprises:

a first part on the upper surface of the top surface of the semiconductor structure; and

a second part on the upper surface of the top surface of the semiconductor structure,

wherein the first part is closer to the second electrode than the second part, and

wherein the first part is thicker than the second part.

17. The light emitting device according to claim 1, wherein the substrate includes a material selected from the group consisting of sapphire, ZnO, GaN, SiC, and AlN.