Thin-film LED with P and N contacts electrically isolated from the substrate

• US 8,536,601 B2
• Filed: 07/13/2010
• Issued: 09/17/2013
• Est. Priority Date: 06/10/2009
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Toshiba Techno Center Inc. (Toshiba Corporation)
• Inventors: Lin, Chao-Kun
• Primary Examiner(s): STARK, JARRETT J
• Application Number:
  US12/835,632
• Publication Number:
  US 20100314651A1
• Time in Patent Office: 1,162 Days
• Field of Search: 257/98, 257E33062-E33068
• US Class Current: 257/98
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• 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 2924/00014 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 2924/01322 Eutectic Alloys, i.e. obtained by a liquid transforming into two solid phases
• 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 2933/0091 Scattering means in or on the semiconductor body or semiconductor body package H01L33/22 takes precedence
• CPC Class Codes: H01L 33/005 Processes
• CPC Class Codes: H01L 33/0093 Wafer bonding; Removal of the growth substrate
• CPC Class Codes: H01L 33/405 Reflective materials
• CPC Class Codes: H01L 33/46 Reflective coating, e.g. dielectric Bragg reflector
• 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
• CPC Class Codes: H01L 33/64 Heat extraction or cooling elements

Abstract

A thin-film LED includes an insulating substrate, an electrode on the insulating substrate, and an epitaxial structure on the electrode.

Claims

1. A thin-film light emitting diode, comprising:

a substrate;

an insulating dielectric film layer on the substrate;

a reflective electrode disposed on the insulating dielectric film layer via a conductive adhesive layer, wherein the conductive adhesive layer and the reflective electrode comprises metal and together form a metallic current spreading layer; and

an epitaxial structure on the reflective electrode.

2. The thin-film light emitting diode of claim 1, wherein the substrate is electrically conductive.

3. The thin-film light emitting diode of claim 1, wherein the substrate is an insulator.

4. The thin-film light emitting diode of claim 1, wherein the metallic current spreading layer having a thickness greater than about 1 um.

5. The thin-film light emitting diode of claim 1, wherein the reflective electrode and conductive adhesive layer are recessed from an edge of the thin-film light emitting diode.

6. The thin-film light emitting diode of claim 1, further comprising a metal layer on a bottom surface of the substrate.

7. The thin-film light emitting diode of claim 1, further comprising:

a second insulating dielectric film layer on a bottom surface of the substrate; and

a metal layer on the second insulating dielectric film layer.

8. The thin-film light emitting diode of claim 1, further comprising a metal contact coupled to the electrode.

9. The thin-film light emitting diode of claim 8, wherein the metal contact is on the electrode.

10. The thin-film light emitting diode of claim 1, wherein the substrate is reflective for the wavelength between about 300 nm and 700 nm with a reflectance greater than about 50%.

11. The thin-film light emitting diode of claim 1, wherein the substrate is transparent for the wavelengths between about 300 nm and 700 nm with a transmittance greater than about 50%.

12. The thin-film light emitting diode of claim 1, wherein the epitaxial structure comprises a first epitaxial layer, a second epitaxial layer, and an active region between the first epitaxial layer and the second epitaxial layer.

13. The thin film light emitting diode of claim 12, wherein the first epitaxial layer has a roughened surface with micro-structures, the micro-structures being between about 100 nm and 500 nm in size.

14. The thin-film light emitting diode of claim 12, wherein the first epitaxial layer is an n-type GaN-based layer and the second epitaxial layer is a p-type GaN-based layer.

15. The thin-film light emitting diode of claim 12, further comprising a patterned second electrode on the first epitaxial layer.

16. The thin-film light emitting diode of claim 15, wherein the epitaxial structure is formed to be a mesa on the electrode and the patterned second electrode is on a top surface of the mesa.

17. The thin-film light emitting diode of claim 1, wherein the substrate is not an original growth substrate for the epitaxial structure.