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

• US 8,207,547 B2
• Filed: 06/10/2009
• Issued: 06/26/2012
• Est. Priority Date: 06/10/2009
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd. (Samsung Group)
• Original Assignee: Brudgelux Incorporated
• Inventors: Lin, Chao-Kun
• Primary Examiner(s): STARK, JARRETT J
• Application Number:
  US12/482,413
• Publication Number:
  US 20100314643A1
• Time in Patent Office: 1,112 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:

an insulating substrate;

a conductive adhesive disposed directly on the insulating substrate;

a reflective metal electrode disposed directly on the conductive adhesive, wherein the conductive adhesive layer is metal and with the metal electrode together form a metallic current spreading layer, the metallic current spreading layer having a thickness greater than about 1 um; and

a single epitaxial structure on the electrode.

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

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

4. The thin-film light emitting diode of claim 3, wherein the metal contact is on the metal electrode.

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

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

7. 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.

8. The thin film light emitting diode of claim 7, 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.

9. The thin-film light emitting diode of claim 7, wherein the first epitaxial layer is an n-type GaN-based layer and the second epitaxial layer is a p-type GaN-based layer.

10. The thin-film light emitting diode of claim 7, further comprising a patterned second electrode is on the first epitaxial layer.

11. The thin-film light emitting diode of claim 10, 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.

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