MICRO LED DISPLAY

• US 20140299837A1
• Filed: 06/23/2014
• Published: 10/09/2014
• Est. Priority Date: 11/18/2011
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: LuxVue Techonology Corporation (Apple Inc.)
• Inventors: Bibl, Andreas, Higginson, John A., Law, Hung-Fai Stephen, Hu, Hsin-Hua
• Granted Patent: US 10,297,712 B2
• Time in Patent Office: Days
• US Class Current: 257/13
• CPC Class Codes: F21V 7/00 Reflectors for light sources characterised by cooling arrangements F21V29/505
• CPC Class Codes: H01L 2224/95 at chip-level, i.e. with connecting carried out on a plurality of singulated devices, i.e. on diced chips
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• CPC Class Codes: H01L 27/15 including semiconductor components having potential barriers, specially adapted for light emission
• CPC Class Codes: H01L 29/0684 characterised by the shape, relative sizes or dispositions of the semiconductor regions or junctions between the regions
• CPC Class Codes: H01L 33/0093 Wafer bonding; Removal of the growth substrate
• CPC Class Codes: H01L 33/04 with a quantum effect structure or superlattice, e.g. tunnel junction
• CPC Class Codes: H01L 33/06 within the light emitting region, e.g. quantum confinement structure or tunnel barrier
• CPC Class Codes: H01L 33/20 with a particular shape, e.g. curved or truncated substrate
• CPC Class Codes: H01L 33/28 containing only elements of Group II and Group VI of the Periodic Table
• CPC Class Codes: H01L 33/30 containing only elements of Group III and Group V of the Periodic Table

Abstract

A micro light emitting diode (LED) and a method of forming an array of micro LEDs for transfer to a receiving substrate are described. The micro LED structure may include a micro p-n diode and a metallization layer, with the metallization layer between the micro p-n diode and a bonding layer. A conformal dielectric barrier layer may span sidewalls of the micro p-n diode. The micro LED structure and micro LED array may be picked up and transferred to a receiving substrate.

Claims

1. A display substrate comprising:

a plurality of micro LED devices bonded to a corresponding plurality of driver contacts;

wherein each micro LED device comprises;

a p-n diode including;

a p-doped layer;

an n-doped layer; and

a quantum well layer between the n-doped layer and the p-doped layer;

wherein the p-n diode is less than 3 μ

m thick and less than 10 μ

m wide; and

a lower metallization layer on the p-n diode, wherein the lower metallization layer is bonded to a corresponding driver contact.

2. The display substrate of claim 1, further comprising a common contact line formed of a transparent material over and in electrical contact with the plurality of micro LED devices.

3. The display substrate of claim 2, wherein the common contact line comprises indium tin oxide.

4. The display substrate of claim 1, further comprising a plurality of bonding layers, wherein each lower metallization layer is bonded to a corresponding driver contact with a corresponding bonding layer.

5. The display substrate of claim 4, wherein each bonding layer comprises indium.

6. The display substrate of claim 1, wherein each p-n diode has a square configuration with tapered corners.

7. The display substrate of claim 1, further comprising a plurality of dielectric barrier layers, wherein each dielectric barrier layer spans sidewalls of a corresponding p-n diode.

8. The display substrate of claim 7, wherein each dielectric barrier layer covers the quantum well layer of a corresponding p-n diode.

9. The display substrate of claim 8, further comprising a common contact line formed of a transparent material over and in electrical contact with the plurality of micro LED devices.

10. The display substrate of claim 9, wherein common contact line is on each dielectric barrier layer, such that each dielectric barrier layer electrically insulates a corresponding quantum well from the common contact line.

11. The display substrate of claim 10, wherein the plurality of micro LED devices are arranged in a pixel group.

12. The display substrate of claim 11, wherein the pixel group includes a red-emitting micro LED device, a green-emitting micro LED device, and a blue-emitting micro LED device.

13. The display substrate of claim 9, wherein each dielectric barrier layer surrounds a corresponding p-n diode, corresponding metallization layer, and corresponding bonding layer.

14. The display substrate of claim 1, wherein the p-doped layer is thinner than the n-doped layer.

15. The display substrate of claim 1, wherein the p-n diode comprises an inorganic II-VI or III-V semiconductor.