LED device with embedded nanowire LEDs

• US 9,583,533 B2
• Filed: 03/13/2014
• Issued: 02/28/2017
• Est. Priority Date: 03/13/2014
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Hu, Hsin-Hua, Bibl, Andreas
• Primary Examiner(s): Warren, Matthew E
• Application Number:
  US14/210,295
• Publication Number:
  US 20150263066A1
• Time in Patent Office: 1,083 Days
• Field of Search: 257/13, 257/79, 257/81, 257/91, 257/95, 257/100
• US Class Current: 1/1
• CPC Class Codes: H01L 2221/68368 used in a transfer process involving at least two transfer steps, i.e. including an intermediate handle substrate
• CPC Class Codes: H01L 2224/95001 involving a temporary auxiliary member not forming part of the bonding apparatus, e.g. removable or sacrificial coating, film or substrate
• CPC Class Codes: H01L 24/75 Apparatus for connecting with bump connectors or layer connectors
• CPC Class Codes: H01L 24/83 using a layer connector
• CPC Class Codes: H01L 24/95 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 27/153 in a repetitive configuration, e.g. LED bars
• CPC Class Codes: H01L 29/0669 Nanowires or nanotubes carbon nanotubes as material of solid-state device active part H10K85/211
• CPC Class Codes: H01L 29/0676 oriented perpendicular or at an angle to a substrate
• 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 33/08 with a plurality of light emitting regions, e.g. laterally discontinuous light emitting layer or photoluminescent region integrated within the semiconductor body H01L27/15 takes precedence
• CPC Class Codes: H01L 33/16 with a particular crystal structure or orientation, e.g. polycrystalline, amorphous or porous
• CPC Class Codes: H01L 33/18 within the light emitting region
• CPC Class Codes: H01L 33/24 of the light emitting region, e.g. non-planar junction

Abstract

A nanowire device and a method of forming a nanowire device that is poised for pick up and transfer to a receiving substrate are described. In an embodiment, the nanowire device includes a base layer and a plurality of nanowires on and protruding away from a first surface of the base layer. An encapsulation material laterally surrounds the plurality of nanowires in the nanowire device, such that the nanowires are embedded within the encapsulation material.

Claims

1. A nanowire device comprising:

a base layer including a first surface and a second surface opposite the first surface, wherein the second surface has a maximum lateral dimension of 1 to 100 μ

m;

a plurality of nanowires on and protruding away from the first surface of the base layer;

wherein each nanowire comprises a core, a shell, and an active layer between the core and the shell;

an encapsulation material laterally surrounding the plurality of nanowires, such that the plurality of nanowires is embedded within the encapsulation material;

a top electrode layer on the second surface of the base layer opposite the first surface and in electrical contact with the core of each nanowire; and

a bottom electrode layer in electrical contact with the shell of each nanowire.

2. The nanowire device of claim 1, wherein the top electrode layer is transparent or semi-transparent to the visible wavelength spectrum.

3. The nanowire device of claim 1, wherein the bottom electrode includes a mirror layer.

4. The nanowire device of claim 1, wherein the bottom electrode includes a bonding layer formed of a noble metal.

5. The nanowire device of claim 1, further comprising one or more bottom conductive contacts on and surrounding the shells of the plurality of nanowires, wherein the bottom electrode layer is in electrical contact with the one or more bottom conductive contacts.

6. The nanowire device of claim 5, wherein the bottom electrode layer spans along a bottom surface of the encapsulation material.

7. The nanowire device of claim 1, further comprising a patterned mask layer on the base layer, wherein the cores of the plurality of nanowires extend through corresponding openings in the patterned mask layer.

8. The nanowire device of claim 1, wherein the encapsulation material comprises a thermoset material.

9. The nanowire device of claim 7, wherein the encapsulation material is transparent to the visible wavelength spectrum.

10. The nanowire device of claim 1, wherein the second surface has a maximum lateral dimension of 1 to 20 μ

m.

11. The nanowire device of claim 1, further comprising a through-hole through an entire thickness of the base layer located laterally between two nanowires.

12. The nanowire device of claim 1, wherein the bottom electrode layer is bonded to and in electrical contact with a contact pad of a display substrate.

13. The nanowire device of claim 1, wherein the bottom electrode layer is bonded to a display substrate with a material comprising indium or tin.

14. The nanowire device of claim 1, wherein the top electrode layer has a planar top surface.

15. A structure comprising:

a carrier substrate;

a stabilization layer on the carrier substrate;

an array of nanowire devices on the stabilization layer;

wherein each nanowire device comprises;

a base layer including a first surface and a second surface opposite the first surface, wherein the second surface has a maximum lateral dimension of 1 to 100 μ

m;

a plurality of nanowires on and protruding away from the first surface of the base layer;

wherein each nanowire comprises a core, a shell, and an active layer between the core and the shell;

an encapsulation material laterally surrounding the plurality of nanowires, such that the plurality of nanowires is embedded within the encapsulation material;

a top electrode layer on the second surface of the base layer opposite the first surface and in electrical contact with the core of each nanowire; and

a bottom electrode layer in electrical contact with the shell of each nanowire.

16. The structure of claim 15, further comprising a sacrificial release layer spanning between the stabilization layer and the array of nanowire devices.

17. The nanowire device of claim 16, wherein the stabilization layer comprises a thermoset material.

18. The nanowire device of claim 16, wherein the stabilization layer comprises an array of staging cavities, and the array of nanowire devices is within the array of staging cavities.

19. The nanowire device of claim 16, wherein the stabilization layer comprises an array of stabilization posts, and the array of nanowire devices is supported by the array of stabilization posts.

20. The nanowire device of claim 19, wherein the bottom electrode layer for each nanowire device is bonded to a corresponding stabilization post.