LED DEVICE WITH EMBEDDED NANOWIRE LEDS

• US 20150263066A1
• Filed: 03/13/2014
• Published: 09/17/2015
• Est. Priority Date: 03/13/2014
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: LuxVue Techonology Corporation (Apple Inc.)
• Inventors: Hu, Hsin-Hua, Bibl, Andreas
• Granted Patent: US 9,583,533 B2
• Time in Patent Office: Days
• 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;

a plurality of nanowires on and protruding away from a 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 a 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. 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;

a plurality of nanowires on and protruding away from a 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 a 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.

11. The structure of claim 10, further comprising a sacrificial release layer spanning between the stabilization layer and the array of nanowire devices.

12. The nanowire device of claim 11, wherein the stabilization layer comprises a thermoset material.

13. The nanowire device of claim 11, wherein the stabilization layer comprises an array of staging cavities, and the array of nanowire devices is within the array of staging cavities.

14. The nanowire device of claim 11, wherein the stabilization layer comprises an array of stabilization posts, and the array of nanowire devices is supported by the array of stabilization posts.

15. The nanowire device of claim 14, wherein the bottom electrode layer for each nanowire device is bonded to a corresponding stabilization post.

16. A method of forming a nanostructure comprising:

forming an encapsulation material laterally surrounding an array of nanowires and over a handle substrate, such that the array of nanowires is embedded within the encapsulation material;

etching an array of mesa trenches through the encapsulation material, wherein each mesa trench surrounds a plurality of nanowires;

depositing a sacrificial release layer over the encapsulation material and within the array of mesa trenches;

bonding the handle substrate to a carrier substrate with a stabilization layer, wherein the sacrificial release layer is between the array of nanowires and the stabilization layer; and

removing the handle substrate.

17. The method of claim 16, wherein forming the encapsulation material laterally surrounding an array of nanowires and over the handle substrate comprises, coating a first thermosetting material layerover the array of nanowires and reducing a thickness of the first thermosetting material layer to expose a bottom conductive contact on each of the nanowires.

18. The method of claim 17, further comprising depositing a bottom electrode on the bottom conductive contact of each of the nanowires.

19. The method of claim 16, wherein bonding the handle substrate to the carrier substrate with the stabilization layer comprises:

coating a second thermosetting material over the sacrificial release layer; and

curing the second thermosetting material.

20. The method of claim 16, further comprising etching the sacrificial release layer using a vapor or plasma etching technique to remove the sacrificial release layer from between the array of nanowires and the stabilization layer.