Monolithic integration of different light emitting structures on a same substrate

Patent metadata

Field	Value
Publication number	US-12191418-B2
Application number	US-202318305778-A
Country	US
Kind code	B2
Filing date	Apr 24, 2023
Priority date	Apr 12, 2019
Publication date	Jan 7, 2025
Grant date	Jan 7, 2025

Abstract

The disclosure describes various aspects of monolithic integration of different light emitting structures on a same substrate. In an aspect, a device for light generation is described having a substrate with one or more buffer layers made a material that includes GaN. The device also includes light emitting structures, which are epitaxially grown on a same surface of a top buffer layer of the substrate, where each light emitting structure has an active area parallel to the surface and laterally terminated, and where the active area of different light emitting structures is configured to directly generate a different color of light. The device also includes a p-doped layer disposed over the active area of each light emitting structure and made of a p-doped material that includes GaN. The device may be part of a light field display and may be connected to a backplane of the light field display.

First claim

What is claimed is:

1. A device for light generation, comprising:
a substrate including at least one buffer layer including gallium nitride (GaN);
a plurality of light emitting structures defined from an epitaxial layer disposed on a surface of the at least one buffer layer, each of the plurality of light emitting structures having an active area that is parallel to the surface and is laterally terminated,
the plurality of light emitting structures including:
a first light emitting structure configured to emit light of a first color;
a second light emitting structure configured to emit light of a second color different than the first color; and
a third light emitting structure configured to emit light of a third color different than the first color and the second color;

a respective p-doped layer disposed on the active area of each of the plurality of light emitting structures, the respective p-doped layers including GaN; and
a single contact metal electrically disposed on a portion of the at least one buffer layer and configured to be electrically connected to a backplane for driving the plurality of light emitting structures via the backplane, the single contact metal being laterally spaced, on the at least one buffer layer, from the first light emitting structure, the second light emitting structure, and the third light emitting structure.

2. The device of claim 1 , wherein the first single contact metal is disposed in a recessed portion of the substrate.

3. The device of claim 1 , further comprising a dielectric layer that electrically isolates the single contact metal from the first light emitting structure, the second light emitting structure, and the third light emitting structure.

4. The device of claim 1 , wherein the first light emitting structure, the second light emitting structure, and the third light emitting structure are monolithically disposed on the substrate.

5. The device of claim 4 , wherein the first light emitting structure, the second light emitting structure, and the third light emitting structure include respective layers that are epitaxial to the substrate.

6. The device of claim 4 , wherein the first light emitting structure, the second light emitting structure, and the third light emitting structure have respective active regions configured to emit different colors of light.

7. The device of claim 1 , wherein the first light emitting structure, the second light emitting structure, and the third light emitting structure are included in a pixel of the device.

8. The device of claim 1 , wherein the first light emitting structure, the second light emitting structure, and the third light emitting structure are mesa-shaped.

9. The device of claim 1 , wherein the first light emitting structure, the second light emitting structure, and the third light emitting structure are disposed on the substrate, and adjacent to one another.

10. The device of claim 1 , wherein the substrate includes gallium nitride.

11. A micro-LED display, comprising:
a substrate including at least one buffer layer including gallium nitride (GaN);
a red micro-LED, a green micro-LED, and a blue micro-LED defined from an epitaxial layer disposed on a surface of the at least one buffer layer, the red micro-LED, the green micro-LED, and the blue micro-LED each having an active area that is parallel to the surface and is laterally terminated,
respective p-doped layers disposed on the active area of each of the red micro-LED, the green micro-LED, and the blue micro-LED, the respective p-doped layers including GaN; and
a single contact metal electrically disposed on a portion of the at least one buffer layer and configured to be electrically connected to a backplane for driving the red micro-LED, the green micro-LED, and the blue micro-LED via the backplane, the single contact metal being laterally spaced, on the at least one buffer layer, from the red micro-LED, the green micro-LED, and the blue micro-LED.

12. The micro-LED display of claim 11 , wherein the single contact metal is disposed in a recessed portion of the substrate.

13. The micro-LED display of claim 11 , further comprising a dielectric layer that electrically isolates the single contact metal from the red micro-LED, the green micro-LED, and the blue micro-LED.

14. The micro-LED display of claim 11 , wherein the red micro-LED, the green micro-LED, and the blue micro-LED are monolithically disposed on the substrate.

15. The micro-LED display of claim 14 , wherein the red micro-LED, green micro-LED, and the blue micro-LED include respective layers that are epitaxial to the substrate.

16. The micro-LED display of claim 14 , wherein the red micro-LED, the green micro-LED, and blue micro-LED have respective active regions configured to emit different colors of light.

17. The micro-LED display of claim 11 , wherein the red micro-LED, the green micro-LED, and blue micro-LED are included in a pixel of the micro-LED display.

18. The micro-LED display of claim 11 , wherein the red micro-LED, green micro-LED, and the blue micro-LED are mesa-shaped.

19. The micro-LED display of claim 11 , wherein the red micro-LED, the green micro-LED, and the blue micro-LED are disposed on the substrate, and adjacent to one another.

20. The micro-LED display of claim 11 , wherein the substrate includes gallium nitride.

Assignees

• Google Llc

Inventors

• He Gang
• Hurtt Sheila K

Classifications

• H10H20/8252

  characterised by the dopants · CPC title

• H10H20/821 Primary

  of the light-emitting regions, e.g. non-planar junctions · CPC title

• H10H20/815

  having stress relaxation structures, e.g. buffer layers · CPC title

• H10H29/142 Primary

  Two-dimensional arrangements, e.g. asymmetric LED layout · CPC title

• H10H20/812

  within the light-emitting regions, e.g. having quantum confinement structures · CPC title