# US 12,191,418 B2 · Monolithic integration of different light emitting structures on a same substrate > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,191,418 B2 - Document ID: US12191418B2 - Status: Granted - Kind: B2 - Application number: 18/305,778 - Filed: 2023-04-24 - Published: 2023-11-30 - Granted: 2025-01-07 - Earliest claimed: 2019-04-12 - Assignees: Google Inc. - Applicants: Google LLC - Inventors: Gang He; Sheila K. Hurtt - Web page: https://patentgrep.com/patent/US12191418B2 ## CPC - H10H 20/821: of the light-emitting regions, e.g. non-planar junctions - H10H 20/812: within the light-emitting regions, e.g. having quantum confinement structures - H10H 20/815: having stress relaxation structures, e.g. buffer layers - H10H 20/825: containing nitrogen, e.g. GaN - H10H 20/8252: {characterised by the dopants} - H10H 29/142: {Two-dimensional arrangements, e.g. asymmetric LED layout} - H10H 20/84: Coatings, e.g. passivation layers or antireflective coatings - H10H: INORGANIC LIGHT-EMITTING SEMICONDUCTOR DEVICES HAVING POTENTIAL BARRIERS ## 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. ## Claims ### Claim 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. ### Claim 2 (depends on 1) The device of claim 1, wherein the first single contact metal is disposed in a recessed portion of the substrate. ### Claim 3 (depends on 1) 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. ### Claim 4 (depends on 1) 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. ### Claim 5 (depends on 4) 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. ### Claim 6 (depends on 4) 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. ### Claim 7 (depends on 1) 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. ### Claim 8 (depends on 1) 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. ### Claim 9 (depends on 1) 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. ### Claim 10 (depends on 1) The device of claim 1, wherein the substrate includes gallium nitride. ### Claim 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. ### Claim 12 (depends on 11) The micro-LED display of claim 11, wherein the single contact metal is disposed in a recessed portion of the substrate. ### Claim 13 (depends on 11) 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. ### Claim 14 (depends on 11) 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. ### Claim 15 (depends on 14) 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. ### Claim 16 (depends on 14) 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. ### Claim 17 (depends on 11) 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. ### Claim 18 (depends on 11) The micro-LED display of claim 11, wherein the red micro-LED, green micro-LED, and the blue micro-LED are mesa-shaped. ### Claim 19 (depends on 11) 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. ### Claim 20 (depends on 11) The micro-LED display of claim 11, wherein the substrate includes gallium nitride.