Facebook Technologies, LLC

Meta Platforms Technologies, LLC

Michael Grundmann

Chloe Astrid Marie Fabien

Daniel Henry Morris

John Goward

Stephan Lutgen

Markus Broell

William Padraic Henry

David Massoubre

Thomas Lauermann

Daniel Bryce Thompson

Anurag Tyagi

David Hwang

Alexander Tonkikh

François Gérard Franck Olivier

Vasily Zabelin

Brian Matthew Mcskimming

Alexander Franke

For small, high-resolution, light-emitting diode (LED) displays, such as for a near-eye display in an artificial-reality headset, LEDs are spaced closely together. A backplane can be used to drive an array of LEDs in an LED display. A plurality of interconnects electrically couple the backplane with the array of LEDs. The backplane can have a different coefficient of thermal expansion (CTE) than the array of LEDs. During bonding of the backplane to the array of LEDs, CTE mismatch can cause misalignment of bonding sites. The higher the bonding temperature, the greater the misalignment of bonding sites. Lower temperature bonding, using materials with lower melting or bonding temperatures, can be used to mitigate misalignment during bonding so that interconnects can be more closely spaced, which can allow LEDs to be more closely spaced, to enable a higher-resolution display.

Bonding interface for hybrid TFT-based micro display projector

A micro-light emitting diode includes a mesa structure that includes a first set of one or more semiconductor layers, an active layer configured to emit light, a second set of one or more semiconductor layers on the active layer, and a dielectric layer in sidewall regions of the mesa structure. A center region of the second set of one or more semiconductor layers is thicker than a sidewall region of the second set of one or more semiconductor layers, such that a distance from a surface of the sidewall region of the second set of one or more semiconductor layers to the active layer is less than a distance from a surface of the center region of the second set of one or more semiconductor layers to the active layer, thereby forming a surface potential-induced lateral potential barrier at a sidewall region of the active layer.

Surface potential barrier for surface loss reduction at mesa sidewalls of micro-LEDs

Disclosed herein are techniques for forming a thin-film circuit layer on an array of light-emitting diodes (LEDs). LEDs in the array of LEDs can be singulated by various processes, such as etching and ion implantation. Singulating LEDs can be performed before or after forming the thin-film circuit layer on the array of LEDs. The array of LEDs can be bonded to a transparent or non-transparent substrate.

Process flow for hybrid TFT-based micro display projector

Disclosed herein are methods, systems, and apparatuses for an light emitting diode (LED) array apparatus. In some embodiments, the LED array apparatus may include a plurality of mesas etched from a layered epitaxial structure. The layered epitaxial structure may include a P-type doped semiconductor layer, a active layer, and an N-type doped semiconductor layer. The LED array apparatus may also include one or more regrowth semiconductor layers, including a first regrowth semiconductor layer, which may be grown epitaxially over etched facets of the plurality of mesas. In some cases, for each mesa, the first regrowth semiconductor layer may overlay etched facets of the P-type doped semiconductor layer, the active layer, and the N-type doped semiconductor layer, around an entire perimeter of the mesa.

Regrowth of epitaxial layer for surface recombination velocity reduction in light emitting diodes

Techniques disclosed herein relate to micro light emitting diodes (micro-LEDs) for a display system. A display system includes an array of micro light emitting diodes (micro-LEDs), an array of output couplers optically coupled to the array of micro-LEDs and configured to extract light emitted by respective micro-LEDs in the array of micro-LEDs, a waveguide display, and display optics configured to couple the light emitted by the array of micro-LEDs and extracted by the array of output couplers into the waveguide display. Each output coupler in the array of output couplers is configured to direct a chief ray of the light emitted by a respective micro-LED in the array of micro-LEDs to a different respective direction.

Micro-LED design for chief ray walk-off compensation

For small, high-resolution, light-emitting diode (LED) displays, such as for a near-eye display in an artificial-reality headset, LEDs are spaced closely together. A backplane can be used to drive an array of LEDs in an LED display. A plurality of interconnects electrically couple the backplane with the array of LEDs. As spacing between LEDs becomes smaller than interconnect spacing, a thin-film circuit layer can be used to reduce a number or interconnects between the backplane and the array of LEDs, so that interconnect spacing can be larger than LED spacing. This can allow LEDs in the LED display to be more densely arranged while still allowing use of a silicon backplane with drive circuitry to control operation of the LEDs in the LED display.

Architecture for hybrid TFT-based micro display projector

Growing community of inventors

Kirkland, WA, United States of America

Michael Grundmann