Facebook Technologies, LLC

David Massoubre

Stephan Lutgen

Andrew John Ouderkirk

Lu Lu

Scott Charles McEldowney

Pasi Saarikko

Giuseppe Calafiore

Wanli Chi

Babak Amirsolaimani

Wai Sze Tiffany Lam

Hee Yoon Lee

Barry David Silverstein

Andrew Maimone

Maxwell Parsons

Pooya Saketi

Daniel Brodoceanu

William Padraic Henry

Gang Li

Ningfeng Huang

Alexander Koshelev

Celine Claire Oyer

Oscar Torrents Abad

Joseph O'Keeffe

Patrick Joseph Hughes

Padraig Hughes

Francois Olivier

James Small

Markus Broell

Thomas Lauermann

Daniel Bryce Thompson

Karsten Moh

Michael Grundmann

Tilman Zehender

Anneli Munkholm

Francois Gerard Franck Olivier

Vasily Zabelin

Vaishali Chopra

François Gérard Franck Olivier

Celine Oyer

A emitting diode (LED) includes an epitaxial structure defining a base and a mesa on the base. The base defines a light emitting surface of the LED and includes current spreading layer. The mesa includes a thick confinement layer, a light generation area on the thick confinement layer to emit light, a thin confinement layer on the light generation area, and a contact layer on the thin confinement layer, the contact layer defining a top of the mesa. A reflective contact is on the contact layer to reflect a portion of the light emitted from the light generation area, the reflected light being collimated at the mesa and directed through the base to the light emitting surface. In some embodiments, the epitaxial structure grown on a non-transparent substrate. The substrate is removed, or used to form an extended reflector to collimate light.

Micron-sized light emitting diode designs

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

A waveguide assembly is provided. The waveguide assembly includes a pair of pupil-replicating waveguides. The first pupil-replicating waveguide is configured for receiving an input beam of image light and providing an intermediate beam comprising multiple offset portions of the input beam. The second pupil-replicating waveguide is configured for receiving the intermediate beam from the first pupil-replicating waveguide and providing an output beam comprising multiple offset portions of the intermediate beam. The input beam may be expanded by the waveguide assembly in such a manner that pupil gaps are reduced or eliminated.

Cascaded pupil-replicating waveguides

A pupil-replicating waveguide suitable for operation with a coherent light source is disclosed. A waveguide body has opposed surfaces for guiding a beam of image light. An out-coupling element is disposed in an optical path of the beam for out-coupling portions of the beam at a plurality of spaced apart locations along the optical path. Electrodes are coupled to at least a portion of the waveguide body for modulating an optical path length of the optical path of the beam to create time-varying phase delays between the portions of the beam out-coupled by the out-coupling element.

Waveguide with coherent interference mitigation

Techniques related to molded etch masks are disclosed. Etch masks can be formed based on pressing a mold against a layer of pliable masking material applied to a surface of an epitaxial layered structure. The epitaxial layered structure includes a first semiconductor layer, a second semiconductor layer, and a light-emitting layer between the first and second semiconductor layers. The epitaxial layered structure is etched using the molded etch masks to form etched structures. The etched structures may be optical structures that modify light emitted through the surface or epitaxial mesas that collimate light within the epitaxial layered structure.

Molded etch masks

A method for manufacturing a display element comprising a plurality of pixels, each comprising a plurality of sub-pixels. The method comprises undertaking, using a pick up tool, a first placement cycle () comprising picking up a plurality of first, untested LED dies and placing them on a display substrate at locations corresponding to the plurality of pixels, testing () the first LED emitters on the display substrate to determine one or more locations of non-functional first LED emitters, selecting one or more second tested LED dies based on a result of the test, configuring the selected one or more second LED dies to enable their pick up and placement on the display substrate and undertaking, using the PUT, a second placement cycle () comprising picking up the selected one or more second LED dies and placing them on the display substrate at the determined locations of the non-functional first LED emitters.

Assembly of semiconductor devices using multiple LED placement cycles

Micron-sized light emiting diode designs

Systems and methods for fabricating parabolic LEDs are provided. The parabolic shape of the LEDs is precisely-controlled and highly-uniform across a substrate. By precisely controlling the shape, and providing a high-uniformity across the substrate, the luminance and process yield of the LEDs is enhanced. The precise-control and high-uniformity of the shape is enabled via a precisely-shaped and highly-uniform mask formed on the substrate. The ability to precisely-control both the shape and uniformity the mask is achieved by forming the mask utilizing three-dimensional (3D) patterning and/or machining methods. The mask includes a precisely-shaped boss with the same shape as the LED, and a cylindrical protrusion extending beyond the boss. The combination of the boss and cylindrical protrusion allows for the mask to be over-etched, without significantly effecting the shape of the LED. Thus, any non-uniformities etching process do not decrease the luminance, nor uniformity, of the LEDs.

Fabricating parabolic-shaped LEDs

Techniques related to laser lift-off masks are disclosed. In some embodiments, masking material is applied to a substrate that is attached to a plurality of semiconductor device sets. More specifically, the masking material is applied to one or more regions of the substrate between the semiconductor device sets. When the semiconductor device sets are embedded in a filling material, the masking material may be situated between the substrate and the filling material. Thus, transmitting light through the substrate toward the semiconductor device sets causes the substrate to become detached from the semiconductor device sets. However, the light is at least partially occluded by the masking material.

Laser lift-off masks

A micro-light emitting diode (LED) is manufactured using a lift-off substrate that is removed using a laser-lift-off process. A method for manufacturing the LED may include forming an epitaxial structure of the LED on a growth substrate, and attaching an open side of the epitaxial structure with a gallium-based layer and a lift-off substrate, the gallium-based layer between the epitaxial structure and the lift-off substrate. The growth substrate is separated from the epitaxial structure, and the epitaxial structure may be processed into the LED. Light is applied to the gallium-based layer through the lift-off substrate to debond the second portion of the gallium-based layer and the lift-off substrate. The lift-off substrate is separated from the second portion of the gallium-based layer to expose a light emitting surface of the LED on the second portion of the gallium-based layer.

Wafer bonding for laser lift-off

Embodiments relate to a micro light-emitting-diode (&#x3bc;LED) fabricated using a self-aligned process. To fabricate the &#x3bc;LED, a metal layer is deposited on a p-type semiconductor. The p-type semiconductor is on an n-type semiconductor and the n-type semiconductor is on a top side of a substrate. The metal layer is patterned to define a p-metal. The p-type semiconductor is etched using the p-metal as an etch mask. Similarly, the n-type semiconductor is etched using the p-metal and the p-type semiconductor as an etch mask. A negative photoresist layer is deposited over the patterned p-metal and the p-type semiconductor. The negative photoresist is then exposed from the back side of the substrate, thus exposing the regions of the negative photoresist that are not masked by the p-metal. The negative photoresist is then developed to expose the p-metal.

Self-alignment process for micro light emitting diode using back-side exposure

A method for manufacturing a display element comprising a plurality of pixels, each comprising a plurality of subpixels. The method comprises undertaking, using a pick up tool, a first placement cycle () comprising picking up a plurality of first, untested LED dies and placing them on a display substrate at locations corresponding to the plurality of pixels, testing () the first LED emitters on the display substrate to determine one or more locations of non-functional first LED emitters, selecting one or more second tested LED dies based on a result of the test, configuring the selected one or more second LED dies to enable their pick up and placement on the display substrate and undertaking, using the PUT, a second placement cycle () comprising picking up the selected one or more second LED dies and placing them on the display substrate at the determined locations of the nonfunctional first LED emitters.

Assembly of semiconductor devices

A light emitting diode (LED) is manufactured using a process in which hydrogen diffuses out of a p-doped semiconductor layer via an exposed side wall of the p-doped semiconductor layer. The process includes forming a light generation layer on a base semiconductor layer and forming the p-doped semiconductor layer on the light generation layer. A tunnel junction layer is formed on the p-doped semiconductor layer and a contact layer is formed on the junction layer. The process also includes etching through at least the contact layer, the tunnel junction layer, and the p-doped semiconductor layer to expose the side wall of the p-doped semiconductor layer and enabling hydrogen to diffuse out of the p-doped semiconductor layer at least partially through the exposed side wall.

Light emitting diode with tunnel junction

LEDs are manufactured on a substrate layer and picked and placed using a pick-up tool (PUT) onto a target substrate. The PUT typically attaches to an LED via an elastomer layer deposited on a surface of the LED. A given batch of manufactured LEDs may contain operational LEDs as well as non-operational LEDs. In order to separate the operational and non-operational LEDs, the LEDs are placed on a unidirectional conductive film. A photo-curable polymer is deposited on a surface of each LED. A voltage difference is applied across the electrodes of each LED via the unidirectional conductive film, causing the operational LEDs to emit light and cure the photo-curable polymer to form an elastomer layer, while the polymer deposited on the non-operational LEDs will not cure. As such, the PUT will be able to pick up the operational LEDs, while being unable to pick up the non-operational LEDs.

Method of direct wafer mapping by determining operational LEDs from non-operational LEDs using photo-reactive elastomer deposition

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Cork, Ireland

David Massoubre